Wettability Survey in Bakken Shale With Surfactant-Formulation Imbibition
- Dongmei Wang (University of North Dakota) | Raymond Butler (University of North Dakota) | Jin Zhang (University of North Dakota) | Randall Seright (New Mexico Tech PRRC)
- Document ID
- Society of Petroleum Engineers
- SPE Reservoir Evaluation & Engineering
- Publication Date
- December 2012
- Document Type
- Journal Paper
- 695 - 705
- 2012. Society of Petroleum Engineers
- 2.5.2 Fracturing Materials (Fluids, Proppant), 5.2 Reservoir Fluid Dynamics, 5.8.4 Shale Oil, 1.6.9 Coring, Fishing
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- 1,565 since 2007
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For ultratight shale reservoirs, wettability strongly affects fluid flow behavior. However, wettability can be modified by numerous complex interactions and the ambient environment, such as pH, temperature, or surfactant access. This paper is a third-phase study of the use of surfactant imbibition to increase oil recovery from Bakken shale. The surfactant formulations that we used in this paper are the initial results that are based on our previous study, in which a group of surfactant formulations was examined--balancing the temperature, pH, salinity, and divalent-cation content of aqueous fluids to increase oil production from shale with ultralow porosity and permeability in the Middle Member of the Bakken formation in the Williston basin of North Dakota. In our previous study, through the use of spontaneous imbibition, brines and surfactant solutions with different water compositions were examined. With oil from the Bakken formation, significant differences in recoveries were observed, depending on compositions and conditions. Cases were observed in which brine and surfactant (0.05 to 0.2 wt% concentration) imbibition yielded recovery values of 1.55 to 76% original oil in place (OOIP) at high salinity (150 to 300 g/L; 15 to 30 wt%) and temperatures ranging from 23 to 120°C. To advance this work, this paper determines the wettability of different parts of the Bakken formation. One goal of this research is to identify whether the wettability can be altered by means of surfactant formulations. The ultimate objective of this research is to determine the potential of surfactant formulations to imbibe into and displace oil from shale and to examine the viability of a field application. In this paper, through the use of modified Amott-Harvey tests, the wettability was determined for cores and slices from three wells at different portions of the Bakken formation. The tests were performed under reservoir conditions (90 to 120°C, 150- to 300-g/L formation-water salinity), with the use of Bakken crude oil. Both cleaned cores (cleaned by toluene/methanol) and untreated cores (sealed, native state) were investigated. Bakken shale cores were generally oil-wet or intermediate-wet (before introduction of the surfactant formulation). The four surfactant formulations that we tested consistently altered the wetting state of Bakken cores toward water-wet. These surfactants consistently imbibed to displace significantly more oil than brine alone. Four of the surfactant imbibition tests provided enhanced-oil-recovery [(EOR) vs. brine water imbibition alone] values of 6.8 to 10.2% OOIP, incremental over brine imbibition. Ten surfactant imbibition tests provided EOR values of 15.6 to 25.4% OOIP. Thus, imbibition of surfactant formulations appears to have a substantial potential to improve oil recovery from the Bakken formation. Positive results were generally observed with all four surfactants: amphoteric dimethyl amine oxide, nonionic ethoxylated alcohol, anionic internal olefin sulfonate, and anionic linear a-olefin sulfonate. From our work to date, no definitive correlation is evident in surfactant effectiveness vs. temperature, core porosity, core source (i.e., Upper Shale or the Middle Member), or core preservation (sealed) or cleaning before use.
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Abdallah, W., Buckley J.S., Carnegie, A., et al. 2007. Fundamentals ofWettability. Oilfield Review 19 (4): 44-61.
Adibhatla, B., Sun, X., Mohanty, K.K. 2005. Numerical Studies of OilProduction From Initially Oil-Wet Fracture Blocks by Surfactant BrineImbibition. Paper SPE 97687 presented at the SPE International Improved OilRecovery Conference in Asia Pacific, Kuala Lumpur, Malaysia, 5-6 December. http://dx.doi.org/10.2118/97687-MS.
Adibhatla, B., and Mohanty, K.K. 2006. Oil Recovery From FracturedCarbonates by Surfactant-Aided Gravity Drainage: Laboratory Experiments andMechanistic Simulations. Paper SPE 99773 presented at the SPE/DOE Symposium onImproved Oil Recovery, Tulsa, Oklahoma, April 22-26. http://dx.doi.org/10.2118/99773-MS.
Amott, E. 1959. Observations Relating to the Wettability of Porous Rock.Pet. Trans. AIME 219: 156-162.
Buckley, J.S., Liu, Y., Monsterleet, S. 1998. Mechanisms of WettingAlterations by Crude Oils. SPE J. 3 (1): 54-61. http://dx.doi.org/10.2118/37230-PA.
