Abstract:

The Fuling shale gas field is located at the Jiaoshiba structure, eastern margin of the Sichuan Basin, which has proven geological reserves of 380.6 billion cubic meters. It is the first commercial shale gas field outside the North America. The Jiaoshiba structure is a rhomboid faulted anticline, which is controlled by the northeast and northsouth trending fault system, whose special structural settings play an important role in shale gas enrichment. The Fuling shale gas production layer is WufengLongmaxi shale, which is characterized by a large thickness of organicrich shale, high content of total organic matter (TOC), high degree of thermal maturity, high content of brittle minerals, overpressure, high initial production rates, welldeveloped natural fracture networks and alkane carbon isotopic reversal. After more than three years of development, it is confirmed that the Fuling shale gas field has abundant shale gas resource with stable production and high formation pressure. Through the analysis of regional geological features and comparison with gas fields in the U.S., the basic characteristics, enlightenment and thinking of shale gas in Fuling are summarized and put forward. Firstly, there are high production and enrichment of shale gas fields in China; but the controlling factors are different from the gas fields in the U.S. Forward structure and advanced regional strikeslip effect are extremely important. Secondly, the development of natural fractures is key to the enrichment of shale gas. Thirdly, almost all of the commercial shale gas plays have overpressure. Fourthly, through the migration and transportation of shale gas by relatively short distances, a wide range of migration and accumulation could be achieved. Fifthly, the production patterns based on different perspectives of business returns and resource utilization may impact the production performance of the Fuling shale gas field. Finally, the development of Chinas shale gas needs technology, innovative thinking and longterm perspective, and we must pay attention to the studies of shale gas in the deep marine continental strata and normal pressure strata in the outer of basin.

Key words: shale gas, enrichment regularity, WufengLongmaxi Formations, Jiaoshiba, Fuling shale gas field, enlightenment, thinking