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Page 10. 0 Formulae and Conversion Factors 1 10. 1 Glossary for Well Control Operations 5 FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS SECTION 10 :

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Drilling conversions

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Page 1: Drilling conversions

Page

10. 0 Formulae and Conversion Factors 1

10. 1 Glossary for Well Control Operations 5

FORMULAE, CONVERSIONFACTORS & GLOSSARY OF TERMSSECTION 10 :

Page 2: Drilling conversions

WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

10- 1

FORMULAE AND CONVERSION FACTORS

10.0 EQUATION SHEET FOR OILFIELD/FIELD UNITS

1. Pressure Gradient psi/ft = Mud Weight ppg x 0.052

2. Mud Weight ppg = Pressure Gradient psi/ft ÷ 0.052

3. Hydrostatic Pressure psi = Mud Weight ppg x 0.052 x True Vertical Depth ft

4. Formation Pressure psi = Hydrostatic Pressure in Drill String psi + SIDPP psi(with bit on bottom)

5. Equivalent MudWeight ppg = Pressure psi ÷ True vertical Depth ft ÷ 0.052

6. Pump Output bbls/min = Pump Output bbls/stk x Pump Speed spm

7. Annulus Velocity ft/min = Pump Output bbls/min ÷ Annulus Volume bbls/ft

8. Initial CirculatingPressure psi = SCR psi + SIDPP psi

9. Final CirculatingPressure psi = SCR psi x (Kill Mud Weight ppg ÷ Original Mud ppg)

10. Kill Weight Mud ppg = (SIDPP psi ÷ TVD ft ÷ 0.052) + Original Mud ppg

11. Shut in Casing [(Mud Grad psi/ft - Influx Grad psi/ft) x InfluxPressure psi = Height ft] + SIDPP psi

12. Equivalent circulating (Annulus Pressure loss psi ÷ TVD ft ÷ 0.052)density ppg = + Original Mud ppg

13. Height of influx ft = Kick size bbls ÷ Annulus Volume bbls/ft

(SICP psi - SIDPP psi)14. Gradient of Influx psi/ft = (Mud weight ppg x 0.052) ––––––––––––––––

Influx Height ft

15. Trip Margin/safety = (Safety factor psi ÷ TVD ÷ 0.052) + Mud factor ppg Weight ppg

16. Pump Pressure/Pump StksRelationship psi = Present Pressure psi x (New SPM ÷ Old SPM)2

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

17. Max. Allowable Mud (Surface Leak Off psi ÷ Shoe TVD ft ÷ 0.052)Weight ppg = + Test Mud ppg

18. New MAASP psi = (Max. Allowable Mud Weight ppg -Current Mud Weight ppg)

(Kill mud weight ppg - Old mud weight ppg) x 150019. Barite to raise mud = ––––––––––––––––––––––––––––––––––––––––––––

weight lbs/bbl (35.8 - kill weight mud ppg)

20. Percolation Rate ft/hr = Drill pipe pressure increase psi/hr ÷ Mudgradient psi/ft

(MAASP - (Mud gradient psi/ft - Influx Grad ft)) x Influx Height ft21. Kick Tolerance ppg = ––––––––––––––––––––––––––––––––––––––––––––

TVD x 0.052

Kick tolerance in feet MAASP - SIDPPor [–––––––––––––] = Max Tol Length of Influx

GM- GI

P1V1 V1P122. Boyle’s Law: P1V1 = P2V2 P2 = –––– V2 = –––––

V2 P2

Mud grad psi/ft x Metal Disp bbls/ft23. Pressure drop per ft. = ––––––––––––––––––––––––––––––

tripping dry pipe Casing cap. bbls/ft - Metal Disp bbls/ft

Mud grad psi/ft x (Metal disp bbls/ft + Pipe disp bbls/ft)24. Pressure drop per ft. = –––––––––––––––––––––––––––––––––––––––––––

tripping wet pipe Annulus Volume bbls/ft

Length of collars ft x metal disp bbls/ft25. Level drop for pulling = –––––––––––––––––––––––––––––––

collars out of hole ft Casing cap. bbls/ft

Overbalance psi x (casing cap. bbls/ft - pipe disp bbls/ft)26. Length of pipe to pull = –––––––––––––––––––––––––––––––––––––––––––

before well starts to flow ft Mud gradient psi/ft x pipe Disp bbls/ft

Mud grad psi/ft x Casing Cap bbls/ft x differential height ft27. Hydrostatic Pressure = ––––––––––––––––––––––––––––––––––––––––––––

loss if casing float fails (casing capacity + Annulus capacity bbls/ft)

Page 4: Drilling conversions

WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

10- 3

W228. Volume displace by slug = Slug Vol x ––– - 1

W1 ∆P

29. Riser Margin = ––––– ÷ .052 R TVD

Where ∆P = [Pmud] - [Psw] Riser Sea-water

R TVD = [L of hole RKB/TVD] - [L of Riser RKB/BML]

or the total increase in mud Wt required before disconnected.

