U . S . D e p a r t m e n t o f E n e r g y • O f f i c e o f F o s s i l E n e r g y

N a t i o n a l E n e r g y T e c h n o l o g y L a b o r a t o r y

Microhole Technology

Microhole TechnologyBackgroundAn estimated 407 billion barrels ofonshore discovered oil in the U.S. isnon-recoverable with currentdrilling and production technolo-gies. Of that total, 218 billion bar-rels can be found at the relativelyshallow depths of 5,000 feet or less.Even at today’s high oil prices,industry-sponsored research remainson the decline, and operators tend touse familiar technologies rather thanrisk failure with advanced technolo-gy. To bridge this technology gap,DOE partners with industry todevelop and demonstrate new tech-nologies to access domestic petrole-um resources.

The Microhole Technology (MHT)Program is developing a promisingsuite of technologies that enabledrilling of wells with casings lessthan 41/2 inches in diameter usingcoiled tubing drill rigs that are rela-tively small and easily mobilized.These technologies have the poten-tial to reduce the cost of drillingshallow- and moderate-depth holesfor exploration, field development,and long-term subsurface monitor-ing.

GoalThe goal of DOE’s MHT Program is todevelop cost-effective technologies thatenable:

• Development of shallow (<5,000 feet),currently uneconomic oil and gas resources.

• Acquisition of high-resolution, real-time reservoir imaging with-out interrupting production.

• Reduced environmental impact via lower volumes of drilling fluid, small-er operational footprint and pad/extended-reach drilling.

To accomplish these goals the near-term MHT program focuses on two areas of technology development:

• Field demonstrations where existing coiled tubing rigs are showing that economic resource recovery can resultfrom wells with less than 41/2-inch cas-ing.

• Development of tools to drill, evaluate, complete, and produce fromlateral microholes drilled out of 41/2-inch casing.

A Systems ApproachThe key to developing resources inmature, complex reservoirs is to recog-nize that a combination of interrelatedtechnology systems working togethertoward this common objective will berequired. The MHT program employs asystems approach in that it considers thelarger picture and takes into account howfactors such as technology, research,risk, and the business environment con-tribute to the overall success or failure ofresource development. The systems solu-tions to resource development mustaddress the following “resource develop-ment drivers”:

• Reduced reservoir access cost (drilling, including mobilization) to allow more holes to be drilled to pene-trate reservoir seals.

• Cost-effective, high-resolution imagingto locate bypassed oil and reservoir seals and allow better management of sweep efficiency in enhanced oil recovery processes.

• Increased drilling efficiency (expressedin more completed wells per week) that will require high-penetration-rate drilling assemblies.

• Smaller drilling footprints to minimizedisruption of landowner activities, especially considering the larger num-ber of wells required for access.

407 Billion Bbls Remaining Discovere

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Domestic oil production, proven reserves, and discovered and undiscovered resource.

Source: EIA 2004, 2005; MMS 2006; USGS 2004.

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The systems approach used to achievethe desired near-term results is bestdepicted in the MHT Program Systemdiagram shown below. Technologiesselected for the program were those thatbest satisfy the resource developmentdrivers.

The technologies being developed in theMHT program that are in the R&D stageare listed in the blue box. The red boxcontains those systems that are market-ready. They are technologies that arerecognized by operators or businessunits within major intergrated servicecompanies as having short-term applica-tion. The hybrid coiled tubing (CT)drilling rig (shown in green) was usedcommercially immediately after comple-tion, underscoring the need for the tech-nology. This quickly established com-merciality is expected to hasten marketpenetration for other technologies beingdeveloped in the program that supportexpanded use of hybrid CT rigs. The useof these technologies in combinationwith leading-edge, high-resolution seis-mic imaging technologies is expected tobe very effective in furthering develop-ment of America’s mature oilfields.

ApplicationsNear-term applications of the microholetechnologies being developed in thisprogram include drilling:

• Shallow development wells with one third the surface area and one third the number of equipment loads when compared with a rotary drilling rig.

• Shallow re-entry wells that allow drilling of multilaterals for economic access into compartmentalized reser-voirs.

• Drilling deep exploration tails in existing wells that can cheaply extend the wellbore to evaluate and produce new zones.

Longer-term MHT applications includedrilling dedicated wells for continuousreservoir monitoring to enable:

• High-resolution vertical seismic pro-filing, 4-D seismic imaging of reser-voir fluid movement and bypassed oil.

• Low-impact, high-resolution imaging of targets beneath environmentally sensitive areas to allow development via pad/extended-reach drilling.

• Use of passive seismic imaging to take advantage of “free” seismic sources provided by naturally occur-ring seismic events to provide further resolution for improved reservoir modeling.

BenefitsThe MHT Program’s potential benefitsto the Nation include lower drilling costsresulting from reduced materials, labor,and support equipment; reduced environ-mental impact from lower volumes ofdrilling waste, smaller footprints, andlighter equipment; lower exploration riskfrom low-cost exploration wells; andincreased quality and quantity of high-resolution, dynamic, and continuousreservoir data.

Microhole Monobore Casing & Screen Systems

Microhole Radar Look-ahead SystemWater Jet Drilling System

CT Friction Reduction System

Microhole Zero Torque Drilling System

Adv. Zero Discharge Mud System Low Cost Wireless MWD/LWD

Onshore Adv. CT Drilling System

Microhole MWD/LWD Smart Steering System

CT Drilling Tractor Microhole Turbine Drilling System

Hybrid CT Drill Rig

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Novel High-Speed DrillingMotor for Oil Exploration &Production

DE-FC26-04NT15501

GoalThe project goal is to design and develop ahigh-speed mud motor assembly, compati-ble with a coiled tubing drilling (CTD)system, to drill small-diameter holes forvertical, horizontal, and multilateral wells.

PerformerAPS Technology Inc.Cromwell, CT

ResultsAll of the subtasks of the first year’s maintask essentially have been completed, withthe exception of the critical frequencyanalysis, which will continue in parallelwith the laboratory testing. The manufac-ture of the laboratory prototype is some-what ahead of schedule and will begin dur-ing Year 1 of the program.

BenefitsThis project is intended to develop a high-speed, small-diameter drilling system,with a motor powered by drilling fluidflow and with the ability to support a CTDoperation. The use of high-speed motorand bit combinations has the prospect ofgreatly increasing drilling rates and there-by reducing the costs of both explorationand development wells. The use of small-er-diameter bits and systems, and CTDequipment in conjunction with these sys-tems, will further reduce drilling costs andenhance hydrocarbon recovery in envi-ronmentally sensitive and marginally eco-nomical areas.

BackgroundThe area of high-speed drillbit develop-ment has progressed steadily. It is recog-nized that a suitable downhole motor willbe necessary to fully develop the capabili-ties of these bits. High-speed drilling holdsthe potential to reduce drilling costs andproduce a smaller environmental footprint.This project will pursue the developmentof a suitable downhole motor.

SummaryThe principal objective of this project is todesign and develop a high-speed mudmotor assembly compatible with a CTDsystem, to drill small-diameter holes forvertical, horizontal, and multilateral wells.The drilling motor assembly must containboth a conventional mud motor and anefficient gearing system to produce drillbitspeeds of 10,000 rpm and match therequirements of new drillbits now underdevelopment.

To accomplish this high-speed drilling, anefficient, reliable, gearing system must becoupled to a conventional mud motor. Oneadvantage of this coupling approach is thatby changing the gear ratio, the motor maybe adapted to a variety of bits and drillbitrequirements. It is anticipated these bitsand motors will be initially employed forsmall-diameter coiled tubing-drilled wells.

Phase I calls for the overall system and keycomponents design and modeling. Thesecomponents include the motor power sec-tion, gearbox, flexible coupling, seals, andbearings. A vital consideration is thereduction of vibrations caused by possibleimbalances at high rotation rates; anappropriate vibration damper is to beincorporated into the design. In Phase I,the equipment required to test the motoralso is to be designed. Phase II calls for themotor and the test equipment to be built totest the motor in the laboratory. These testsare to be followed by testing at industrialtest facilities or test wells.

Current Status (October 2005)The project is proceeding at or ahead ofschedule. APS researchers presented thecompany profile, related projects, currentproject goals, and project status to NETLin Tulsa, OK, on March 9, 2005.

Project Start / End: 10-1-04 / 9-30-06DOE / Performer Cost: $799,081 / $199,770Contact Information:NETL – Paul West (paul.west@netl.doe.gov or 918-699-2035)APS – Carl Perry (cperry@aps-tech.com or 860-613-4450)

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Microhole Smart Steeringand Logging-While-DrillingSystem

DE-FC26-03NT15473

GoalThe overall goal of this project is to pro-vide a modular coiled tubing drilling(CTD) system that allows operators to pro-duce existing U.S. oil reservoirs in a muchmore effective way than is possible today.

The objectives of this project are to designand build 1) a smart drillbit steering motorintegrated with a high-performance down-hole motor and 2) a logging-while-drilling(LWD) formation resistivity evaluationsensor that provides real-time informationabout the rock being drilled. The tools willbe designed for deployment in ultra-smalldiameter wellbores.

PerformerBaker Hughes INTEQHouston, TX

ResultsProject accomplishments include thedevelopment and evaluation of a numberof rib steering motor (RSM) design con-cepts, and the selection and approval of afinal design. This design is now undergo-ing final manufacture, and assembly of thefirst of two prototype tools is underwayprior to expected field testing in the firstquarter of 2006.

Project accomplishments for the magneticpropagation resistivity (MPR) tool includethe development of test bench devices andsoftware modeling, which indicate that aresistivity tool employing both 400-KHz and 2-MHz frequencies can bedeployed in a 23/8-inch design. A mechani-cal design was realized over a couple ofiterations, and two prototype tools are cur-rently in manufacturing. It is expected thatthe tool will meet all project goals.

BenefitsThe advanced drilling, steering, and log-ging bottomhole assembly (BHA) isexpected to enable faster drilling,increased well-path accuracy, improvedhole quality, and longer horizontal sec-tions. The improvements in drilling andLWD will lead to increased productionwhile decreasing the number of wells.

Lower costs and reduced environmentalrisks of drilling smaller holes with smaller-footprint rigs and minimal drilling fluidvolumes make the technology ideal forproducing remaining oil in shallow,mature U.S. reservoirs. Step-out wells, lat-eral deep perforations, and well deepeningall can improve recovery of domesticresources.

