Rapid dissociation and on-site saturation evaluation of methane hydrate sediment samples for natural gas hydrate exploitation

Abstract

Natural gas hydrate is a kind of clean energy with huge reserves, and the saturation (volume percentage of hydrate in pore space of sediments) is the key parameter for determining whether the reservoir is worthy of exploitation. In this work, rapid hydrate dissociation by the combination of heat injection and NaCl inhibitor addition was studied, and an on-site evaluation method for hydrate saturation in sediment samples was proposed by using a core sampler to transfer hydrate samples under pressure. The results showed that the average gas production rate per unit volume was increased significantly to reach 7.22 L/Lr·min-1 by the injection of NaCl aqueous solution with 50.9 °C, which was attributed to the increase of the chemical potential to further accelerate the rate of hydrate dissociation in the presence of NaCl. Furthermore, for the measurement of methane hydrate samples saturation with a volume of 673 cm³ (which contained 1.4 mol hydrates with the saturation of 58%), hydrate saturation could be accurately achieved within 30 min with a relative error lower than 11.7% This work may provide new thoughts for on-site saturation evaluation and rapid dissociation of hydrate samples during natural gas hydrate exploitation.

Keywords

Natural gas hydrate / Saturation / Rapid on-site measurement / NaCl solution / Rapid dissociation

Declaration of competing interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

This study has been supported by the National Natural Science Foundation of China (21736005), and the National Key R&D Program of China (2016YFC0304006 and 2017YFC0307302).

References

[1] X.S. Li, C.G. Xu, Y. Zhang, et al., Investigation into gas production from natural gas hydrate: a review, Appl. Energy 172 (2016) 286-322.

[2] T. Nakajima, Y. Kakuwa, Y. Yasudomi, et al., Formation of pockmarks and submarine canyons associated with dissociation of gas hydrates on the Joetsu Knoll, eastern margin of the Sea of Japan, J. Asian Earth Sci. 90 (4) (2014) 228-242.

[3] N. Vedachalam, S. Srinivasalu, G. Rajendran, et al., Review of unconventional hydrocarbon resources in major energy consuming countries and efforts in realizing natural gas hydrates as a future source of energy, J. Nat. Gas Sci. Eng. 26 (2015) 163-175.

[4] Y. Song, Y. Lei, J. Zhao, et al., The status of natural gas hydrate research in China: a review, Renew. Sustain. Energy Rev. 31 (2014) 778-791.

[5] Portnoy Alexey, Ann E. Cook, E. Sawyer Derek, et al., Clustered BSRs: evidence for gas hydrate-bearing turbidite complexes in folded regions, example from the Perdido Fold Belt, northern Gulf of Mexico, Earth Planet Sci. Lett. 528 (2019) 115843.

[6] Laxmi Pandey, Sain Kalachand, K. Joshi Anju, Estimate of gas hydrate saturations in the Krishna-Godavari basin, eastern continental margin of India, results of expedition NGHP-02, Mar. Pethol. Geol. 108 (2019) 581-594.

[7] Bappa Mukherjee, Sain Kalachand,Prediction of reservoir parameters in gas hydrate sediments using artificial intelligence (AI): a case study in Krishna-Godavari basin (NGHP Exp-02), J. Earth Syst. Sci. 128 (7) (2019) 199.

[8] Shankar Uma,Pandey Ashok Kumar, Estimation of gas hydrate saturation using isotropic and anisotropic modelling in the Mahanadi basin, J. Earth Syst. Sci. 128 (6) (2019) 163.

[9] C. Peng, C.C. Zou, Z.Q. Lu, et al., Evidence of pore-and fracture-filling gas hydrates from geophysical logs in consolidated rocks of the muli area, Qinghai-Tibetan plateau permafrost, China, J. Geophys. Res. Solid Earth 124 (7) (2019) 6297-6314.

[10] Shankar Uma, Michael Riedel, Heat flow and gas hydrate saturation estimates from Andaman Sea, India, Mar. Petrol. Geol. 43 (2013) 434-449.

[11] Kun Xiao, Changchun Zou, Biao Xiang, et al., Acoustic velocity log numerical simulation and saturation estimation of gas hydrate reservoir in Shenhu area, South China Sea, Sci. World J. (2013) 1-13.

[12] A. Malinverno, M. Kastner, M.E. Torres, et al., Gas hydrate occurrence from pore water chlorinity and downhole logs in a transect across the northern Cascadia margin (Integrated Ocean Drilling Program Expedition 311), J. Geophys. Res.: Solid Earth 113 (B8) (2008).

