Effects of pore connectivity and water saturation on matrix permeability of deep gas shale

Jiale Zhao, Mengdi Sun, Zhejun Pan, Bo Liu, Mehdi Ostadhassan, Qinhong Hu

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Abstract


Shale matrix permeability is an important indicator for evaluating gas transport and production. However, the effects of pore connectivity and water saturation on the matrix permeability in deep gas shales have not been adequately studied. In this study, the permeability of deep shales in the Yichang area of the Middle Yangtze was characterized using three methods. These included the determination of apparent permeability in different directions via pulse-decay, also matrix permeability obtained via the Gas Research Institute method, and the connected pore network permeability via the mercury injection capillary pressure technique. The results revealed a significant difference between the horizontal and vertical permeability of deep shales. The smaller the size of the multiple connected pore network, the larger was the effective tortuosity and the lower the permeability. Comparison of the three permeabilities and combined microscopic observations revealed that microfractures and laminae were the dominant gas transport channels. Importantly, the matrix permeability decreased exponentially with increasing water saturation, with water vapor adsorption experiments revealing that water occupation of pores and pore-throat spaces smaller than 10 nm in diameter was the main reason for this decrease in matrix permeability. Collectively, proposed method of evaluating effective permeability with an index for shale gas reservoirs is significant for sweet spot selection and production prediction of shale gas reservoirs around the globe.

Cited as: Zhao, J., Sun, M., Pan, Z., Liu, B., Ostadhassan, M., Hu, Q. Effects of pore connectivity and water saturation on matrix permeability of deep gas shale. Advances in Geo-Energy Research, 2022, 6(1): 54-68. https://doi.org/10.46690/ager.2022.01.05


Keywords


Matrix permeability, pore structure, water vapor adsorption, deep shale, Wufeng-Longmaxi shale

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References


Achang, M., Pashin, J. C., Atekwana, E. A. The influence of moisture on the permeability of crushed shale samples. Petroleum Science, 2019, 16(3): 492-501.

Achang, M., Pashin, J. C., Cui, X. The influence of particle size, microfractures, and pressure decay on measuring the permeability of crushed shale samples. International Journal of Coal Geology, 2017, 183: 174-187.

Chávez-Páez, M., Workum, K. V., de Pablo, L., et al. Monte Carlo simulations of Wyoming sodium montmorillonite hydrates. Journal of Chemical Physics, 2001, 114(3): 1405-1413.

Chen, K., Li, J., Tang, X., et al. Key geological factors for shale gas accumulation in the Wufeng-Longmaxi Formation in the central Yangtze area. Natural Gas Industry B, 2021, 8(1): 1-12.

Cui, G., Liu, J., Wei, M., et al. Why shale permeability changes under variable effective stresses: New insights. Fuel, 2018, 213: 55-71.

Cui, X., Bustin, A. M. M., Bustin, R. M. Measurements of gas permeability and diffusivity of tight reservoir rocks: Different approaches and their applications. Geofluids, 2009, 9(3): 208-223.

Davudov, D., Moghanloo, R. G., Zhang, Y. Interplay between pore connectivity and permeability in shale sample. International Journal of Coal Geology, 2020, 220: 103427.

Duan, W., Li, C., Luo, C., et al. Effect of formation over-pressure on the reservoir diagenesis and its petroleum geological significance for the DF11 block of the Yingge-hai Basin, the South China Sea. Marine and Petroleum Geology, 2018, 97: 49-65.

Fisher, L. R., Israelachvili, J. N. Direct experimental verification of the Kelvin equation for capillary condensation. Nature, 1979, 277: 548-549.

Gao, J., Li, Z. Water saturation-driven evolution of helium permeability in Carboniferous shale from Qaidam Basin, China: An experimental study. Marine and Petroleum Geology, 2018, 96: 371-390.

Gao, Z., Hu, Q. Estimating permeability using median pore-throat radius obtained from mercury intrusion porosimetry. Journal of Geophysics and Engineering, 2013, 10(2): 025014.

