Low gas-liquid ratio foam flooding for conventional heavy oil

Pet. Sci.(2011)8:335-344335Dol10.1007/s12182-011-0150-0Low gas-liquid ratio foam floodingfor conventional heavy oilWang Jing, Ge Jijiang", Zhang Guicai, Ding Baodong, Zhang Li andJin luchaoSchool of Petroleum Engineering, China University of Petroleum, Qingdao, Shandong 266555, ChinaC China University of Petroleum( Beijing) and Springer-Verlag Berlin Heidelberg 2011Abstract: The recovery of heavy oil by water flooding is 10% lower than that of conventional crude oilso enhanced oil recovery(EOR) is of great significance for heavy oil. In this paper, foam flooding with agas-liquid ratio(GLR) of 0. 2: 1 for the Zhuangxi heavy oil(325 mPas at 55C)was performed on corescand packs and plate model In sand pack tests, polymer enhanced foam flooding increased oil recoveryby 39.8%, which was 11.4% higher than that for alkali/surfactant/polymer(ASP)flooding under the sameconditions. Polymer enhanced foam flooding in plate models shows that the low GLR foam floodingincreased oil recovery by about 30%, even when the extended water flooding was finished at 90%watercut. Moreover, it was discovered by microscopy that foam was more stable in heavy oil than in light oilThese results confirm that low GLR foam flooding is a promising technology for displacing conventionalheavy oilKey word: Low gas-liquid ratio, foam flooding, enhanced oil recovery, conventional heavy oil1 IntroductionHowever, conventional foam flooding has twodisadvantages. The high cost of gas injection is the firstWater drive heavy oil reservoirs are characterized by obstacle. The gas-liquid ratio(GLR) of the conventionalloosely consolidated sand with well-developed flow channels. foam flooding is generally required to be 1: 1(Yuan et al,Moreover, much oil is bypassed because of the high mobility 2004; Lin and Yang, 2006; Zhou et al, 2006; Li et al, 2009:ratio between the displacing fluids and oil(Abrams, 1975; Ren et al, 2009; Tang, 2009; Zhang et al, 2009). AssumingAlbartamani et al, 1999; Miller, 2006; Wassmuth et al, that the reservoir pressure is 10 MPa, the GLR under surface2007: Mai et al, 2009; Aladasani and Bai, 2010 ). Generally conditions should be nearly as large as 100: 1. The productionspeaking, the recoveries of water flooding for these reservoirs cost of nitrogen is at least 1.5 Yuan(RMB)m(under standardare at least lower 10% than those for conventional oil conditions), and then 150 Yuan will be allocated for Im'reservoirs( Bryan et al, 2008). So it is more important to liquid displacing agent(about 50 Yuan). It can be seen thatimprove sweep efficiency than microscopic displacement the cost of gas injection is a considerable part of the total costefficiency for the enhanced oil recovery(EOR) techniques of foam flooding. The second problem is the high injectionsuitable for heavy oil reservoirspressure. Water-alternating-gas(WAG)injection is often usedFoam flooding as an EOR technique has been used for in field tests of foam flooding, nonetheless high injectionabout 50 years. Because foam has higher apparent viscosity pressure still remains. For example, in the pilot test ofthan the conventional displacing fluids, it is often used as a combined foam flooding in the Sabei North Block 2, Daqingmobility control agent in conventional reservoirs( Llave et al, Oilfield, the gas injection pressure was almost 10 MPa higher1990, Li et al, 2008; Farajzadeh et al, 2009; Srivastava et al, than that of water flooding( Chao, 2006), and the same2009). With the development of high temperature resistant phenomenon emerged in nitrogen enhanced foam floodingfoaming agents, foam is becoming the main profile control in well 28-8 drilled in the Gudao Middle Block 2, Shengliagent in thermal recovery. Previous research has proved that Oilfield( Zhang et al, 2005)foam can reduce the relative permeability of the injectedIn view of the above-mentioned disadvantages of thechemical slug, increase the sweep efficiency and displacement conventional foefficiency of the displacing system, and thus increase oil in terms of siH中国煤化工 LR foam floodingcer and gas can berecovery(Kang et al, 2010; Wang et al, 2001).carried out desCN\oD the laboratorystudies in China, the lowest GLR was 0. 