Research progress and scientific challenges in the depressurization exploitation mechanism of clayey-silt natural gas hydrates in the northern South China Sea

Cheng Lu, Xuwen Qin, Jinsheng Sun, Ren Wang, Jianchao Cai

Abstract view|146|times       PDF download|70|times

Abstract


Natural gas hydrate reservoirs in the northern South China Sea primarily comprise clayey silt, making exploitation more challenging relative to sandy reservoirs in other countries and regions. This paper provides an overview of the latest research developments in the exploitation mechanism covering the past five years, focusing on hydrate phase transition, multiphase flow in the decomposition zone, the seepage regulation of reservoir stimulation zone, and production capacity simulation, all of which are relevant to the previously conducted two rounds of hydrate trial production in offshore areas of China. The results indicate that the phase transition of clayey-silt hydrate remains in a dynamic equilibrium, with the decomposition efficiency mainly controlled by the coupling of heat and flow and high heat consumption during decomposition. The decomposition zone exhibits strong hydrophilicity, easy adsorption, and sudden permeability changes. A temperature drop is present that is concentrated near the wellbore, and once a water lock has formed, the gas-phase flow capacity significantly decreases, leading to potential secondary hydrate formation. To enhance permeability and increase production, it is imperative to implement reservoir and temperature field reconstruction based on initial formation alterations, which will further optimize and improve the transport capacity of the reservoir.

Document Type: Current minireview

Cited as: Lu, C., Qin, X., Sun, J., Wang, R., Cai, J. Research progress and scientific challenges in the depressurization exploitation mechanism of clayey-silt natural gas hydrates in the northern South China Sea. Advances in Geo-Energy Research, 2023, 10(1): 14-20. https://doi.org/10.46690/ager.2023.10.03


Keywords


Clayey-silt, hydrate phase transition, multiphase flow, seepage regulation, production simulation

Full Text:

PDF

References


Bian, H., Qin, X., Luo, W., et al. Evolution of hydrate habit and formation properties evolution during hydrate phase transition in fractured-porous medium. Fuel, 2022, 324: 124436.

Bian, H., Qin, X., Sun, J., et al. The impact of mineral compositions on hydrate morphology evolution and phase transition hysteresis in natural clayey silts, Energy, 2023, 274: 127303.

Bian, H., Xia, Y., Lu, C., et al. Pore structure fractal characterization and permeability simulation of natural gas hydrate reservoir based on CT images. Geofluids, 2020, 2020: 6934691.

Cai, J., Xia, Y., Lu, C., et al. Creeping microstructure and fractal permeability model of natural gas hydrate reservoir. Marine and Petroleum Geology, 2020a, 115: 104282.

Cai, J., Xia, Y., Xu, S., et al. Advances in multiphase seepage characteristics of natural gas hydrate sediments. Chinese Journal of Theoretical and Applied Mechanics, 2020b, 52(1): 208-223. (in Chinese)

Cui, Y., Teng, B., Luo, W., et al. A new study of multi-phase mass and heat transfer in natural gas hydrate reservoir with an embedded discrete fracture model. Frontiers in Earth Science, 2023, 11: 1132970.

China University of Geosciences-Beijing (CUGB). I-Core Data Manger V1.0. 2022SR0752671, 2022.

Gao, D. Discussin on development modes and engineering techniques for deepwater natural gas and its hydrates. Natural Gas Industry, 2020, 40(8): 136-143. (in Chinese)

Geng, L., Cai, J., Lu, C., et al. Phase equilibria of natural gas hydrates in bulk brine and marine sediments from the South China Sea. Journal of Chemical and Engineering Data, 2021, 66, 4064-4074.

Institute of Geology and Geophysics, Chinese Academy of Sciences (IGGCAS). Multi-physics coupled simulation software for hydrate development. V1.0. 2021SR0700374, 2021.

Lei, X., Yao, Y., Qin, X., et al. Pore structure changes induced by hydrate dissociation: An example of the unconsolidated clayey-silty hydrate bearing sediment reservoir in the South China Sea. Marine Geology, 2022, 443: 106689.

Li, S., Guo, S., Chen, M., et al. Advances and recommendations for multi-field characteristics and coupling seepage in natural gas hydrate development. Chinese Journal of Theoretical and Applied Mechanics, 2020, 52(3): 828-842. (in Chinese)

Li, S., Sun, Y., Lu, C., et al. A thermodynamic method for the estimation of free gas proportion in depressurization production of natural gas hydrate. Frontiers in Earth Science, 2022, 10: 859111.