If this technology is developed anddeployed, as many as 5,000 new or re-entered wells per year are possible.

BackgroundState-of-the-art BHAs for CTD of 31/2-inchdiameter (microhole) horizontal wells tendto drill holes that are not smooth andstraight. The lack of straightness leads tohigher friction when sliding the coil, whichlimits the maximum horizontal extensionthat can be drilled with coiled tubing equip-ment.

Also absent in the currently available CTDBHAs for microholes is a suitable LWDtool. In order to keep the well within the tar-get zone and above the oil-water contact,resistivity measurements taken during thedrilling process are needed to provideinstantaneous information about the dis-tance to the water boundary. This allows thewell to be drilled for maximum recoveryand minimum risk of water invasion.

Furthermore, such formation evaluationsensors will be able to detect trapped hydro-carbons along the well path.

SummaryA 23/8-inch diameter RSM is beingdesigned to serve a 31/2-inch or smallerdiameter hole. Modules are beingdesigned so they fit seamlessly in the com-mercially available, modular 23/8-inchCoilTrak™, a CTD assembly. Hydraulicallypowered moveable ribs on the steeringmotor generate steering forces in everydirection, allowing both smooth curvesand straight borehole sections to be drilled.

An MPR tool is being developed formicroholes that will allow true real-timegeosteering with instantaneous steeringactions based on resistivity (and gamma)measurements.

Current Status (January 2006)Both components of the project, the RSMprototype and the MPR prototype, havebeen designed, have passed designreviews, and are currently in manufactur-ing and assembly. Once assembled, theprototypes will be extensively lab-testedprior to field trails. A special short-radius,3-inch, bi-center PDC bit has beendesigned by Hughes Christensen for initialfield trials, which are expected to occurMarch 2006.

Schematic of the 23/8-inch rib steering motor being developed in this project.

Project Start / End: 10-1-04 / 3-31-06DOE / Performer Cost: $738,667 / $183,417Contact Information:NETL – Sue Mehlhoff (sue.mehlhoff@netl.doe.gov or 918-699-2044)Baker Hughes INTEQ – John Macpherson (john.macpherson@inteq.comor 713-625-6558)

Steering rib

Bearing assembly

Drive sub

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Microhole Wireless Steering-While-Drilling System

DE-FC26-05NT15488

GoalThe project goal is to provide a smart steer-ing tool for a modular and economic coiledtubing drilling (CTD) system that allowsdomestic operators to produce more oilfrom existing reservoirs. This will beachieved by providing accurate and precisereal-time geosteering even under condi-tions where the rig surface gear and equip-ment need to be minimized for cost-effec-tiveness. The following objectives supportthis goal:

• Develop a 23/8-inch diameter bi-directionalpower and communications module(BCPM) as a part of the modular CTDbottomhole assembly (BHA).

• Develop a fit-for-purpose surface controlsystem that communicates with the BHA.

PerformerBaker Hughes INTEQHouston, TX

ResultsA new, smart steering tool for a modularCTD system is the expected result.Progress has been made in the design of aBCPM that complements the existing mod-ular CoilTrak™ drilling BHA. The systemincludes a fit-for-purpose surface controlsystem.

BenefitsThe new BCPM for the 23/8-inch steerableCTD BHA will considerably reduce thecapital expenditure needed to drill a“smart”, yet relatively shallow, land well.The BCPM eliminates the need for a coilwith an electric wire connection, therebyenabling the use of a smart drilling BHA inlocations where an electric line is notaffordable. The elimination of the electri-cally supplied coil saves the cost of onecomplete reel, which could reach about$100,000. In addition, with land rig dayrates averaging $30,000 or more, consider-able operational savings may be realized ifa change in reels (between wired and non-wired) is avoided for special operations,such as cementing or window cutting.

The manufacturing and testing phase com-mences after a decision to proceed to man-ufacturing: This phase consists of manu-facture of two prototype 23/8-inch BCPMsand a surface control system, field testingof the prototypes, and evaluation of theirperformance.

Conceptual design reviews for the BCPMwere held, and preliminary designs for thealternator and pulser currently are beingdeveloped. Components for a test setup arebeing designed and constructed to evaluatepower requirements to generate sufficientpulse height with flow rates of 150-300liters/minute. Long lead-time materialswere placed on order.

Current Status (January 2006)The project is in the preliminary designphase, and the design appears stable.Prototype components were machined andassembled for low-loop testing in January-February 2006, and the design will be re-evaluated based on those tests.

BackgroundFor drilling 31/2-inch diameter develop-ment wells, CTD technology offers manybenefits over rotary drilling. However,insufficient steering accuracy and lowborehole quality are often experiencedduring CTD drilling. Electric wire is cur-rently needed with coiled tubing strings toprovide power to the steering tool and fordownhole-to-surface communication; how-ever, there are cases where a wired coilrequires too much of an effort or expendi-ture.

This project builds on an existing wirelessBCPM for a 63/4-inch tool that integratesan alternator-based electric power supply,an actuator to send information to the sur-face, and the capability to receive digitalsignals downhole.

SummaryProject tasks break down into two phases:the system design and the manufacturingand testing phase. The design phase con-sists of system concept evaluation, draftand detailed design of downhole compo-nents, and manufacturing decision.

Schematic of the bi-directional power and communications module MWDcomponent. The surface control system communicates via mudpulse signals.The turbine/alternator provides power to other MWD components in the BHA.

Project Start / End: 2-1-05 / 9-30-06DOE / Performer Cost: $760,000 / $253,334Contact Information:NETL – Daniel Ferguson (daniel.ferguson@netl.doe.gov or 918-699-2047)Baker Hughes INTEQ – John Macpherson (john.macpherson@inteq.comor 713-625-6558)

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Advanced Mud System forMicrohole Coiled TubingDrilling

DE-PS26-03NT15476

GoalThe overall objective of the project is todevelop a mud system that is compatiblewith a coiled tubing drilling (CTD) systemto drill microholes for vertical, horizontal,and multilateral drilling and completionapplications. The system must be able tomix the required fluids, circulate that mix-ture downhole, clean and store thereturned fluids, and perform these func-tions in an underbalanced condition withzero discharge and acceptable levels ofenvironmental impact. A secondary objec-tive is to design and test drilling with anabrasive slurry jet (ASJ) drilling system.

PerformersBandera Petroleum Exploration LLCTulsa, OK

Impact Technologies LLCTulsa, OK

ResultsThe basic designs and concepts for theAdvanced Mud System have been devel-oped. The results include setting specifica-tions for components of the system,including pumps to convey the drilling flu-ids downhole, a subsystem to process thereturned well fluids, and a method to drilla hole in rock with an ASJ.

BenefitsAdvances in technology that create moreefficient development of hydrocarbonresources help the United States to becomemore energy self-sufficient, create activityand jobs in oil and gas basins, and gener-ate royalty revenue.

More-efficient hydrocarbon developmentthrough microhole drilling can be measuredin lower finding and production costs and inlower environmental impact when comparedwith existing conventional technology.

BackgroundMicrohole drilling offers numerous advan-tages to develop reserves that are currentlybeing bypassed. However, it also presentsa new set of equipment and operationalhurdles that will have to be solved beforeCTD systems can be commercialized.

One isolated piece of the puzzle is the mudsystem, which will have to be a departurefrom currently available and appliedpumps and mud processing equipmentused on conventional rigs. Proper sizingfor a coiled tubing application is a key ele-ment for the mud system. The ability todrill holes in rock with abrasive-laden flu-ids has been of interest to the industrysince the 1950s, but there have been equip-ment or technical limits that prevented itsapplication. The concepts of microholeand coiled tubing drilling make abrasivejet drilling a promising adjunct, and thelogical place to develop the ASJ is withinthe advanced mud system.

SummaryProject researchers have:

Validated drilling synergies for micro-hole CTD. The requisite hydraulics, mudtypes, pump types, and mud processingequipment applicable to microhole CTDwas confirmed through computer model-ing and investigation of industry stan-dards.

Investigated ASJ drilling. After a litera-ture review of previous work and con-sideration of microhole CTD parame-ters, a laboratory demonstration was ableto cut a hole in rock larger than the noz-zle diameter while continuously deliver-ing abrasives to the downhole tools.

Set pump specifications and identifiedavailable pumps. After defining trueoperating parameters for mud pumps inmicrohole CTD, specific manufacturerand models were identified for viableapplications.

Set mud processing parameters andidentified mud processing equipment.Mud processing equipment was identi-fied based on drilling fluids and flowrates applicable to microhole CTD andthe resulting desired fluid properties.

Current Status (January 2006)Budget Phase I has been completed, and afinal report was submitted. DOE approvalwill allow the project to proceed to BudgetPhase II, which will entail manufacturingor purchasing and testing prototypes of thedesigns and concepts from Budget Phase I.

A small-capacity mud processing system for microhole drilling.

Project Start / End: 8-2-04 / 2-1-07DOE / Performer Cost: $473,600 / $118,400Contact Information:NETL – Jim Barnes (jim.barnes@netl.doe.gov or 918-699-2076)Bandera Petroleum – Bruce Galbierz (bruce@banderapetroleum.com or918-747-7771)

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Advanced Monobore ConceptCFEX Self-ExpandingTubular Technology

DE-FC26-05NT15483

GoalThe goals of this project are to prove tech-nical, economic, and manufacturing con-cepts for innovative, self-expanding cas-ing technology for monodiameter wellsand to successfully deploy a small sectionof the casing in a demonstration well.

PerformersConfluent Filtration SystemsHouston, TX

AMET, Inc.Rexburg, ID

Southwest Research InstituteSan Antonio, TX

ResultsProgress was made in the design of a moreefficient, mechanically robust, and eco-nomically feasible self-expanding well cas-ing system for use in both microhole andconventional drilling.

BenefitsThe development of expandable casing formonobore wells promises to reducedrilling risks and improve economicsthroughout exploration and production.Self-expanding technology allows reduc-tion of hole volume, increased inside-diameter production tubing, shortenedfield schedules, and minimized drillsitefootprint. The technology is well-suitedfor drilling and casing microholes withtight annular spaces.

BackgroundCurrent expandable tubular technologyrelies on fluid pressure to plastically deformthe tubular. A fundamental problem withdeforming steel is that the process requiresshrinkage along its other dimensions.Irregularities in tubular chemistry and wall-thickness—coupled with more-irregularborehole conditions, including excess bendseverity, diameter restrictions, and non-con-centricity—further reduce current tubularexpansion reliability.