4: 1(Yuan et al, 2004).Correspondingauthor.email:gej@upc.edu.cnand low Glr foam flooding was overlooked as most attentionReceived October 23, 2010had been paid on the evaluation of sealing characteristics andPet. Sci(2011)8:335-344oil displacement performance of high GLR foam. However, first consisted of 0. 2wt%DS and 0.5wt% Na, CO, the otherthe results of foam flooding field test in the Daqing Oilfield was composed of 0. 2wt%DS, 0.5wt% Na,CO,, and 0. Iwt%showed that though the real GLR was only 0.34: 1 (designed HPAM. The foam generated by the first foaming system isGLR is 1: 1 ), the oil recovery due to foam flood was still 25% called ordinary foam and the foam generated by the secondhigher than that due to water injection(Chao, 2006). This foaming system is named polymer enhanced foamresult confirms the feasibility of low GLR foam flooding in The basic parameters of cores and sand packs used inoilfieldsdisplacement tests are given in Table 3. Ten core samples,There is an amount of residual oil that is left in the each 15 cm long and 2.5 cm in diameter, were obtainedervoir after a water flooding program due to characteristics from the Geological Scientific Research Institute of Shengliof heavy oil reservoirs. Whether the residual oil can affect Oilfield. Three sand packs were prepared in linear sand packthe stability of foam or not is the key factor to successfully cells(30 cm long and 2.5 cm in diameter)using 80-100 meshimplement foam flooding in heavy oil reservoirs. Previous quartz sand. In the process of packing the cells, the quartzworks proved that oil had a strong destabilizing effect on sand was added in several increments. deionized water wasfoam. Some research(Suffridge et al, 1989; Schramm and used to moisten the sand and the cells were gently vibratedNovosada, 1990; Schramm et al, 1993; Vikingstad et al, 2006) to ensure a homogenous packing density. In this process, thefound that alkanes with lower molecular weight offered a water surface was kept above the sand surface to avoid themore adverse environment to foam wu et al (2008)evaluated entrapment of air. all the cores and sand packs are water wet.the interactions between foam and Daqing crude oil, andThe plate model is a homogeneous sand-packed modeldiscovered that the light oil containing less asphaltene and 30cmx30cmx6cm Fig. I is a schematic of the plate modelresin was more destructive to foam than heavy oil.The injection well 3 and the production well 2 were locatedIn this paper, the foam stability in the presence of at diagonally opposite corners of the model. Wells 1,5, anddifferent oils and the effect of low GLR foam flooding on 4 were only used in the process of saturating the model withthe Zhuangxi heavy oil are investigated. This provides some water or oil. The quartz sand used in this test was a mixtureguidance for the implementation of low GLR foam flooding of quartz sand 100 mesh and 80-100 mesh with a weight ratioin waterflooded heavy oil reservoirsof 3: 1 The plate model were prepared as follows: The platemodel was filled with the mixed sand and fixed then the2 Experimentalwater was injected from well 3 and produced from wells 1,2,2.1 Materialsand 4 in turn, until the production rate of the three productionwells was equal to the injection rate The basic parameters ofDS, a sulfonate surfactant synthesized in the laboratory, the plate model are listed in Table 3was used as a foamer. Partially hydrolyzed polyacrylamide(HPAM) with a molecular weight of 1, 400x10 was obtainedProduction wellfrom the Beijing Hengju Chemical Group Company. Na, CO3(analytical purity) was commercially availableThe oil was collected from well 106-15-18 drilled inthe Zhuangxi heavy oil reservoir, Shengli Oilfield and5its properties are listed in Table 1. The initial reservoir Injection welltemperature is 55C. The salinity and composition o4formation water collected from well 106-15-18 are shownin Table 2. Synthetic formation water was prepared with thereagent-grade chemicals based on the analysis of formationwater.All solutions used were prepared with the synthetic30cmformation water.Fig. 1 A schematic of the plate modelTable 1 Basic properties of the Zhuangxi heavy oil2.2 Evaluation of foaming systemsAcid number RAsphaltene2.2. 