[Pmuda + Psw] = P0

D2

30. Conversion of pipe diameter to bbls/ft = ––––––– = bbls/ft 1029.42

D2 - d2

or ––––––– = bbls/ft 1029.42

31. Max Mud Wt [Offshore]

[Psw] + [Pf] ÷ [BML - TVD] ÷ [.052]

32. Estimated Casing setting depth beneath sea floor

[P Mud] - [P sw] ÷ [G.F.B. - G.M] Riser Sea-water

33. 'U' Tube formula

SIDPP + [Pmud]DS = [SICP] + [Pmuda] +[Psasa]

[ ]

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

APPROPRIATE CONVERSIONS

DEPTH Feet x 0.3048 to give Metres (m)Metres x 3.2808 to give Feet (ft)

VOLUME (U.S.) Gallon x 0.003785 to give Cubic Metres (m3)(U.S.) Barrel x 0.1590 to give Cubic Metres (M3)Cubic Metre x 6.2905 to give Barrel (U.S.)

PRESSURE PSI x 6.895 to give Kilo Pascals (KPa)KPA x 0.14503 to give Pounds per Square Inch (psi)Kg/cm2 x 98.1 to give Kilo Pascals (KPa)Bar x 100 to give Kilo Pascals (KPa)

MUD WEIGHT PPG x 119.8 to give Kilogram per Cubic Metre (Kg/m3)Kg/m3 x 0.00835 to give (Pounds per Gallon)

ANNULAR Feet/Minute x 0.3048 to give Metres per Minute (m/min)VELOCITY Metres/Minute x 3.2808 to give Feet per Minute (ft/min)

FLOW RATE Gallons/Minute x 0.003785 to give Cubic Metres per Minute (m3/min)Barrels/Minute x 0.159 to give Cubic Metres per Minute (M3/min)Cubic Metres/Minute x 6.2905 to give Barrels per Minute (bbl/min)Cubic Metres/Minute x 264.2 to give Gallons per Minute (gals/min)

FORCE Pound Force x 0.445 to give Decanewtons(eg WEIGHT ON BIT) Decanewtons x 2.2472 to give Pound Force

MASS Pounds x 0.454 to give Kilograms (Kg)

Tons(Long-2240 lbs) x 1017 to give Kilograms (Kg)

Tonnes(Metre-2205 lbs) x 1001 to give Kilograms (Kg)

Kilograms x 2.2026 to give Pounds (lbs)

PRESSURE PSI/Foot x 22.62 to give Kilo Pascals per Metre (K/Pa/m)GRADIENT KPa/Metre x 0.04421 to give Pounds per Square Inch per Foot (psi/ft)

MUD WEIGHT PPG x 0.052 to give Pounds per Square Inch per Foot (psi/ft)TO PRESSURE [Pressure Gradient]GRADIENT SG x .433 to give Pounds per Square Inch per Foot (psi/ft)

b/ft3 ÷ 144 to give Pounds per Square Inch per Foot (psi/ft)Kg/m3 x 0.000434 to give Pounds per Square Inch

or ÷ 2303 per Foot (psi/ft)Kg/m3 x 0.00982 to give Kilo Pascals per Metre (K/Pa/m)

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

10- 5

10.1 GLOSSARY FOR WELL CONTROL OPERATIONS

Abnormal Pressure - Pore pressure in excess of that pressure resulting from thehydrostatic pressure exerted by a vertical column of water salinity normal for thegeographic area.

Accumulator - A vessel containing both hydraulic fluid and gas stored underpressure as a source of fluid power to operate opening and closing of blowoutpreventer rams and annular preventer elements. Accumulators supply energy forconnectors and valves remotely controlled.

Accumulator Bank Isolator Valve - The opening and closing device locatedupstream of the accumulators in the accumulator piping which stops flow offluids and pressure in the piping.

Accumulator Relief Valve - The automatic device located in the accumulatorpiping that opens when the pre-set pressure limit has been reached so as to releasethe excess pressure and protect the accumulators.

Accumulator Unit - The assembly of pumps, valves, lines, accumulators, andother items necessary to open and close the blowout preventer equipment.

Air Breather - A device permitting air movement between the atmosphere and thecomponent in which it is installed.

Air Pressure Switch Bypass Valve - The opening and closing device located in theair supply line which blocks air flow in one line to be redirected through another.In open position, air flow is not routed through the air pressure switch forautomatic shutoff thereby allowing the air pumps to continue to run.