Current expandable tubular technology isnot feasible for microhole coiled tubingdrilling because the pressures required toexpand the tubulars are too great.

Prototype construction, which willinclude construction of a variety of pro-totypes to be used in physical tests andfield demonstrations.

Physical testing, which entails conven-tional laboratory evaluation of mechani-cal performance against theoretical prop-erties.

Manufacturing study, which will includeresearch, evaluation, and conceptualdevelopment of various methods of join-ing and forming materials

Field demonstration, which calls fordeployment of a prototype section in atest well.

Current Status (January 2006)During late 2005, the best of several designconcepts was selected for optimization andplanned prototyping. The chosen design iscapable of 200% expansion and indefinitepressure capacity. Interest in the new tech-nology has been expressed by privateinvestors and major companies with a viewtowards rejuvenating maturing fields. Thenext project milestone is completion ofdesign optimization and detailed designphases, to be followed by prototype con-struction.

This project is developing an expandablecasing that consists of pre-stressed cells thateliminate shrinkage and don’t require pres-sure for deployment.

SummaryThe expandable casing being developed inthis project consists of volumetricallyadjustable cells (honeycomb structures)that are compressed to reduce the outsidediameter. The reduced size is held in placeby temporary metallurgical bonds estab-lished between various interior “cell-spring” surfaces. Once inserted into thewellbore, those stabilizing bonds areremoved by specific chemical or mechani-cal activity, and the casing recovers to nearits original dimensions.

Tasks of the project include the following:

Concept development, which includesthe development of user definitions and performance measures, basic research ofspecifications, and detailed qualitativeevaluation of prospective design concepts.

Design optimization, which involves theuse of computer analytical methods,design by analysis routines, finite-ele-ment analysis, and 3-D geometry exportfor computer-aided machining.

Elastomer ridges in a self-expanding casing.

Project Start / End: 2-7-05 / 8-31-07DOE / Performer Cost: $975,644 / $270,600Contact Information:NETL – Paul West (paul.west@netl.doe.gov or 918-699-2035)Confluent Filtration – Jeffery Spray (jaspray@earthlink.net or 281-597-8784)

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Self-Expanding SandscreenTechnology

DE-FC26-05NT15491

GoalThe goals of this project are to prove techni-cal concepts for an innovative self-expand-ing sand-control screen technology, deter-mine manufacturing systems and econom-ics, and successfully deploy a small sectionof the screen in a demonstration well.

PerformersConfluent Filtration SystemsHouston, TX

AMET, Inc.Rexburg, ID

Southwest Research InstituteSan Antonio, TX

Stress Engineering ServicesHouston, TX

ResultsThe project is expected to result in thedevelopment of self-expanding screens thatare capable of <150 micron particle reten-tion, have improved hydraulic efficienciesthat will allow increased production, andwill work well in the tight annular clear-ances of microholes. The technology isexpected to solve the problems of highflow-rate erosion and pressure loss inherentin microhole producing clearances.

BenefitsUse of a high-flow, stand-alone sandscreencan result in faster well cleanup andreduced field time. Because the sand-screens are designed to be relatively plug-resistant, erosion-less and corrosion-less,fewer shutdowns and greater overall pro-duction should result from their use. Thesandscreen is expected to weigh and costone half that of conventional screens.

BackgroundSmall-diameter wellbores pose a unique setof completion and production problems.The fluid velocities inherent in microholesaccelerate sand movement, which tends toplug, erode, and corrode sandscreens. Theuse of gravel packs in microhole operationsis constrained by the limited annular vol-umes. Placing screen tubulars in microholesmay create difficulties in allowing passageof other completion equipment, includingpumps, sleeves, packers, geophysical tools, etc.

finite element analysis, and 3-D geome-try export for computer-aided machin-ing.

Prototype construction and physical test-ing, which entails laboratory evaluationof mechanical performance against theo-retical properties.

Field demonstration, which calls fordeployment of a prototype section in atest well.

Current Status (January 2006)Currently, modeling activities are beingcompleted. The modeling work shows thatthe concept is capable of becoming the firstexpandable screen capable of service to allmarket requirements, with a particle reten-tion as small as 25µ, or .002 inch. The proj-ect also is designing the tubulars to with-stand collapse values in excess of 4,000psi, or 2-14 times the current industry stan-dard. The new sandscreen design also hasexpansion capability in excess of 150% andcan produce in excess of 400-psi bias forsought-after compliant wellbore support.

This project aims to develop a sandscreentechnology that offers high flow rates andhigh hydraulic efficiencies, uses metalalloys resistant to erosion and corrosion,and is lighter and thinner-walled than con-ventional tubulars.

SummaryThe sandscreen technology being devel-oped in this project is a highly supported,grid-type construction of close-tolerancestructural panels that have been designedfor high hydraulic efficiency. The grid ele-ments are flush about the inside diameter,allowing smooth surfaces for downholeoperations. The elements are optimallyrecessed on the outside diameter, creating agreater open area toward the formation.The tubular strength results from the largenumbers of flexible cell bodies, which likewire rope, acquires strength from numbersof components acting collectively. Theproject entails the following tasks:

Design model development, whichincludes adaptation of industry specifi-cations and modification according toself-expansion principles, optimizationthrough computer analytical methods,

An artist’s cutaway rendering of a self-expanding sandscreen.

Project Start / End: 2-7-05 / 8-31-07DOE / Performer Cost: $254,596 / $64,400Contact Information:NETL – Paul West (paul.west@netl.doe.gov or 918-699-2035)Confluent Filtration – Jeffery Spray (jaspray@earthlink.net or 281-597-8784)

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Friction Reduction forMicrohole Coiled TubingDrilling

DE-FC26-05NT15485

GoalThe project will create a robust, economi-cal microhole coiled tubing drilling (CTD)friction reduction system that will enablethe drilling of wellbores with 3,000 feet ormore of horizontal displacement in a 31/2-inch wellbore without the use of anyother downhole coiled tubing friction mit-igation device.

PerformerCTESConroe, TX

ResultsSelected Phase 1 accomplishments for thisreport period include the following:

Researchers completed vibration test fix-ture fabrication and instrumentation.

“Free-ended” vibration energy tests wereperformed over a continuous frequencyrange of 20-60 Hz for axial, torsional, lateral, and circular vibration modes.

Test fixture results indicate that vibrationenergy transmission coefficients increaseas vibration frequency is increased.

Axial vibration modes provided for sig-nificantly better vibration energy trans-mission coefficients versus other modes.Notably, torsional vibrations yieldedslightly better results than circular or lat-eral vibration.

BenefitsThe primary benefits resulting from thisproject will include 1) drilling-cost reduc-tion resulting from the use of less-expen-sive CTD for long, horizontal wellbores;and 2) the ability to develop additionalhydrocarbon reserves in a more environ-mentally friendly manner due to the small-er footprint associated with a CTD rig.

BackgroundA key barrier hindering increased utiliza-tion of CTD for inclined/horizontal wells isthe cost of overcoming downhole frictionwhen attempting to drill long (>2,000 feet)horizontal sections. When drilling theselong laterals, the downhole friction forcesreach such high levels that the drilling oper-

depth, engineering and construction of avibration test fixture, testing and valida-tion of the vibration attenuation model inthe vibration test fixture, and conceptualdesign and optimization of a full-scalefriction-reduction system.

Phase 2 work also encompasses four tasks,including finalizing design of the friction-reduction surface equipment, fabricatingsurface equipment, component-testing sur-face equipment, and field-testing the com-plete friction-reduction system.

Current Status (January 2006)The project is on schedule to complete allPhase 1 tasks by early second quarter2006. Testing in the vibration test fixtureis ongoing. These data will be used forsoftware model validation. Vibration testfixture results also will be used to identifythe optimum vibration mode to be used inthe conceptual design of a friction-reduc-tion system that could be utilized in thefield.

ation is stopped prematurely, or a costlydownhole drilling tractor must be used tohelp pull the coiled tubing at the bottom ofthe well in order to continue drilling.

The current approach to reducing downholefriction involves the application of down-hole vibrators or drilling tractors. Both ofthese technical approaches have significantlimitations. Vibrating pipe to mitigate fric-tion is a proven technology for convention-al “jointed” drillpipe operations. However,CTD surface equipment is significantly dif-ferent from that of a conventional drillingrig. This difference limits the ability to applysome of the existing types of vibration.

SummaryThe project consists of two 12-monthphases, with a Go/No Go decision point atthe conclusion of the initial phase. Phase 1work contains four major tasks, includingdevelopment of a software model to pre-dict downhole vibration attenuation versus

Microhole coiled tubing drilling friction reduction system for horizontalwellbores.

Project Start / End: 4-1-05 / 3-31-07DOE / Performer Cost: $756,570 / $189,140Contact Information:NETL – Virginia Weyland (virginia.weyland@netl.doe.gov or 918-699-2041)CTES – Edward Smalley (ed.smalley@ctes.com or 936-521-2222)

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Field Demonstration ofExisting Microhole CoiledTubing Rig

DE-PS26-04NT15482

GoalThe project goal is to field-test a state-of-the-art microhole coiled tubing drilling(CTD) rig and to conduct technology-trans-fer efforts to generate interest in and gainacceptance of the technology. Utilization ofthis technology will enable development ofmarginal oil and gas wells while minimiz-ing environmental impact.

PerformersGas Technology InstituteDes Plaines, IL

Rosewood ResourcesDallas, TX

ResultsThis project has demonstrated the advan-tages of microhole and CT drilling and doc-umented the advantages and economic ben-efits when compared with conventionaldrilling. Dissemination of these resultsthrough publications and presentations willfacilitate expanded use of this technique.

Twenty-three gas wells have been drilledand completed in the mature play of theNiobrara formation of western Kansas andeastern Colorado. A total 40,000 feet of 43/4-inch hole was drilled, ranging in depthper well from 1,500 feet to 3,100 feet. Eachof the wells was monitored for rig perform-ance, including rate of penetration, time forrig mobilization, and other parameters.

The small size of the rig resulted in severalenvironmental advantages, including smalldrilling pads of 1/10th acre and the absenceof mud pits where tanks were used to storeand move drilling fluids.