Ghasemi, F., Ghaedi, M., Escrochi, M. A new scaling equation for imbibition process in naturally fractured gas reservoirs. Advances in Geo-Energy Research, 2020, 4(1): 99-106.

Guo, X., Li, Y., Borjigen, T., et al. Hydrocarbon generation and storage mechanisms of deep-water shelf shales of Ordovician Wufeng Formation–Silurian Longmaxi Formation in Sichuan Basin, China. Petroleum Exploration and Development, 2020, 47(1): 193-201.

He, Z., Li, S., Nie, H., et al. The shale gas “sweet window”: “The cracked and unbroken” state of shale and its depth range. Marine and Petroleum Geology, 2019, 101: 334-342.

Heller, R., Vermylen, J., Zoback, M. Experimental investigation of matrix permeability of gas shales. AAPG Bulletin, 2014, 98(5): 975-995.

Hu, Q., Zhang, Y., Meng, X., et al. Characterization of micro-nano pore networks in shale oil reservoirs of Paleogene Shahejie Formation in Dongying Sag of Bohai Bay Basin, East China. Petroleum Exploration and Development, 2017, 44(5): 720-730.

Katz, A. J., Thompson, A. H. Quantitative prediction of permeability in porous rock. Physical Review B, 1986, 34(11): 8179-8181.

Katz, A. J., Thompson, A. H. Prediction of rock electrical conductivity from mercury injection measurements. Journal of Geophysical Research, 1987, 92(B1): 599-607.

Lastoskie, C., Gubbins, K. E., Quirke, N. Pore size distribution analysis of microporous carbons: A density functional theory approach. Journal of Chemical Physics, 1993, 97: 4786-4796.

Lei, G., Liao, Q., Chen, W., et al. Stress dependent gas-water relative permeability in gas hydrates: A theoretical model. Advances in Geo-Energy Research, 2020, 4(3): 326-338.

Li, J., Li, X., Wang, X., et al. Water distribution characteristic and effect on methane adsorption capacity in shale clay. International Journal of Coal Geology, 2016, 159: 135-154.

Li, J., Yang, Z., Wu, S., et al. Key issues and development direction of petroleum geology research on source rock strata in China. Advances in Geo-Energy Research, 2021, 5(2): 121-126.

Luffel, D. L., Guidry, F. K. Core-analysis results: Comprehensive study wells, Devonian shale. Topical report, United States, May 1989.

Luffel, D. L., Guidry, F. K. New core analysis methods for measuring reservoir rock properties of Devonian shale. Journal of Petroleum Technology, 1992, 44(11): 1184-1190.

Ma, Y., Pan, Z., Zhong, N., et al. Experimental study of anisotropic gas permeability and its relationship with fracture structure of Longmaxi Shales, Sichuan Basin, China. Fuel, 2016a, 180: 106-115.

Ma, Y., Zhong, N., Cheng, L., et al. Pore structure of the graptolite-derived OM in the Longmaxi Shale, southeast-ern Upper Yangtze Region, China. Marine and Petroleum Geology, 2016b, 72: 1-11.

Milliken, K. L., Rudnicki, M., Awwiller, D. N., et al. Organic matter-hosted pore system, Marcellus Formation (Devonian), Pennsylvania. AAPG Bulletin, 2013, 97(2): 177-200.

Nguyen, P. T., Do, D. D., Nicholson, D. Pore connectivity and hysteresis in gas adsorption: A simple three-pore model. Colloids & Surfaces A Physicochemical & Engineering Aspects, 2013, 437: 56-68.

Pan, Z., Ma, Y., Connell, L. D., et al. Measuring anisotropic permeability using a cubic shale sample in a triaxial cell. Journal of Natural Gas Science and Engineering, 2015, 26: 336-344.

Peng, S., Loucks, B. Permeability measurements in mudrocks using gas-expansion methods on plug and crushed-rock samples. Marine and Petroleum Geology, 2016, 73: 299-310.

Peng, S., Ren, B., Meng, M. Quantifying the influence of fractures for more-accurate laboratory measurement of shale matrix permeability using a modified gas-expansion method. SPE Reservoir Evaluation & Engineering, 2019, 22: 1293-1304.

