Water Leakoff During Gel Placement in Fractures: Extension to Oil-Saturated Porous Media
- Bergit Brattekås (The National IOR Centre of Norway and University of Stavanger) | Randall Seright (New Mexico Tech) | Geir Ersland (University of Bergen)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- May 2020
- Document Type
- Journal Paper
- 202 - 213
- 2020.Society of Petroleum Engineers
- leakoff, filter-cake, multiphase flow, polymer gel, conformance
- 8 in the last 30 days
- 188 since 2007
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Crosslinked polymers extrude through fractures during placement of many conformance-improvement treatments, as well as during hydraulic fracturing. Dehydration of polymer gel during extrusion through fractures has often been observed and was extensively investigated during recent decades. Injection of highly viscous gel increases the pressure in a fracture, which promotes gel dehydration by fluid leakoff into the adjacent matrix. The present comprehension of gel behavior dictates that the rate of fluid leakoff will be controlled by the gel and fracture properties and, to a lesser extent, be affected by the properties of an adjacent porous medium. However, several experimental results, presented in this work, indicate that fluid leakoff deviates from expected behavior when oil is present in the fracture-adjacent matrix. We investigated fluid leakoff from chromium (Cr)(III)-acetate hydrolyzed polyacrylamide (HPAM) gels during extrusion through oil-saturated, fractured core plugs. The matrix properties were varied to evaluate the effect of pore size, permeability, and heterogeneity on gel dehydration and leakoff rate. A deviating leakoff behavior during gel propagation through fractured, oil-saturated core plugs was observed, associated with the formation of a capillary driven displacement front in the matrix. Magnetic resonance imaging (MRI) was used to monitor water leakoff in a fractured, oil-saturated, carbonate core plug and verified the position and existence of a stable displacement front. The use of MRI also identified the presence of wormholes in the gel, during and after gel placement, which supports gel behavior similar to the previously proposed Seright filter-cake model. An explanation is offered for when the matrix affects gel dehydration and is supported by imaging. Our results show that the properties of a reservoir rock might affect gel dehydration, which, in turn, strongly affects the depth of gel penetration into a fracture network and the gel strength during chase floods.
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Andersen, P. Ø., Lohne, A., Stavland, A. et al. 2018. Core Scale Simulation of Spontaneous Solvent Imbibition From HPAM Gel. Presented at the SPE Improved Oil Recovery Conference, Tulsa, 14–18 April. SPE-190189-MS. https://doi.org/10.2118/190189-MS.
Barati, R., Hutchins, R., Friedel, T. et al. 2009. Fracture Impact of Yield Stress and Fracture-Face Damage on Production With a Three-Phase 2D Model. SPE Prod & Oper 24 (2): 336–345. SPE-111457-PA. https://doi.org/10.2118/111457-PA.
Brattekås, B. and Fernø, M. A. 2016. New Insight From Visualization of Mobility Control for Enhanced Oil Recovery Using Polymer Gels and Foams. In Chemical Enhanced Oil Recovery (cEOR)—A Practical Overview, ed. L. Romero-Zêron, Chap. 3, 101–121. London, UK: InTechOpen. https://doi.org/10.5772/61394.
Brattekås, B., Graue, A., and Seright, R. S. 2016. Low-Salinity Chase Waterfloods Improve Performance of Cr(III)-Acetate Hydrolyzed Polyacrylamide Gel in Fractured Cores. SPE Res Eval & Eng 19 (02): 331–339. SPE-173749-PA. https://doi.org/10.2118/173749-PA.
Brattekås, B., Haugen, Å ., Ersland, G. et al. 2013. Fracture Mobility Control by Polymer Gel—Integrated EOR in Fractured, Oil-Wet Carbonate Rocks. Presented at the EAGE Annual Conference & Exhibition Incorporating SPE Europec, London, 10–13 June. SPE-164906-MS. https://doi.org/10.2118/164906-MS.
Brattekås, B., Haugen, Å ., Graue, A. et al. 2014. Gel Dehydration by Spontaneous Imbibition of Brine From Aged Polymer Gel. SPE J. 19 (1): 122–134. SPE-153118-PA. https://doi.org/10.2118/153118-PA.
Brattekås, B., Pedersen, S. G., Nistov, H. T. et al. 2015. Washout of Cr(III)-Acetate-HPAM Gels From Fractures: Effect of Gel State During Placement. SPE Prod & Oper 30 (2): 99–109. SPE-169064-PA. https://doi.org/10.2118/169064-PA.
Ekdale, A. A. and Bromley, R. G. 1993. Trace Fossils and Ichnofabric in the Kjølby Gaard Marl, Uppermost Cretaceous, Denmark. Bull Geol Soc Denmark 31: 107–119.
