The Qingdao Institute of Marine Geology, China Geological Survey, has recently made new progress in its research on engineering geological risk assessment of marine hydrates.

　　This study focuses on the dual-well extraction process in natural gas hydrate reservoirs, revealing the relationships among multiple physical fields, production rates, and well spacing during dual-well extraction. It also establishes a method for determining the optimal well spacing for dual-well extraction in natural gas hydrate reservoirs. The findings have been published in "Energy," a top-tier international journal in the energy field (Zone 1 Top, impact factor 8.857).

　　A multi-well extraction system can effectively enhance both the production rate and extraction speed of natural gas hydrates, making it one of the viable and effective approaches for achieving commercial-scale exploitation of natural gas hydrates. Therefore, clarifying the dynamic response characteristics of the reservoir and the interwell interactions during multi-well extraction is crucial and forms the foundation for subsequent productivity evaluation and the development of optimal exploitation strategies. To this end, researchers have conducted numerical simulations of the dual-well extraction process for natural gas hydrates, analyzing how well spacing affects the hydrate dissociation process, reservoir response characteristics, and production capacity trends.

　　On this basis, a method for determining the well spacing between two wells is proposed, taking into account the hydrate dissociation front and production rate during dual-well exploitation. This method allows for the estimation of a reasonable well spacing while ensuring sufficient production, thus providing a new approach for determining the layout of multi-well exploitation systems.

　　The above research was jointly supported by the National Natural Science Foundation of China, the China Scholarship Council, and a major project under the 14th Five-Year Plan of the Laoshan Laboratory. It was conducted jointly by research teams from the Qingdao Institute of Marine Geology, the Laoshan Laboratory, China University of Petroleum (East China), and the University of Waterloo in Canada. (Dong Lin, Li Yanlong)