Canadian Natural GasUnconventional Gas and Reservoir Stimulation Technologies

Unconventional Gas and Reservoir Stimulation Technologies

nn NaturalngasnfromnunconventionalnsourcesnisnannimportantnenginenofngrowthnandnemploymentnfornCanada’snnaturalngasnproductionnindustry.

nn Newntechnologiesn–nenhancingnthencapabilitiesnofntime-testedngasnproductionnmethodsn–nhavenunlockednthenvastnpotentialnofnnaturalngasnfromnunconventionalnsourcesnthatnwerenpreviouslynnotneconomicallynviablenforndevelopment.n

nn Accordingntonan2010nestimatenbynthenCanadiannSocietynfornUnconventionalnGas,nCanadanhasnanmarketablennaturalngasnresourcenbasenbetweenn700n-1300nTrillionncubicnfeetn(Tcf),nenoughntonsupportncurrentnproductionnlevelsnfornovern100nyears.n

nn Stringentnandnlong-standingnregulationsngovernnnaturalngasndevelopmentninnCanada.nThengasnindustryncompliesnwithnthesenregulationsntonensurendevelopmentnofnthenresourcenisnconductedninnansustainablenmannernrespectingnhumannhealthnandnenvironmentalnintegrity.nn

nn Canadiannjurisdictionsnalsonregulatentheninterfacenbetweennwaternandnthennaturalngasnindustry,nandnthenapplicationnofnevolvingnhydraulicnfracturingntechniquesnfornunconventionalngasndevelopmentnisnnonexception.nnThesenregulationsnarensetnandnadministerednbynannumbernofnministries,nincludingnenvironment,nnaturalnresources,nsustainablendevelopment,nenergy,nandnothers.nInnaddition,nmajornproducingnjurisdictionsnhavenoilnandngasnregulatorynentities.

nn Industryncontinuesntonworknwithnregulatorsnandnpolicymakersntonensurendevelopmentnisnconductedninnanresponsiblenmanner.n

1

Thentermn“unconventionalngas”nrefersntonthentypesnofnreservoirsnwherenthengasnisnfound,nandninnsomencasesnthenmechanismnofnstorageninnannundergroundnreservoir.nnThenthreenmostncommonntypesnofnunconventionalnnaturalngasnare:n

n ShalenGas,nfoundninnextremelynfine-grained,nessentiallynimpermeablensedimentarynrocksnnnn requiringncomplexnreservoirnstimulationntonhelpnthennaturalngasnflow.

n TightnGas,nfoundninnthenporenspacenofnsedimentarynrocksnthatnhavenverynlownpermeability.nnn Reservoirnstimulationnisnrequiredntonrecoverntightngasnresources.

n CoalnBednMethanen(CBM)nisnformednduringnthenprocessnofncoalification.nnInnthisnprocess,nn methanenisngeneratednandntrappednasnpeatnturnsnintonlignitenandnlater,nintoncoal.nnInncoalnseams,nn methanenisnprimarilynstorednbynadsorptionntonsolidnhydrocarbonnmolecules.nnAnrangenofn

What is Unconventional Gas?

2

n reservoirnstimulationnmethodsnarenusedntonrecovernthenresource.

Thentraditionalnwayntonproducenconventionalnnaturalngasnisnbyndrillingnanwellnthatntapsnintonrocksninnthensubsurface,nwherengasnisnstorednunderncompressionninnthenporesnofnpermeablenrock.nThisngasnisneasilynproduced.nHowever,nnaturalngasnalsonoccursninnabundanceninnlessnpermeablengeologicalnformations,nwherenthengasnisntrappednmuchnmorentightlynwithinnthenrock.nnThesenwidespreadngasnfieldsnarenfoundninnseveralnregionsninnCanadanandnformnthenbasisnfornthencountry’snunconventionalngasnindustry.n

Releasingnthengasnfromnthesenformationsnisnthengoalnofnunconventionalngasnproduction.nCentralntonthenmatternisnthenfactnthatnnaturalngasnresourcesnarennotnlimitedntonansinglentypenofnrocknformation.nGeologicalncharacteristicsnandnrockntypesnvary,nresultingninnuniquen

characteristicsnatndifferentnlocations.nEachnlocationnrequiresnsite-specificntechniquesntonextractnthenresource,nandneachngasnwellnrequiresncarefulnanalysisntonmatchnthenwell’snparametersnwithnthenmethodsnused.

Withnthenundergroundntargetninnmind,neachnsurfacenlocationnmustnbensurveyednandnassessednwithncarenatneverynstagenofnexplorationnandndevelopment.nThroughnfullnevaluation,nengineersnandnscientistsnarenablentondeterminenthenmostnsuitablenwellndrillingntechniques.nThenterrain,nenvironment,nwaternresource,nandnbuiltnstructuresn

A Wellspring of Innovation

33

ofnthensurroundingnareanarenevaluated.nThen,nmovingndeepnunderground,nthenrockntypesnandndistribution,nandnsubsurfacenstructuresnarenstudied.n

Withnsonmanynfactorsnatnplay,ntherenarendozensnofncombinationsnofninherentnconditionsnandnoperatornchoicesntondesignnanwell.nItnisnoftennnecessaryntonemploynreservoirnstimulationntechniques,noftennreferredntonasnfracturingnorn“fracing,”nwherenthenrocknholdingnthennaturalngasnisncracked,nmuchnlikensafetynglassnbeingnshattered.nBynusingnancombinationnofntechniquesncustomizednforneachnwellnthatnmaynincludenhorizontalndrillingnandnmulti-stagenreservoirnstimulations,nnaturalngasnproducersncannaccessnnaturalngasnfoundninnanvarietynofnchallengingngeologicalnformations.n

generallynlimitingnusenofnthisndrillingntechniquentondeepernreservoirs.nn

Horizontalnwellsnalsonhavenenvironmentalnbenefits.nFornunconventionalngasnreservoirsnwhichnrequirenmanyncloselynspacednwells,nthenusenofnhorizontalndrillingnreducesnsurfacendisturbancensincen

