Stress sensitivity of multiscale pore structure of shale gas reservoir under fracturing fluid imbibition
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Abstract
Generally, huge amounts of fracturing fluid are used in a shale gas well but the flowback efficiency is low. Since the distribution characteristics of imbibed fracturing fluid in shale are complex, they need further evaluation. This paper takes the Longmaxi Shale as the research object, including matrix cores, natural fracture cores and cores of artificial fracture with proppant. Stress sensitivity experiments are carried out on the above three kinds of cores under different degrees of imbibition and retention state of fracturing fluid. The results show that when the degree of aqueous phase retention is 0-0.78 pore volume, water mainly appears in the pores with a diameter of 2-50 nm. As the water saturation increases to more than 0.9 pore volume, the amounts of aqueous phase in the pores or fractures with a hydraulic diameter of 100-1,000 nm and larger than 1,000 nm increase significantly. Both the stress sensitivity of nanopores and natural fractures are enhanced by aqueous phase retention. With the increase in effective stress, the permeability damage rate of artificial fracture cores with proppant is inversely proportional to the degree of fracturing fluid retention. Aqueous phase retention in the pores with a diameter of 2-50 nm significantly contributes to the stress sensitivity of matrix cores. With the increase in effective stress, aqueous phase retention in pores with diameter larger than 100 nm increases the stress sensitivity of natural fracture cores. It is recommended that the retention degree of fracturing fluid in a shale gas reservoir should be controlled below 0.5 pore volume. In this case, the stress sensitivity of natural fractures will be less aggravated by fracturing fluid retention, and the stress sensitivity of artificial fracture with proppant will be reduced to a certain extent.
Document Type: Original article
Cited as: Chen, M., Yan, M., Kang, Y., Cao, W., Bai, J., Li, P. Stress sensitivity of multiscale pore structure of shale gas reservoir under fracturing fluid imbibition. Capillarity, 2023, 8(1): 11-22. https://doi.org/10.46690/capi.2023.07.02
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Abaa, K., Thaddeus, M., Adewumi, M. Effect of acoustic stimulation on aqueous phase trapping in low-permeability sandstones. Journal of Energy Resources Technology, 2017, 139(6): 062905.
Ai-Hajri, S., Negash, B., Rahman, M., et al. Perspective Review of polymers as additives in water-based fracturing fluids. ACS Omega, 2022, 7(9): 7431-7443.
Cai, J., Chen, Y., Liu, Y., et al. Capillary imbibition and flow of wetting liquid in irregular capillaries: A 100-year review. Advances in Colloid and Interface Science, 2022, 304: 102654.
Cai, J., Jin, T., Kou, J., et al. Lucas-Washburn equation-based modeling of capillary-driven flow in porous systems. Langmuir, 2021, 37(5): 1623-1636.
Chen, L., Jiang, Z., Liu, K., et al. Quantitative characterization of micropore structure for organic-rich Lower Silurian shale in the Upper Yangtze Platform, South China: Implications for shale gas adsorption capacity. Advances in Geo-Energy Research, 2017, 1(2): 112-123.
Chen, M., Kang, Y., Zhang, T., et al. Characteristics of multiscale mass transport and coordination mechanisms for shale gas. Scientia Sinica Technologica, 2018, 48(5): 473-487. (in Chinese)
Chen, M., Li, P., Kang, Y., et al. Effect of aqueous phase trap ping in shale matrix on methane sorption and diffusion capacity. Fuel, 2021, 289: 119967.
Chen, H., Wei, J., Cheng, H., et al. Stress densitivity of proppant-containing fractures and its influence on fas well productivity. Geofluids, 2023, 2023: 8851149.
Denney, D. Tight reservoirs: Proppant transport in slickwater fracturing of shale-gas formations. Journal of Petroleum Technology, 2010, 62(10): 56-69.
Edwards, R., Celia, M. Shale gas well, hydraulic fracturing, and formation data to support modeling of fas and water flow in shale formations. Water Resources Research, 2018, 54(4): 3196-3206.
Gasparik, M., Ghanizadeh, A., Bertier, P., et al. High-pressure methane sorption isotherms of black shales from the Netherlands. Energy & Fuels, 2012, 26(8): 4995-5004.
Han, D., Wang, H., Wang, C., et al. Differential characterization of stress sensitivity and its main control mechanism in deep pore-fracture clastic reservoirs. Scientific Reports, 2021, 11(1): 7374.
Jacobs, T. Shale sector’s switch to slickwater highlights compatibility issues with produced water. Journal of Petroleum Technology, 2019, 71(11): 31-32.
Kang, Y., Bai, J., Li, X., et al. Influence of water-rock interaction on stress sensitivity of organic-rich shales: A case study from Longmaxi formation in the southeast area of Chongqing. Petroleum Reservoir Evaluation and Development, 2019, 9(5): 54-62. (in Chinese)
Li, N., Jin, Z., Wang, H., et al. Investigation into shale softening induced by water/CO2-rock interaction. International Journal of Rock Mechanics and Mining Sciences, 2023, 161: 105299.
Liang, Y., Lai, F., Dai, Y., et al. An experimental study of imbibition process and fluid distribution in tight oil reservoir under different pressures and temperatures. Capillarity, 2021, 4(4): 66-75.
Lin, H., Yang, B., Song, X., et al. Fracturing fluid retention in shale gas reservoir from the perspective of pore size based on nuclear magnetic resonance. Journal of Hydrology, 2021, 601: 126590.
