View
213
Download
0
Category
Preview:
Citation preview
CasingGas
• Oilinforma:onsincludesnaturalgasinsolu:on• Foroiltoflowintoawell,thepressureatthebo@omofthewellmustbelessthanthatoftheforma:on.Asoilflowsintothewell,gaswillcomeoutofsolu:onandcollectinthecasing
• Thisgaswastradi:onallydealtwithinoneoftwoways– Ven:ngthecasingtoatmosphere– Connec:ngthecasingtotheflowline
CasingPressure
Venttoatmosphere• Ven:ngmethaneto
atmosphereisbadfortheenvironment,methanehas25xthegreenhouseeffectofCO2(basedon100yearglobalwarmingpoten:al)
• Was:ngapoten:allyvaluableandfiniteresource
• Thisprac:ceisnowillegalinmanycountriesfortheabovereasons
Connecttoflowline• Canreducewell
performanceduetohighbackpressureonforma:on
• Convenient,only1pipelinerequired,gascanbeseparatedfromstreamandusedatba@ery
WhyCasingGasCompression?
• Noven:ng–delivergastoflowline• Canusegasasfuelorsellit• Reducecasingpressure,loweringthebackpressureontheforma:on.Thiswill:– Increaserateofoilproduc:on– Increaseoveralloilrecovery
Whatdoesitdo
• Reducepressureincasing,loweringbo@omholepressure• Differen:alpressurebetweentheforma:onandbo@omholeis
whatdrivestheinflowofoiltothewell• Maximumflowlinepressurescanreachbetween1380-2070kPa/
200-300psi• Acompressorcantypicallyreducecasingpressureto35-207kPa/
5-30psi,dependingonsizeandgasflow• Reduc:onofbackpressureagainsttheforma:onresultsinhigher
oilrecoveryrate• Thiseffectwillbemoresignificantonlowpressureforma:ons
– Forma:onpressureof20700kPa(3000psi),wellis1380kPa(200psi),dropsto207kPa(30psi),changeis6%
– Forma:onpressureis6894kPa(1000psi),wellis1380kPa(200psi),dropsto207kPa(30psi),changeis18%
IPRCurves
• InflowPerformanceRela:onship• Indicatechangeininflowrateswithchangeofbo@omholepressure
• Essen:ally,thereservoir’sabilitytoflowtothewellatarangeofbo@omholepressures
• Dependsonreservoirstructure,permeability,pressure,andotherfactors
• Canbeusedasafirstindicatorofawellpoten:allysuitedforcasinggascompression
WellsPronetoGasLock
• Gaslockmayoccurduetoavarietyofcondi:ons,suchashighGOR,pumpspacing,andpumplandingloca:on
• Agaslockedpumpcancausesevereequipmentdamage• Onwellswherethisisaknownissue,acasinggascompressormay
aggravatetheproblem,asloweringdownholepressurewillincreasetherateofgasbreakout
• Poten:alsolu:onswouldbe:– Resefngpumpspacingtomaximizepumpcompressionra:o– Addingagasanchororothergassepara:ondevicetothepump– Changetoapumpdesignedtohandlegas– Re-landingthepumpfurtherbelowtheperfora:ons
• Ifthesedonotsolvetheproblem,thiswellmaynotbesuitableforcasinggascompression
• Thesolu:onmaybetoincreaseheadpressureonthepump.Thiswouldinvolvemaintaininggreaterfluidheightinthewell.Essen:ally,givingupsomeamountofproduc:onrateinordertoavoidgaslockissues.