1 Foaming ability and foam stability measurementsmg KOH/ g oil%The Waring blender test was used to measure theproperties of the two foaming systems. The procedure of this09302329.70835test was as follows: 100 mL of foaming solution was pouredinto a l-liter Waring blender cup and stirred for exactly 1Table 2 Analysis of the formation brinminute at a speed of 2, 000 rpm, then the resulting foam wasimmediately transferred into a 1,000 mL graduated cylinder.几The initialtim1凵中国煤化s was recorded. TheNa ca?+half of its initialolume wasCNMHGfe1751.0103011.147423.760222501.050398352.2.2 Emulsification testsConsidering the characteristics of heavy oil, not onlyTwo foaming systems were used in the experiments. The good foaming capacity but also excellent emulsificationPet. Sci.(20l1)8:335-344Table 3 Basic parameters of cores/sand packs used in displacement tests: Run No. Porous medium Permeability to water Porosity Initial oil saturationChemical slugGLR DesignedslugPVcore86.20.l:1874Ordinary foam0.2:1234567Core55886.7Ordinary foam03:1Core25.68857Ordinary foamCore24.8787.6Core86.2Ordinary foaml111111Core55825.8285.3Ordinary foamCore85.0Ordinary foam0.2:1Core23.9287.102:19o1234Core836Ordinary foam02:139.17814Polymer enhanced foam 0. 2: 12058892Polymer enhanced foam 0. 2: 106199839lASP solutionPlate model43.l184.6Polymer enhanced foam 0. 2: 103capacity is required for a foaming system. This performance relationship between the volume of aqueous phase separatewas evaluated by the instability index(ISI). The procedure from the emulsion and the separation time of the emulsion.of this test is as follows: 5 mL foaming solution and 5 mL 2.2.3 Interfacial tension measurementscrude oil were poured into a graduated test tube (10 ml),The oil-water interfacial tensions(IFTs)were determinedthen the tube was sealed with a glass stopper and oscillated with a Texas-500 spinning drop interfacial tensionmeterup and down 50 times, then the tube was immediately put (USA). Equipped with an image capture device and imageinto a constant temperature water bath vertically and timing acquisition software, this instrument can automatically recordtarted. The volume in milliliters of aqueous phase separated the dynamic interfacial tension.from the test emulsion formed from the oil and foamingsolution was recorded every 2 minute for 30 minutes, curves 2.3 Physical simulation experimentsbetween aqueous phase and time were plotted and the IsISchematics of displacement tests in cores and plate modelwas calculated as followsre shown in Figs. 2 and 3, respectivelyA 201-FKASVBAA gas mass flow meter, produced byISI=[v(r)dr/t( Parker Hannififlow rate of gas accurately in the experiments. Its highestwhere ISI is the instability index, mL; t is the separation resistant pressure was 6 MPa and the flow-rate range wastime of the emulsion system, min; v(ois the functional 0-50 mL/min under standard conditionsT言1012中国煤化工CNMHGFig. 2 A schematic of displacement apparatus for the l-D physical modelI-Nitrogen cylinder, 2-Booster pump, 3-High-pressure nitrogen cylinder, 4-Gas mass flow control system, 5-Constant flow pump, 6-Thermostatic chamber, 7-oillinder,8-Water cylinder, 9-Foam generator, I0-Vent valve, 11-Core/sand pack holder, 12-Back pressure valve, 13-Fluid measuring system, 14-Hand pump38Pet. Sci(.20118:335-344菌Fig. 3 A schematic of displacement apparatus for the plate model1-Nitrogen cylinder, 2-Booster pump, 3-High-pressure nitrogen cylinder, 4-Gas mass flow control system, 5-Constant flow pump6-Thermostatic chamber, 7-oil cylinder, 8-Water cylinder, 9-Foam generator, 10-Vent valve, 11-Plate model, 12-Back pressure valve.13-Fluid measuring system, 14-Pressure acquisition system, 15-Hand pumpThe procedure of displacement tests is as follows: 1) the foam/oil interaction. This apparatus consisted of aThe core(or plate model)was saturated with synthesized glass etched micromodel with pore sizes of 50-800 um,aformation water at room temperature to determine its microscope, a digital video camera, a pressure transducer, arpermeability and pore volume; 2) The core was saturated with injection pump etc.oil at 55C to measure its initial oil saturation; 3)Synthetic Each experiment was conducted at 55C. a clean microformation water was pumped into the core to displace oil until model was first saturated with synthetic formation water, andthe water cut of