Qu, H., Pan, Z., Peng, Y., et al. Controls on matrix permeability of shale samples from Longmaxi and Niutitang formations, China. Journal of Natural Gas Science and Engineering, 2016, 33: 599-610.

Ryan, B. A discussion on moisture in coal implications for coalbed gas and coal utilization. British Columbia Resource Development and Geoscience Branch, Summary of Activities, 2006, 49: 139-149.

Sang, G., Liu, S., Elsworth, D. Water vapor sorption properties of Illinois shales under dynamic water vapor conditions: Experimentation and modeling. Water Resources Research, 2019, 55(5): 7212-7228.

Sun, M., Yu, B., Hu, Q., et al. Pore connectivity and tracer migration of typical shales in south China. Fuel, 2017, 203: 32-46.

Sun, M., Zhang, L., Hu, Q., et al. Multiscale connectivity characterization of marine shales in southern China by fluid intrusion, small-angle neutron scattering (SANS), and FIB-SEM. Marine and Petroleum Geology, 2020, 112: 104101.

Tan, Y., Pan, Z., Feng, X., et al. Laboratory characterisation of fracture compressibility for coal and shale gas reservoir rocks: A review. International Journal of Coal Geology, 2019, 204: 1-17.

Tang, X., Ripepi, N., Valentine, K. A., et al. Water vapor sorption on Marcellus shale: Measurement, modeling and thermodynamic analysis. Fuel, 2017, 209: 606-614.

Tinni, A., Fathi, E., Agarwal, R., et al. Shale permeability measurements on plugs and crushed samples. Paper SPE 162235 Presented at the SPE Canadian Unconventional Resources Conference, Calgary, Alberta, Canada, 30 October, 2012.

Wang, M., Yu, Q. Comparing the permeability of dry and moisturized crushed shales determined by the dynamic process data of methane adsorption. Journal of Hydrology, 2020, 590: 125375.

Wang, P. F., Jiang, Z. X., Chen, L., et al. Pore structure characterization for the Longmaxi and Niutitang shales in the Upper Yangtze Platform, South China: Evidence from focused ion beam-He ion microscopy, nano-computerized tomography and gas adsorption analysis. Marine and Petroleum Geology, 2016, 77: 1323-1337.

Xu, R., Prodanović, M., Landry, C. Pore-scale study of water adsorption and subsequent methane transport in clay in the presence of wettability heterogeneity. Water Resources Research, 2020, 56(10): e2020WR027568.

Yang, R., Hu, Q., He, S., et al. Wettability and connectivity of overmature shales in the Fuling gas field, Sichuan Basin (China). AAPG Bulletin, 2019, 103(3): 653-689.

Yang, R., Jia, A., He, S., et al. Water adsorption characteristics of organic-rich Wufeng and Longmaxi Shales, Sichuan Basin (China). Journal of Petroleum Science and Engi-neering, 2020, 193: 107387.

Zhang, J., Tao, J., Li, Z., et al. Prospect of deep shale gas resources in China. Natural Gas Industry, 2021, 41(1): 15-28. (in Chinese)

Zhao, J., Hu, Q., Liu, K., et al. Pore connectivity characterization of shale using integrated wood’s metal impregnation, microscopy, tomography, tracer mapping and porosimetry. Fuel, 2020, 259: 116248.

Zolfaghari, A., Dehghanpour, H., Holyk, J. Water sorption behaviour of gas shales: I. Role of clays. International Journal of Coal Geology, 2017a, 179: 130-138.

Zolfaghari, A., Dehghanpour, H., Xu, M. Water sorption behaviour of gas shales: II. Pore size distribution. International Journal of Coal Geology, 2017b, 179: 187-195.

Zou, C., Zhao, Q., Cong, L., et al. Development progress, potential and prospect of shale gas in China. Natural Gas Industry, 2021, 41(1): 1-14. (in Chinese)




DOI: https://doi.org/10.46690/ager.2022.01.05

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