Lu, C., Qin, X., Ma, C., et al. Onsite data analysis platform for hydrate production and tests—Hydrate Captain V1.0. 2020SR0916459, 2020.

Lu, C., Qin, X., Ma, C., et al. Investigation of the impact of threshold pressure gradient on gas production from hydrate deposits. Fuel, 2022a, 319: 123569.

Lu, C., Qin, X., Mao, W., et al. Experimental study on the propagation characteristics of hydraulic fracture in clayey-silt sediments. Geofluids, 2021a, 2021: 6698649.

Lu, C., Qin X., Tian Y., et al. Natural gas hydrate production test data analysis platform—GH Captain V2.0. 2021SR0245279, 2021b.

Lu, C., Qin, X., Yu, L., et al. The characteristics of gas-water two-phase radial flow in clay-silt sediment and effects on hydrate production, Geofluids, 2021c, 2021: 6623802.

Lu, H., Shang, S., Cheng, X., et al. Research progress and development direction of numerical simulator for natural gas hydrate development. Acta Petrolei Sinica, 2021d, 42(11): 1516-1530.

Lu, C., Xia, Y., Qin, X., et al. Micro- and nano-scale pore structure characterization and mineral composition analysis of clayey-silt porous media of natural gas hydrate reservoir in the South China Sea. Geofluids, 2022b, 2022: 2837193.

Lu, C., Xia, Y., Sun, X., et al. Permeability evolution at various pressure gradients in natural gas hydrate reservoir at the Shenhu Area in the South China Sea. Energies, 2019, 12(19): 3688.

Lu, C., Xie, P., Li, H., et al. Study on the Mechanical Properties of Silty Clay Sediments with Nodular Hydrate Occurrence. Journal of Marine Science and Engineering, 2022c, 10(8): 1059.

Ma, C., Qin, X., Sun J., et al. Secondary hydrate formation in gas hydrate production by depressurization. Journal of China University of Petroleum (Edition of Natural Science), 2022, 46(6): 21-30. (in Chinese)

Moridis, G. J., Collett, T. S., Dallimore, S., et al. Analysis and interpretation of the thermal test of gas hydrate dis- sociation in the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well. Bulletin-Geological Survey of Canada, 2005, 585: 1-21.

Ning, F., Liang, J., Wu, N., et al. Reservoir characteristics of natural gas hydrates in China. Natural Gas Industry, 2020, 40(8): 1-24. (in Chinese)

Numasawa, M. Objectives and operation over view of the JOGMEC/NRCan/Aurora Mallik gas hydrate production test. Paper Presented at Proceedings of the 6th International Conference on Gas Hydrates, Vancouver, Canada, 6-10 July, 2008.

Oyama, A., Masutani, S. M. A review of the methane hydrate program in Japan. Energies, 2017, 10(10): 1447.

Pan, J., Wang, H., Leng, F., et al. 2022 Research fronts: Development trends and key research questions in 11 broad research areas. Bulletin of Chinese Academy of Sciences, 2023, 38(1): 154-166. (in Chinese)

Qi, R., Qin, X., Bian, H.,et al. Overview of molecular dynamics simulation of natural gas hydrate at nanoscale. Geofluids, 2021, 2021: 6689254.

Qi, R., Qin, X., Lu, C., et al. Experimental study on the isothermal adsorption of methane gas in natural gas hydrate argillaceous silt reservoir. Advances in Geo-Energy Research, 2022, 6(2), 143-156.

Qin, X., Liang, Q., Ye, J., et al. The response of temperature and pressure of hydrate reservoirs in the first gas hydrate production test in South China Sea. Applied Energy, 2020a, 278: 115649.

Qin, X., Lu, J., Lu, H., et al. Coexistence of natural gas hydrate, free gas and water in the gas hydrate system in the Shenhu Area. South China Sea. China Geology, 2020b, 3(2): 210-220.

Qin, X., Lu, C., Ma, C. Hydrate engine platform-Hydrate Smart V1.0. 2019SR1329033, 2019.

Qin, X., Lu, C., Tian, Y., et al. Comprehensive management platform of reservoir physical property data—GH Properties V1.0. 2021SR0245278, 2021.

Qin, X., Lu, C., Wang, P., et al. Hydrate phase transition and seepage mechanism during natural gas hydrates production tests in the South China Sea: A review and prospect. China Geology, 2022, 5(2): 201-217.

