Alkaline/Surfactant/Polymer Chemical Flooding Without the Need for Soft Water

Authors
Adam K. Flaaten (University of Texas at Austin) | Quoc P. Nguyen (University of Texas at Austin) | Jieyuan Zhang (Tiorco LLC) | Hourshad Mohammadi (University of Texas at Austin) | Gary A. Pope (University of Texas at Austin)
DOI
http://dx.doi.org/10.2118/116754-PA
Document ID
SPE-116754-PA
Publisher
Society of Petroleum Engineers
Source
SPE Journal
Volume
15
Issue
01
Publication Date
March 2010
Document Type
Journal Paper
Pages
184 - 196
Language
English
ISSN
1086-055X
Copyright
2010. Society of Petroleum Engineers
Disciplines
6.5.1 Simulator Development, 6.4.6 Chemical Flooding Methods (e.g., Polymer, Solvent, Nitrogen, Immiscible CO2, Surfactant, Vapex)
Keywords
metaborate, microemulsion, oil mobilization, high salinity, surfactant
Downloads
18 in the last 30 days
2,203 since 2007
Show more detail
SPE Member Price: USD 10.00
SPE Non-Member Price: USD 30.00
View rights & permissions

Summary

Alkaline/surfactant/polymer (ASP) flooding using conventional alkali requires soft water. However, soft water is not always available, and softening hard brines may be very costly or infeasible in many cases depending on the location, the brine composition, and other factors. For instance, conventional ASP uses sodium carbonate to reduce the adsorption of the surfactant and generate soap in-situ by reacting with acidic crude oils; however, calcium carbonate precipitates unless the brine is soft. A form of borax known as metaborate has been found to sequester divalent cations such as Ca++ and prevent precipitation. This approach has been combined with the screening and selection of surfactant formulations that will perform well with brines having high salinity and hardness. We demonstrate this approach by combining high-performance, low-cost surfactants with cosurfactants that tolerate high salinity and hardness and with metaborate that can tolerate hardness as well. Chemical formulations containing surfactants and alkali in hard brine were screened for performance and tolerance using microemulsion phase-behavior experiments and crude at reservoir temperature. A formulation was found that, with an optimum salinity of 120,000 ppm total dissolved solids (TDS), 6,600 ppm divalent cations, performed well in corefloods with high oil recovery and almost zero final chemical flood residual oil saturation. Additionally, chemical formulations containing sodium metaborate and hard brine gave nearly 100% oil recovery with no indication of precipitate formation. Metaborate chemistry was incorporated into a mechanistic, compositional chemical flooding simulator, and the simulator was then used to model the corefloods. Overall, novel ASP with metaborate performed comparably to conventional ASP using sodium carbonate in soft water, demonstrating advancements in ASP adaptation to hard, saline reservoirs without the need for soft brine, which increases the number of oil reservoirs that are candidates for enhanced oil recovery using ASP flooding.

Introduction

This paper describes a laboratory and modeling approach to ASP flooding in reservoirs containing very hard, saline brines without the need for soft brine. Our target reservoir is a low temperature (52°C), light oil (45°API) sandstone reservoir containing hard, saline formation brine with 157,000 mg/L TDS of salinity, of which 8600 mg/L are Ca++ and Mg++. Our objective was to design an ASP slug to use as much of the formation brine as possible and eliminate the need for soft water. We show that a novel alkali, sodium metaborate, can provide tolerance to high divalent cation concentrations that the conventional alkali sodium carbonate cannot. Our laboratory approach uses quick, inexpensive microemulsion phase-behavior experiments to screen chemical formulations for both performance and tolerance to salinity and hardness. Well performing formulations are validated in coreflood experiments for good oil recovery, low pressure gradient, and low surfactant retention using prepared Berea sandstone cores saturated with very hard, saline brine at residual oil saturation.

File Size   964 KBNumber of Pages   13
References 1 

References

Anderson, J.L., Eyring, E.M., and Whittaker, M.P. 1964. Temperature Jump Rate Studies ofPolyborate Formation in Aqueous Boric Acid. The Journal of PhysicalChemistry  68 (5): 1128-1132. doi: 10.1021/j100787a027.

Aoudia, M., Wade, W.H., and Weerasooriya, V. 1995. Optimum microemulsionsformulated with propoxylated tridecyl alcohol sodium sulfates. Journalof Dispersion Science and Technology  16 (2): 115-135. doi:10.1080/01932699508943664.

Austad, T. and Milter, J. 2000. Surfactant Flooding in Enhanced OilRecovery. In Surfactants: Fundamentals and Applications in the PetroleumIndustry, ed. L.L. Schramm, Chap. 6, 203-249. Cambridge, UK: CambridgeUniversity Press.

Bhuyan, D. 1989. Development of an Alkaline/Surfactant/Polymer CompositionalReservoir Simulator. PhD dissertation, University of Texas, Austin, Texas(December 1989).