Air Pump Suction Valve - The opening and closing device located in the pipingline that draws fluid from the reservoir into the fluid end of the pump when theair motor is operating.

Air Regulator - The adjusting device to vary the amount of air pressure enteringas to the amount to be discharged down the piping lines.

Air Supply Valve - The opening and closing device in the connecting line of thecompressed air routed to flow into the accumulator system lines as a power sourcefor components.

Ambient Temperature - The temperature of all the encompassing atmospherewithin a given area.Ampere - The unit used for measuring the quantity of an electric current flow. Oneampere represents a flow of one coulomb per second.

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

Annular - A large valve, usually installed above the ram preventers, that forms aseal in the space between the pipe and wellbore or on the wellbore itself. The spacearound a pipe in a wellbore, the outer wall of which may be the wall of either theborehole or the casing.

Annular Preventer - A device which can seal around any object in the wellbore orupon itself. Compression of a reinforced elastomer packing element by hydraulicpressure effects the seal.

Annular Regulator - The device located in the annular manifold header to enableadjustment of pressure levels which will flow past to control the amount of closureof the annular preventer.

Annulus Friction Pressure - Circulating pressure loss inherent in annulus betweenthe drill string and casing or open hole.

Back Pressure (Casing Pressure, Choke Pressure) - The pressure existing at thesurface on the casing side of the drill pipe/annulus flow system.

Baffle - A partition plate inside the reservoir to prevent unbalancing by suddenweight shifting of the hydraulic fluid.

Barite Plug - A settled volume of barite particles from a barite slurry placed in thewellbore to seal off a pressured zone.

Barite Slurry - A mixture of barium sulphate, chemicals, and water of a unitdensity between 18 and 22 pounds per gallon (lb/gal).

Belching - A slang term to denote flowing by heads.

Bell Nipple (Mud Riser, Flow Nipple) - A piece of pipe, with inside diameterequal to or greater than the blowout preventer bore, connected to the top of theblowout preventer or marine riser with a side outlet to direct the drilling fluidreturns to the shale shaker or pit. Usually has a second side outlet for the fill-upline connection.

Bleeding - Controlled release of fluids form a closed and pressured system inorder to reduce the pressure.

Blind Rams (Blank, Master) - Rams whose ends are not intended to seal againstany drill pipe or casing. They seal against each other to effectively close the hole.

Blind/Shear Rams - Blind rams with a built-in cutting edge that will sheartubulars that may be in the hole, thus allowing the blind rams to seal the hole.Used primarily in subsea systems.

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

10- 7

Blowout - An uncontrolled flow of gas, oil, or other well fluids into theatmosphere. A blowout, or gusher, occurs when formation pressure exceeds thepressure applied to it by the column of drilling fluid.

Blowout Preventer - The equipment installed at the wellhead to enable the drillerto prevent damage at the surface while restoring the balance between the pressureexerted by the column of drilling fluid and formation pressure. The BOP allowsthe well to be sealed to confine the well fluids and prevent the escape of pressureeither in the annular space between the casing and drill pipe or in an open hole.The blowout preventer is located beneath the rig at the land’s surface on land rigsor at the water’s surface on jack-up or platform rigs and on the sea floor forfloating offshore rigs.

Blowout Preventer Drill - A training procedure to determine that rig crews arecompletely familiar with correct operating practices to be followed in the use ofblowout prevention. A dry run of blowout preventive action.

Blowout Preventer Operating and Control System (Closing Unit) - The assemblyof pumps, valve, lines, accumulators and other items necessary to open and closethe blowout preventer equipment.

Blowout Preventer Stack - The assembly of well control equipment includingpreventers , spools, valves and nipples connected to the top of the wellhead.

Blowout Preventer Test Tool - A tool to allow pressure testing of the blowoutpreventers stack and accessory equipment by sealing the wellbore immediatelybelow the stack.

Bleeder Valve - An opening and closing device for removal of pressurised fluid.

Borehole Pressure - Total pressure exerted in the wellbore by a column of fluidand/or back pressure imposed at the surface.

Bottom-hole Pressure - Depending upon context, either a pressure exerted by acolumn of fluid contained in the wellbore or the formation pressure at the depth ofinterest.

Broaching - Venting of fluids to the surface or to the sea-bed through channelsexternal to the casing.

Bullheading - A term to denote pumping into a closed-in well without returns.

Casinghead/Spool - The part of the wellhead to which the blowout preventerstack is connected.

Casing Pressure - see Back Pressure.

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

Casing Seat Test - A procedure whereby the formation immediately below thecasing shore is subjected to a pressure equal to the pressure expected to be exertedlater by a higher drilling fluid density or by the sum of a higher drilling fluiddensity and back pressure created by a kick.

Chain Guard - The metal enclosure surrounding the electric pump driving chainto protect and contain an oil lubricate for the chain.