The performance of the drilling rig has con-tinuously improved throughout the project.Initially, 1,500-foot Niobrara wells weredrilled in one day. Currently, 3,000-footNiobrara wells are being drilled in 19 hours,including move-in, rig-up, drilling, logging,setting casing, cementing, and rig-downmove-out. Rate of penetration (ROP) wasas high as 500 feet/hour, with an averageROP per well of 400 feet/hour. The wellsdrilled resulted in a gauge hole with littlehole deviation.

with CTD are likely to facilitate additionalproduction through the development ofresources that are uneconomic at currentdrilling costs. The most significant econom-ic impact will be the additional oil and gasresources that will be made available toU.S. consumers.

SummaryIn this project, a next-generation microholeCTD rig is being field-tested. The rig beingused is the MOXIE experimental rig fabri-cated by ATD/CTS specifically for micro-hole CTD to depths as great as 5,000 feet.

Sites in Kansas and Colorado that haveknown gas resources at 1,200-3,500 feet indepth are being drilled and cased with themicrohole CTD rig. The rig is being evalu-ated in six areas: mobilization and rig-uptime, drilling surface and production holes,running surface casing and cementing, log-ging and evaluation, running productioncasing and cementing, and rigging downand moving the equipment from the drill-site. Measurements are being made of time,equipment weight, penetration rates, rpm,torque, drag, pumping pressures, mudproperties, solids control, and other meas-ures of rig performance.

During the early field testing and monitor-ing of the microhole CT rig, the percentageof time for each operation was calculated.Operations considered included rig-uptime, 9%; pick-up of bottomhole assembly(BHA), 9%; drilling, 26%; lay-down of theBHA, 9%; logging, 17%; and casing/cementing, 30%. The relatively lowdrilling time illustrates the advantage ofusing CTD where the drillpipe connectionis eliminated when compared with conven-tional drilling. The average rate of penetra-tion for the initial eight wells drilled was204 feet per hour.

Current Status (January 2006)All of the field work has been completed.Twenty-three project wells were monitoredin the field with over 40,000 feet of 43/4-inch hole drilled. The project contractrequired only three wells and 1,000 feet of43/4-inch hole be drilled.

The overall rig performance has led to anew approach for marginal gas fields. Wellsthat encounter thin pay with gas-water con-tacts near the perforated interval are beingdesigned for production without hydrauli-cally fracturing. This approach, if provensuccessful, will allow production of previ-ously non-producible gas reserves.

BenefitsBased on Coiled Tubing Solutions’ (CTS)drilling experience with CT rigs in Kansas,Montana, Texas, and Canada, microholetechnology can cut the drilling cost ofwells by up to 38%. The reduced costtranslates to $55,000 cost savings per1,200-foot well. The CTS rig design pro-vides technical advances over existingdrilling systems in seven areas: reduceddrilling cost, low mobilization/demobi-lization times, improved pipe-handling,increased safety, measurement-while-drilling, reduced environmental impact,and increased wellbore transmissivity.

BackgroundCurrently, about 800 wells are drilled peryear using coiled tubing in the UnitedStates, with the potential for a much largernumber if CTD becomes a proven tool. Inaddition, the cost savings and rig design

Project Start / End: 2-7-05 / 2-6-06DOE / Performer Cost: $999,794 / $1,000,000Contact Information:NETL – Jim Barnes (jim.barnes@netl.doe.gov or 918-699-2076)Gas Technology Institute – Kent Perry (kent.perry@gastechnology.org or847-768-0961)

This coiled tubing drilling rig hasdrilled over 40,000 feet of 43/4-inchborehole. The project garnerednominations as a finalist in the 2005World Oil Awards and for Operatorof the Year by the Colorado Oil andGas Commission in 2005.

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Counter-Rotating TandemMotor Drilling System

DE-FC26-05NT15489

GoalThe project objective is to increase thesupply of natural gas available to theUnited States with minimal environmentalimpact by decreasing the cost and foot-print of drilling operations for slim holes(31/2 inches) at relatively shallow depths.The technology is specifically directedtoward gas reserves in unconventional orlow-permeability formations in which alarge number of wells are necessary toeffectively drain the reservoir. In suchcases, economic development requiresthese wells to be drilled at a lower cost andwith less environmental impact than cur-rent technology allows.

The project goal is to develop a novelcoiled tubing drilling (CTD) system,specifically designed to drill at high ratesof penetration (ROP) with low weight onbit and low reactive torque. The Counter-Rotating Tandem Motor Drilling System(CRTMDS) will aid in achieving higherROP with a coiled tubing system.

PerformersGas Technology InstituteDes Plaines, IL

Dennis Tool CompanyHouston, TX

ResultsManufacturing has begun following devel-opment and evaluation of a detailed designfor a CRTMDS. After evaluation of thedesign, the decision was made to proceedwith the fabrication and testing of a proto-type system. The prototype system isundergoing an extensive testing program toevaluate its performance and reliability vs.conventional CTD systems. By the end ofthe program, a system suitable for use incommercial gas wells is expected to beavailable.

A similar tool design was tested for LosAlamos National Laboratory (LANL) inSeptember 2005 at the Rocky MountainOilfield Testing Center near Casper, WY.The smaller, 2.625-inch tool averaged 82feet/hour drilling 130 feet in 1.6 hours.Conventional 2.625-inch PDC bits average10-30 feet/hour.

to apply high WOB to the bottomholeassembly and the torque-handling capacityof the coiled tubing. These two limitationswork against the goal of high ROP.

SummaryThe CRTMDS developed in this projectwill combine a counter-rotating pilot bitand reamer to drill with low WOB andreduce reactive torque transmitted to thecoiled tubing. The system uses a small-diameter, left-hand polycrystalline dia-mond compact (PDC) pilot bit driven by aleft-hand turning PDM to drill a small pilothole. A 31/2-inch PDC reamer with an inte-grated stabilizer is run in tandem with andpowered by a right-hand turning PDM. Thebit contains premium PDC cutting insertsmanufactured with advanced microwave-sintered carbide substrates.

The proposed project is divided into sixtasks:

• Conceptual design.

• Final design.

• Prototype fabrication.

• Bit testing and evaluation.

• Tool modification.

• Technology transfer.

Current Status (January 2006)Final designs have been completed andmanufacturing begun on the pilot bit, stabi-lizer, reamer, and left-hand PDM. Firsttests of the tool were expected in February2006 at the GTI Catoosa Test Facility nearTulsa, OK.

The LANL test proved the design elementsof higher ROP using low weight on bit(WOB)—about 700 pounds—and lowreactive torque.

Design changes to the CRTMDS tool basedon the LANL test have been made to main-tain the diameter ratio of pilot bit to ream-er. A resulting increase in pilot bit sizefrom 2.25 to 2.75 inches allows for the useof a larger, 2.875-inch, right-hand positive-displacement motor (PDM) and a 2.125-inch, left-hand PDM.

BenefitsDrilling costs will be lowered through thedevelopment of an improved drilling sys-tem suitable for CTD operations. CurrentCTD systems are able to drill at relativelylow cost and with improved environmentalcharacteristics as compared with conven-tional drilling rigs. However, CTD wouldhave a much greater impact on oil and gasdevelopment if the rate of penetrationcould be increased by 25-60%, whiledecreasing the drilling cost by up to 40%.

BackgroundOverall drilling costs can be lowered bydrilling a well as quickly as possible. Forthis reason, a high ROP is desired. In gen-eral, high ROP can be achieved by increas-ing the WOB, the amount of torque on thebit, and the rotary speed of the bit. Twoimportant limitations commonly associatedwith coiled tubing systems are the inability

Reamer, flow diverter and bit forCRTMDS tool.

Project Start / End: 2-1-05 / 1-31-07DOE / Performer Cost: $654,953 / $163,743Contact Information:NETL – Jim Barnes (jim.barnes@netl.doe.gov or 918-699-2076)Gas Technology Institute – Kent Perry (kent.perry@gastechnology.org or847-768-0961)

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Advanced Ultra-High-SpeedMotor for Drilling

DE-FC26-04NT15502

GoalThe project goal is to design ultra-high-speed (10,000 rpm) electric inverted con-figured motors in two sizes for drilling theearth and man-made materials.

PerformersImpact Technologies LLCTulsa, OK

University of Texas-ArlingtonArlington, TX

ResultsResearchers have developed electromag-netic designs for radial and axial motors in2 outer diameters (OD) for speeds up to10,000 rpm. Magnetic saturation andpower/torque estimations have been madeat various speed and loading conditions.Bearing and seal materials have been stud-ied, but their final design must wait untilthe electromagnetic motor design has beenfinalized.

The project completed:

Review and analysis of ultra-high-speedcutters and bits.

Selection of motor diameters andtorque/horsepower requirements.

Electric-magnetic radial motor design of1.69-inch OD for microbore drilling.

Electric-magnetic radial motor design of3.0-inch OD for slimhole drilling.

Electric-magnetic axial motor design of1.69-inch OD for microbore drilling.

Initial review of materials for ultra-high-speed bearings (configuration dependentupon final motor design selected).

BenefitsA new motor and drilling process combi-nation will benefit oil and gas explorationand production by finding new reserves asa result of lower finding costs andincreased production from existing wellswith horizontal drilling applications. Thedrilling method is applicable to extremelyhard or deep reservoirs that are difficult todrill with current technology. The gas stor-age industry can benefit from horizontaldrilling in storage fields, which allows

of an “inverted motor” configuration vs. anelectrical motor is that the internal high-pressure fluids are not in contact with theelectrical components. The weaker perma-nent magnets are lined inside the outerrotating housing and thus are supportedfrom the extreme centrifugal forces gener-ated by such high speeds. The internal andexternal flows can efficiently cool the elec-trical/magnetic-induced heat load. Air gapclearances and magnetic-strength satura-tion are ongoing concerns.

Radial and axial designs for both OD sizeshave been accomplished but not finalized.Both power control and power inverterboards have been designed. Manufacturersof bearings have been identified and con-tacted, but final design must await the com-pleted final electrical-mechanical design.Ultra-high-speed seals will be selected last,based on the generated heat and pressureranges required.

Current Status (January 2006)Researchers are finalizing the electromag-netic design of the motor. The current focusis on electric-magnetic axial design of a 3-inch OD motor for slimhole drilling andon bearing materials and design. The nextsteps are to mate final electromagnetic-mechanical designs with appropriate bear-ings and seals, perform heat transfer analy-sis of final designs, and prepare finalmachine drawings for prototyping.

enhanced deliverability. Significant bene-fits are expected for the trenchless utilityindustries (telephone, fiber-optics, com-munications, water, etc.) and pipelineinstallations across roads and rivers.

