CH_(4)和CO_(2)的水合物沉积物力学特性对比研究  

Comparative study on the mechanical properties of CH_(4) and CO_(2) hydrate-bearing sediments

作　　者：朱一铭 王嘉君 徐源鸿 应展烽[1] ZHU Yiming;WANG Jiajun;XU Yuanhong;YING Zhanfeng(School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学能源与动力工程学院,南京210094

出　　处：《非常规油气》2021年第5期1-8,共8页Unconventional Oil & Gas

基　　金：江苏省自然科学基金资助项目“天然气水合物沉积层动强度及变形机理研究”(BK20180479);中国博士后科学基金资助项目“二氧化碳置换开采天然气水合物过程沉积层强度特性及变形机理研究”(2020M681611);中央高校基本科研业务费专项资金资助项目“置换开采过程水合物沉积层变形特性与微观机理研究”(30919011286)。

摘　　要：为了深入探讨CO_(2)置换开采技术的可行性,针对开采过程中可能引起的水合物储层力学稳定性变化等问题,该文基于CH_(4)和CO_(2)水合物沉积物的三轴压缩实验,开展了力学特性对比研究工作。结果表明:置换前后水合物沉积物的应力应变关系均呈现应变硬化型;围压、温度对2种水合物沉积物的强度及模量的影响规律基本保持一致;在相同工况条件下,CO_(2)水合物沉积物具有更高的强度与模量值,即与CH_(4)水合物沉积物相比,CO_(2)水合物沉积物具有力学稳定性优势,从而证实了CO_(2)置换开采技术的力学可靠性。通过对CH_(4)和CO_(2)水合物沉积物力学性质差异性的对比分析,阐明了置换开采过程水合物沉积层的强度特性及变形机理,为系统评估CO_(2)置换开采技术的地层安全稳定性提供数据支持与理论依据。In order to deeply explore the feasibility of this replacement exploitation technology, based on the triaxial compression experiments of CH_(4)and CO_(2) hydrate-bearing sediment, the mechanical properties of sediments were comparatively studied and the possible changes in the mechanical stability of hydrate reservoir were analyzed.The results showed that the stress-strain relationship of hydrate-bearing sediments both behaved strain-hardening deformation before and after replacement.The influences of confining pressure and temperature on the strength and modulus of the two kinds of hydrate-bearing sediments remained nearly the same.Under the same condition, the CO_(2) hydrate-bearing sediment has higher strength and modulus;that is, the CO_(2) hydrate-bearing sediment has mechanical stability advantage over the CH_(4) hydrate-bearing sediment, which confirmed the mechanical reliability of the CO_(2) replacement exploitation technology.Based on the comparative analysis of mechanical properties of the two kinds of sediments, the strength characteristics and deformation mechanism of sediments are clarified during the replacement process, which provides data support and theoretical basis for systematic evaluation of sedimentary stability of CO_(2) replacement exploitation technology.

关 键 词：水合物沉积物 置换开采 应力应变关系 强度 刚度 

分 类 号：TK01[动力工程及工程热物理]