[13] M. Riedel, T.S. Collett, R.D. Hyndman, Gas hydrate concentration estimates from chlorinity, electrical resistivity and seismic velocity, Geol. Surv. Can 4934 (2005) 28.

[14] M.W. Lee, Gas hydrates amount estimated from acoustic logs at the Blake Ridge, sites 994, 995 and 997, Scientific Results,in: C. K. Paull, R. Matsumoto, P.J. Wallace, et al.Eds.), (Proceedings of the Ocean Drilling Program, 2000, pp. 193-198, 164.

[15] M.W. Lee, T.S. Collett, In-situ gas hydrate saturation estimated from various well logs at the Mount Elbert gas hydrate stratigraphic test well, Alaska North Slope, Mar. Petrol. Geol. 28 (2011) 439-449.

[16] Youhai Zhu, Pingkang Wang, Shouji Pang, Shuai Zhang, Rui Xiao, A review of the resource and test production of natural gas hydrates in China, Energy Fuel. 35 (2021) 9137-9150.

[17] X. Wang, D.R. Hutchinson, S. Wu, S. Yang, Y. Guo, Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea, J. Geophys. Res. Solid Earth 116 (2011) 1-18.

[18] Jin Qian, Xiujuan Wang, Timothy S. Collett, et al., Downhole log evidence for the coexistence of structure II gas hydrate and free gas below the bottom simulating reflector in the South China Sea, Mar. Petrol. Geol. 98 (2018) 662-674.

[19] Tao Liu, Xuewei Liu, Tieyuan Zhu, Joint analysis of P-wave velocity and resistivity for morphology identification and quantification of gas hydrate, Mar. Petrol. Geol. 112 (2020) 104036.

[20] Haojie Pan, Hongbing Li, Jingyi Chen, et al., A unified contact cementation theory for gas hydrate morphology detection and saturation estimation from elastic-wave velocities, Mar. Petrol. Geol. 113 (2020) 104146.

[21] Jingchun Feng, Yi Wang, Xiaosen Li, Dissociation characteristics of watersaturated methane hydrate induced by huff and puff method, Appl. Energy 211 (2018) 1171-1178.

[22] Huiru Sun, Bingbing Chen, Guojun Zhao, et al., The enhancement effect of water-gas two-phase flow on depressurization process: important for gas hydrate production, Appl. Energy 276 (2020) 115559.

[23] Shuxia Li, Ruyi Zheng, Xinhua Xu, et al., Energy efficiency analysis of hydrate dissociation by thermal stimulation, J. Nat. Gas Sci. Eng. 30 (2016) 148-155.

[24] Yongchen Song, Tingting Luo, B.N. Madhusudhan, et al., Strength behaviors of CH4 hydrate-bearing silty sediments during thermal decomposition, J. Nat. Gas Sci. Eng. 72 (2019) 103031.

[25] Shuxia Li, Zhiqiang Wang, Xinhua Xu, et al., Experimental study on dissociation of hydrate reservoirs with different saturations by hot brine injection, J. Nat. Gas Sci. Eng. 46 (2017) 555-562.

[26] A.M. Gambelli, F. Rossi, The use of sodium chloride as strategy for improving CO2/CH4 replacement in natural gas hydrates promoted with depressurization methods, Arab. J. Geoences 13 (2020) 898.

[27] Yi Gao, Zhanquan Ma, Mingjun Yang, et al., Dissociation characteristic of remolded methane hydrates deposits from South China Sea using depressurization, Energy Procedia 158 (2019) 5355-5360.

[28] Jiafei Zhao, Zihao Zhu, Yongchen Song, et al., Analyzing the process of gas production for natural gas hydrate using depressurization, Appl. Energy 142 (2015) 125-134.

[29] Tingting Luo, Yanghui Li, Weiguo Liu, et al., Experimental studies on gas production rate of in-situ hydrate-bearing clay in thermal recovery and depressurization methods, Energy Procedia 158 (2019) 5251-5256.

[30] Yi Wang, Jingchun Feng, Xiaosen Li, Experimental Investigation of influence of well spacing on hydrate dissociation by heat stimulation in sandy sediment, Energy Procedia 158 (2019) 5699-5704.

[31] Mingjun Yang, Zhanquan Ma, Yi Gao, et al., Dissociation characteristics of methane hydrate using depressurization combined with thermal stimulation, Chin. J. Chem. Eng. 27 (2019) 2089-2098.