BackgroundDrilling boreholes at ultra-high speeds(>10,000 rpm) has been shown to penetratefaster than at lower speeds. Using abrasiveand/or acidic fluids at high pressures alsohas been shown to increase drill rate.Employing an electric motor in the new“inverted” configuration allows the combi-nation of these two mechanisms (ultra-highspeed and high-pressure fluids) to be usedfor even faster and more-efficient drilling.

SummaryThis project initially focused on drillbitsthat are to be used in ultra-high-speeddrilling applications. This was important todetermine the required load, torque, horse-power, and sizes. From this study, it wasfound that few cutter elements and bits canwithstand the generated heat, abrasiveness,and shock of this environment, althoughcurrent work in this area is encouraging.

Based on this work, the motor require-ments were set as a first pass for the elec-tromagnetic design. Two sizes planned forinitial design were 1.69 inches and 3 inch-es OD, with the lengths variable and motorpower sections stackable. The chief benefit

Magnetic field distribution in a small, ultra-high-speed electric motor.

Project Start / End: 10-1-04 / 3-31-06DOE / Performer Cost: $165,882 / $55,441Contact Information:NETL – Paul West (paul.west@netl.doe.gov or 918-699-2035)Impact Technologies – Ken Oglesby (oakk@aol.com or 918-627-8035)

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14

Advanced Sealed-BearingAssembly for PositiveDisplacement Motors Used inMicro-Borehole Drilling

DE-FG02-05ER84206

GoalThe goal of this research project is thedevelopment of an advanced sealed-bear-ing assembly for positive displacementmotors (PDMs) suitable for microholedrilling.

PerformerKalsi Engineering, Inc.Sugarland, TX

ResultsExpected outcome of the project is thedevelopment of advanced hydrodynamicrotary seal and thrust bearing designs, aswell as the sealed-bearing assembly, in aneffort to meet the challenges posed by tech-nical issues related to scaling down compo-nents for microhole drilling.

Field tests performed over the last twoyears with the newly developed, hydrody-namically lubricated, load-responsive,hydrodynamic thrust bearings in 43/4-inchPDMs used in coiled tubing drilling appli-cations have demonstrated that they arevery durable and are able to provide longlife and reliable performance under thesevere loads imposed by high vibrationswithout any damage, whereas the conven-tional rolling-element bearings had routine-ly experienced premature failures. Thenew bearing technology will be critical inthese coiled tubing microdrilling applica-tions, which are expected to impose higherlevels of shock and vibrations.

BenefitsDOE has identified the development ofPDMs as a critical technology need for itsmicrohole drilling program. This researchwill lead to an advanced sealed-bearingassembly for PDMs that is very durable,has long life, and can perform reliablywith low operating cost under the higherdifferential pressures required for effi-ciently drilling microholes. The advancedtechnology will be available as a modular,self-contained unit that readily mates withthe power section of various PDMs beingdeveloped by industry. This intensive,parallel development effort will acceleratecommercialization of the other critical

cleaning, or some combination of both tooptimize the penetration rate.

SummaryKalsi Engineering, Inc. will apply its back-ground, field experience, and technicalinsights to extend this high-pressure, rotaryseal-and-bearing technology to the sealed-bearing assembly for the 2-inch and smaller-diameter microhole PDMs targeted underthis program. These advances will be accom-plished through a systematic and rigorousdevelopment program, including detailedanalyses, design, and testing to address scal-ing issues, higher pressures, more-severevibrations, and proportionately larger radialdeflections caused by bit side loads.

The research is aimed at developing thesealed-bearing assembly technology formicrohole drilling with PDMs. The tech-nology also can potentially benefit IRPMsfor microdrilling.

Current Status (January 2006)Kalsi Engineering has worked withNovatek and Dresser-Rand to develop twodifferent technologies for rotary percussiondrilling to meet sealing requirements. Themore recent technology, patented byDresser-Rand, requires rotary seals capableof performing under higher pressures.These technologies also will need scaled-down versions of the advanced, high-pres-sure rotary seals for the microhole drillingprogram.

technologies being developed for themicrohole program.

This technology will be a key contributorto the microhole program goal of faster,cheaper, and safer oil and gas drilling, withDOE projecting savings of 30-50% indrilling costs and 90% in equipment cost.This also will contribute towards the U.S.goal of maintaining global technical lead-ership.

BackgroundDOE has undertaken a new research anddevelopment initiative to develop micro-hole technologies that use portable drillingrigs with a smaller footprint and lower envi-ronmental impact. It identified PDMs asone of five critical technology developmentinitiatives needed to support the microholeinitiative. Another critical technology areaidentified is the development of integratedrotary-percussion motors (IRPMs). Thedetailed analysis of the requirements for thedrilling-fluid circulation system for micro-hole drilling (performed by Los AlamosNational Laboratory) showed that 1) largerpressure drops will be required across thePDMs as compared with current design,and 2) the motors will need sealed bearingsthat are cooled by the flow through themotor as opposed to flow through a bearingassembly that bypasses the bit to providethe maximum pressure drop across the bit.The higher pressure drop at the bit nozzleswill be converted to jet drilling power, hole-

Basic geometry and principle of operation of the hydrodynamic rotary seal.

Project Start / End: 6-27-05 / 3-26-06DOE / Performer Cost: $99,739 / $0Contact Information:NETL – Daniel Ferguson(daniel.ferguson@netl.doe.gov or 918-699-2047)Kalsi – Monmohan Kalsi (281-240-5400)

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The Application and Use ofMicroholes for VerticalSeismic Profiling

FWP ESD04-006

GoalThe project goal is to evaluate and developvertical seismic profiling (VSP) technologyfor microholes to be used to enhance imageresolution and depth penetration beyondcurrent technology in a low-cost fashion.

PerformersLawrence Berkeley National Laboratory Berkeley, CA

Los Alamos National LaboratoryLos Alamos, NM

Sandia National LaboratorySandia, NM

Rocky Mountain Oilfield Testing Center Casper, WY

ResultsA low-cost vertical seismic instrumentationsystem that can be deployed in a low-costmanner was developed for use in micro-holes. VSP surveys were completed at theRocky Mountain Oilfield Testing Center(RMOTC) using a 20-level hydrophonestring and a 20-level geophone string. Thesurveys demonstrated that VSP data can becollected without using expensive rigs andextensive manpower. This work will serveas a baseline study in preparation for afuture CO2 injection monitoring program.

BenefitsThe low-cost and easily deployed seismicsystem developed in this project will makeVSP surveys more available to small oper-ators with limited resources.

The increased resolution afforded by VSPcan more accurately image subsurface reser-voir rock and fluids and is particularly use-ful in understanding fractured and compart-mentalized reservoirs.

Smaller equipment needed to run VSP sur-veys saves time, makes the system easilytransportable through rough terrain andfragile environments, and reduces opera-tional footprint.

BackgroundWhile VSP is not a new technology, the rou-tine, low-cost application of VSP at thesame scale of surface seismic has not

Los Alamos National Laboratory atRMOTC in Teapot Dome, WY. The focusof the project is to model, design, carry out,and process multiple shallow VSP surveys(500-700 feet deep) in microdrilled holes inan area that is well-characterized. The VSPresults will be compared with surface seis-mic and other information such as welllogs, existing models, and core analyses.

Current Status (January 2006)The project’s 2006 work in progressincludes the following:

Extending the application of microholeVSP to commercial sites (in planning).

Tertiary Oil Recovery Project Kansassite. This includes active time-lapsemonitoring of CO2 injection and pas-sive monitoring of the reservoirbetween time-lapse measurements.

Wyoming deep (>8,500 feet) CO2

EOR (Perfection Oil).

Barnett shale hydrofracture monitoring.

Investigating the next generation ofinstrumentation.

Fiber optic sensors.

Microelectromechanical systems and nanosensors.

Adapting processing for improved“look-ahead” capability.

Improved methods of imaging verti-cal features in homogeneous geology.

occurred. As oil and gas resources becomeharder to find and produce in the UnitedStates, there is a critical need to enhanceseismic resolution of the subsurface. WhileVSP offers such an increase in resolution, ithas been held back by the use of expensiveholes and large-scale deployments.Microhole technology offers a means todeploy VSP at lower cost and denser sam-pling than “conventional” VSP surveys.

SummaryThe project achievements include:

A low-cost, easily deployed system forconducting VSP surveys was developedand tested.

The use of hydrophone (fluid-coupled)and geophone (directly clamped) sensorstrings were compared. The test showedthat geophones were the most effectivetype of sensor for the situation investi-gated.

A new “vacuum-assisted” geophoneclamping mechanism was developed andused to minimize the overall size of thesensor package.

Initial VSP surveys have been completedin and processed from 800-foot microholes.

This project is an integrated program ofmodeling, instrumentation evaluation andtesting, and data acquisition and process-ing. The effort is tightly coupled with themicrodrilling program being conducted by

The complete system used to acquire the VSP data. The simplicity of the sys-tem allowed for hand deployment, a rental vehicle for the “doghouse,” and asmall vibrator for the source. Note the small tripod used to support the sensorstring; normally, a workover rig and many more personnel are needed.

Project Start / End: 3-12-04 / 3-11-06DOE / Performer Cost: $400,000 / $0Contact Information:NETL – Purna Halder (purna.halder@netl.doe.gov or 918-699-2084)LBNL – Ernest L. Majer (elmajer@lbl.gov or 510-486-6709)

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16

Technology Development andDemonstration of MicroholeOil Production/Microholesfor Designer Seismic inSupport of CO2 EOR

FEW03FE06-04/FEW03FE06-06

GoalThe primary goal of the first project is toshow that microholes provide downholeaccess at significantly lower cost than con-ventional wells and provide superioracoustic performance when compared withthe use of temporarily converted produc-tion or injection wells. The second—andrelated—project’s goal is to adapt micro-hole systems for deploying microseismicarrays in CO2 enhanced oil recovery operations.

PerformersLos Alamos National Laboratory (LANL)Los Alamos, NM

Lawrence Berkeley National Laboratory(LBNL) Berkeley, CA

Dennis Tool CompanyHouston, TX

Quality TubingHouston, TX

Rocky Mountain Oilfield Testing Center(RMOTC), Casper, WY

ResultsResearchers have demonstrated the techni-cal feasibility of microdrilling 13/4-25/8-inchholes to depths of as much as 1,310 feetusing coiled tubing-deployed drillingassemblies consisting of PDC (polycrys-talline diamond compact) bits and PDM(positive displacement) motors.