Check Valve - A valve that permits flow in only one direction.

Choke - A variable diameter orifice installed in a line through which high pressurewell fluids can be restricted or released at a controlled rate. Chokes also control therate of flow of the drilling mud out of the hole when the well is closed in with theblowout preventer and a kick is being circulated out of the hole.

Choke Line - The high pressure piping between blowout preventer outlets orwellhead outlets and the choke manifold.

Choke Line Valve - The valve(s) connected to and a part of the blowout preventerstack that control the flow to the choke manifold.

Choke Manifold (Control Manifold) - The system of valves, chokes, and pipingto control flow from the annulus and regulate pressures in the drill pipe/annulusflow system.

Choke Pressure - See Back Pressure.

Circuit Breaker - An electrical switching device able to carry an electrical currentand automatically break the current to interrupt the electrical circuit if adverseconditions such as shorts or overloads occur.

Circulating Head - A device attached to the top of drill pipe or tubing to allowpumping into the well without use of the kelly.

Clamp Connection - A pressure sealing device used to join two items withoutusing conventional bolted flange joints. The two items to be sealed are preparedwith clamp hubs. These hubs are held together by a clamp containing two to fourbolts.

Closing Unit - The assembly of pumps, valves, lines, accumulators and otheritems necessary to open and close the blowout preventer equipment.

Closing Ratio - the ratio of the wellhead pressure to the pressure required to closethe blowout preventer.

Conductivity - The capability of a material to carry an electrical charge. Usuallyexpressed as a percentage of copper conductivity (copper being one hundred 100

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

10- 9

percent). Conductivity is expressed for a standard configuration of conductor.

Conductor - The substance or body capable of transmitting electricity, heat, light,or sound.

Conductor Pipe - A relatively short string of large diameter pipe which is set tokeep the top of the hole open and provide a means of returning the upflowingdrilling fluid from the wellbore to the surface drilling fluid system until the firstcasing string is set in the well. Conductor pipe is usually cemented.

Continuity - The uninterrupted flow of current in a conductor.

Contract Block - The conductor located in the electric panels which bring togetherthe electrical connections of the operation pushbuttons with those of the operatorvalves.

Control Manifold - The system of valves and piping used to control the flow ofpressured hydraulic fluid to operate the various components of the blowoutpreventer stack.

Control Panel, Remote - A panel containing a series of control that will operatethe valves on the control manifold from a remote point.

Control Pod - An assembly of subsea valves and regulators which when activatedfrom he surface will direct hydraulic fluid through special apertures to operateblowout preventer equipment.

Corrosion Inhibitor - Any substance which slows or prevents the chemicalreactions of corrosion.

Cut Drilling Fluid - Well control fluid which has been reduced in density or unitweight as a result of entrainment of less dense formation fluids or air.

Cylinder - A device which converts fluid or air power into linear mechanical forceand motion. It consists of a movable element such as a piston and piston rod,plunger rod, plunger or ram, operating within a cylindrical chamber.

Degasser - A vessel which utilizes pressure reduction and/or inertia to separateentrained gases from the liquid phases.

Discharge Check Valve - The device located in the expelling line of a pump (air orelectric) which allows fluid to flow out only and thereby prevents a back flow offluid into the pump.

Displacement - The volume of steel in the tubulars and devices inserted and/orwithdrawn from the wellbore.

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

Diverter - A device attached to the wellhead or marine riser to close the verticalaccess and direct any flow into a line away from the rig.

Drain Port - The plugged openings on the lower side portions of the reservoirwhich can be opened to empty or release the hydraulic fluid, and through whichthe reservoir can be cleaned.

Drilling Fluid Weight Recorder - An instrument in the drilling fluid system whichcontinuously measures drilling fluid density.

Drilling Spool - A connection component with ends either flanged or hubbed. Itmust have an internal diameter at least equal to the bore of the blowout preventerand can have smaller side outlets for connecting auxiliary lines.

Drill Pipe Safety Valve - An essentially full-opening valve located on the rig floorwith threads to match the drill pipe in use. This valve is used to close off the drillpipe to prevent flow.

Drill Stem Test (DST) - A test conducted to determine production flow rate and/or formation pressure prior to completing the well.

Drill String Float - A check valve in the drill string that will allow fluid to bepumped into the well but will prevent flow from the well through the drill pipe.

Drive Pipe - A relatively short string of large diameter pipe driven or forced intothe ground to function as conductors pipe.

Dust Cap - The screw on covering for the electric panel connector receptacleswhich protect the electrical contacts from foreign matter and moisture.

Electric Pump Suction Valve - The opening and closing device located in thepiping line that draws fluid from the reservoir into the pump inlet when the motoris operating.