Advancesninnhorizontalndrillingncapabilityninnrecentnyearsn(includingnspecializednrigs,ndrillingnbits,nandnbitnsteeringntechnology)nhavenextendednthenlateralnreachnofnhorizontalnwellsnandnbroadenednthenscopenofnapplicationnofnhorizontalndrilling.nnThenturningnradiusnfromnthenverticalnwellborentonthenhorizontalnlegncontinuesntonbenanconstraintnatnshallowndepths,n

manynwellsncannbendrillednfromnansinglensurfacenlocationn(anmulti-wellnpad).nMulti-wellnpadsnoffernansignificantlynsmallernfootprintnthannmultiplenverticalnwellnpads,nroads,npipelines,nandnsurfacenfacilities,nandnancorrespondingnreductionninnhabitatnfragmentation.

Drilling

4

Hydraulicnfracturing,nthenprocessnofninducingnfracturesninnreservoirs,nhasnbeennannintegralnpartnofnnaturalngasn(andnoil)nresourcendevelopmentninnCanadanforndecades.nnWithoutnthenapplicationnofnhydraulicnfracturingntechniques,nthenvastnmajoritynofnnaturalngasnwellsndrilledninnCanadanwouldnnotnbeneconomic.nnReservoirnstimulationnbynfracturingnwasnfinrstndevelopedninnthenUnitednStatesninnthen1950sntonincreasenproduction,natnthatntimeninnconventionalnverticalnwells.nn

Advancesninnhydraulicnfracturingntechnologyn(betternmetallurgy,nspecializedndownnholenequipment,npurposenbuiltnflnuidnandnmechanicalnsystems,nspecifincallynbuiltnhighnhorsepowernpumpingnunits),nbasednonnovernfinftynyearsnofnexperience,ncombinednwithnmodernnhorizontalndrilling,nallownthennaturalngasnindustrynthenopportunityntonproducennaturalngasnfromnrocknformationsnthatnpreviouslynwouldnhavenbeenntoondiffincultnandnexpensiventonconsider.n

Hydraulicnfracturingnisnthenprocessnofncreatingnpressurentoncracknrocksndeepnunderground.nThisnisndonenafternanwellnisndrilled,ncased,nandncementednbynpumpingnanflnuid,noftenn

containingnansuspendednproppantn(typicallynsand),ndownnintonanwellboreninnorderntonincreasenproductivitynofnanwell.nnThenpressurenappliedncracksnthenrocksnandnthenproppantnlodgesninnthencracksnkeepingnthenfracturenopen.nThensubstancesnusednfornfracturingnarencarefullynmatchednwithnthengeologynofnthensitentonensurenthenbestnresults.nManynvariables,nandnmultiplenpossibilitiesnwithinnvariables,nareninvolvedninnidentifyingnannappropriatenreservoirnfracingnmethod.nThenvariablesnthatnmustnbenconsideredninclude:n

ReservoirncharacteristicsReservoirnpressureStratigraphicnandnothern

geologicalnattributes

Thencombinationnofnthenpumpingnratesnandnpressuresncausesnthenrockntonfracturenorncrack.nnOncenthentreatmentnisncomplete,nsomenornallnofnthenfracnflnuidncannbenrecoverednbynflnowingnbacknthenwell.nIfnan

Gas-rich shaleGas-rich shale

SandstoneSandstone

LimestoneLimestoneHYDRAULIC

FRACTURING

Shallow groundwater aquifer

Deep groundwater aquifer

Protective steel casing:Steel casing and

cement provide wellcontrol and isolate

groundwater zones

Horizontal bore

Induced shale fractures

1,000m

2,000m

2,300m

1,500m

Surface

Note: Buildings andwell depth not to scale

Private water well

Municipal water well

Surface gas-well lease

proppantnwasnused,nitnisnleftnbehind,nproppingnopennthenfractures.nnThennewlyncreatednfracturenenablesnnaturalngas,nfracnflnuidsnandnformationnwaterntonflnowntonthenwellbore.nn

Innorderntonensureneffincientnfracingnoperations,nunderstandingnofnreservoirnbehaviournandnoptimalnusenofnfracingncapitalnindustrynhasndevelopednanvarietynofntechniquesntonaidninnunderstandingnthendistributionnandncharacternofninducednfractures.nnThesentechniquesnincludenmicroseismicnmonitoringnandndetailednproductionntestingnandnmodelling.nnMicroseismicn

Fracturing

5

monitoringnisnemployedntondetectnextremelynsmallngroundnmovementsndeepninnthensubsurface,nidentifyingnthenorientationnandncomplexitynofnfracturingngeneratednbynthenoperation.nnImportantly,nthentechniquenalsonidentifiesnbothnthenlateralnandnverticalnextentnofntheninducednfracturing.nnWhennappliednduringnhydraulicnfracturingnoperations,nmicroseismicnmonitoringnallowsnmodellingntonoptimizenthenorientationnandnspacingnofnfuturenwells,nandnthenoptimalnnumbernandnspacingnofnhydraulicnfracturingnstagesninnthenhorizontalnwell.nnDetailednproductionntestingnenablesnidentificationnofnareasnwherenthenrocknwasnsuccessfullynfracturednandnareasnwherenfracturingnwasninadequatenornwherenhydraulicnfracturingnfluidndidnnotnflownbackntonthenwell,nremainingninnthenreservoirnandninhibitingnproduction.

