四川盆地陆相页岩气形成条件及勘探开发前景

与北美页岩气主要形成于海相富有机质泥页岩层系相比，我国主要含油气盆地页岩气具有赋存于陆相及海陆过渡相富有机质泥页岩层系的特点，是未来非常规油气资源勘探开发新的重要领域。为此，综合应用野外地质剖面勘测、岩心及其测试分析资料，对四川盆地陆相页岩气形成条件、含气特征及可采性等进行了分析。结果表明：四川盆地上三叠统须家河组和下侏罗统自流井组的河、湖相泥页岩具分布广、厚度大、有机质丰度较高、保存条件好、脆性矿物含量高的特点，有利于页岩气的成藏和压裂改造。通过老井复查和常规兼探，已在川东建南、涪陵地区和川东北元坝地区自流井组，川西新场地区须家河组泥页岩中获得良好的天然气显示和工业气流。结论认为：四川盆地陆相页岩气与北美海相页岩气形成条件相当，优于圣胡安盆地海陆过渡相Lewis页岩，具有良好的勘探开发前景。初步优选川中阆中-平昌、三台-广安，川东南涪陵-长寿为自流井组页岩气勘探的有利地区，川西孝泉-新场、川中三台-广安为须家河组（须五段）页岩气勘探的有利地区。

Pooling conditions of non-marine shale gas in the Sichuan Basin and its exploration and development prospect

In North America,shale gas plays are dominated by organic rich marine shales.In contrast,shale gas plays are predominated by organic-rich shales of continental facies and transitional facies in the major petroliferous basins in China.Non-marine shale gas plays will be new frontiers for exploration and development of unconventional gas in the future in China.In view of this,field outcrop observation,core observation and test data were integrated to study the pooling conditions of shale gas,gas-bearing properties and producibility of the non-marine shales in the Sichuan Basin.The non-marine shales in the Upper Triassic Xujiahe and the Lower Jurassic Ziliujing formations in the Sichuan Basin are characterized by extensive distribution,great thickness,high organic abundance,good sealing conditions,and high content of brittle minerals,which are favorable for shale gas pooling and hydraulic fracture stimulation.Through old well review and exploratory drilling,significant gas shows have been obtained and industrial gas flows have been tested in the Ziliujing Formation shales in the Jiannan and Fuling areas in the eastern Sichuan Basin and the Yuanba area in the northeastern Sichuan Basin,as well as the Xinchang area in the Xujiahe Formation in the western Sichuan Basin.It is believed that the non-marine shales in the Sichuan Basin have comparable conditions for gas pooling with the marine shales in North America,and even are better than the Lewis Shale of transitional facies in the San Juan Basin,thus their shale gas exploration potential is great.The following play fairways were preliminarily selected: the Langzhong-Pingchang and Santai-Guang’an areas in the Central Sichuan Basin and the Fuling-Changshou area in the southeastern Sichuan Basin favorable for shale gas exploration in the Ziliujing Formation;the Xiaoquan-Xinchang area in the western Sichuan Basin and the Santai-Guang’an area in the Central Sichuan Basin favorable in the Xujiahe Formation.