Element (Filter) - The substance of porous nature which retains foreign particlesthat pass through the containing chamber to separate and clean the gas or liquidflow.Equivalent Circulating Density (ECD) - The sum of pressure exerted byhydrostatic head of fluid, drilled solids, and friction pressure losses in the annulusdivided by depth of interest and by 0.052, if ECD is to be expressed in pounds pergallon (lb/gal).

Feed-in (Influx, Inflow) - The flow of fluids from the formation into the wellbore.

Fill Port - The plugged opening in the top of the fluid reservoir through whichhydraulic oil is added.

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

10- 11

Fill-up Line - A line usually connected into the bell nipple above the blowoutpreventers to allow adding drilling fluid to the hole while pulling out of the holeto compensate for the metal volume displacement of the drill string being pulled.

Filter (Air) - Apparatus used to clean air flow of dirt, moisture and othercontaminants.

Filter (Hydraulic) - A device whose function is the retention of insolublecontaminants from a fluid.

Final Circulating Pressure - Drill pipe pressure required to circulate at theselected kill rate adjusted for increase in kill drilling fluid density over the originaldrilling fluid density; used from the time kill drilling fluid reaches the bottom ofthe drill string until kill operations are completed or a change in either kill drillingfluid density or kill rate is effected.

Flow Meter - A device which indicates either flow rate, total flow, or acombination of both, that travels through a conductor such as pipe or tubing.

Flow Rate - The volume, mass, or weight of a fluid passing through anyconductor, such as pipe or tubing, per unit of time.

Fluid - A substance that flows and yields to any force tending to change its shape.Liquids and gases are fluids. The accumulator system pressurises fluid to be usedas a source of power to open and close valves and rams on the BOP stack.

Fluid Density - The unit weight of fluid; e.g., pounds per gallon (lb/gal).

Formation Breakdown - An event occurring when borehole pressure is ofmagnitude that the exposed formation accepts whole fluid from the borehole.

Formation Competency (Formation Integrity) - The ability of the formation towithstand applied pressure.

Formation Competency Test (Formation Integrity Test) - Application of pressureby superimposing a surface pressure on a fluid column in order to determineability of a subsurface zone to withstand a certain hydrostatic pressure.Formation Integrity - See Formation Competency.

Formation Integrity Test - See Formation Competency Test.

Formation Pressure (Pore Pressure) - Pressure exerted by fluids within the poresof the formation (see Pore Pressure).

Flowline Sensor - A device to monitor rate of fluid flow from the annulus.

Fracture Gradient (Frac. Gradient) - The pressure gradient (psi/ft) at which the

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

formation accepts whole fluid from the wellbore.

Full Load Current - The amount of current used by an electrical circuit when thecircuit is operating at its designed or rated maximum capacity.

Function - The term given to the duty of operating the control valves of theaccumulator system. The action performed by the control valves when operatingthe ram preventers or gate valves.

Gage - A standard method of specifying the physical size of a conductor (wire)diameter based on the circular mil system. 1 mil equals .001. The higher thenumber, the smaller the diameter.

Gas Buster - A slang term to denote a mud gas separator.

Gate Valve - A valve which employs a sliding gate to open or close the flowpassage. The valve may or may not be full-opening.

Gauge - An instrument for measuring fluid pressure that usually registers thedifference between atmospheric pressure and the pressure of the fluid byindicating the effect of such pressure on a measuring element (as a column ofliquid, a bourdon tube, a weighted piston, a diaphragm, or other pressure-sensitive devices).

Gland - The cavity of a stuffing box.

Ground - An electrical term meaning to connect to the earth, or another largeconducting body to serve as earth, thus making a complete electrical circuit. Theconducting connection of a circuit to the earth.

Gunk Plug - A volume of gunk slurry placed in the wellbore.

Gunk Slurry - A slang term to denote a mixture of diesel oil and bentonite.

Gunk Squeeze - Procedure whereby a gunk slurry is pumped into a subsurfacezone.

H2S - An abbreviation for hydrogen sulphide.

Hard Close In - To close in a well by closing a blowout preventer with the chokeand/or choke line valve closed.

Hydrostatic - Relating to liquids at rest and the pressure they exert.

Hydrostatic Head - The true vertical length of fluid column, normally in feet.

Hydrostatic Pressure (Hydrostatic Head) - The pressure which exists at any point

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SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

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in the wellbore due to the weight of the vertical column of fluid above that point.

Indicating Light - The bulbs of the electric control panels that shine to point outwhich electrical contacts have made a circuit. The electric panel bulbs make circuitcontacts through pressure switches, transducers, and solenoid valves todemonstrate activation.

Inflow - See Feed-in.

Influx - See Feed-in.

