岩土工程学报2025，Vol.47Issue(7)：1354-1364,11.DOI:10.11779/CJGE20240762
CO2置换开采CH4水合物的深海地层多场耦合连续介质数值方法研究
Multi-field coupling continuum numerical method for exploiting CH4 by CO2 replacement in deep-sea formation
摘要
Abstract
The extraction method that induces hydrate dissociation may deteriorate the mechanical properties of methane hydrate bearing sediments(MHBS),potentially leading to a series of significant disasters.The carbon dioxide(CO2)replacement method can effectively improve the sediment strength,but few methods have considered its mechanical response.So,a numerical method for the CO2 replacement method as well as its application is studied.Based on TOUGH+HYDRATE,a numerical simulator,T+MixH V1.0 is developed to simulate the CO2 replacement process by incorporating the Chen-Guo hydrate model to calculate the multi-component hydrate phase equilibrium conditions.The reliability of the simulator is validated by comparing with other experimental and numerical results.Then,a thermo-hydro-mechanic-chemical multi-field coupling numerical method for the CO2 replacement is established by coupling with FLAC3D.Finally,the gas hydrate exploitation is simulated through depressurization and CO2 replacement methods in the South China Sea,as well as the plate loading tests on MHBS ground during gas production.The results indicate that the CO2 replacement increases gas production and mitigates subsidence of the ground,which comes from that depressurization causes energy loss,limiting the decomposition of CH4 hydrate,whereas the CO2 replacement method occurs spontaneously,and the generated CO2 hydrate provides support in the ground.Besides,the bearing characteristics of MHBS ground are mainly affected by two factors:the effective stress variation caused by pore pressure changes,and the bond strength variation induced by gas hydrate decomposition/generation.关键词
深海能源土/二氧化碳置换法/Chen-Guo水合物模型/多场耦合模拟/地基承载力Key words
methane hydrate bearing sediment/carbon dioxide replacement method/Chen-Guo hydrate model/coupling simulation/bearing capacity of ground分类
土木建筑引用本文复制引用
蒋明镜,李子煜,李承超,姜朋明..CO2置换开采CH4水合物的深海地层多场耦合连续介质数值方法研究[J].岩土工程学报,2025,47(7):1354-1364,11.基金项目
国家自然科学基金重点项目(52331010) （52331010）
国家自然科学基金重大项目课题(51890911) （51890911）
国家自然科学基金青年项目(52309139) （52309139）
江苏省高校自然科学面上基金项目(22KJB570004) （22KJB570004）
江苏省研究生科研创新计划项目(KYCX23_3330)This work was supported by Key Program of National Natural Science Foundation of China(Grant No.52331010) （KYCX23_3330）
Major Program of National Natural Science Foundation of China(Grant No.51890911) （Grant No.51890911）
Youth Program of National Natural Science Foundation of China(Grant No.52309139) （Grant No.52309139）
the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province(Grant No.22KJB570004) （Grant No.22KJB570004）
the Jiangsu Provincial Graduate Research and Practice Innovation Program(Grant No.KYCX23_3330). （Grant No.KYCX23_3330）