• Tes:ngiscri:cal,theonlywaytoensurethatawellissuitableforcasinggascompressionistotestinadvance
Tes:ngforsuitability
• Trailermountedcompressorsaresimpletomovearound,savinglaborand:meovertes:ngwithaskidmountedunit
• Screwcompressorsarequiteflexibleinperformancecanbeadaptedtoawiderangeofopera:ngcondi:ons
• Gasdriven,willrunoffcompressedgas,noneedforanelectriciantohookuppower
• Atestcompressorwilldetermineexactlyhowawellwillrespondtocasinggascompression,makingtheeconomicsoftheapplica:onacertaintyratherthanspecula:on
• Canbeequippedwithaflowmetertopreciselydeterminerequiredsizeofcompressor
Howdowedoit
• Varietyofcompressionelements,chosenbasedonopera:ngcondi:ons– HydraulicReciproca:ng
• Lowflow(0.1-2e3m3/dayor0.3-70mcfd)• Highpressure(upto3450kPa/500psi)
– SmallFrameReciproca:ng• Mediumflow(0.5-6e3m3/dayor17-200mscfd)• Highpressure(upto2750kPa/400psi)
– Screw• Highflow(6-37e3m3/dayor200-1300mscfd)• Mediumpressure(upto2070kPa/300psi)
HydraulicCasingGasCompressor• Purposedesignforlowvolumecasinggasapplica:ons• Idealforsinglewellapplica:on• Compressorisdesignedforsweetorsourservice• Nooperatorsetuporadjustmentisrequired• Eliminatesissuescommonwithconven:onalcasinggascompressors
– Noprocessvalvesorcoolerstobecomecontaminated• Noinletvalve• Norecyclevalve• Nointercooler
– Noliquidhandlingsystem(compressorcanpumpliquidorgas)• Noseparator• Nolevelshutoff• Nolevelswitch• Noliquidpump
• Ultrareliablegearpumpandelectricmotorpowersupply• Minimummovingparts• Satellitecalloutsystemno:fiesoperatorsifunitshutsdown• Noexternalleakpointsforoilorgasseals• Automa:crestartifgridpowerislost• Capacitycontrol
– Compressorwilladjustcycleratetomatchflow– Upto100%turndown
HCGPerformance(USunits)HC613CompressorwithHPP-13EPowerpack
MaximumΔP:225psiDISCHARGEPRESSURE
SUCT
IONPRE
SSURE
75 100 125 150 175 200 225 250 275
5 38 37 35 34 33 32 31 10 49 48 47 45 44 43 42 15 61 59 58 56 55 54 53 20 72 70 69 68 66 65 64 30 95 93 91 90 88 87 86 84 40 118 116 114 112 111 109 108 106 50 140 139 137 135 133 132 130 129 127
*ProjectedPerformancebasedon2500k,gasdensity.665,temp68ºFPressuresinPSIFlowRatesinMSCFD
HC616CompressorwithHPP-13EPowerpackMaximumΔP:350psi DISCHARGEPRESSURE
SUCT
IONPRE
SSURE
200 225 250 275 300 325 350 375 400
5 20 19 19 18 17 16 16 10 27 26 26 25 24 23 23 15 34 33 32 32 31 30 29 20 41 40 39 39 38 37 36 30 55 54 54 53 52 51 50 49 40 70 69 68 67 66 65 64 63 50 84 83 82 81 80 79 78 77 76
HCGPerformance(metric)HC613CompressorwithHPP-13EPowerpack
MaximumΔP:1550kPaDISCHARGEPRESSURE
SUCT
IONPRE
SSURE
510 690 860 1035 1200 1380 1550 1720 1900 35 1.1 1.1 1.0 1.0 0.9 0.9 0.9 70 1.4 1.4 1.3 1.3 1.3 1.2 1.2 100 1.7 1.7 1.7 1.6 1.6 1.5 1.5 140 2.1 2.0 2.0 1.9 1.9 1.9 1.8 200 2.7 2.7 2.6 2.6 2.5 2.5 2.5 2.4 275 3.4 3.3 3.3 3.2 3.2 3.1 3.1 3.0 345 4.0 4.0 3.9 3.9 3.8 3.8 3.7 3.7 3.6
*ProjectedPerformancebasedon760m,gasdensity.665,temp20ºCPressuresinkPaFlowRatesin1000m3/day
HC616CompressorwithHPP-13EPowerpackMaximumΔP:2400kPa DISCHARGEPRESSURE
SUCT
IONPRE
SSURE
1380 1550 1720 1900 2070 2240 2400 2585 2760
35 0.6 0.6 0.6 0.5 0.5 0.5 0.5 0.5 0.570 0.8 0.8 0.8 0.7 0.7 0.7 0.7 0.7 0.7100 1.0 1.0 1.0 0.9 0.9 0.9 0.9 0.9 0.8140 1.2 1.2 1.2 1.1 1.1 1.1 1.1 1.1 1.0200 1.6 1.6 1.6 1.5 1.5 1.5 1.5 1.5 1.4275 2.0 2.0 2.0 2.0 1.9 1.9 1.9 1.9 1.8345 2.5 2.4 2.4 2.4 2.3 2.3 2.3 2.3 2.2
Shutdownsandwarnings
• ThePLCmanagesallaspectsofcompressoropera:on.Itwillprovidethefollowingalarms:– Lowsuc:onpressure– Highdischargepressure– Highdischargetemperature– Highoiltemperature– Lowoillevel– Capacityloss