Liu, D., Ge, H., Liu, J., et al. Experimental investigation on aqueous phase migration in unconventional gas reservoir rock samples by nuclear magnetic resonance. Journal of Natural Gas Science and Engineering, 2016, 36(A): 837-851.
Liu, J., Liu, J., Liu, H., et al. Mechanism study on release of “Water blocking damage” of tight sandstone by nano-fluid and case study. Paper ARMA 2020-1041 Presented at the 54th U.S. Rock Mechanics/Geomechanics Symposium, physical event cancelled, 28 June-1 July, 2020.
Liu, X., Pan, Y., Li, M., et al. Permeability of hydrated shale rocks under cyclic loading and unloading conditions. Journal of China Coal Society, 2022, 47(S1): 103-114. (in Chinese)
Ogata, S., Yasuhara, H., Kinoshita, N., et al. Modeling of coupled thermal-hydraulic-mechanical-chemical processes for predicting the evolution in permeability and reactive transport behavior within single rock fractures. International Journal of Rock Mechanics and Mining Sciences, 2018, 107: 271-281.
Rashid, S., Boyun, G., Philip B., et al. Stress-sensitivity of fracture conductivity of Tuscaloosa Marine Shale cores. Journal of Petroleum Science and Engineering, 2022, 210: 110042.
Shaoul, L., Zelm, V., Pater, C. Damage mechanisms in unconventional-gas-well stimulation a new look at an old problem. SPE Production & Operation, 2011, 26(4): 388-400.
Sheng, G., Wang, W., Zhao, H., et al. Study of fracturing fluid imbibition impact on gas-water two phase flow in shale fracture-matrix system. Paper URTEC 2020-3323 Presented at the SPE/AAPG/SEG Unconventional Resources Technology Conference, Virtual, 20-22 July, 2020.
Shi, W., Zhang, C., Jiang, S., et al. Study on pressure-boosting stimulation technology in shale gas horizontal wells in the Fuling shale gas field. Energy, 2022, 254: 124364.
Wang, Y., Kang, Y., Wang, D., et al. Liquid phase blockage in micro-nano capillary pores of tight condensate reservoirs. Capillarity, 2022, 5(1): 12-22.
Wang, X., Zhu, Y., Fu, C., et al. Experimental investigation of the stress-dependent permeability in the Longmaxi Formation shale. Journal of Petroleum Science and Engineering, 2019, 175: 932-947.
Wijaya, N., Sheng, J. Shut-in effect in removing water blockage in shale-oil reservoirs with stress-dependent permeability considered. SPE Reservoir Evaluation & Engineering, 2020, 23(1): 81-94.
Xu, Y., Liu, X., Hu, Z., et al. Bottom-hole pressure draw down management of fractured horizontal wells in shale gas reservoirs using a semi-analytical model. Scientific Reports, 2022, 12(1): 22490.
Yang, L., Wang, S., Cai, J., et al. Main controlling factors of fracturing fluid imbibition in shale fracture network. Capillarity, 2018, 1(1): 1-10.
Yang, D., Wang, W., Chen, W., et al. Experimental investigation on the coupled effect of effective stress and gas slippage on the permeability of shale. Scientific Reports, 2017, 7(1): 44696.
You, L., Wang, Q., Kang, Y., et al. Influence of fracturing fluid immersion on stress sensitivity of shale reservoir. Petroleum Geology and Recovery Efficiency, 2014, 21(6): 102-106. (in Chinese)
Zeng, F., Zhang, Q., Guo, J., et al. Capillary imbibition of confined water in nanopores. Capillarity, 2020, 3(1): 8-15.
Zhang, Y., Ge, H., Shen, Y., et al. The retention and flowback of fracturing fluid of branch fractures in tight reservoirs. Journal of Petroleum Science and Engineering, 2021, 198: 108228.
Zhang, W., Wang, Q., Ning, Z., et al. Relationship between the stress sensitivity and pore structure of shale. Journal of Natural Gas Science and Engineering, 2018, 59: 440-451.
Zheng, X., Zhang, B., Sanei, H., et al. Pore structure characteristics and its effect on shale gas adsorption and desorption behavior. Marine and Petroleum Geology, 2019, 100: 165-178.
Zhong, Y., Zhang, H., Kuru, E., et al. Mechanisms of how surfactants mitigate formation damage due to aqueous phase trapping in tight gas sandstone formations. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2019, 573: 179-187.
Zhou, X., Chen, D., Xia, Y., et al. Spontaneous imbibition characteristics and influencing factors of Chang 7 shale oil reservoirs in Longdong Area, Ordos Basin. Earth Science, 2022, 47(8): 3045-3055. (in Chinese)
Zhou, M., Li, J., Luo, Z., et al. Impact of water-rock interaction on the pore structures of red-bed soft rock. Scientific Reports, 2021, 11(1): 7398.
Zhou, S., Ning, Y., Wang, H., et al. Investigation of methane adsorption mechanism on Longmaxi shale by combining the micropore filling and monolayer coverage theories. Advances in Geo-Energy Research, 2018a, 2(3): 269-281.
Zhou, Z., Teklu, T., Li, X., et al. Experimental study of the osmotic effect on shale matrix imbibition process in gas reservoirs. Journal of Natural Gas Science and Engineering, 2018b, 49: 1-7.
Zou, C., Pan, S., Jing, Z., et al. Shale oil and gas revolution and its impact. Acta Petrolei Sinica, 2020, 41(1): 1-12. (in Chinese)
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