Potential and future exploration direction of marine shale gas resources in China

Abstract

Marine shale gas, represented by the shale gas from Wufeng-Longmaxi formations in southern China, is the main field for shale gas exploration and development in China. In recent years, marine shale gas exploration and development have been constantly facing new problems and challenges. Expanding new fields of shale gas resources and increasing shale gas production are still top priorities. The distribution characteristics, resource potential, and favorable area prediction of shale gas in typical marine formations in China are sorted out, with the results as follows. The geological and recoverable resources of shale gas in Wufeng-Longmaxi formations in Sichuan Basin and its peripheral regions are (17.50-33.19)×1012 m3 and (3.50-6.14)×1012 m3, respectively, with deep shale gas resources accounting for over 50%, mainly distributed in the high and steep structural belt in eastern Sichuan and in the low steep structural belt in southern Sichuan. The geological and recoverable resources of shale gas in the Permian Wujiaping Formation are (8.7-24.6)×1012 m3 and (1.3-3.7)×1012 m3, respectively, with exploration potential in areas such as Kaijiang-Liangping, Longjuba, Jiannan, and Sanxing in eastern Sichuan. The geological and recoverable resources of shale gas in the Qiongzhusi Formation are (5.69-12.71)×1012 m3 and (0.89-1.06) ×1012 m3, respectively, with favorable areas mainly distributed in areas such as Jingyan-Jianwei-Weiyuan-Ziyang in southwestern Sichuan, Nanjiang in northern Sichuan, and Yichang in the middle Yangtze region. The ancient marine formations such as the Doushantuo Formation, Hongshuizhuang Formation, and Xiamaling Formation have certain potential of shale gas resources, which are potential continuation of shale gas resources. The favorable areas for shale gas in the Doushantuo Formation are mainly distributed in western Hunan and Hubei and southeast Chongqing, while the favorable areas for shale gas in the Hongshuizhuang Formation are mainly distributed in the Chengde-Kuancheng area of Hebei. The favorable areas for shale gas in the Xiamaling Formation are mainly distributed in the areas of Zhuozhou in Hebei, Fangshan, Mentougou, Changping in Beijing, and Lanqi-yingzi. Based on this, three suggestions are further proposed for the future exploration direction of marine shale gas: the first is to focus on deep to ultra-deep and normal pressure shale gas, move towards new layers, and expand the field of shale gas exploration; the second is to deepen and enrich the exploration theory of deep to ultra-deep shale gas, normal pressure shale gas, and shale gas of new layer in the new area; the third is to focus on the improvement and innovation of deep to ultra-deep shale gas drilling and production technology and supporting equipment, and reduce the drilling and production costs of single wells of normal pressure shale gas.

Keywords

• marine shale gas
• resource potential
• favorable area
• deep-ultra deep layers
• exploration prospect