Initial Circulating Pressure - Drill pipe pressure required to circulate initially atthe selected kill rate while holding casing pressure at the close-in value;numerically equal to kill rate circulating pressure plus closed-in drill pipepressure.

Inside Blowout Preventer - A device that can be installed in the drill string thatacts as a check valve allowing drilling fluid to be circulated down the string butprevents back flow.

Inspection Port - The plugged openings on the sides of the fluid reservoir whichcan be opened to view the interior fluid level and return lines from the relief,bleeder, control valves, and regulators.

Insulation - A non-conductive material usually surrounding or separating thecurrent carrying parts from each other or from the core.

Kelly Cock - A valve immediately above the kelly that can be closed to confinepressures inside the drill string.

Kelly Valve - Lower. An essentially full opening valve installed immediatelybelow the kelly with outside diameter equal to the tool joint outside diameter.

Kick - Intrusion of formation fluids into the wellbore.

Kill Drilling Fluid Density - The unit weight e.g. pounds per gallon (lb/gal),selected for the fluid to be used to contain a kicking formation.

Kill Line - A high-pressure fluid line connecting the mud pump and the wellheadat some point below a blowout preventer. This line allows heavy drilling fluids tobe pumped into the well or annulus with the blowout preventer closed to control athreatened blowout.

Kill Rate - A predetermined fluid circulating rate, expressed in fluid volume perunit time, which is to be used to circulate under kick conditions; kill rate is usuallysome selected fraction of the circulating rate used while drilling.

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WELL CONTROL for the Rig-Site Drilling Team

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

Kill Rate Circulating Pressure - Pump pressure required to circulate kill ratevolume under non-kick conditions.

Leak-off Test - Application of pressure by superimposing a surface pressure on afluid column in order to determine the pressure at which the exposed formationaccepts whole fluid.

Lost Circulation (Lost Returns) - The loss of whole drilling fluid to the wellbore.

Lost Returns - See Lost Circulation.

Lubrication. Alternately pumping a relatively small volume of fluid into a closedwellbore system and waiting for the fluid to fall toward the bottom of the well.

Lubricator (Air) - A device which adds controlled or metered amounts of asubstance into the air line of a fluid power system to prevent or lessen friction.

Manifold Bleeder Valve - The opening and closing device in the piping thatconnects the manifold header and the reservoir, and which can be opened torelease the fluid pressure and vent it back into the reservoir.

Manifold Header - The piping system which serves to divide a flow throughseveral possible outlets. The 4-Way control valve inlets connect to the piping sothat high pressure fluid is available to pass through any or all of the valves.

Manifold Regulator - The device located in the manifold header which can varythe amount of pressure that enters and exits its chamber. The manifold regulatorcontrols the pressure level of the fluid flowing through and out the 4-Way controlvalves.

Manifold Regulator Bypass Valve - The opening and closing device which blocksflow in one line to be redirected through another. This valve is located in themanifold piping so that in the open position the high pressure fluid does not flowthrough the regulator in the manifold header, thereby allowing higher pressurefluid to be available to the 4-Way control valves.

Manifold Relief Valve - The automatic opening device located on the manifoldheader that opens when the present pressure limit has been reached so any excesspressure is released, thereby protecting the manifold header.

Meter - An instrument, operated by an electrical signal, that indicates ameasurement of pressure.

Meter Circuit Board - Printed circuit board used with the electrical meters toprovide the circuits necessary for calibration of the meter.

Micron - (A millionth of a meter or about 0.0004 inch). The measuring unit of the

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10- 15

porosity of filter elements.

Mil - A measurement used in determining the area of wire. The area of a circle one1/thousandth inch in diameter.

Minimum Internal Yield Pressure - The lowest pressure at which permanentdeformation will occur.

Motor Starter - Automatic device which starts or stops the electric motor drivingthe duplex or triplex pump which works in conjunction with the automaticelectrical pressure switch for pressure limits of pump start-up and shutoff.

Mud-gas Separator - A vessel for removing free gas from the drilling fluid returns.

Needle Valve - A shutoff (2-Way) valve that incorporates a needle point to allowfine adjustments in flow.

Normal Pressure - Formation pressure equal to the pressure exerted by a verticalcolumn of water with salinity normal for the geographic area.

Ohm - A unit of electrical resistance, the resistance of a circuit in which a potentialdifference of one volt produces a current of one ampere.

Ohmmeter - The measuring instrument which indicates resistance in ohms.

Opening Ratio - The ration of the well pressure to the pressure required to openthe blowout preventer.

Overbalance - The amount by which pressure exerted by the hydrostatic head offluid in the wellbore exceeds formation pressure.

Overburden - The pressure on a formation due to the weight of the earth materialabove that formation. For practical purposes this pressure can be estimated at1 psi/ft of depth.