Field demonstrations have been conductedat RMOTC’s Teapot Dome oilfield at theNaval Petroleum Reserve No. 3 in CentralWyoming using a prototype coiled tubingunit, an off-the-shelf drilling-mud cleaningunit, and a surplus shallow-well cementingunit to simulate a highly mobile, self-con-tained, microhole drilling system.

BenefitsMicro-instrumentation holes potentiallycould cost as little as a quarter to a tenththat of conventional boreholes. Successfuldemonstration of a nonmetallic casingsuch as PVC line pipe may reduce acoustic

drilled and completed six microwells at theRMOTC Teapot Dome field.

LANL is evaluating commercial equipmentwith the potential to enhance the perform-ance of microdrilling. Two demonstrationsare ongoing with good early results:

Quality Tubing Inc.’s QT16Cr80 stain-less steel coiled tubing as a drill stem formicrodrilling.

Dennis Tool Company’s low-torque, lowweight-on-bit drilling assembly.

Current Status (August 2005)The LANL drilling team has completeddrilling a four-microinstrumentation-holepattern to field LBNL microseismic arraysat Teapot Dome field. Researchers present-ly are preparing to deploy to—as yet unde-termined—CO2 EOR sites that very likelywill require more adaptations of the micro-drilling systems to operated in new drillingconditions and possibly different regulato-ry requirements.

The project has completed early-stagedemonstrations. The research effort todemonstrate the applications will begin inthe new project FEW03FE06-06.

noise and improve the performance ofmicro-instrumentation holes dedicated toreservoir-monitoring service.

BackgroundLANL’s experience with seismic dataacquisition in oilfields indicates that low-cost, dedicated microholes for deploymentof seismic sensors are needed to enhanceacoustic data monitoring of the subsurface.Dedicated data acquisition holes providereduced natural surface and cultural noise,reduced or eliminated seismic-signal travelpaths through highly attenuating surfacelayers, and a greatly improved signal-to-noise ratio.

Accordingly, microholes promise a low-costalternative to conventional wells; they can beplaced in the desired location and designedfor optimal acquisition of seismic data.

SummaryProject researchers are demonstrating thetechnical and economic feasibility ofdeveloping a highly mobile, self-contained,microhole drilling system for seismic dataacquisition and other applications. Usingprototype systems to simulate the conceptmicrohole drilling system, LANL has

LANL microdrilling at the RMOTC-operated Teapot Dome Field at NPR No. 3.The microdrilling rig includes the coiled tubing drilling unit on the right, mudcleaning system on the left, and the RMOTC drilling-water truck in the center.

Project Start / End: 3-15-03 / 3-14-06 2-15-06 / 2-14-07DOE / Performer Cost: $1,300,000 / $0 $550,000 / $0Contact Information:NETL – Daniel Ferguson (daniel.ferguson@netl.doe.gov or 918-699-2047)LANL – Donald Dreesen (dreesen@lanl.gov or 505-667-1913)

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Demonstration of Microholesfor Oil Production andEmplacement of SubsurfaceSeismic Instrumentation

FEW 04FE09

GoalThe chief objective of this project is tofield-test a microhole drilling system capa-ble of drilling and completing small-diam-eter wells. The wells will be drilled with acoiled tubing rig to lower overall explo-ration and production costs.

A second objective of the project is to eval-uate new commercial drilling and comple-tion equipment. The Los Alamos micro-drilling equipment serves as a platform toevaluate commercial technology that is ormay be appropriate for microdrilling andcompletion services.

PerformersLos Alamos National Laboratory (LANL)Los Alamos, NM

Rocky Mountain Oilfield Testing Center(RMOTC)Casper, WY

Lawrence Berkeley National Laboratory(LBNL)Berkeley, CA

University of WyomingLaramie, WY

ResultsThe acoustic performance of the geologicformations in the CO2 injection area hasbeen modeled and was used to select fourwell locations for CO2 flood monitoring.Seismic arrays were selected, and theequipment needed to assemble and deploythe arrays was procured.

The first micro-instrumentation CO2-moni-toring hole—one of two 800-foot micro-holes planned—was drilled and completedin October 2004. The 808-foot well wascompleted with PVC casing set below 587feet, where intermediate steel casing wascemented to isolate the Shannon formation.The second micro-instrumentation holewas drilled to 407 feet and later similarlycompleted. A multi-offset, vertical seismicprofile survey was conducted successfullyin one of the 800-foot microholes.

Microholes (wellbores less than 31/2-inchdiameter) have the advantage of being rel-atively inexpensive to drill, and locationsand completion designs can be selected foroptimal acquisition of seismic data.

SummaryThis project will 1) investigate the feasibil-ity of installing 3/4-inch coiled tubing on theLANL coiled tubing unit to extend micro-hole depth capability to 1,500 feet; 2)improve the performance of the LANLlow-cost, highly portable, micro-sizedcement mixing equipment and displace-ment pumps; 3) demonstrate a low-costmicro-wellhead concept for production;and 4) complete a demonstration microholeproduction system at RMOTC.

Current Status (January 2006)Completion of the second monitoring welland drilling and completion of two addi-tional microwells began in spring 2005.The high-resolution seismic data are beingprocessed. CO2 injection is presentlyscheduled to begin in late 2006.

BenefitsThe overall objective of this project is todemonstrate the technical and economicfeasibility of a highly mobile, self-con-tained, microhole drilling system as anenabling technology for commerciallyviable seismic-data acquisition.Succeeding in these objectives will resultin reduced well cost and improved qualityof data. Air-filled microholes completedwith PVC (or other nonmetallic casing) areexpected to provide the lowest noise envi-ronment possible for retrievable seismicinstrumentation.

BackgroundThe use of production and injection wellsfor seismic data acquisition has a numberof disadvantages. Deploying seismic sen-sors and other logging-type tools interruptsfield operations, resulting in loss of moneythrough temporarily stopped productionand idle time for expensive equipment andpersonnel. Production and injection wellsoften are not positioned in the most advan-tageous locations for obtaining reservoirdata. Conventional wells dedicated to seis-mic monitoring are expensive to drill.

Foreground: LBNL microgeophone array sonde in the deployment cable.Background: contract vibroseis unit.

Project Start / End: 7-8-04 / 7-7-06DOE / Performer Cost: $705,000 / $0Contact Information:NETL – Daniel Ferguson (daniel.ferguson@netl.doe.gov or 918-699-2047)Los Alamos – Donald Dreesen (dreesen@lanl.gov or 505-667-1913)

18

A Built-for-Purpose CoiledTubing Rig

DE-PS26-03NT15474

GoalThe project goal is to develop a microholecoiled tubing drilling (CTD) rig capableof drilling a 31/2-inch open hole to 6,000 fttotal measured depth with a 1,000-foot lat-eral section. The rig will be capable ofrotary and coiled tubing drilling and beable to drill efficiently, safely, cost-effec-tively, and with minimal environmentalimpact.

PerformerSchlumberger Well ServicesSugar Land, TX

ResultsThe project started with the review of cur-rent CTD rigs, with a plan to modify anexisting rig for use as a microhole CT rig(MCTR). Research showed that the major-ity of built-for-purpose CTD rigs werevery large and could prove difficult tomove about on small lease roads. This ledto a plan to reduce the overall size of theunits, without hindering any of the effi-ciency factors that current purpose-builtunits have.

Phase 1 is complete, in which many tech-nical issues regarding the operation of theMCTR were addressed. These technicalissues then were used to generate a con-cept for the development of a built-for-purpose MCTR.

BenefitsMicrohole technology offers an alternativeto conventional rotary drilling techniques.Rotary drilling typically has larger com-pletion sizes due to limitations imposed byjointed pipe. These larger completionsaccount for higher costs for drilling, com-pletion, and disposal. The CTD rig’s partin microhole technology is to keep theoperating cost to a minimum so that all ofthe economic benefits of drilling a micro-hole can be realized.

Cost savings to the operator could be asmuch as $1,071,144 per year. The estimat-ed cost savings was based primarily onincreases in efficiency compared with con-ventional units and the reduction of acci-dents. Based on economic calculation, theMCTR could perform an additional 50

days of drilling, or nearly $1,100,000worth of billable drilling, each year. A dayrate of $20,000 for basic overbalanceddrilling was used in the estimate.

BackgroundCoiled tubing drilling of oil and gas wellshas been practiced since the early1990s. Primary drivers for the develop-ment of coiled tubing services have beenthe ability to perform through-tubing re-entry work and to drill underbalanced. Avariety of purpose-built CTD rigs existsaround the world. None of them is specifi-cally designed to access the shallow oiland gas reservoirs in the United States in acost-effective way.

SummaryThis project is developing and building anMCTR for U.S. shallow oil and gas reser-voirs. The rig is being designed to improvethe economics of shallow-well drilling byusing small and purposed-built equipmentthat is easy to move and fast to mobilize,yet versatile in its application.

Among the project’s achievements:

Market analysis for the MCTR has beencompleted, illustrating the need for ascalable rig that can perform slimhole as

well as microhole work. This will ensurethat utilization is kept high, which willkeep the unit’s day rate as low as possi-ble.

Operational analysis showed that it isfeasible to drill a microhole with coiledtubing. However, with smaller coiledtubing, artificial means of obtainingweight on bit may be necessary.

Operating scenarios were developed toevaluate various MCTR concepts withregard to rig-up efficiency and the abili-ty to perform the necessary tasks associ-ated with drilling a microhole.

The final concept was developed and iscurrently in the detailed design process.

Current Status (January 2006)The original proposal called for the devel-opment of an MCTR. Because of timeconstraints, a suitable CTD unit was foundthat could be modified to make therequirements set forth in the MicroholeInitiative. The rig performance is beingevaluated before modifications begin.

Project Start / End: 10-1-04 / 9-30-07DOE / Performer Cost: $1,200,000 / $636,423Contact Information:NETL – Daniel Ferguson (daniel.ferguson@netl.doe.gov or 918-699-2047)Schlumberger Well Services – Warren Zemlak (warrenz@sugar-land.oilfield.slb.com or 281-285-7068)

Coiled tubing unit to be modified.

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in tracking an air-soil boundary in con-ductive soil.