Innsomenplacesnandnfornsomenresourcesnunconventionalngasndevelopmentncannrequiren

largenquantitiesnofnwater.nnInnallnsituationsnCanadiannregulatorsnandnthennaturalngasnindustrynarenfocusednonnthenprotectionnofnsurfacenandngroundwaternandnthenmitigationnofnrisk.nnAllnCanadiannjurisdictionsnregulatentheninterfacenbetweennwaternandnthennaturalngasnindustry,nandnthenapplicationnofnevolvingnhydraulicnfracturingntechniquesnfornunconventionalngasndevelopmentnisnnonexception.nnThesenregulationsnarensetnandnadministerednbynannumbernofngovernmentnministries,nincludingnenvironment,nnaturalnresources,nsustainablendevelopment,nenergy,nandnothers.nInnaddition,nmajornproducingnjurisdictionsnhavenoilnandngasnregulatorynentitiesn–neithernprovincialnboardsnornthenfederalnNationalnEnergynBoard.n

Innsomenreservoirsnfracturingnisnthenmostnwater-intensenactivitynassociatednwithnnaturalngasnproduction.nTherenisnanverynwidenrangeninnthenvolumenofnwaternusednfornhydraulicnfracturingnoperations,nanfunctionn

ofnthengeologynandnreservoirncharacteristics.nnInnmanynregionsnantypicalnfracturingnoperationninnandeepnhorizontalnshalengasnwellnmightnusenbetweenn3500nm3nton15000nm3nofnwaterntonenhancenthenrecoverynofnthengas.nnInnothernareasnfracturingnoperationsnmaynusenseveralntimesnthisnwaternvolume,nandnelsewherenfracturingnoperationsnmaynusengasesnornothernliquids,nandnnonwaternatnall.nnThenhydraulicnfracturingnoperationntypicallyntakesnplacenonlynoncenpernfracturednwell,natnthenbeginningnofnthenwellnoperation.nMostnwellsnthennproducenforn20nton30nyearsnwithoutnrequiringnanynfurthernfracturingnandnrelatednwaternuse.nnInnrecognitionnofnthenintensitynofnwaternuseninnsomenregions,nnaturalngasnproducersnarenconsideringn(andninnsomencasesnimplementing)nmethodsnsuchnasnwaternrecyclingntechniques,nornfracturingnwithnnon-potablenbrackishnwaterntonoffsetnincreasedndemandnfornwaternandntonreducenimpactsnonnsurfacenwaternandnaquifers.n

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Innsomenshalendevelopmentnareasnthenlengthnofnhorizontalnlateralsnandnthennumbernofnfracturingnstagesnisnincreasing.nnThisnhasntheneffectnofnincreasingnthenamountnofnwaternusedntonfractureneachnwell,nbutnisnoffsetnbyncapturingnangreaternvolumenofnthenresourcenwithneachnwellnandnultimatelynreducingnthennumbernofnwellsnandnwellnpadsnthatnwouldnotherwisenbenrequired.

Multistage Hydraulic Fracturing Operation Underway

Production Operations at a Multi-Well Padt

PhotoncourtesynofnCalfracnWellnServicesnLtd.

PhotonCourtesynofnTridentnExplorationnCorp.

Canadian Electricity Generation Portfolio - 1990 to 2007

2% 4% 5% 6%

16% 15%19% 18%

62% 60%

60% 60%

16% 18%13% 14%

4% 3% 4% 3%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1990 1995 2000 2007Source: NRCan End Use Database

Other

Nuclear

Hydro

Coal

Natural Gas

7

Common Fracturing TechniquesNAMe Technique Pros and Cons

Frac-Through-Coil (FTC) Steel coiled tubing is fed into the wellhead from a specialized unit. At the bottom of the coiled tubing, a set of tools isolates the targeted zone from the rest of the well and allows the slurry to be placed into the tar-geted zone. The operator on surface raises and lowers the coiled tubing as needed, usually working from the bottom of the well and moving upwards.

• Coiled tubing units can stimulate multiple isolated zones• There is a decrease of time on location, and a smaller footprint in comparison to larger fracs that require more equipment • Requires fewer employees to operate• Pumping rate is limited due to friction, total reach (length) of coil is highly variable reflecting local conditions• Increased equipment costs

Abrasive Jet Multi Stage Fracturing

A unique coiled tubing approach that combines isola-tion and perforating into one tool.

This coiled tubing-deployed bottom hole assembly (BHA) incorporates an abrasive jet perforating nozzle and an isolation technique - multi-setting bridge plugs or sand plugs.

• Combines many technologies to speed up comple-tion of the well and to reduce costs• It also reduces the amount of services needed for the well which decreases the environmental impact around the wellhead• Patent limitations and licensing costs• Limited pumping rates due to coiled tubing and pipe configurations• High utilization of coiled tubing and associated costs

Multi-Stage Packers Isolates specific zones for treatment. After the first zone is treated, a ball/dart is launched into the well, pushed by the frac fluid. This object seats on a frac port to both isolate the first zone and open the second zone, this process is repeated on each zone. Once all zones have been fraced, the balls are milled out to open the ports for production.