Packoff or Stripper - A device with an elastomer packing element that depends onpressure below the packing to effect a seal in the annulus. Used primarily to run orpull pipe under low or moderate pressures. This device is not dependable forservice under high differential pressures.

Petcock - The small faucet or valve used to release compression or drain moistureaccumulated in the anterior chamber of the lubricator.

Phase (3-Phase Motor) - A particular stage or point of advancement in anelectrical cycle. The fractional part of the period through which the time hasadvanced, measured from some arbitrary point usually expressed in electricaldegrees where 360° represents one cycle.

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Pipe Rack - The connecting pipelines between the control valve outlets and theBOP stack preventers which carry the high pressure operating fluid. The lines ofpipe are laid together and are often covered with a grating to create a walkway.

Pipe Rams - Rams whose ends are contoured to seal around pipe to close theannular space. Separate rams are necessary for each size (outside diameter) pipe inuse.

Pit Volume Indicator - A device installed in the drilling fluid tank to register thefluid level in the tank.

Pit Volume Totaliser - A device that combines all of the individual pit volumeindicators and registers the total drilling fluid volume in the various tanks.

Plug Valve - A valve whose mechanism consists of a plug with a hole through iton the same axis as the direction of fluid flow. Turning the plug 90 opens or closesthe valve. The valve may or may not be full-opening.

Pore Pressure (Formation Pressure) - Pressure exerted by the fluids within thepore space of a formation.

Potable - A liquid that is suitable for drinking.

Pressure Gradient, Normal - The normal pressure divided by true vertical depth.

Pressure Switch (Air) - The automatic device to start and stop the air pumpoperation when the present pressure limits are reached.

Pressure Switch (Electric) - An electrical switch, operated by fluid pressure,which automatically starts and stops the electrical pump when the presentpressures are reached.

Pressure Transmitter - Device which sends a pressure signal to be converted andcalibrated to register the equal pressure reading on a gauge. The air outputpressure in proportion to the hydraulic input pressure.

Primary Well Control - Prevention of formation fluid flow by maintaining ahydrostatic pressure equal to or greater than formation pressure.

Pump (Air) - A device that increases the pressure on a fluid or raises it to a higherlevel by being compressed in a chamber by a piston operated with an air pressuremotor.

Pump (Electric) - A device that increases the pressure on a fluid and moves it to ahigher level using compression force from a chamber and piston that is driven byan electric motor.

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Pushbutton/Indicating Light - The control valve operates with bulbs on theelectrical remote panel which change and indicate the position of the controlvalves.

Ram - The closing and sealing component on a blowout preventer. One of threetypes - blind, pipe, or shear - may be installed in several preventers, mounted in astack on top of the wellbore. Blind rams, when closed, form a seal on a hole thathas no drill pipe in it; pipe rams, when closed, seal around the pipe; shear ramscut through drillpipe and then form a seal.

Recorder - An automatic device that reads and records pressure outputscontinually on a revolving chart to provide continuous evidence of pressures.

Regulator - A device that varies and controls the amount of pressure of a liquid orgas that passes through its chambers.

Relay - An electrical device to automatically control the operation of anotherdevice in another circuit by passing on an electric current.

Relay Socket - A device used to interconnect a relay with its circuitry and whichallows quick and easy removal of the relay without special tools.

Relief Well - An offset well drilled to intersect the subsurface formation to combatblowout.

Replacement - The process whereby a volume of fluid equal to the volume of steelin tubulars and tools withdrawn from the wellbore is returned to the wellbore.

Reservoir - The container for storage of liquid. The reservoir houses hydraulicfluid at atmospheric pressure as the supply for fluid power.

Resistance - The property of an electrical circuit which determines for a givencurrent, the rate at which electrical energy is converted into heat and has a valuesuch that the current squared, multiplied by the resistance, gives the powerconverted.

Rotating Head - A rotating, low pressure sealing device used in drillingoperations to seal around the drill stem above the top of the blowout preventerstack.

Rupture Disk - A device whose breaking strength (the point at which it physicallycomes apart) works to relieve pressure in the system. The rupture disk iscontained as a safety device for the test unit system.

Safety Factor - In the context of this publication, an incremental increase indrilling fluid density beyond the drilling fluid density indicated by calculations tobe needed to contain a kicking formation.

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Salt Water Flow - An influx of formation salt water into the wellbore.

Shear Rams - Blowout preventer rams with a built in cutting edge that will sheartubulars that may be in the hole.

Soft close In - To close in a well by closing a blowout preventer with the chokeand choke line valve open, then closing the choke while monitoring the casingpressure gauge for maximum allowable casing pressure.

Solenoid Valve - The opening/closing device which is activated by an electricalsignal to control liquid or gas pressured flow to be sent to open or close the 4-Waycontrol valves. The valve position is controlled by an electromagnetic bar, enclosedby a coil.

