世界首个海洋天然气水合物固态流化开采大型物理模拟实验系统

天然气水合物(以下简称水合物)分别蕴藏于海洋和陆地永冻土带中,但前者的储量约为后者的100倍。海洋环境中的大部分脉状、块状水合物以及细粒沉积物中的水合物都属于非成岩天然气水合物,一般没有像常规油气藏和砂岩水合物储层那样稳定的圈闭构造。针对海洋非成岩水合物的物理特征、成藏特点,依据水合物固态流化开采法的工艺流程,建立了世界首个海洋天然气水合物固态流化开采实验室。该实验室定位于"全自动化的白领型实验室",实验系统共分为大样品快速制备及破碎、高效管输、高效分离、快速检测等模块单元。该实验室的主体功能包括:(1)高效破岩能力评级;(2)海洋天然气水合物层流化试采携岩能力评价;(3)水合物非平衡分解规律及流态动变规律评价;(4)不同机械开采速率条件下水合物安全输送;(5)井控安全规律模拟。该实验室的关键技术指标:工作压力12 MPa、水平管长度65 m、立管长度30 m、管径3英寸。该实验室能模拟1 200 m水深的全过程水合物固态流化开采工艺过程,是西南石油大学联合中国海洋石油总公司、宏华集团原始创新自主设计、自主研发的标志性实验室。

The first global physical simulation experimental systems for the exploitation of marine natural gas hydrates through solid fluidization

Natural gas hydrates (NGHs) are restored in seas and terrestrial frozen soil on the earth. Marine NGH reserves are about 100 times that in land. In a marine environment, most of the veins-like or bulk hydrates and hydrates in fine-grained sediments belong to nondiagenetic NGHs, and there is no such a stable entrapment structure like a conventional hydrocarbon reservoir or sandstone hydrate reservoir. According to the physical characteristics and reservoir characteristics of marine NGHs, Southwest Petroleum University innovatively proposed a solid fluidization exploitation method, and established the first global laboratory for the solid fluidization exploitation of marine NGHs. This lab owns high-quality devices and equipment as well as automatic experimental systems, which consist of several modules including rapid preparation of large samples & fragmentation, efficient pipe transportation, efficient separation, rapid detection and so on. Its main functions are rating of efficient rock breaking capacity, evaluation of rock carrying capacity in marine NGH fluidization pilot exploitation, evaluation of hydrate non-equilibrium decomposition and flow patterns dynamic change laws, safe hydrate transportation under different mining rates, and simulation of well control safety. Its key technical indicators are as follows: 12 MPa working pressure , 65 m-long horizontal pipes, 30 m-long standpipes, and three-inch pipe diameter. In this lab the whole process of solid fluidization exploitation of NGHs 1 200 meters deep under water can be simulated, which is a landmark of this laboratory with original innovation, independent design, independent research and development. It was jointly built by the Southwest Petroleum University, CNOOC and the Honghua Group Limited.