The data transmission system uses fre-quency-shift keying modulation of 91.5-kHz signals. Radio waves are inductivelycoupled to and from the skin of the drillpipe using loop antennas. The systemtakes advantage of the natural waveguideproperties of the hydrocarbon seam; theentire drill rod and the immediate sur-rounding layers of rock become the datatransmission channel. The system trans-mits data collected by the DSP radar at arate of 2,400 bits/second. The system alsois equipped with a downhole navigationpackage (3-axis magnetometer andaccelerometer) that provides bottomholeassembly orientation data that comple-ments the data from the radar.

Current Status (January 2006)With the communications concept provedwith the success of the first prototype inthe Deer Creek mine, the focus has beenon the design and fabrication of a second,more robust pre-production prototype suit-able for MWD applications. This secondprototype refines the communication con-cept and focuses on the practical and oper-ational design aspects required duringactual drilling conditions.

gation, the operator can eliminate theexpensive practice of sidetracking in hori-zontal drilling.

BackgroundThe information from MWD sensors in abottomhole assembly must quickly betransmitted to the drill operator for real-time navigation of the drillbit. Two meth-ods are currently employed. One commonmethod of transmitting downhole sensordata to the surface is by sending extremelylow-frequency (e.g., 40 Hz) signals thoughthe layers of the earth to reach a surfacereceiver antenna. This method provides aslow communications channel due to itslow frequency. The other method uses wirelines (or fiber optics) embedded in the drillpipe to provide high-speed communica-tions with the topside receiver. This is gen-erally an expensive and irreversible process.Stolar’s data communications system is acost-effective alternative to these methodsof MWD communication.

Currently, the location of the drillbit in thehydrocarbon reservoir is determined fromthe gamma ray, neutron, and resistivitysensors. There is no tool available to let thehorizontal drilling operator know the dis-tance between the drillbit and the bound-ing walls of the reservoir. The radar navi-gation tool eliminates this deficiency.

SummaryAmong the project highlights:

A proof-of-concept prototype data com-munications system suitable for propa-gating communications signals alongthe outer skin of a metal drill rod hasbeen designed, fabricated, and success-fully tested in a borehole.

A prototype DSP-based radar systemhas been designed and fabricated thatcan detect and map the reservoir bound-ary.

A test of a prototype, 800-kHz system,which employed a transmitter/receiverpair of loop antennas in a deviated bore-hole, showed that the resonant frequen-cy and the transmission loss can be used

Development of RadarNavigation and Radio DataTransmission for MicroholeCoiled Tubing BottomholeAssemblies

DE-PS26-03NT15477

GoalThe overall goals of this project are todesign, manufacture, and test twoadvanced technologies for the oil and gasindustry: 1) real-time measurement-while-drilling (MWD) for guidance and naviga-tion of coiled tubing drilling in hydrocar-bon reservoirs and 2) two-way inductiveradio data transmission on coiled tubing orvia an insulated slickline fed inside thecoiled tubing.

PerformerStolar ResearchRaton, NM

ResultsA data transmission system has beendeveloped that uses only the outer surfaceof the drill pipe to propagate communica-tions signals. The system, which is smallenough to fit inside a 1.661-inch diameterhousing, was successfully tested over 500feet of pipe inside an uncased, water-filledtest hole in the Deer Creek coal mine inUtah. The signal-to-noise ratio at thereceiver for the one-way communicationstest was better than 30 dB. During above-ground tests that simulated borehole con-ditions, the system was successfully testedover 1,700 feet of pipe.

A prototype digital signal processing(DSP)-based radar system capable ofcoherent detection of radio waves has beendesigned and fabricated that providesMWD guidance and navigation of coiledtubing. To track the boundaries in an oilreservoir, a radar system has been devisedthat operates below 1 MHz with multipletransmitter and receiver antennas to pro-vide directionality and spatial diversity.

BenefitsThe technologies developed in this projectallow real-time navigation and imagingduring exploration with minimum landdisturbance and fewer drillholes. The pro-posed technologies are expected toimprove the recovery efficiency of shallowproduction wells. Through real-time navi-

Radar measurements while drillingfor horizontal directional drilling, navigating, and structure detection.

Project Start / End: 7-26-04 / 9-25-06DOE / Performer Cost: $737,000 / $184,875Contact Information:NETL – Purna Halder (purna.halder@netl.doe.gov or 918-699-2084)Stolar – Larry G. Stolarczyk (lgstolar@aol.com or 505-445-3607)

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High-Power Turbodrill andDrillbit for Drilling withCoiled Tubing

DE-FC26-05NT15486

GoalThe project entails developing and testingan effective downhole drive mechanismand a novel drillbit for drilling small-diam-eter vertical and horizontal wellbores withcoiled tubing.

PerformersTechnology International, Inc.Houston, TX

Smith International, Inc. Houston, TX

ResultsBaseline testing of an existing 27/8-inchdiameter turbodrill with polycrystallinediamond compact (PDC) and impregnateddiamond drillbits has been successfullyperformed at Gas Technology Institute’sCatoosa, OK, field test site. The hydraulicefficiency of the baseline MK2 turbineblades has been increased so far by 13%.

BenefitsBenefits to the industry from successfuldevelopment of a microhole coiled tubing(CT) turbodrill and high-speed drillbitinclude:

Delivery of more power to the bit thanwith positive displacement motors.

Lower reactive torque for improveddirectional control.

Longer drillbit life, less vibration, andsteady dynamics at the bit.

Smaller cuttings that are easier to cleanfrom the hole.

Drilling at a higher rate of penetration(ROP) with less weight on bit (higherrotary speeds to 2,200 rpm providehigher ROP and lower cost per footdrilled).

Operation at high downhole tempera-tures.

Operation in two-phase muds at higherrotary speeds and for underbalanceddrilling applications.

Improved hole quality and high reliability.

design of components that ultimately willlead to a higher-power turbine section.

The next step in the project is to incorpo-rate the design improvements into a newdownhole drilling assembly for a micro-hole drilling system. Tools will be madeavailable to microhole project partners forindependent field applications in re-entrywells and workover operations using com-mercial coiled tubing rigs.

A thermal model is being developed to pre-dict cutter temperatures while drilling hardand abrasive rock at high rpm. Being ableto estimate cutter tip temperatures will aidin the development of a more durable drill-bit employing high-temperature cutters.

A fluid dynamic model developed byNASA Ames Research Center, MountainView, CA, is being used to increase thehydraulic efficiency of the existing 27/8-inch diameter Turbodrill. The resultwill be a shorter tool to aid directional con-trol and greater torque to increase ROP.

Current Status (January 2006)Initial tests of prototype hardware wereconducted at drilling research centers toexpedite the testing process and to ensuremaintenance of carefully controlled operat-ing conditions not compromised by cus-tomers’ operational drilling requirements.Task 1, the baseline turbodrill and drillbittesting, was completed in March 2005. Aturbine blade hydraulic design model wasused to redesign the turbine blades, andsuccessful dynamometer testing was com-pleted in June 2005. Further Turbodrillhydraulic modeling is under way, as well asthermal modeling of the drillbit cutters.

A drillbit thermal model has been complet-ed and is being tested for 31/2-41/8-inchdiameter fixed-cutter bit designs employ-ing both PDC and thermally stable dia-mond cutters. Cutter temperatures will beestimated for bits operating at rotary speedsthat match the capabilities of the improved27/8-inch diameter Turbodrill, with rotaryspeed capabilities up to 2,200 RPM.

BackgroundDr. Steve Holditch, 2002 president of theSociety of Petroleum Engineers, said, “Toeconomically recover gas, we need tolearn how to drill smaller boreholes morerapidly and less expensively.” But drillingtoday does not necessarily mean using aconventional drilling rig. CT units increas-ingly are being used to drill for oil and nat-ural gas deposits at lower costs and with amuch smaller environmental footprint. CTdrilling is a cost-effective alternative fordrilling highly deviated wells or drillingnew hole sections in existing wells. Theuse of a relatively high-speed turbodrilland high-temperature drillbit will reducethe cost per foot drilled.

SummaryThe prototype CT turbine motor and drill-bit being developed in this project aredesigned to:

Drill a vertical hole to 5,000 feet and drilllaterals to 1,000 feet.

Demonstrate the economic advantages ofthe CT drilling operation when com-pared with conventional drillpipe-con-veyed downhole assemblies.

The performance of the turbodrill and bitsystem will lead to an advance in the

The PDC and impregnated dia-mond drillbit being developed inthis project.

Project Start / End: 2-7-05 / 8-6-06DOE / Performer Cost: $759,668 / $200,000Contact Information:NETL – Dan Ferguson (daniel.ferguson@netl.doe.gov or 918-699-2047)Technology Int’l. – Robert Radtke (radtke@kingwoodcable.com or 281-359-8520

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Small, Mechanically AssistedHigh-Pressure WaterjetDrilling Tools

DE-FC26-05NT15484

GoalThe goal of this project is to produce a high-pressure jet-drilling system that will dra-matically reduce the torque and thrustrequired for drilling, thereby increasing reli-ability, drilling rate of penetration (ROP),and lateral reach.

PerformerTempress Technologies, Inc.Kent, WA

ResultsProject researchers have:

Completed review of the jet drilling sys-tem commercial market, configuration,and sizing, including integration withmicrohole-sized coiled tubing drilling(CTD) equipment.

Completed modeling and designs for gasseparator, intensifier, jet drill, and circula-tion in coiled tubing.

BenefitsThe economic benefits of the high-pressurewaterjet microhole CTD system arederived from both increased capabilitiesand reduced drilling costs. This drillingsystem will be able to drill deeper and far-ther in deviated wells than current coiledtubing technology because of 1) increaseddownhole power, 2) the ability to drillunderbalanced, 3) improved cuttings trans-port, 4) reduced tendency to stick in thehole, and 5) increased drilling efficiency inpressure-sensitive shales. Other economicbenefits result from the decreased holesize. When the volume of a 31/2-inch diam-eter hole is compared with that of a con-ventional 81/2-inch diameter hole, 83% lessfluid is required to fill and circulate themicrohole.

BackgroundSmall downhole positive-displacementmotors (PDMs) have limited power outputand are prone to stall when run with aggres-sive polycrystalline diamond compact bits.PDMs are designed to operate at a limitedpressure differential on single-phase, water-based mud. Also, as lateral reach increases,the thrust available for mechanical drillingdrops due to coiled tubing friction and heli-

Fabricating and testing components.

A review of high-pressure jet drilling andmechanically assisted jet drilling was car-ried out to define the bottomhole assembly(BHA) configuration and DHI perform-ance specifications for CTD applications.Two BHA configurations were evaluated:mechanically assisted high-pressure jetdrilling with the DHI deployed below aPDM drill motor and high-pressure jetdrilling with the DHI deployed upstream ofa rotary jet drill.

