Leak-off behavior and water shut-off performance of a polymer/chromium (Cr³⁺) gel in fractured media

Abstract

During gel treatments for fractures, the leak-off behavior of gelant has a great effect on the water shut-off performance of gel. Experiments were carried out using a polymer/chromium (Cr³⁺) gel system to explore the leak-off behavior and the water shut-off performance of gel in fractured media. Results of the gelant leak-off study show that the gelant leak-off from fracture into matrix contributes to the formation of the gelant leak-off layer during the gelant injection. Moreover, because of the gradual formation of the gelant leak-off layer along fracture, the initial leak-off ratio of gelant is relatively high, but it declines and finally levels off with the increase of the injection volume. The polymer concentration of gelant has a great effect on the chromium output in fluids produced from fractures. With the increase of the polymer concentration, the chromium concentration first decreases and then increases, and the leak-off depth of gelant into matrix is gradually reduced. Results of the water shut-off study present that the decrease of the chromium concentration inside the fracture greatly reduces the water shut-off performance after the gel formation. Therefore, because of the relatively high degree of chromium leak-off, enough injection volume of gelant is essential to ensure the sufficient chromium concentration inside the fracture and to further achieve a favorable water shut-off performance. On the premise of gel strength assurance inside the fracture, the water shut-off performance of gel gradually declines with the extension of the distance from the fracture inlet, and different leak-off degrees of gelant along the fracture are responsible for this phenomenon. Therefore, a proper degree of gelant leak-off contributes to enhancing the water shut-off performance of gel for fractures.

Keywords

polymer / gelant / gel / leak-off / water shut-off / fracture

References

[1] LinM, ZhangG, ZhaoH, ZhaoQ, SunF. Conformation and plugging properties of crosslinked polymer microspheres for profile control [J]. Colloids Surf A: Physicochem Eng Asp, 2015, 475: 2-8

[2] ShiJ T, VaraveiA, HuhC, DelshadM, SepehrnooriK, LiX F. Viscosity model of preformed microgels for conformance and mobility control [J]. Energy Fuels, 2011, 25: 5033-5037

[3] SerightR S. Use of preformed gel for conformance control in fractured systems [C]//. SPE/DOE Tenth Symposium on Improved Oil Recovery, 1996

[4] SidiqH, AminR, KennairdT. A laboratory investigation of water abatement chemicals for potential use in the Wanaea field [J]. J Petrol Sci Eng, 2009, 65: 89-92

[5] YaoC J, LeiG L, LiL, GaoX M. Selectivity of pore-scale elastic microspheres as a novel profile control and oil displacement agent [J]. Energy Fuels, 2012, 26: 5092-5101

[6] AbdulbakiM, HuhC, SepehrnooriK, DelshadM, VaraveiA. A critical review on use of polymer microgels for conformance control purposes [J]. J Petrol Sci Eng, 2014, 122: 741-753

[7] GoudarziA, ZhangH, VaraveiA, TaksaudomP, HuY P. A laboratory and simulation study of preformed particle gels for water conformance control [J]. Fuel, 2015, 140: 502-513

[8] BaiB, WeiM, LiuY. Injecting large volumes of preformed particle gel for water conformance control [J]. Oil Gas Sci Technol, 2012, 67: 941-952

[9] Al-GhazaM, Al-DriweeshS, Al-SagrA, KrishnanG. A new temporary chemical packer enables efficient stimulation of a lower zone in a gas well [C]//. Abu Dhabi International Petroleum Exhibition and Conference, 2012

[10] ZengL, LiuH. Influence of fractures on the development of low-permeability sandstone reservoirs: A case study from the Taizhao district, Daqing Oilfield, China [J]. J Petrol Sci Eng, 2010, 72: 120-127

[11] ZhaoJ Z, JiaH, PuW F, LiaoR. Influences of fracture aperture on the water shutoff performance of polyethyleneimine cross-linking partially hydrolyzed polyacrylamide gels in hydraulic fractured reservoirs [J]. Energy Fuels, 2011, 25: 2616-2624

[12] SerightR S. Reduction of gas and water permeabilities using gels [J]. SPE Prod Fac, 1995, 10: 103-108