• Aswellasshutdownsforthesecondi:ons:– Oillevellow– Oilleakdetected– Motoroverload– Failuretocycle
• Compressorwillsendamessageviasatellitetoindicateanalarmorshutdowncondi:on
CG25Sweet-StandardCCICompressorPackage
• 2stagereciproca:ng• 25hpelectric• 0-205kPa/0-30psiinlet• 690-2760kPa/100-400psi
discharge• Op:onalInletscrubberand
autodrainpump• Sweetnaturalgas
Compact Compression Inc. CG 25 Quincy QRNG 370 2 Stage Sweet
DISCHARGE PRESSURE
Su
cti
on
150 200 250 300 3505 85 83 81 79 77
10 108 106 104 102 10020 155 153 151 149 14730 199 197 195 193
*Performance based on Sea Level, gas density .65, temp 68 ºF Pressures in PSI
Flow Rates in MSCFD High Efficiency Intercooler required for flows in grey
Reciproca:ngcompressor
• Suc:onpressurefrom0-205kPa(0-30psi)• Dischargepressurefrom690-2760kPa(100-400psi)• Flowsupto5.5e3m3/day(200mscfd)• Sourcompa:blecompressorsavailable
Inletregulator
• Whenwellisshutin,casingpressurewillincreasetoshut-inpressure(canbe2060kPa/300+psi)
• Compressorcannotprocessgasabove206kPa/30psi• Inletregulatorreducesincominggaspressuretoatolerablelevelforthecompressor
LowPressureRecycleRegulator
• Compressorspeedcanneverbeperfectlymatchedtogasflow
• Recycleregulatorprovidessimpleandeffec:vecapacitycontrol,upto100%turndown(noflowintocompressor)
• Maintainsspecifiedminimumpressureoncasing(35-70kPa/5-10psi)
ShutdownSwitches
• Suc:onpressurelow– Ifrecycleregulatorfails,compressorwillpullvacuum,soitwillbeshutdownatspecifiedlowpressureoninlet
• Dischargepressurehigh– Ifcompressordischargeisblocked,itwillshutdownatspecifiedpressuretoprotectinternalcomponents
• Dischargetemperaturehigh– Compressorvalvessuscep:bletodamagefromoverhea:ng.Compressorwillshutdownbeforetemperaturesthatmaydamagevalvesarereached
• Compressoroilpressurelow– Ifcompressoroilpressureislow,compressorwillshutdowntoavoidrunningwithoutlubrica:on
InletScrubber
• Removesliquidsthathavecondensedoutofthegasstreamcomingintothecompressor
• Protectsthecompressorfrompossibleliquidslugsduetodepressionsortrapsintheplumbing
• Notalwaysnecessary–Inhotclimatestheremaybeveryli@lecondensa:onintheline,andiftherearenoliquidtrapstherewillbenobuildupofslugs
• Thecasingdoesmostofthejobofremovingliquidsentrainedinthegasstream
AutodrainPump
• Removesopera:onalrequirementofdailydrainingofinletscrubber,simplifiesdisposalofcondensate
• Pneuma:corelectricdriven• Pumpsliquidsoutofscrubberandintodischarge,willbecarriedintoflowlinewithgasdischarge
Intercooler
• Coolingisrequiredbetweenstagesofamul:-stagecompressor
• Coolingiscri:caltomaintainacceptablecylindertemperaturesinsecondstage
• Highperformanceintercoolerrecommendedforhotclimatesandhighpressurera:os
AkerCooler
• Coolsgasbeforeitleavesthecompressor• Onlyrequiredifthereareconcernswithelevatedtemperaturesatthesurface-176°C(350°F)max
• Hightempofgasdischargewillotherwisebeabsorbedbytheoiloftheflowline– 2e3m3ofnaturalgas@176°C(350°F)flowinginto400bbl/dayof30°C(86°F)crudeoil,willraisethetemperatureby0.37°C(0.67°F)
ShutdownInterlock
• Whencompressorshutsdowncasingpressurewillrise• Thisleadstoadropoffininflowtothewell• Itispossiblethatwhilethecompressorisshutoffthe
pumpjackcouldpumpitselfoff,damagingequipment• Usinganinterlocksothatbothcompressorandpumpjack
shutofftogetherwillpreventthis• Oncertainwellsthismaynotbeneeded,asimpleauto
bypassmaybesufficienttomaintainproduc:onun:lthecompressorcanberestarted
Recommended