Bhuyan, D., Lake, L.W., and Pope, G.A. 1990. Mathematical Modeling of High-pHChemical Flooding. SPE J.  5 (2): 213-220. SPE-17398-PA.doi: 10.2118/17398-PA.

Bhuyan, D., Lake, L.W., and Pope, G.A. 1991. Simulation of High-pH CorefloodExperiments Using a Compositional Chemical Flood Simulator. Paper SPE 21029presented at the SPE International Symposium on Oilfield Chemistry, Anaheim,California, USA, 20-22 February. doi: 10.2118/21029-MS.

Bourrel, M. and Schechter, R.S. 1988. Microemulsions and Related Systems:Formulation, Solvency, and Physical Properties, Vol. 30. New York:Surfactant Science Series, Marcel Dekker.

Camilleri, D., Engelson, S., Lake, L.W., Lin, E.C., Ohnos, T., Pope, G.A.,and Sepehrnoori, K. 1987. Description of an ImprovedCompositional Micellar/Polymer Simulator. SPE Res Eng  2(4): 427-432; Trans., AIME, 283. SPE-13967-PA. doi:10.2118/13967-PA.

Delshad, M. and Pope, G.A. 1989. Comparison of the three-phase oil relativepermeability models. Transport in Porous Media  4 (1):59-83.

Delshad, M., Delshad, M., Bhuyan, D., Pope, G.A., and Lake, L.W. 1986. Effect of Capillary Number on theResidual Saturation of a Three-Phase Micellar Solution. Paper SPE 14911presented at the SPE Enhanced Oil Recovery Symposium, Tulsa, 20-23 April. doi:10.2118/14911-MS.

Delshad, M., Delshad, M., Pope, G.A., and Lake, L.W. 1987. Two- and Three-Phase RelativePermeabilities of Micellar Fluids. SPE Form Eval  2 (3):327-337; Trans., AIME, 283. SPE-13581-PA. doi:10.2118/13581-PA.

Delshad, M., Pope, G.A., and Sepehrnoori, K. 1996. A compositional simulatorfor modeling surfactant enhanced aquifer remediation, 1 formulation. J.Contamin. Hydrol.  23 (4): 303-327.doi:10.1016/0169-7722(95)00106-9.

Falls, A.H., Thigpen, D.R., Nelson, R.C., Ciaston, J.W., Lawson, J.B., Good,P.A., Ueber, R.C., and Shahin, G.T.1994. Field Test of Cosurfactant-EnhancedAlkaline Flooding. SPE Res Eng  9 (3): 217-223.SPE-24117-PA. doi: 10.2118/24117-PA.

Emeleus, H.J. and Sharpe, A.G. 1982. Advances in Inorganic Chemistry andRadiochemistry, Vol. 26, 229. New York: Academic Press.

Flaaten, A.K, Zhang, J., Nguyen, Q.P., and Pope, G.A. 2008. A Systematic Laboratory Approach toLow-Cost, High-Performance Chemical Flooding. Paper SPE 113469 presented atthe SPE/DOE Symposium on Improved Oil Recovery, Tulsa, 20-23 April. doi:10.2118/113469-MS.

Flaaten, A.K. 2007. Experimental Study of Microemulsion Characterization andOptimization in Enhanced Oil Recovery: A Design Approach for Reservoirs withHigh Salinity and Hardness. MS thesis, The University of Texas at Austin,Austin, Texas (December 2007).

Green, D.W. and Willhite, G.P. 1998. Enhanced Oil Recovery. TextbookSeries, SPE, Richardson, Texas 6.

Healy, R.N., Reed, R.L., and Stenmark, D.K. 1976. Multiphase Microemulsion Systems.SPE J.  16 (3): 147-160; Trans., AIME, 261.SPE-5565-PA. doi: 10.2118/5565-PA.

Hirasaki, G.J. 1982. IonExchange With Clays in the Presence of Surfactant. SPE J. 22 (2): 181-192. SPE-9279-PA. doi: 10.2118/9279-PA.

Hirasaki, G.J., Miller C.A., Pope, G.A., and Jackson, R.E. 2004. SurfactantBased Enhanced Oil Recovery and Foam Mobility Control. 1st Annual TechnicalReport (July 2003-June 2004), Contract No. DE-FC26-03NT15406, US DOE,Washington, DC (July 2004).

Hirasaki, G.J., van Domselaar, H.R., and Nelson, R.C. 1983. Evaluation of the Salinity GradientConcept in Surfactant Flooding. SPE J.  23 (3): 486-500.SPE-8825-PA. doi: 10.2118/8825-PA.

Ingri, N. 1963. Equilibrium studies of polyanions containing BIII, SiIV,GeIV and VV. Svensk Kemisk Tidskrift  75: 199.

Jackson, A.C. 2006. Experimental Study of the Benefits of Sodium Carbonateon Surfactants for Enhanced Oil Recovery. MS thesis, The University of Texas atAustin, Austin, Texas (December 2006).