produced fluids reached 98%; 4)A specified then saturated with the heavy oil. The oil displacement startedvolume of chemical flooding system was injected into the with the injection of foam and stopped when the foam was incore,and the synthetic formation water was subsequently full contact with oil. Meanwhile, video of interface betweenpumped into the core until the water cut of produced fluids foam and oil was recorded and the effect of crude oil on foamreached 98%. In foam flooding tests, this step was carried out stability was analyzedas follows: firstly aqueous surfactant solution and nitrogenwere added in a foam generator at a desired rate, and the vent 3 Results and discussionvalve was opened under certain back pressure until uniformfoam was generated; secondly the vent valve was closed and 3. 1 Performance of foaming systemsthe uniform foam was injected into the core to mobilize oil;and finally water was pumped to displace the oil until the The foaming performance and emulsification capacity ofwater cut of produced fluids reached 98%. 5) The oil recovery the two foaming systems used in the study are listed in Table 4and water cut during the displacement were calculated.In displacement tests, the injection rate of liquid was 1.0Table 4 Performance of the foaming systemsmL/min and the back pressure was fixed at 2 MPa unlessotherwise specifiedFoaming performancecapacityIn foam flooding tests, the liquid flow rate was keptFoaming systemFoam volume half-lifeconstant and it is necessary to convert the gas flow rate underLstandard conditions into the value at the inlet pressure. The0.2wt% DS+O 5wt% Na,CO,gas-liquid ratio( GLR) during the experiments is calculated asfollows:0. 2wt DS+0.Swt% Na, CO,600b=47The foaming performance of the two foaming systemswhere g is the gas fow rate under standard conditions, mL/ shows that a more stable foam can be achieved by using0. lwt% HPmin;g, is the liquid flow rate, mL/min; P is the inlet pressuincreased the中国煤化工 addition oMPaThe drainagHHCNMHGeased and the rate of2.4 Microscopic oil displacement experimentsthe gas diffusion between bubbles was reduced( Shen et al2006Fig. 4 shows the experimental set-up used to visualizOil displacement system with a low instability index canPet, Sc(201)8335-344generatorqueousDigital videoNitrogenof foamMicromodelLight sourceInjecFig. 4 A schematic of the micromodel apparatusemulsify oil easily, so the oil remained in the swept area will 3.2 Stability of foam in heavy oilbe flooded out. The ISi of the emulsions generated from thefoaming systems and Zhuangxi heavy oil were zero. ThisTaking 0.2wt% DS+O 5wt% Na2 CO +0. lwt%HPAM asresult indicates that both foaming systems exhibited good the foaming system, this paper presents a microscopic studyemulsification performanceof foam stability in different oils, as shown in Figs. 6 and 7To examine the interaction of alkali and surfactantIt is discovered that the foam stability and the way of bubblesthe dynamic interfacial tensions of heavy oil and brine coalescing in heavy oil are completely different from those inwere measured for systems containing 0.2wt% Ds, diesel oil0.2wt% DS+0.5wt% Na2 CO,, and 0. 2wt% DS+0. 5wt%igs. 6 and 7 show that the foam is much more stableNa2 CO,+0.Iwt% HPAM. Fig. 5 shows the interfacial in heavy oil than in diesel oil. The time required for threesizable bubbles to coalesce to a large bubble in heavy oil wastensions between the Zhuangxi heavy oil and three aqueous four times longer than that in diesel oil. That is because thedynamic interfacial tension was reduced by nearly one order asphaltene and resin molecules in heavy oil are much largerof magnitude with the addition of 0. 5wt% Na, CO,. Thispenetrate into micellar aggregates that deplete surfactantindicates that alkali had a synergistic effect with surfactant on molecules from the gas/liquid interface while the heavy oillowering interfacial tension. Although the addition of HPAMled to an increase in the interfacial tension of oil and brine, is less likely to enter aggregates due to large asphaltene andinterfacial tension could be still reduced to the order of 10i resin molecules in it.The way of bubbles coalescing in heavy oil is that smallbubbles become smaller and big bubbles become bigger untilthe smaller ones disappear completely. However, bubblesin diesel mainly undergo rapid pairwise coalescence, the0.2wt% DS0.2wt% DS+0. 