• The use of this treatment allows for multiple zones to be treated, with specialized programs for each zone• Initial cost for isolation packers is high, if issues occur while placing tools some, or all, of the well may be lost• Post treatment milling of balls and packers is costly and time consuming• Balls and darts can get caught and zones may be lost, unable to properly complete the well• Delay from stimulation to milling can locally dam-age the reservoir making production difficult

Plug and Perf The deepest set of perforations in a well are stimu-lated, then a bridge plug is set to isolate the zone. A second set of perforations can then be introduced and fractured. The bridge plugs are removed when all fracturing is complete.

• The process can repeat itself for as many times as needed to cover the zone of interest• This process is slow and multiple services are needed sequentially to ensure smooth operation• Long standing history of process• Workable distance from wellhead is limited• Increased delay from stimulation to production may reduce well productivity

CHeMICAl TReATMeNTS

Acid treatments Acidizing (typically with a diluted solution of hydro-chloric acid) is used as a fracture treatment, pre-treat-ment prior to a fracture and/or as general maintenance measure to clean a wellbore.

• In many fracturing operations a relatively small volume of acid is pumped ahead of the frac slurry as a ‘spearhead’ to improve communication with the formation prior to the fracture • Longstanding common practice • Reduces pressure required to fracture the forma-tion, and increases production by removing scale deposits

8

Thenslurriesn(fluids)nusedninnunconventionalnnaturalngasnextractionnarenmixesnofnliquidsnandnproppants.nFornhydraulicnfracturingnoperationsnthenobjectivenisntonhavenanliquidnsuspensionnofnproppantnthatncannbenpumpednatnhighnpressurenintonthenwellnbore.nThenliquidnisnusuallynthennthinnednsonthatnitncannbenrecoverednfromnthenwell,nwhilenleavingnbehindnthenproppantntonincreasenthenpermeabilitynofnthenrock.n

Oncenthentreatmentnisncompletenandnthenwellnisnpumpednout,nallnfluidnisncollectednandntakenntonanprocessingnplant.nnNonfluidnisnleftnbehindnonnlocation;nitnisnallncarriednawaynandnprocessed,nrecyclednornproperlyndisposednof.nnnn

Waternisnthenbasisnfornmostnhydraulicnfracturing.nnWaternsourcesnmaynincludenrecyclednfracturingnfluids,nproducednwaternfromnothernoilfieldnoperations,nornbrackishn(salty)nwaternthatnisndrawnnfromnbelownthenwaterntable,nbutnthenmostncommonnsourcentodaynisnsurfacenfreshnwater.nnWaternmaynbenpumpednasnanmixturenwithnmethanolnfornwater-sensitivenrocks.nnRecentlyntherenhasnbeennanhugenincreaseninnthenusenofnrecyclednfracturingnfluidsninnNorthnAmerica,nwithnmanyn“slickwaternfracs”nre-usingnthenflowbacknwaternfromnanpreviousntreatmentnmanyntimesnover.nn

Fracturingnoilnisnanothernfracturingnfluidnthatnisnbeingnre-used.nnFracnoilsnareneithernrecyclednfornre-usenornsoldnasnproductionnoil.nnInnthenpastndieselnhasnbeennusednbutnitnisnverynuncommon,nandnisnprohibitedninnsomenjurisdictions.nnNewntechnologynhasnintroducednthensafenandnregulatednusenofnliquidnpropanenasnanfluidnmediumninsteadnofnwaternornfracnoil.nn

Tonenhancenthenperformancenofnthenfracturingnoperationnvariousnadditivesncannbenblendednwithnthenfracturingnfluid.

liquids & Proppants

Fluids

Additives

GAS TReATMeNTS

High Rate Nitrogen Nitrogen gas is pumped into a formation at high rates and pressures. Used for shallow application, typically coalbed methane (CBM). Occasionally a small amount of sand proppant is added to the nitrogen, in essence creating a high-powered sand blast. Nitrogen is com-monly used as an energy source additive for fracturing fluids.

• Opens cleats, or natural fractures, in the coal and removes damaged areas in order for natural gas to flow more easily into the well• No fluids are added to this system; therefore no added chemicals are introduced into the formation• High Rate Nitrogen is limited in its ability to stimu-late• Energy is unable to transfer very far from the near wellbore area

Liquid CO2 Pure liquid Carbon Dioxide (CO2) is pumped into the wellbore.

Commonly used as an energy source additive for frac-turing fluids (shake a pop can).

• No added chemicals are required• Most Liquid CO2 fracture treatments are done for research and development because CO2 is con-sidered to be a low-damaging fluid in terms of its impact on the rock • Liquid CO2 is limited in its ability to suspend a proppant and has limited potential for commercial natural gas production

9

TyPe Source Pros/Cons

Gellants or gelling agents: increase viscosity, proppant suspension and provide lubrication.

Guar Gum (most common gellant in use)

Guar bean, grown in India and Pakistan. Used as a food additive.

Creates a natural polymer chain. Can be refined mul-tiple times to improve its qualities such as methanol tolerance, decreased hydration time, and increased viscosity.

Polyacrylamide Chemically produced long-chain molecule, known as a polymer. Commonly used in water treatment as a floc-culent, or for products such as soft contact lenses.

Used to make water slippery for slickwater fractur-ing.

Crosslinkers : used in small quantities to join polymers in a three-dimensional shape.

Boron, zirconium, titanium, or iron

Naturally occurring elements, mined at various loca-tions.

Increases the viscosity of the liquid by linking the polymers.

Clay Control: used in water sensitive formations to pre-vent clays from swelling.

