川北二叠系大隆组页岩气勘探潜力及方向

综合利用地质、地球物理等资料，对川北地区二叠系大隆组富有机质泥页岩的时空展布特征及基本地质条件进行研究，明确了川北地区大隆组页岩储层具有“高有机碳含量，高孔隙度，高脆性矿物含量，高含气量”的有利地质条件，勘探潜力大，有望形成川北地区新的勘探领域。一是川北地区大隆组深水陆棚有利相带发育，泥页岩厚度20~45 m，分布广泛；二是大隆组富有机质泥页岩脆性矿物含量平均为82.3%，有机碳含量平均达到8.32%，有机质类型以腐殖腐泥型为主，热演化程度（R_o）平均为2.43%，孔隙度平均为3.0%，总含气量平均为4.62 m3/t；三是研究区与控盆米仓山断裂有断洼相隔，往盆内方向保存条件好。南江地区大隆组深水陆棚相富有机质泥页岩发育，保存条件好，埋深适中（2 000~5 000 m），是近期有望实现勘探突破的最有利区。 

Shale gas exploration potential and target of Permian Dalong Formation in northern Sichuan

The temporal and spatial distribution characteristics and basic geological conditions of organic rich shale in the Permian Dalong Formation in northern Sichuan Basin were studied based on the comprehensive analysis of geological and geophysical data. The Dalong Formation shale reservoir in the northern Sichuan region has favorable geological conditions of “high TOC content, high porosity, high brittle mineral content, and high gas content”, showing a great exploration potential. The first significant property is the development of favorable facies belts in the deep-water shelf of the Dalong Formation in the northern Sichuan, with a thickness of 20-45 m and a wide areal distribution. Secondly, the average brittle mineral content of organic rich shale in the Dalong Formation is 82.3%, the organic matter type is humic-sapropel type, the average organic carbon content is 8.32%, the average thermal evolution degree(R_o) is 2.43%, the average porosity is 3.0%, and the average total gas content is 4.62 m3/t. The third positive factor is that the study area is separated from the basin-controlled Micangshan Fault by fault depressions, and the preservation conditions in the direction of the basin are good. It is proposed that the deep-water shelf facies of the organic-rich mud shale of the Dalong Formation in Nanjiang area is well-preserved, and the burial depth is moderate (2 000-5 000 m). It is a most favorable area for exploration in the near future.