The analysis showed that high-pressure jet-drilling with a high-pressure drill motorand DHI could allow drilling at 3-5 timesconventional drilling rates.

The project will provide both a mechani-cally assisted, high-pressure jet-drillingtool and a pure high-pressure rotary jet-drilling tool. Both tools will utilize a com-mon DHI. The downhole intensifier andhigh-pressure rotary jet drill designs repre-sent modifications of existing toolsdesigned for coiled tubing scale milling.Researchers will work with PDM, seal, andbearing suppliers to provide high-loadbearings and seals to maximize the pres-sure capacity of conventional motors andwith a bit supplier to provide a customdual-passage drillbit to provide both high-pressure jetting and mechanical cuttingcapabilities. The tools then will be assem-bled for functional testing. Endurance test-ing on two-phase flow will be carried out ina pressure-test facility with full powerwater and nitrogen pumpers.

The jet-drilling system is expected to pro-vide sustained drilling rates of 80 feet perhour or more with a microhole CTD sys-tem, while providing over 100 hours ofreliable motor operation.

Current Status (January 2006)Design of the system components is com-plete, and the prototype tools are currentlybeing fabricated. Tempress has obtained ano-cost time extension to accommodatedelays in manufacturing and availability oftest equipment. The prototype tools arescheduled for yard testing in spring 2006.

cal buckling. Drilling with high-pressurefluid jets makes more efficient use of avail-able downhole power and has proven effec-tive in most rock formations. High-pressurejet drilling dramatically reduces the torqueand thrust required for drilling, thusincreasing ROP and lateral reach.

SummaryThis project involves the development of adownhole intensifier (DHI) to boost thehydraulic pressure available in conventionalCTD to the level required for high-pressurejet erosion of rock. The first phase of theproject consists of three major tasks:

Analyzing the CTD system to define oper-ating parameters for the drilling assembly(completed).

Designing the downhole intensifier, jet drill,PDM motor modifications, and drillbit.

Project Start / End: 2-10-05 / 1-31-07DOE / Performer Cost: $737,000 / $184,875Contact Information:NETL – Dan Ferguson (daniel.ferguson@netl.doe.gov or 918-699-2047)Tempress – Jack Kolle (jkolle@tempresstech.com or 425-251-8120)

Tempress jet drill (top). Sandstoneshowing, 1.165-inch diameter toolface and tight-gage hole (bottom).

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Microhole Coiled TubingBottomhole Assemblies

DE-FC26-05NT15487

GoalThe project goal is to combine existingtechnologies for measurement-while-drilling (MWD) and logging-while-drilling(LWD) into an integrated measurementsystem to facilitate low-cost drilling ofsmall (31/2-inch diameter), shallow (<5,000foot depth) boreholes using coiled tubingdrilling (CTD) technology. The project willdeliver two prototypes ready for field testing.

PerformerUltima LabsHouston, TX

ResultsThe project was launched in April 2005.The first prototypes are scheduled for fieldtesting in 2007. The measurement systemwill provide critical enabling measure-ments for efficient CTD and formationevaluation. MWD measurements includeinclination and azimuth for directional con-trol and weight on bit (WOB), torque, andbore and annular pressure for drilling opti-mization. LWD measures natural gammaray and propagation resistivity.

BenefitsThe project will combine existing, proventechnologies for MWD and LWD into anintegrated, cost-effective downhole meas-urement system. Drillers will use theMWD measurements to optimize drillingperformance. Geologists will use the LWDmeasurements to optimize wellbore place-ment and completion for maximum pro-duction and to estimate resources in place.

Widespread adoption of microhole tech-nology will enable low-risk infill develop-ment that could potentially tap billions ofbarrels of bypassed hydrocarbons at shal-low depths in mature fields. Explorationefforts in search of new reserves will ben-efit from the anticipated cost and environ-mental benefits. DOE estimates remainingU.S. shallow resources at 218 billion bar-rels. Recovery of just 10% of the targetedresource would yield a volume equivalentto 10 years of OPEC imports at currentrates.

Mature producing areas worldwide alsowill benefit from the technology.

Detailed design will accelerate during Q12006 as additional personnel are added tothe project. Individual subassemblies willbe tested and incorporated into the proto-types during prototype assembly. The com-pleted prototypes will be tested in the laband in a flow loop to verify pulser opera-tion prior to the first field test.

Here is the project timetable:

• Project launch, April 2005.

• Conceptual design, Q3-Q4 2005.

• Detailed design, Q4 2005-2006.

• Prototype assembly, Q3-Q4 2006.

• Two prototypes ready for field test, Q1 2007.

Current Status (January 2006)Efforts to date have focused on the detaileddesign specification and conceptual design.Valuable industry feedback was received atMicrohole Technology Integration meet-ings in August and November sponsored bythe Petroleum Technology TransferCouncil. Staffing on the project is beingincreased for detailed design efforts.

Development of technology that expandsglobal sources of hydrocarbons ensures adiversity of supplies and maintains theUnited States as the leading global suppli-er of oilfield technology.

BackgroundAs the technology to drill microhole wellsdevelops, the tools to conduct downholemeasurements in the smaller holes will beneeded as well. This project is developingan integrated tool to improve drilling effi-ciency and reduce cost. In addition, theincreased information about the downholerocks and environment will allow moreaccurate reserves estimates and develop-ment planning.

SummaryThe early phase of the project establishesdesign requirements and generates a con-ceptual design that meets these require-ments. The conceptual design phase hasbeen extended to incorporate industry inputon sensor placement. Following reviewand approval of the conceptual design bythe project team, most detailed design willbegin on the mechanical and electronicsubassemblies and sensors. Some detaileddesign and evaluation of low-cost direc-tional sensors is already underway.

Project Start / End: 2-1-05 / 1-31-07DOE / Performer Cost: $795,515 / $189,879Contact Information:NETL – Jim Barnes (jim.barnes@netl.doe.gov or 918-699-2076)Ultima – Don Macune (dmacune@ultimalabs.com or 713-266-9303)

Ultima Labs’ bottomhole assembly.

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Microhole DownholeDrilling Tractor

DE-PS26-03NT15475

GoalThe project goal is to design, manufacture,and demonstrate a reliable and economical,hydraulically powered coiled tubing (CT)tractor that will transport the drillbit andbottomhole assembly into long (>3,000feet) horizontal well sections.

PerformerWestern Well Tool, Inc.Anaheim, CA

ResultsThe baseline design of a 31/4-inchMicrohole Drilling Tractor (MDT) wascompleted. Experiments were conductedwith low-solids drilling mud that verifiedcomponent functionality and operationallife.

Work started on a redesign of the MDT.The MDT is being completely redesignedwith a 33/8-inch outside diameter. Thisallows a greater inside diameter for flow tothe downhole motor and drillbit, forreturning cuttings to the surface, and forimproved hole cleaning.

Improved start-stop valve and gripperdesigns are being developed. Long-leaditems are being designed and released on apriority basis to shorten manufacturingtimes.

BenefitsThe MDT will allow drilling of horizontalholes up to 2,000 feet beyond convention-al CT drilling.

Using CT and the MDT can be 25-50%less expensive than rotary rigs in someapplications, especially in environmentswhere set-up time is costly.

Controls are simple and direct using theinjector and pump pressure, thus eliminat-ing need for expensive electrical controls.

The MDT is capable of high loads (3,500+lbs) through dog-legs up to 15 degrees per100 feet.

Grippers for tractor movement are highlyreliable, have a long life (>175,000 feettraveled before maintenance), are highly

debris- and fluid-tolerant, can efficientlytraverse washed-out hole sections, do notdamage casing, and are proven to operatein both very soft and hard formations.

Using a simple principle of operation,power is provided by differential pressureof the drilling mud at the tool.

BackgroundAlthough there are many advantages ofCT drilling, one area of needed technologydevelopment is a method to exert enoughweight on the bit to drill through rock.Coiled tubing easily buckles, which makesit difficult to impart drillbit weight. Onetechnology that has been recently devel-oped to overcome this problem is a down-hole tractor that thrusts the drillbit into theformation while pulling the coiled tubingalong behind.

SummaryThe MDT to be designed and manufac-tured is a drilling fluid-powered unidirec-tional downhole CT tool. The tractor out-side diameter will be 33/8 inches to accom-modate 35/8-inch holes, and the tractor willbe able to drill >3,000 foot horizontal wellsections.

The MDT builds on previously developedWestern Well Tool Tractor technology thathas demonstrated the capability to operatedownhole with a variety of drilling muds,operating parameters, and drilling equip-ment. The tractor consists of a central con-trol assembly that directs the mud flow andprovides the pull and thrust of the tractorand a forward and aft shaft assembly withpatented grippers that operate successfullyin soft and hard formations.

The microhole tractor walking processconsists of several steps. A forward roller-toe gripper is expanded (inflated) againstthe walls of the hole, thrusting the bit for-ward and pulling the coiled tubing as thetractor progresses. The forward roller-toegripper deflates while the aft roller-toegripper expands against the hole wall,pushing the bit forward and pulling thedrillstring into the new position. Thisprocess repeats, allowing the tractor to“walk” down the hole while drilling infront of the tractor and pulling the drill-string behind it.

In the first phase of the project, a drillingtractor will be designed that is reliable,economical, field-ready, and can drill hor-izontal well sections of 3,000 feet or more.In the second phase of the project, a proto-type drilling tractor will be built and field-tested to demonstrate its performance witha CT rig by drilling multiple inclined andhorizontal holes.

Current Status (December 2005)Design of the major components, includ-ing the control assembly, grippers, andshaft assemblies is nearing completion. Procurement will begin in first quarter2006, with the long-lead items ordered ona priority basis.

A three-well demonstration program isscheduled for fourth quarter 2006.

Profile of microhole drilling tractor gripper expanded against hole.

Project Start / End: 7-1-04 / 8-22-06DOE / Performer Cost: $795,515 / $189,879Contact Information:NETL – Virginia Weyland (virginia.weyland@netl.doe.gov or 918-699-2041)Western Well Tool – Bruce Moore (nbmoore@wwtco.com or 714-632-0810)

National EnergyTechnology Laboratory

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Roy LongTechnology Manager, E&P918-699-2017roy.long@netl.doe.gov

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U.S. Department of EnergyOffice of Fossil Energy

March 2006