Potassium Chloride Potash, used in the preparation of many types of fertil-izer. Potassium chloride is used occasionally as a table salt substitute.

Reduces damage to reservoirs by inhibiting the reaction of certain clay minerals with water.

Breakers: Breaks the polymer chain created by the gelling agent.

Oxidizers Manufactured substances that release oxygen Reduces viscosity of polymers and allows the fluid to flow back to surface

enzymes A naturally occurring agricultural by-product Consumes Guar Gum polymers.

Surfactants: lower the sur-face tension on the fractur-ing fluid.

Flow back additives Akin to soap, these additives enhance the ability of water to flow back to surface following treatment.

Allows easier flow back of the fluid after the treat-ment is complete.

Biocides: Prevent the introduction of sulphate reducing and other bacteria into wells

Natural and manufactured biocides

Can be derived from bacteria or plants, or prepared from chemicals.Biocides are used in pesticides, antibacterial cleaners.Many companies are evaluating alternatives including ultraviolet light.

Prevents introduction of bacteria that can produce highly toxic hydrogen sulphide (H2S), corrosive acids, or fouling chemicals or precipitates in the reservoir.

Used in small quantities.

energizers: gases used to energize (or foam) fluids for fracturing treatments.

Carbon Dioxide (CO2) Common element found in the atmosphere. Carbon Dioxide can exist as a liquid, gas or solid, (known as ‘dry ice’).

Odourless and non-toxic.Improves the recovery of fluid, while reducing the potential of formation damage. Carbon Dioxide is moderately soluble in water and highly soluble in oil, particularly under pressure.

Nitrogen (N2) A naturally occurring element, nitrogen is stored, trans-ported and pumped as a cryogenic liquid, then heated and injected into the wellbore as a gas.

Improves recovery of stimulation or well fluids.

10

Commonly-usednproppantsnincludensand,nceramic,nornresin-coatednsands.nnManyndifferentnproppantsnhavenbeennusedninnthenpast,nincludingnwalnutnshellsnandnglassnbeads.

Sandnisnthenmostncommonnproppantnusedninnfracturentreatments.nnSandnmustnmeetnindustrynspecificationn(API)nandnisnsourcednbothnlocallynandnimportednfromnthenUnitednStates.nn

Ceramicnproppantsnarenanmanufacturednalternativenton

sand.nnThisntypenofnproppantntendsntonbenstrongernandnmorencrushnresistantntonstressnthannnaturalnsand.nGenerally,nthesenarenmanufacturednfromnfirednclay.

Resin-coated sandsnarentacky,nwhichnreducesnproppantnflow-backnwhennthenfluidsnarenwithdrawnnfromnthenwellbore.nnResinncoatednproppantsnarenusuallynpumpedninnsmallnquantitiesnatnthenendnofnjobs.nnAnchemicalnactivatornisnsometimesnpumpednwithnanresin-coatedn

proppantninnorderntonactivatenthenstickynqualitiesnofnthenresin.nnOthernresin-coatednproppantsndonnotnrequirenthenusenofnannactivatornbecausentheynarentemperature-sensitivenandnactivatednbynthenhotterntemperatureninnthenreservoir.

Guar Beans – source of the most common additive.

Proppants

A wide variety of proppants are available for modern hydraulic fracturing operations

11

undernpressurenthroughnthensteelnplumbingnornproductionncasingntonpushnagainstnthenrocknformationsnhundredsntonthousandsnofnmetersnbelownthensurfacenofnthenground.nThenpressureninnbothncasesnmustnbenbelownthenpressurenratingnofnallnofnthenplumbingnitnencountersnandnthenfluidnmustnwithstandnthenrigorsnofnthenprocessnitngoesnthrough.

Hydraulicnfluidninnthentractornisncommonlynantypenofnoilnthatnisnanveryngoodnlubricant,nbeingnslipperynandnthick,nandncannholdnthesenpropertiesnasnitnisncyclednmanyntimesnasnthenequipmentnisnused.nHydraulicnFracturenfluidnisnmorencommonlynanwater-basednentitynandnwaternisnnotnslipperynornthicknwhenncomparedntonhydraulicnoil.nSlipperinessnandnthicknessnarenthentwonfeaturesnthatnarencriticalntonthensuccessnofnbeingnablentonpushnwatern

throughnpipe.nWhy?nWaternlikesntongrabnontonthenplumbingnandnpushnbacknagainstnthenpumps.nThisnfrictionncausesnthenpumpntonworknhardernmeaningnthenworkingnpressuresninnthenplumbingnarenhighernandnthenamountnofnenergy,nhorsepower,nandnfuelnneededntondonthenworknalsongoesnup.nInnorderntonworknatnthenlongndistancesnawaynfromnthensurfacenthencharacteristicsnofnwaternmustnbenchangedntonallownsafenandnefficientnwork,nandnthisnisndonenwithnadditives.n

Waternbynitselfncannotnmovensandnornothernproppants.nItnneedsnhelpnfromngravitynandnlargenvolumesnofnwaternlikeninnanfloodntonbuildnupnspeedntonbenablentonpicknupnrocksnandnmaterialnornparticlesnandnmoventhemndownnanriver.nTonmakenwaternanbetterntransporternofnparticlesnatnlownflowingnratesnitnisnnecessaryntonchangenitsncharacteristicsnandnmakenitnthickerntonbetterncarrynornholdnupnanparticle.n