5wt%Na comechanism of which is difficult to distinguish.0.2wt% DS+0.5wt% Na co+0. 1wt% HPAM3.3 Core and sand pack displacement tests3.3.1 The effect of GLRIn order to evaluate the effect of gas-liquid ratio on therecovery efficiency of foam injected into the core, seven foamdisplacement tests( Runs 1 to 7 in Table 3)were performed on,cores at different gas-liquid ratios(ranging from 0.1: I to 2: 1)Fig. 8 shows the core inlet pressure for Run 2. It can be seenthat the pressure rose gradually after foam injection. Thisindicates that most of the foam went into and then effectivelyplugged the wiThe injection ral中国煤化工 water floodingand gas were keptconstant in theCNMHGtion. The ratio ofFig. 5 Dynamic interfacial tension between aqueous solutionsgas to liquid was set to be 0. 2: I based on the inlet pressureand zhuangxi heavy oil (at 55C)at the end of water flooding. Therefore, the real gas-liquidratio(calculated from Eq (2)in the porous media decreasedPet. Sci.(2011)8:335-344e00:042200:06:01Diesel oil00:22:0600:2227Fig. 6 Bubble coalescence in diesel oil00:40:5000:3042▲01:16:001:24:27TH中国煤化工CNMHGFig. 7 Bubble coalescence in heavy oilet. Sci.(2011)8:335-34341with the increase of the injection pressure and may be far less 3.3.2 The efifect of slug sizethan 0. 2. However, the oil production curve(Fig. 9)indicatesMaintaining the GLR at 0. 2: 1, the effect of foam slugthat the oil recovery increased by 26.2% and the water cut size was evaluated. Taking 0.2wt%DS+O5wt% Na2CO3 asdecreased by 28% after foam flooding. This result confirms the foaming system, the slug size was varied from 0.2 porethat although the real gas-liquid ratio was lower than 0. 2: 1, volume(Pv) in Run 8, to 0.4 PV in Run 9, to 0.6 PV in Runthe effect of foam flooding on oil recovery is obvious.10, and to 1.0 PV in Run 2. Taking 0. 2wt% DS+o 5wt%Na, CO +0. 1wt% HPAM as the foaming system, the slugsize was varied from 0.3 PV in Run 11, to 0.6 PV in Run 12(see Table 3). The results of these core flood tests are listedin Table 5. Table 5 indicates that a large slug size leaded to a0.22put pressurehigh oil recovery increment. The polymer enhanced foam had0.21better displacement efficiency than the foam system withoutr019ing polymer. Polymer enhanced foam flooding achieved a0.180.17m. L2sg high oil recovery increment even using a small foam slugAn alkali/surfactant/polymer(ASP) flood (0. 2wt%DS+O lwt% HPAM+0.5wt% Na, CO3)test was conducted0.15and its result was compared with the results from polymer0.13Real GLRenhanced foam flood test. Figs. 12 and 13 show that the0.12polymer enhanced foam improved oil recovery by about39.8% while the ASP flood improved oil recovery by02468101214161820about 28.4%. The oil recovery increment of foam floodingFoam injection time, minFig. 8 The change of real GLR and inlet pressureduring foam injection( designed GLR was 0. 2: 1)Water floodingExtended water flooding r 12010一 Oil recoveryGLR0.1:1GLR 0.2:4-Pressure drop +60一GLR03:1GLR 0. 4: 1GLR0.5:1GLR 10:1GLR 20:1Foam flooding01.17PvVolume of produced water, PVVolume of produced fluid, PVFig. 10 Cumulative oil recovery curves of foamflooding with different GLRs(IPVFIg. 9 oil production curves of foam floodinwith GLR of 0. 2: 1(1.17 pore volumes(PV)The oil production curves of seven core displacementtests( Fig. 10)shows that the oil recovery increased rapidlywith the injection of foam after water flooding. The recoveryincrement becomes higher with the increase in the gas-liquid528The curves of tertiary oil recovery versus GLR forthese seven flooding tests are plotted in Fig. 11. It showsthat when the gLR was below 0.5: 1, the oil recovery 8 20increased drastically with the increase in GLR. When theGLR was above 1: 1, the increase in GLR only resulted in 346a small incremental recovery. This is because when theV中国煤化工GLR increased from 0. 1: 1 to 0.5: 1, more bubbles would begenerated in the porous media leading to stronger blockingCNMHG 16effect. However, when the glr continued to increase, the gasGas liquid ratiobreakthrough occurred, and the EOR effect of foam floodingFIg. 