Schoderbek, D., Farrell, H., Howard, J., et al. ConocoPhillips gas hydrate production test. NT0006553, 2013.

Sloan, E. D., Koh, C. A. Clathrate Hydrates of Natural Gases. New York, USA, CRC Press, 2007.

Su, P., Liang, J., Zhang, W., et al. Natural gas hydrate accumulation system in the Shenhu sea area of the northern South China Sea. Natural Gas Industry, 2020, 40(8): 77-89. (in Chinese)

Sun, J., Cheng, Y., Qin, X., et al. The exploration and production test of gas hydrate and its research progress and exploration prospect in the northern South China Sea. Bulletin of National Natural Science Foundation of China, 2021a, 35(6): 940-951. (in Chinese)

Sun, Y., Li, S., Lu, C., et al. The characteristics and its implications of hydraulic fracturing in hydrate-bearing clayey silt. Journal of Natural Gas Science and Engineering, 2021b, 95: 104189.

Sun, Y., Lu H., Lu C., et al. Hydrate dissociation induced by gas diffusion from pore water to drilling fluid in a cold wellbore. Advances in Geo-Energy Research, 2018, 2(4): 410-417.

Terao, Y., Lay, K., Yamamoto, K. Design of the surface flow test system for 1st offshore production test of methane hydrate. Paper OTC 24719 Presented at Offshore Technology Conference Asia, Kuala Lumpur, 25-28 March, 2014.

Wei, C., Yan, R., Tian, H., et al. Geotechnical status and challenges of natural gas hydrate exploitation. Natural Gas Industry, 2020, 40(8): 116-132. (in Chinese)

Wu, N., Huang, L., Hu, G., et al. Geological controlling factors and scientific challenges for offshore gas hydrate exploration. Marine Geology and Quaternary Geology, 2017, 37(5): 5-15. (in Chinese)

Wu, N., Li, Y., Liu, L., et al. Controlling factors and research prospect on creeping behaviors of marine natural gas hydrate-bearing-strata. Marine Geology and Quaternary Geology, 2021, 41(5): 3-11. (in Chinese)

Xu, J., Qin, H., Li, H., et al. Enhanced gas production efficiency of class 1,2,3 hydrate reservoirs using hydraulic fracturing technique. Energy, 2023, 263: 126003.

Xu, W., Qin, C., Lu, P., et al. Hydrate phase transition and seepage mechanism during natural gas hydrates production tests in the South China Sea: A review and prospect. China Geology, 2022, 5(2): 201-217.

Xu, T., Zhang, Z., Li, S., et al. 3D numerical evaluation of gas hydrate production performance of the depressurization and backfilling with in-situ supplemental heat method. Journal of Engineering Geology, 2021a, 29(6): 1926-1941.

Xu, T., Zhang, Z., Li, S., et al. Numerical evaluation of gas hydrate production performance of the depressurization and backfilling with an in situ supplemental heat method. ACS Omega, 2021b, 6(18): 12274-12286.

Ye, J., Qin, X., Xie, W., et al. The second natural gas hydrate production test in the South China Sea. China Geology, 2020, 3(2): 197-209.

Zhang, Q., Qin, X., Zhang H., et al. Experimental insights into the in situ formation and dissociation of gas hydrate in sediments of Shenhu, South China Sea. Frontiers in Earth Science, 2022, 10: 882701.

Zhang, W., Liang, J., Lu, J., et al. Characteristics and controlling mechanism of typical leakage gas hydrate reservoir forming system in the Qiongdongnan Basin, northern South China Sea. Natural Gas Industry, 2020, 40(8): 90-99. (in Chinese)

Zhang, Z., Xu, T., Li, S., et al. Comprehensive effects of heat and flow on the methane hydrate dissociation in porous media. Energy, 2023, 265: 126425.

Zheng, C., Guo, G., Qin, X., et al. Molecular simulation studies on the water/methane two-phase flow in a cylindrical silica nanopore: Formation mechanisms of water lock and implications for gas hydrate exploitation. Fuel, 2023, 333: 126258.

Zou, C., Tao, S., Hou, L. Unconventional Petroleum Geology, 2nd Edition. Beijing, China, Geology Press, 2013. (in Chinese)




DOI: https://doi.org/10.46690/ager.2023.10.03

Refbacks

  • There are currently no refbacks.


Copyright (c) 2023 The Author(s)

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Copyright ©2018. All Rights Reserved