Whennheavynequipmentnhasnactuatingnarmsnlikenthenforksnonnantractornfornliftingnbalesnofnhay,nthesenforksnarenmovednbynhydraulicnfluidnbeingnpushednthroughnhosesntoncylindersntonexertnforcenandnliftnornlowernthenbalesnofnhay.nThenfluidnisnplacednundernpressurenbynanpumpnandncontrollednbynvalvesnthatnallownthenfluidntonflownintonornoutnofncylindersnthatnextendnorncontractndependingnonnthendesiredneffect.nThenflownofnthenhydraulicnfluidnmovesnfromnannareanofnhighnpressurentonannareanofnlowernpressurenasndirectednbynthenplumbingnandnthenvalvesnalongnthenflownpath.nThenpumpnmustnbenablentonexertnmorenpressurenintonthenfluidnthannthenforcesnexertednbynthenmetalnframenandnthenbalenofnhaynresistingnthenraisingnofnthenactuatingnarms.nn

Hydraulicnfracturingnusesnfluidninnansimilarnway.nFluidnisnpushedn

How Fluids Work: A Closer look

12

Guarnflour,ncommonlynusedninnmanynhouseholdsnfornmakingngravy,nhasnthenattributesnofnmakingnwaternbothnthicknandnslippery,nandnisnaddedntonwaterninnhydraulicnfracturingnfluid.nOnlynanfewngramsnofnthenguarnflournwillnthickennanlitrenofnwaternandnmakenitnverynslippery.nThenslipperinessnallowsnthenfluidntonslidenmoreneasilynthroughnthenroughnsteelnpipenandnthenthickernfluidnincreasesnthenwater’snabilityntoncarrynparticles,nsuchnasnsand.n

Anothernimportantnaspectnisntonmaintainnthenstabilitynandnphysicalnconstitutionnofnthenrocknandnclaynthatnholdsnthennaturalngas.nTonensurenthatnthenclaynmaterialsndonnotnreactnbynpullingnthenwaternmoleculesnontonthemselvesnandnswellingnwhennthenhydraulicnfluidnisnpushednintonthenformation,ngeologistsnstudynthenclaynmineralsnthatnarenpresentninnthenzonenofninterest.nBynusingnthenadditivenpotashnornpotassiumnsaltsninnthenwaternitnisnpossiblentoninhibitnclay-waternreactions,nallowingnthenwaterntonmovenpastnthenclaynparticlenwithoutnanyneffectntonthenformation.

Thenproppantnornsandnthatnisnaddedntonhydraulicnfracturingnfluidnisndesignedntonpreventnthenclosurenofnthencracksncreatednwhennthenhydraulicnfluidnisn

pushednintonthenrock.nThenspacesnleftnarenpassagesnthatnaren“propped”nopennandnallownflow.

Sonfarnthreenadditives,nguarnflour,npotassiumnsalts,nandnproppantnhavenbeennaddedntonwaterntonchangenitsncharacteristicsnsonitnwillneasilyncarrynsandnornproppantnthroughnansteelnplumbingnsystemnintonanzonenofninterestnwithoutnchangingnthenformation’snchemistry.nNownthatntherenarencracksnfillednwithnproppantnandnfluid,nthenfluidnmustngetnoutnofnthenwayntonallownhydrocarbonsntonflowntonthenwellnotherwisenitnactsnlikengluenandnsealsnthenproppednspace.nnHundredsntonthousandsnofnmetersnbelownthensurfacenthenweightnofnthenworldnisncrushingndownnonntheninjectednfluidnandnthenfluidnwillnjustncarrynthenproppantnbacknoutnwhennthenpumpsnreleasenthenpressurenonnthenfluid.nThenhydraulicncylindernwillnreversenflow.nnThenfluidnneedsntonlosenitsnabilityntontransportnorncarrynproppantnfornthenwork,nleavingnthenproppantninnthencracks,ntonbensuccessful.n

Thenincreaseninnthencarryingnpowernofnwaternwasnanresultnofnthenguarnflournadditive.nGuarnflournisnsimplynanstarch.nStarchesnarensugarsnthatnmanynlivingnorganismsnbreakndownntonproducenenergy.nThisnbreakingndownnofnthensugarn

13

chainnchangesnthenstarchnsonthatnitnlosesnmanynofnitsnoriginalncharacteristicsnincludingnitsnabilityntonthickennwater.nEnzymesnarennaturallynoccurringnandncommon,nandnbreaknthensugarnchains.nEnzymesnarenfoundninnmostnlivingnorganismsnandnareneasilyncollectednandnusednasnannadditiveninnhydraulicnfracturingnfluids.nnOncenthenenzymenbreakernisnaddedntonthenfracturingnfluidnitnslowlynbreaksndownnthenguarnstarchnornguarngum.nThisnreducesnthenthicknessnofnthencarryingnfluidn(breaksnit)nwhichnresultsninnanthinnernfluidndroppingnandnslippingnawaynfromnthenproppant.nWhennthisnoccursnonlynthenwaternfollowsnthensteelnproductionnplumbingnbackntonsurfacenwhennthenpumpnpressurenisnreleased.n

Thenbreakernenzymenisnfragilenandnitnneedsnspecificnconditionsntonremainnactive.nItnneedsnfood,nthenguarngum,nandnthenenvironmentalnconditionsntonsustainnit.nSeveralnhundrednmetersnintonthengroundnthenconditionsnarenverynhostilenandnnotnsuitedntonenzymensurvival.nAsnlongnasnthenenzymencanndonitsnjobnandnbreakndownnthenthicknessnofnthenfluidnpriorntondeterioratingnitsnjobnisncompleted.n

Tonenhancenfluidnflownbackntonsurfacenitnisncommonnpracticentonaddnsoapnornsurfactantntonthen

fluid.nnSoapnreducesnthensurfacentensionnofnwaternwhichnletsnthenwaternslipnoutnofnthenformationnwithoutnformingnwaternbridgesnornblocksnacrossnthenproppednopenings.