11 Effect of gas-liquid ratio on oil recovery incrementbecame poorof foam flooding(1 Pv)342Pet. Sci(201)8:335-344Table 5 The effect of foam injection volume on oil displacement efficiencyChemical slugReal GLRSlug size Oil recovery in water Oil recoveryflooding operation,after water flooding,02:10.16:144.4313.90.2:1-0.15:10.21:1-0.12:118.10.22:10.13:1400.23:1-0.17:10.342.98Polymer enhanced foam0.22:1-0.16:10.641.76Water flooding Extended water floodiWater floodingExtended water flooding8≥9880一·- Water cut一·一 Oil recovery. - Water cutfoam, 0.32 PVFoam flooding, 0.3 PVVolume of produced fluid, PVVolume of produced fluid, PVFig. 12 Oil production curves of polymer enhanced foam floodingwith GLR of 0. 2: 1 (0.32 PV)FIg. 14 Oil production curves of polymer enhancedfoam flooding with GLR of 0. 2: 1(0.3 PV)Water floodExtended water flooding203P2.18PV100causes a extrusion and entrainment effect on the residual!2moil, which enhance the displacement efficiency of the foamflooding further. This demonstrates a great potential of lowa-Ou recoveryg GLR foam flooding for the ZhPressure drop3. 4 Foam flooding in plate models∴屬A sand pack can be regarded as a one-dimensional model8 To verify the capability of low GLR foam to improve sweepefficiency, a physical simulation was further carried out inASP combinatioystem, 0.31 PVplate models with polymer enhanced foam(theoretical GLRwas 0. 2: 1, foam slug was 0.3 PV).Fig. 14 is the oil production curve when water and gasVolume of produced fiuid, Pvwere injected simultaneously. It indicates that after waterflooding, the low Glr foam would significantly reduce theFig. 13 Oil production curves of ASP flooding(0.31Pv)water cut of produced fluids and improve oil recovery bywas 11.4%higher than the latter. Compared with the ASPFigs 15-17 show the oil distribution in different sectionsflood, the polymer enhanced foam has a better plugging of the sand pack at the end of subsequent water injectioncapacity due to its higher apparent viscosity and higher foam These figuresstability. Moreover, our previous study of the microscopic model was mYH中国煤化 at the bottom of theoil displacement mechanism of foam flood and ASP flood for to the gravitCNMH Gh sides of the mainheavy oil(Pei et al, 2010)shows that polymer enhanced foam diagonal line where the injection and production wells wereflooding achieves a higher sweep efficiency due to the Jamin located had low oil saturation, but there were much remainingeffect, and the deformation of foam in the porous medium oil on both sides of the other diagonal line. The test wasPet. Sci.(2011)8335-344343finished when the water cut was 90%, and the oil recoveryProduction wellincrement was about 30%. It can be seen from these figures,continuing water injection would improve oil recoveryfurther4 Conclusions1) For the Zhuangxi heavy oil (325 mPas at 55C), foamdisplacement tests show that the incremental oil recove(a became higher with the increase in gas-liquid ratio(GLR)When the gLr was above 0.5: 1, its increase only resulted ina small incremental oil recovery.2)Sand pack tests indicate that polymer enhanced foamflooding with a GLR of 0. 2: 1red the oil39.8%, which is 11% higher than that of ASP flooding underthe same conditionsFig. 15 Oil distribution on the bottom of the sand pack3)Polymer enhanced foam flooding with a glr of0. 2: 1 in the plate model shows that there is gravitationaldifferentiation in the model during flooding. Although the②extended water flooding ended when the water cut was 90%the low GLR foam flooding improved oil recovery by about4) Microscopic visualization experiments show that foamin the heavy oil is much stable than in light oil, and the waybubbles coalesce in the heavy oil is different from that ino( diesel oilAcknowledgementsThe authors are grateful for financial support from theInnovation Team Program and New Century Excellent TalentsAwards Program, the Ministry of Education of China, andFok Ying Tung Education FoundationReferencesAbrams A. The influence of fluid viscosity, interfacial tension, and flowFIg. 16 Oil distribution on the section about 1 crvelocity on residual oil saturation left by waterflood. SPE Jourmalfrom the bottom of the sand pack1975.15(5):437-447( Paper SPE5050-PA)Aladasani A and Bai B J. Recent developments and updated screeningcriteria of enhanced oil recovery techniques. 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