Water invasion and remaining gas distribution in carbonate gas reservoirs using core displacement and NMR

Abstract

Water invasion is a common phenomenon in gas reservoirs with active edge-and-bottom aquifers. Due to high reservoir heterogeneity and production parameters, carbonate gas reservoirs feature exploitation obstacles and low recovery factors. In this study, combined core displacement and nuclear magnetic resonance (NMR) experiments explored the reservoir gas–water two-phase flow and remaining microscopic gas distribution during water invasion and gas injection. Consequently, for fracture core, the water-phase relative permeability is higher and the co-seepage interval is narrower than that of three pore cores during water invasion, whereas the water-drive recovery efficiency at different invasion rates is the lowest among all cores. Gas injection is beneficial for reducing water saturation and partially restoring the gas-phase relative permeability, especially for fracture core. The remaining gas distribution and the content are related to the core properties. Compared with pore cores, the water invasion rate strongly influences the residual gas distribution in fracture core. The results enhance the understanding of the water invasion mechanism, gas injection to resume production and the remaining gas distribution, so as to improve the recovery factors of carbonate gas reservoirs.

Keywords

core displacement / gas–water two-phase flow / recovery factor / nuclear magnetic resonance (NMR) / remaining gas distribution

References

[1] LiY, KangZ-j, XueZ-j, ZhengS-qing. Theories and practices of carbonate reservoirs development in China [J]. Petroleum Exploration and Development, 2018, 45(4): 152-162

[2] DurucanS, AhsanM, ShiJ-q, SyedA, KorreA. Two phase relative permeabilities for gas and water in selected European coals [J]. Fuel, 2014, 134: 226-236

[3] GuoP, ZhangH-m, DuJ-f, WangZ-h, ZhangW-b, RenH-mei. Study on gas-liquid relative permeability experiments of fracturedporous reservoirs [J]. Petroleum, 2017, 3(3): 348-354

[4] YeZ-y, LiuH-h, JiangQ-h, ZhouC-bing. Two-phase flow properties of a horizontal fracture: The effect of aperture distribution [J]. Advances in Water Resources, 2015, 76: 43-54

[5] WuY-s, PanL, PruessK. A physically based approach for modeling multiphase fracture-matrix interaction in fractured porous media [J]. Advances in Water Resources, 2004, 27(9): 875-887

[6] FangJ-l, GuoP, XiaoX-j, DuJ-f, DongC, XiongY-m, LongFang. Gas-water relative permeability measurement of high temperature and high pressure tight gas reservoirs [J]. Petroleum Exploration and Development, 2015, 42(1): 92-96

[7] BuckleyS E, LeverettM C. Mechanism of fluid displacement in sands [J]. Transactions of the AIME, 1942, 146(1): 107-116

[8] LiC, ZhouX, YouS, IbragimovJ J. Analysis of two-phase gas-water flow in carbonate reservoirs [J]. Journal of Mining Science, 2018, 53(4): 643-654

[9] HanY-j, ZhouC-c, YuJ, LiC-liu. Experimental investigation on the effect of wettability on rock-electricity response in sandstone reservoirs [J]. Fuel, 2019, 239: 1246-1257

[10] ShenW-j, XuY-m, LiX-z, HuangW-g, GuJ-rui. Numerical simulation of gas and water flow mechanism in hydraulically fractured shale gas reservoirs [J]. Journal of Natural Gas Science & Engineering, 2016, 35: 726-735

[11] ShiL, GaoS-s, XiongWei. Physical simulation of the mechanism for operation of water-encroached (flooded) underground gas storage facilities [J]. Chemistry and Technology of Fuels and Oils, 2012, 47(6): 426-433

[12] FourarM, BoriesS, LenormandR, PersoffP. Two-phase flow in smooth and rough fractures: Measurement and correlation by porous-medium and pipe flow models [J]. Water Resources Research, 1993, 29(11): 3699-3708

[13] LiC-h, LiX-z, GaoS-s, LiuH-x, YouS-q, FangF-f, ShenW-jun. Experiment on gas-water two-phase seepage and inflow performance curves of gas wells in carbonate reservoirs: A case study of Longwangmiao Formation and Dengying Formation in Gaoshiti-Moxi block, Sichuan Basin, SW China [J]. Petroleum Exploration and Development, 2017, 44(6): 983-992

[14] FangF-f, ShenW-j, GaoS-s, LiuH-x, WangQ-f, LiYang. Experimental study on the physical simulation of water invasion in carbonate gas reservoirs [J]. Applied Sciences, 2017, 697(7): 1-12

[15] FangF-f, ShenW-j, LiX-z, GaoS-s, LiuH-x, LiJie. Experimental study on water invasion mechanism of fractured carbonate gas reservoirs in Longwangmiao Formation, Moxi block, Sichuan Basin [J]. Environmental Earth Sciences, 2019, 316: 1-11

[16] CaiJ-c, YuB-m, ZouM-q, LuoLiang. Fractal characterization of spontaneous co-current imbibition in porous media [J]. Energy & Fuels, 2010, 24(3): 1860-1867

[17] FathA H, PouranfardA R, ParandvarR, PourhadiS. An investigation of different gas injection scenarios as enhanced condensate recovery method in a naturally fractured gas-condensate reservoir [J]. Petroleum Science and Technology, 2016, 34(3): 295-301

[18] ShiL, WangJ-m, LiaoG-z, XiongW, GaoS-sheng. Mechanism of gas-water flow at pore-level in aquifer gas storage [J]. Journal of Central South University, 2013, 20(12): 3620-3626

[19] ZhouH W, YueZ Q, ThamL G, XieH. The shape of moving boundary of fluid flow in sandstone: Video microscopic investigation and stochastic modeling approach [J]. Transport in Porous Media, 2003, 50(3): 343-370

[20] LiJ-j, JiangH-q, WangC, ZhaoY-y, GaoY-j, PeiY-l, WangC-c, DongHu. Pore-scale investigation of microscopic remaining oil variation characteristics in water-wet sandstone using CT scanning [J]. Journal of Natural Gas Science and Engineering, 2017, 48: 36-45

[21] WangH, TabordaE A, AlvaradoV, CortésF B. Influence of silica nanoparticles on heavy oil microrheology via time-domain NMR T2 and diffusion probe [J]. Fuel, 2019, 241: 962-972

[22] VincentB, FleuryM, SanterreY, BrigaudB. NMR relaxation of neritic carbonates: An integrated and petrographical approach [J]. Journal of Applied Geophysics, 2011, 74(1): 38-58

[23] XiaoL, MaoZ-q, WangZ-n, JinYan. Application of NMR logs in tight gas reservoirs for formation evaluation: A case study of Sichuan basin in China [J]. Journal of Petroleum Science & Engineering, 2012, 81: 182-195

[24] JiangG-c, LiY-y, ZhangMin. Evaluation of gas wettability and its effects on fluid distribution and fluid flow in porous media[J]. Petroleum Science, 2013, 10(4): 515-527

[25] LiG, RenW-x, MengY-f, WangC-l. WEI Na. Micro-flow kinetics research on water invasion in tight sandstone reservoirs [J]. Journal of Natural Gas Science and Engineering, 2014, 20: 184-191

[26] HerringA L, SheppardA, AnderssonL, WildenschildD. Impact of wettability alteration on 3D nonwetting phase trapping and transport [J]. International Journal of Greenhouse Gas Control, 2016, 46: 175-186

[27] PiniR, KrevorS C M, BensonS M. Capillary pressure and heterogeneity for the CO2/water system in sandstone rocks at reservoir conditions [J]. Advances in Water Resources, 2012, 38: 48-59