WhennanFracturingnFluidncontainsnadditivesntonthicken,ncontrolnclaynswelling,nbreakingnthenfluidnandnansurfactantnfornbetternfluidnrecovery,nitnisnverynadvantageousntonaddnangas.nUsingngasnasnannadditivenwillnreducenthenamountnornquantitynofnadditivesnrequirednbynreducingnthenamountnofnwaternneededntontransportnproppantnintonthenformation.nBecausenthengasnisnundernpressurenitnhelpsnpushnthenwaternbacknoutnofnthenformationntreated.nMuchnlikenancannofnpopnafternbeingnshakennupnandnopened,nthengasnexpandsnasnthenpressurenisnreleasednpropellingnthenthinnednwaternbackntonthensurfacentonbencollected.nAddingngassesn–norninnthencasenofncarbonndioxidenanliquidn–nreducesnthenwater-clayncontactnandnfurthernpreventsnthenswellingnofnclaysnornformationndamagentonoccur.

Waterncomesninnanvarietynofnchemicalncompositions.nVariationsninnwaterncompositionncausenindustryntonworknwithndifferentnchemicalsntoncounterbalancenthenissuesncausednbynthenwaternitself.nThenbiggestnconcernnisnbacterianinn

thenwater.nInnannenvironmentnthatnisnwarmnandnwet,nsulphatenreducingnbacteriancannmultiplynandnquicklynturnnan“sweet”nwell,nrelativelynpurenfornproductionnpurposes,nintonansourngasnwellnthroughnthenbacterialnproductionnofnhighlyntoxicnhydrogennsulphide.nnOtherntypesnofnbacteriancannproducencorrosivenacids,nslimes,nandnothernundesirablencompoundsnthatnplugnupnthenreservoir.nBacterianmustnbencontrolled,nandnmostnmunicipalitiesninnNorthnAmericanusenchlorineninnwaterntreatmentntonkillnbacteria.nThisnisnanhighlynregulatednprocessnandnisnconstantlynmonitorednbynregulators.nUsingndomesticnwaternsuppliesnfromntreatmentnplantsnfornindustrialnpurposesndoesnoccur,nbutnwherenpossiblenfracturingnfluidsnwillnbengeneratednfromnwaternsourcesnclosentonwherenthenworknisnbeingnconducted.nThesensourcesnarenmostnoftennfreshnwater,nbutntheynalsoncontainnallnthenbacteria,nalgae,ndecayingnorganicnmatter,nsedimentsnandnanythingnelsenthatnisnpresentninnthenwaternbody.nTonstaynaheadnofnthenbiologicalngrowthnthatncannquicklynaccumulateninnanholdingntank,nitnisnprudentnpracticentonaddnanbiocidentonthentank.nThesenbiocidesnarenpowerfulnbutnarenlimitedninnbothnquantitynandneffectiveness,nandnaftern2-3ndaysnmanynbiocidesnarencompletelynusednup.nRe-treatmentncannben

14

requirednifnthenwaternisnnotnusedninnthatntimenframe.

Asnwithnanynprocess,nsciencenandntechnologyndriveninnovationnquickly.nInnanfewnshortnyearsninnovationnresultsninnnewndesignsnthatnresultninnbetternandneasierntoolsntonaddressnhumanninterests.nSimilarlynthenhydraulicnfracturingnindustrynhasnalsonpushedntonadvancentechnologynandneachnservicencompanynworksnwithnscientistsnandnchemicalnsuppliersntondevelopnleading-edgenfluidsntonmeetnoperatornandnpublicndemands.nBecausenofnthenintensencompetitionnbetweenncompaniesnfluidnsystemsnarentradensecrets.n

Tonsummarize:nHydraulicnFracturingnFluidsnneedntonhavenuniquencharacteristicsnsontheyncanntravelnmultiplenkilometresnfromnsurfacenintonthenreservoirnwhilenretainingntheirncorenproperties,nandnwithinnanshortntimenchangenbacknintonwaternfornthenreturnnmultiplenkilometrentripntonsurface.nTheyncommonlyncontainnallnornsomencombinationnof:nWater,nthickenernandnanfrictionnreducer,nclaynswellingnsuppressant,nbreaker,nwaternfrictionnreducer/nbubblenmaker/nwaternreducingnsupportnentity,nthickeningnandnmorenclayncontrolngas,nbugnandnbacteriankillernandncommonlynsomensortnofnproppant,nusuallynsand.

Whatevernthenmethodsnchosennfornthenproductionnofnnaturalngas,nstringentnandnlongnstandingnregulationsngovernnbothnconventionalnandnunconventionalnnaturalngasndevelopmentninnCanada.nThenindustrynisncommittedntonenvironmentalnresponsibility,nhealthnandnsafety,nandnsustainability.nIndustryncontinuesntonworknwithnregulatorsnandnpolicynmakersntonensurenthatnallndevelopmentnisnconductedninnannappropriatenmanner.n

InnCanadanwhennancompanynisntransportingnchemicalsnorngoodsnfromntheirnbasenofnoperationsntonanothernlocationntheynarenboundntonfollownregulationsnthatngovernnthesenactivities.nThenpurposen

ofnthenfederalnTransportationnofnDangerousnGoodsn(TDG)nActnandnrelatednregulationsnisntonpromotenandnensurenpublicnsafety;nandnthenActnandnregulationsnapplyntonallnpersonsnwhonhandle,noffernforntransportnorntransportndangerousngoodsnbynanynmeans.