Jin, M., Delshad, M., Dwarakanath, V., McKinney, D.C., Pope, G.A.,Sepehrnoori, K., Tilburg, C.E., and Jackson, R.E. 1995. Partitioning Tracer Test forDetection, Estimation, and Remediation Performance Assessment of SubsurfaceNonaqueous Phase Liquids. Water Resour. Res.  31 (5):1201-1211. doi: 10.1029/95WR00174.

Labrid, J. 1991. The Use of Alkali Agents in Enhanced Oil RecoveryProcesses, Vol. 33. Rueil-Malmaison, France: Critical Reports on AppliedChemistry, IFP.

Lake, L.W. 1989. Enhanced Oil Recovery. Englewood Cliffs, New Jersey:Prentice Hall.

Levitt, D. 2006. Experimental evaluation of high performance EOR surfactantsfor a dolomite reservoir. MS thesis, University of Texas at Austin, Austin,Texas.

Levitt, D.B., Jackson, A.C., Heinson, C., Britton, L.N., Malik, T.,Dwarakanath, V., and Pope, G.E. 2006. Identification and Evaluation ofHigh-Performance EOR Surfactants. Paper SPE 100089 presented at SPE/DOESymposium on Improved Oil Recovery, Tulsa, 22-26 April. doi:10.2118/100089-MS.

Liu, S., Zhang, D.L., Yan, W., Puerto, M., Hirasaki, G.J., and Miller, C.A.2008. Favorable Attributes ofAlkali-Surfactant-Polymer Flooding. SPE J.  13 (1):5-16. SPE-99744-PA. doi: 10.2118/99744-PA.

Mohammadi, H. 2008. Mechanistic Modeling, Design, and Optimization ofAlkaline/Surfactant/Polymer Flooding. PhD dissertation, The University of Texasat Austin, Austin, Texas (August 2008).

Nelson, R.C. and Pope, G.A. 1978. Phase Relationships in ChemicalFlooding. SPE J.  18 (5): 325-338; Trans., AIME,265. SPE-6773-PA. doi: 10.2118/6773-PA.

Nelson, R.C., Lawson, J.B., Thigpen, D.R., and Stegemeier, G.L. 1984. Cosurfactant-Enhanced AlkalineFlooding. Paper SPE 12672 presented at the SPE Enhanced Oil RecoverySymposium, Tulsa, 15-18 April. doi: 10.2118/12672-MS.

Pope, G.A., Tsaur, K., Schechter, R.S., Wang, B. 1982. The Effect of Several Polymers on thePhase Behavior of Micellar Fluids. SPE J.  22 (6):816-830. SPE-8826-PA. doi: 10.2118/8826-PA.

Pope, G.A., Wang, B., and Tsaur, K. 1979. A Sensitivity Study ofMicellar/Polymer Flooding. SPE J.  19 (6): 357-368.SPE-7079-PA. doi: 10.2118/7079-PA.

Prouvost, L., Satoh, T., Sepehrnoori, K., and Pope, G.A. 1984. A New Micellar Phase-Behavior Modelfor Simulating Systems With Up to Three Amphiphilic Species. Paper SPE13031 presented at the SPE Annual Technical Conference and Exhibition, Houston,16-19 September. doi: 10.2118/13031-MS.

Saad, N. and Sepehrnoori, K. 1989. Simulation of Big Muddy SurfactantPilot. SPE Res Eng  4 (1): 24-34; Trans., AIME,287. SPE-17549-PA. doi: 10.2118/17549-PA.

Sanz, C.A. and Pope, G.A. 1995. Alcohol-Free Chemical Flooding: FromSurfactant Screening to Coreflood Design. Paper SPE 28956 presented at theSPE International Symposium on Oilfield Chemistry, San Antonio, Texas, USA,14-17 February. doi: 10.2118/28956-MS.

Satoh, T. 1984. Treatment of Phase Behavior and Associated Properties Usedin a Micellar-Polymer Flood Simulator. MS thesis, The University of Texas atAustin, Austin, Texas (August 1984).

Winsor, P.A. 1954. Solvent Properties of Amphiphilic Compounds.London: Butterworth's Scientific Publications.

Wreath, D., Pope, G.A., and Sepehrnoori, K. 1990. Dependence of PolymerApparent Viscosity on the Permeable Media and Flow Conditions. In Situ 14 (3): 263-283.

Wreath, D.G. 1989. A Study of Polymer Flooding and Residual Oil Saturation.MS thesis, The University of Texas at Austin, Austin, Texas.

Zhang, J., Nguyen, Q.P., Flaaten, A.K., and Pope, G.A. 2008. Mechanisms of Enhanced NaturalImbibition with Novel Chemicals. Paper SPE 113453 to be presented at theSPE/DOE Symposium on Improved Oil Recovery, Tulsa, 20-23 April. doi:10.2118/113453-MS.