Solenoid Valve Box - The explosion proof enclosure, located on the accumulatorunit, which contains the electrically powered actuators for the remote controlelectrical panel. The box is wired to the electrical supply, and houses solenoidvalves, pressure switches and transducers.

Sour Gas - Natural gas containing hydrogen sulphide.

Space Out - Procedure conducted to position a predetermined length of drill pipeabove the rotary table so that a tool joint is located above the subsea preventerrams on which drill pipe is to be suspended (hung-off) and so that no tool joint isopposite a set of preventer rams after drill pipe is hung-off.

Space-Out Joint - The joint of drill pipe which is used to hang off operations sothat no tool joint is opposite a set of preventer rams.

Span Adjustment - The control to vary the space between the electrical contactpoints in the electrical pressure switch.

Squeezing - Pumping fluid into one side of the drill pipe/annulus flow systemwith the other side closed so as to allow no outflows.

Stack - The assembly of well control equipment including preventers, spools,valves, and nipples connected to the top of the casing head.

Strainer - A porous material which retains contaminants passing through a linealong with the gas or liquid flow.

Suction Strainer - The porous element, located in a “y” shaped fitting of the pumpsuction lines, which cleans the hydraulic fluid or air of contaminants beforeentering the pumps.

Surge Damper - The one quart capacity bladder accumulator used to absorb theshock and waves caused by an initial flow of high pressure fluid. Located in thedownstream line of the annular regulator.

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Swabbing - The lowering of the hydrostatic pressure in the wellbore due toupward movement of tubulars and/or tools.

Swivel Joint - A connecting device, joining parts so that each can pivot freely.Swivel joints are used at the ends of the pipe rack to ease connections to thecontrol valve outlets and to the BOP stack.

Target - A bull plug or blind flange at the end of a T to prevent erosion at a pointwhere change in flow direction occurs.

Targeted - Refers to a fluid piping system in which flow impinges upon a lead-filled end (target) or a piping T when fluid transits a change in direction.

Terminal Strip - Grouped electrical conductor endings where screw connectionsare made.

Transducer - The device located in the solenoid valve box which is actuated byhydraulic pressure and converts the force to an electrical force for indication on ameter. The electrical output signal is in proportion to the hydraulic input pressure.

Trip Gas - An accumulation of gas which enters the hole while a trip is made.

Trip Margin - An incremental increase in drilling fluid density to provide anincrement of overbalance in order to compensate for effects of swabbing.

Tubulars - Drill pipe, drill collars, tubing, and casing.Underground Blowout - An uncontrolled flow of formation fluids from asubsurface zone into a second subsurface zone.

Underbalance - The amount by which formation pressure exceeds pressureexerted by the hydrostatic head of fluid in the wellbore.

Unit/Remote Selector - The valve located on the manifold header whose portsallow flow into the annular regulator. The valve position determines the source offlow supply and subsequently controls the location of operation.

Valve, Float - A device that is positioned as either open or closed, depending onthe position of a lever connected to a buoyant material sitting in the fluid to bemonitored.

Valve, Manipulator - A control device having three positions, giving fourdirection selections for flow which alternately pressurises and vents the pressureoutlets. The manipulator style valve vents all pressure outlets when placed in thecentre position.

Valve, Poppet - The opening and closing device in a line of flow which restrictsflow by lowering a piston type plunger into the valve passageway.

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Valve, Pre-charge - The device located on the accumulator bladder ports whichopen and close for the nitrogen pressure contained.

Valve, Relief - A valve that opens at a present pressure to relieve excessivepressures within a vessel or line whose primary function is to limit systempressure.

Valve, Selector - A control device having three positions, giving four directionselections for flow which alternately pressurises and vents the pressure outlets.The selector style valve blocks all pressure points if placed in the centre position.

Valve, Shutoff - A valve which operates fully open or fully closed to control theflow through the lines.

Valve, Shuttle - A connective valve which selects one of two or more circuitsbecause flow or pressure changes between the circuits.

Viscosity - A measure of the internal friction or the resistance of a fluid to flow.

Volt - A unit of electromotive force.

Watt - A unit of electrical power; the power of one ampere of current pushed byone volt of electromotive force.

Weight Cut - The amount by which drilling fluid density is reduced by entrainedformation fluids or air.

Wireline Preventers - Preventers installed on top of the well or drill string as aprecautionary measure while running wirelines. The preventer packing will closearound the wireline.

Zero Adjustment - The control to move the meter gauge indicator for resettingcalibration accuracy. Control used to make the meter read 0 by applying an offsetvoltage to the meter to offset any positive voltage present at the meter, eventhough there is no pressure at the input of the transducer.