Dake, L.P. 1977. Fundamentals of Reservoir Engineering. Amsterdam:Elsevier Scientific Publishing Company.
Elijah, O., Carl, S., Chandra, R. 2011. An NMR Study on Shale Wettability.Paper SPE 147371 presented at the Canadian Unconventional Resources Conference,Calgary, Alberta, Canada, 15-17 November. http://dx.doi.org/10.2118/147371-MS.
Glover, P.W.J. 2001. Formulation Evaluation MSc Course Notes--Wettability.http://www2.ggl.ulaval.ca/personnel/paglover/CD%20Contents/Formation%20Evaluation%20English/Chapter%207.PDF.
Gupta R., Mohan K., Mohanty K.K. 2009. Surfactant Screening for WettabilityAlteration in Oil-Wet Fractured Carbonates. Paper SPE 124822 presented at theSPE Annual Technical Conference and Exhibition, New Orleans, Louisiana, 4-7October. http://dx.doi.org/10.2118/124822-MS.
Gupta, R., and Mohanty, K.K. 2007. Temperature Effects on Surfactant-AidedImbibition Into Fractured Carbonates. Paper SPE 110204 presented at the SPEAnnual Technical Conference and Exhibition, Anaheim, California, November11-14. http://dx.doi.org/10.2118/110204-MS.
Gupta, R., and Mohanty, K.K. 2008. Wettability Alteration of FracturedCarbonate Reservoirs. Paper SPE 113470 presented at the SPE/DOE Symposium onImproved Oil Recovery, Tulsa, Oklahoma, 20-23 April. http://dx.doi.org/10.2118/113407-MS.
Hamouda, A.A., and Karoussi, O. 2008. Effect of Temperature, Wettability andRelative Permeability. Energies 1: 19-34. http://dx.doi.org/10.3390/en1010019.
Hirasaki, G.J. 1991. Wettability, Fundamentals and Surface Forces. SPEForm Eval 6 (2): 217-226. http://dx.doi.org/10.2118/17367-PA.
Høgnesen, E.J., Strand, S., Austad, T. 2005. Waterflooding of PreferentialOil-Wet Carbonates: Oil Recovery Related to Reservoir Temperature and BrineComposition. Paper SPE 94166 presented at the SPE Europe/EAGE AnnualConference, 13-16 June, Madrid, Spain. http://dx.doi.org/10.2118/94166-MS.
Iampen, H.T., and Rostron, B.J. 2000. Hydrogeochemistry of Pre-MississippianBrines, Williston Basin, Canada-USA. J. Geochem. Exploitation 69-70: 29-35. http://dx.doi.org/10.1016/S0375-6742(00)00007-8.
LeFever, J., and Helms, L. 2010. Bakken Formation Reserves Estimates, reportprepared by the North Dakota Department of Mineral Resources, Bismarck, NorthDakota.
Pitman, J.K., Price, L.C., Lefever, J.A. 2001. Diagenesis and FractureDevelopment in the Bakken Formation, Williston Basin: Implications forReservoir Quality in the Middle Member, U.S. Geological Survey ProfessionalPaper 1653, 14-15. http://pubs.usgs.gov/pp/p1653.
Sharma G., and Mohanty, K.K. 2011. Wettability Alteration in HighTemperature and High Salinity Carbonate. Paper SPE 147306 presented at the SPEAnnual Technical Conference and Exhibition, Denver, Colorado, 31 October-2November. http://dx.doi.org/10.2118/147306-MS.
Shuler, P., Tang, H., Lu, Z., et al. 2011. Chemical Process for Improved OilRecovery From Bakken Shale. Paper SPE 147531 presented at the CanadianUnconventional Resources Conference held in Calgary, Calgary, Alberta, Canada,15-17 November. http://dx.doi.org/10.2118/147531-MS.
Wang, D.M, Butler, R., Liu, H., et al. 2011a. Surfactant Formulation Studyfor Bakken Shale Imbibition. Paper SPE 145510 presented at the SPE AnnualTechnical Conference and Exhibition, Denver, Colorado, 31 October-2 November.http://dx.doi.org/10.2118/145510-MS.
Wang, D.M., Butler, R., Liu, H., et al. 2011b. Flow Rate Behavior andImbibition in Shale. SPE Res Eval & Eng 14 (4):505-512. http://dx.doi.org/10.2118/138521-PA.
Xie, X., and Morrow, N.R. 2001. Oil Recovery by Spontaneous Imbibition byWeakly Water-Wet Rocks. Petrophysics 42 (4): 313-322.
Zhang, P., and Austad, T. 2005. Waterflooding in Chalk: Relationship betweenOil Recovery, New Wettability Index, Brine Composition and Cationic WettabilityModifier. Paper SPE 94209 presented at the SPE Europe/EAGE Annual Conference,Madrid, Spain, 13-16 June. http://dx.doi.org/10.2118/94209-MS.