[13] SerightR S, LungJ, SeidaiM. Sizing gelant treatments in hydraulically fractured production wells [J]. SPE Prod Fac, 1998, 13: 223-229

[14] SerightR S. Mechanism for gel propagation through fractures [C]//. Rocky Mountain Regional Meeting, 1999

[15] WisniewskaM, ChibowskiS, UrbanT. Impact of polyacrylamide with different contents of carboxyl groups on the chromium (III) oxide adsorption properties in aqueous solution [J]. J Hazard Mater, 2015, 283: 815-823

[16] JiaH, PuW F, ZhaoJ Z, LiaoR. Experimental investigation of the novel phenol-formaldehyde cross-linking HPAM gel system: Based on the secondary cross-linking method of organic cross-linkers and its gelation performance study after flowing through porous media [J]. Energy Fuels, 2011, 25: 727-736

[17] StandnesD C, SkjevrakI. Literature review of implemented polymer field projects [J]. J Petrol Sci Eng, 2014, 122: 761-775

[18] LakatosI, Lakatos-SzabóJ. Diffusion of chromium ions in polymer/silicate gels [J]. Colloids Surf A: Physicochem Eng Asp, 1998, 141: 425-434

[19] GangulySEffect of Leak-off on behavior of Chromium(III)-PHPA gel in fractured media [D], 2000, Lawrence, University of Kansas

[20] LeD H, DabholkarD S, MahadevanJ, McqueenK. Removal of fracturing gel: A laboratory and modeling investigation accounting for viscous fingering channels [J]. J Petrol Sci Eng, 2012, 88–89: 145-155

[21] LiuJ X, LuX G, LiuJ F, HuS Q, XueB Q. Mechanism and gelling effects of linked polymer solution in the core [J]. Petrol Explor Develop, 2013, 40: 507-513

[22] DangT Q C, ChenZ, NguyenT B N, BaeW. Investigation of isotherm polymer adsorption in porous media [J]. Petro Sci Technol, 2014, 32: 1626-1640

[23] TiraferriA, BorkovecM. Probing effects of polymer adsorption in colloidal particle suspensions by light scattering as relevant for the aquatic environment: An overview [J]. Sci Total Environ, 2015, 535: 131-140

[24] RanQ P, SomasundaranP, MiaoC W, LiuJ P, WuS S, ShenJ. Adsorption mechanism of comb polymer dispersants at the cement/water interface [J]. J Disper Sci Technol, 2010, 31: 790-798

[25] SenguptaB, SharmaV P, UdayabhanuG. Gelation studies of an organically cross-linked polyacrylamide water shut-off gel system at different temperatures and pH [J]. J Petrol Sci Eng, 2012, 81: 145-150

[26] BryantS L, BartosekM, LockhartT P. Propagation of Cr(III) in porous media and its effect on gelant performance [J]. J Petrol Sci Eng, 1996, 16: 1-13

[27] PanthiK, MohantyK K. Effect of alkaline prefl ush in an alkaline-surfactant-polymer flood [J]. Energy Fuels, 2013, 27: 764-771

[28] OdumaboS M, KarpynZ T, AyalaH L F. Investigation of gas flow hindrance due to fracturing fluid leakoff in low permeability sandstones [J]. J Nat Gas Sci Eng, 2014, 17: 1-12

[29] HatzignatiouD G, NorrisU L, StavlandA. Core-scale simulation of polymer flow through porous media [J]. J Petrol Sci Eng, 2013, 108: 137-150

[30] GuhaaH, SaiersJ E, BrookS, JardineP, JayachandranK. Chromium transport, oxidation, and adsorption in manganese-coated sand [J]. J Contam Hydrol, 2001, 49: 311-334

[31] BaiY R, WeiF L, XiongC M, LiJ J, JiangR Y, XuH B, ShuY. Effects of fracture and matrix on propagation behavior and water shut-off performance of a polymer gel [J]. Energy Fuels, 2015, 29: 5534-5543

[32] Moradi-AraghiA. A review of thermally stable gels for fluid diversion in petroleum production [J]. J Petrol Sci Eng, 2000, 26: 1-10

[33] GangulyS. Leak-off during placement of Cr(III)-partially hydrolyzed polyacrylamide gelling solution in fractured porous media [J]. Transport Porous Med, 2010, 81: 443-460