Haugen, Å ., Fernø, M. A., and Graue, A. 2008. Numerical Simulation and Sensitivity Analysis of In Situ Fluid Flow in MRI Laboratory Waterfloods of Fractured Carbonate Rocks at Different Wettabilities. Presented at the SPE Annual Technical Conference and Exhibition, Denver, 21–24 September. SPE-116145-MS. https://doi.org/10.2118/116145-MS.
Hild, G. P. and Wackowski, R. K. 1999. Reservoir Polymer Gel Treatments To Improve Miscible CO2 Flood. SPE Res Eval & Eng 2 (2): 196–204. SPE-56008-PA. https://doi.org/10.2118/56008-PA.
Hjuler, M. L. and Fabricius, I. L. 2007. Diagenesis of Upper Cretaceous Onshore and Offshore Chalk from the North Sea Area. PhD thesis, Kgs. Lyngby: DTU Environment, Denmark (August 2007).
Howard, G. C. and Fast, C. R. 1957. Optimum Fluid Characteristics for Fracture Extension. Drill & Prod Prac. (1 January): 261–270. API-57-261.
Howard, G. C. and Fast, C. R. 1970. Hydraulic Fracturing. Richardson, Texas: Monograph Series, Society of Petroleum Engineers.
Johannesen, E. B. 2008. NMR Characterization of Wettability and How it Impacts Oil Recovery in Chalk. PhD thesis. Dept. of Physics and Technology, University of Bergen, Norway (May 2008).
Kantzas, A., Allsopp, K., and Marentette, D. 1999. Utilization of Polymer Gels, Polymer Enhanced Foams, and Foamed Gels for Improving Reservoir Conformance. J Can Pet Technol 38 (13): 1–8. PETSOC-99-13-58. https://doi.org/10.2118/99-13-58.
Klein, E. and Reuschle, T. 2003. A Model for the Mechanical Behaviour of Bentheim Sandstone in the Brittle Regime. In Thermo-Hydro-Mechanical Coupling in Fractured Rock, ed. H. J. Kümpel. Pageoph Topical Volumes, 833–849. Basel: Springer-Birkha¨user. https://doi.org/10.1007/978-3-0348-8083-1_3.
Penny, G. S. and Conway, M. W. 1989. Fluid Leakoff. In Recent Advances in Hydraulic Fracturing, ed. H. L. Doherty, Vol. 12, 147–176. Richardson, Texas: Monograph Series, Society of Petroleum Engineers.
Portwood, J. T. 2005. The Kansas Arbuckle Formation: Performance Evaluation and Lessons Learned From More Than 200 Polymer-Gel Water-Shutoff Treatments. Presented at the SPE Production and Operations Symposium, Oklahoma City, Oklahoma, 16–19 April. SPE-94096-MS. https://doi.org/10.2118/94096-MS.
Schutjens, P. M. T. M., Hausenblas, M., Dijkshoorn, M. et al. 1995. The Influence of Intergranular Microcracks on the Petrophysical Properties of Sandstone—Experiments To Quantify Effects of Core Damage. Presented at the International Symposium of the Society of Core Analysts, San Francisco, 12–14 September. SCA-9524.
Seright, R. S. 1995. Gel Placement in Fractured Systems. SPE Prod & Fac 10 (4): 241–248. SPE-27740-PA. https://doi.org/10.2118/27740-PA.
Seright, R. S. 2001. Gel Propagation Through Fractures. SPE Prod & Fac 16 (4): 225–231. SPE-74602-PA. https://doi.org/10.2118/74602-PA.
Seright, R. S. 2003a. An Alternative View of Filter-Cake Formation in Fractures Inspired by Cr(III)-Acetate-HPAM Gel Extrusion. SPE Prod & Fac 18 (1): 65–72. SPE-81829-PA. https://doi.org/10.2118/81829-PA.
Seright, R. S. 2003b. Washout of Cr(III)-Acetate-HPAM Gels From Fractures. Presented at the SPE International Symposium on Oilfield Chemistry, Houston, 5–7 February. SPE-80200-MS. https://doi.org/10.2118/80200-MS.
Seright, R. S., Lane, R. H., and Sydansk, R. D. 2003. A Strategy for Attacking Excess Water Production. SPE Prod & Fac 18 (3): 158–169. SPE-84966-PA. https://doi.org/10.2118/84966-PA.
Sydansk, R. D. and Southwell, G. P. 2000. More Than 12 Years Experience With a Successful Conformance-Control Polymer-Gel Technology. SPE Prod & Oper 15 (4): 270–278. SPE-66558-PA. https://doi.org/10.2118/66558-PA.
Tie, H. 2006. Oil Recovery by Spontaneous Imbibition and Viscous Displacement From Mixed-Wet Carbonates. PhD thesis, University of Wyoming, Laramie, Wyoming, USA.
Willhite, G. P. and Pancake, R. E. 2008. Controlling Water Production Using Gelled Polymer Systems. SPE Res Eval & Eng 11 (3): 454–465. SPE-89464-PA. https://doi.org/10.2118/89464-PA.