深层页岩储层孔隙连通性发育特征及其控制因素
——以川南地区龙马溪组为例

Development characteristics of pore connectivity in deep shale reservoirs and its controlling factors: a case study of Longmaxi Formation in southern Sichuan Basin 

郝绵柱 姜振学 聂舟 薛子鑫 钟光海 贺世杰 苏展飞 吴伟

中海石油（中国）有限公司深圳分公司，广东 深圳 518054 中国石油大学（北京）非常规油气科学技术研究院，北京 102249 中国石油大学（北京）油气资源与探测国家重点实验室，北京 102249 四川长宁天然气开发有限责任公司，四川 成都 610000 中国石油西南油气田公司页岩气
研究院，四川 成都 610000 中国石油大庆油田有限责任公司勘探开发研究院，黑龙江 大庆 163712）

Shenzhen Branch of CNOOC Ltd., Shenzhen 518054, China Unconventional Oil and Gas Research Institute, China University of Petroleum, Beijing 102249, China State Key Laboratory of Petroleum Resources and Exploration, China University of Petroleum, Beijing 102249, China Sichuan Changning Natural Gas Development Co., Ltd., Chengdu 610000, China Shale Gas Research Institute, Southwest Oil and Gas Field Company, PetroChina, Chengdu 610000, China Exploration and Development Research Institute, Daqing Oilfield Co., Ltd., Daqing 163712, China

川南地区龙马溪组深层页岩展现了极大的勘探潜力，但目前对此类储层的孔隙连通性发育特征仍然缺乏详细深入的认识。文中选取泸州和长宁西地区6口深层井龙马溪组的6块样品为研究对象，用扫描电镜直接观察样品孔隙形态，运用低温气体吸附和高压压汞等实验手段研究孔隙结构特征，采用去离子水/正癸烷自吸斜率评估亲水/亲油孔隙网络的连通性特征。基于实验结果，讨论了页岩优势矿物组成、镜质组反射率Ro、总有机碳质量分数TOC和孔隙结构参数对孔隙连通性的影响。有机质孔、有机质￣黏土矿物复合孔、有机质￣黄铁矿复合孔为连通性较好的孔隙类型，粒间孔及溶蚀孔的连通性相对较差；亲油孔隙网络较亲水孔隙网络更为发育，也更有利于页岩气的运聚；高含量的石英、适量的黏土矿物、适宜的热演化程度、高TOC以及高孔隙体积易于形成优势连通通道，进而提高储层孔隙连通性。整体上，泸州地区储层孔隙连通性要优于长宁西地区。

The deep shale of Longmaxi Formation in southern Sichuan Basin has shown great exploration potential. However, the pore development characteristics of pore connectivity in deep shale reservoir are still lack of detailed and in-depth understanding. Selecting six samples of Longmaxi Formation from six deep wells in Luzhou and west Changning area as research objects, the pore morphology was directly observed by scanning electron microscopy, the pore structure characteristics were studied by low temperature gas adsorption and high pressure mercury injection, and the spontaneous imbibition slope of deionized water and n-decane was used to evaluate the connectivity characteristics of hydrophilic and hydrophobic pore networks respectively. Based on experiments, the effects of dominant mineral composition, Ro, TOC content and pore structure parameters on pore connectivity are discussed. The organic matter pores, organic-clay composite pores and organic-pyrite composite pores have good connectivity, while intergranular pores and dissolution pores have relatively poor connectivity. Hydrophobic pore network is more developed than the hydrophilic one, which is more conducive to the migration and accumulation of shale gas. High quartz content, a certain amount of clay, suitable degree of thermal evolution, high TOC content and high pore volume are easy to form dominant connectivity channels, thus impro-ving the pore connectivity of the reservoir. On the whole, the pore connectivity of Luzhou area is better than that of west Changning area.

10.6056/dkyqt202206007