Open Access

ARTICLE

Impact of Permeability Heterogeneity on Methane Hydrate Production Behavior during Depressurization with Controlled Sand Production

Junyu Deng^1,2, Rui Zhang^1,*, Xudong Zhao³, Hongzhi Xu^1,2, Peng Ji¹, Zizhen Zhang¹, Yifan Yang¹

1 School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, 266580, China
2 Engineering Technology Research Company Limited, China National Petroleum Corporation (CNPC), Tianjin, 300450, China
3 Changqing General Drilling Company, CNPC Chuanqing Drilling Engineering Company Limited, Xi’an, 710000, China

* Corresponding Author: Rui Zhang. Email:

Energy Engineering 2025, 122(10), 4153-4168. https://doi.org/10.32604/ee.2025.065906

Received 24 March 2025; Accepted 23 May 2025; Issue published 30 September 2025

Abstract

Field tests have demonstrated that depressurization with controlled sand production is an effective technique for natural gas hydrate extraction. Variations in depositional environments and processes result in significant heterogeneity within subsea natural gas hydrate-bearing sediments. However, the influence of permeability heterogeneity on production performance during depressurization with controlled sand production remains inadequately understood. In this study, a multiphase, multi-component mathematical model is developed to simulate depressurization with controlled sand production in methane hydrate-bearing sediments, incorporating geological conditions representative of unconsolidated argillaceous siltstone hydrate deposits in the Shenhu area of the South China Sea. The effects of permeability heterogeneity-specifically, horizontal autocorrelation length and global permeability heterogeneity-on production performance during depressurization with sand production are investigated using geostatistical modeling combined with finite difference method based numerical simulations. Results show that as the horizontal autocorrelation length of permeability distribution increases, cumulative gas production first rises and then declines, reaching its peak at λ_Dh = 0.1, whereas sand production steadily increases. In addition, higher formation permeability heterogeneity results in increased cumulative gas and sand production, suggesting that greater heterogeneity promotes methane hydrate decomposition and gas recovery. These findings can offer valuable insights for optimizing future field development of hydrate-bearing sediments by depressurization with controlled sand production.

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Keywords

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