Thesenrulesnarenenforcednandnmonitorednbyninspectorsn

andnhavenmonetarynandnconfinementnpenaltiesnassociatednwithnthem.nThesenpenaltiesnarenapplicablentonallnpersonsnresponsiblenfornthenviolationnofnthesenregulations.nnAccordingntonthenregulationsnallnpersonsnwhonhandlenandnorntransportngoodsnmustnbentrainednandncertified,nandnthatncertificationnmustnbenrenewedneverynthreenyears.n

The Regulatory environment

15

Eachnpersonnwhontakesnthentrainingnisnissuednancopynofnthenregulationsnandnisnexpectedntonretainnthendocumentationnasntheyngononnwithntheirnduties.nThenTDGnregulationsnarencomplimentednbynthennationwidencommunicationnsystem,nWHMISn(WorkplacenHazardousnMaterialsnInformationnSystem)nwhichnsupportsnthensafenuse,nhandlingnandnstoragenofnproductsninnanworkplace.n

Allnemployersnarenrequiredntondevelopnandnimplementnanneducationnprogramnfornallnworkersnwhonworknwith,nproducenornarennearnproducts.nTheynmustnalsonsupportnthenprogramnsonemployeesncannapplyntheninformationnsuppliednfromnMSDSn(MaterialnSafetynDatanSheets)nandnSuppliern

andnWorkplacenlabelsntonensurenthensafenuse,nhandling,nstoragenandndisposalnofnthesenproducts.nnMSDSndocumentsnprovideninformationnonnpotentialnhazards,nsafenhandling,ntransportation,nstorage,nandnemergencynproceduresnrelatedntonthenpotentialnhazardsnofnansubstance.nnMSDSndocumentsnalsonidentifynwhatnthenappropriatenresponsenshouldnbenifnanhandlingnaccidentnoccurs,nhowntonrecognizensymptomsnofnoverexposure,nandnwhatntondonifnsuchnannincidentnhappens.

AllnadditivesnthatnarenusedninnHydraulicnFracturingnfallnundernthesenregulationsnandnarenstrictlynadheredntonatnallntimes.nAllnstaffnandnmanagementnfornallnofnthenservicencompaniesnarenawarenofnthenregulationsnandnarenmandatedntonfollownthenrulesnsetnoutnbynthenfederaln

government.

InnadditionntonthesenregulationsnthenGovernmentnofnCanadanplaysnankeynroleninnprotectingnhumannhealthnandnthenenvironmentnfromnthenrisksnofnchemicalnsubstancesnundernannumbernofnlaws.nUndernthenCanadiannEnvironmentalnProtectionnAct,n1999n(CEPAn1999),nforninstance,nscientistsnatnHealthnCanadanandnEnvironmentnCanadanassessnchemicalnsubstancesntondeterminenifntheynposenanriskntonhumannhealthnand/ornthenenvironment.nThenGovernmentnofnCanadandevelopsnregulationsnandnothernrisknmanagementnmeasuresnbasednonnthenfindingsnofnthesenassessments.

TwonkeynprogramsnbynwhichnthenGovernmentnofnCanadanmanagesnsubstancesnarenthen

ChemicalsnManagementnPlannandnthenNewnSubstancesnProgram.nnSubstancesnfornuseninnthenoilnandngasnindustryn(e.g.,nlubricants,ndrillingnfluids,ncorrosionninhibitors,nsurfactants,nfracturingnfluidnadditives,ndesulfurizationnagents,nandnbacteriancontrolnagents)narensubjectntonthesentwonprograms.

ThenCEPAn1999nprovidesnfornthenregulationsnthatnarenannintegralnpartnofnthenfederalngovernment’snnationalnpollutionnpreventionnstrategy.nThesenregulationsnbecomenancompletenmanagementnapproachnforntoxicnsubstancesnandnwerencreatedntonensurenthatnnonnewnsubstances,nincludingnchemicalsnandnpolymers,narenintroducednbeforenannassessmentnofnwhetherntheynarenpotentiallyntoxicnhasnbeenncompleted,nandnanynappropriatenornrequiredncontrolnmeasuresnhavenbeenntaken.

Morendetailsnonnthenprogramsnandninformationnonnthenregulations,nresearchnandndecisionsnthatnmustnbenadheredntonbynallnindustries,nincludingnthennoilnandngasnindustry,ncannbenfoundnonnvariousnGovernmentnofnCanadanwebsites:

Transportation of Dangerous Goodshttp://www.tc.gc.ca/eng/tdg/clear-menu-497.htm

Workplace Hazardous Materials Information Systemhttp://www.hc-sc.gc.ca/ewh-semt/occup-travail/whmis-simdut/index-eng.php

Chemicals Management Plan:http://www.chemicalsubstanceschimiques.gc.ca/index-eng.php

New Substances Program:http://www.ec.gc.ca/subsnouvelles-newsubs/default.asp?lang=En&n=AB189605-1

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AppendixEndnotes1.n nHexionnSpecialitynChemicals.nn“FracturingnProppants”.nnhttp://www.hexion.com/Products/TechnicalDataSheets.

aspx?id=629n(AccessednJanuaryn27,n2010).

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Canadian Natural Gas is a made-in-Canada advocacy project sponsored by the following associations:

Canadian Energy Pipeline AssociationAssociation canadienne de pipelines d’énergie