川东北元坝地区上二叠统长兴组超深层礁滩岩性气藏中裂缝特征

Fracture characteristics of ultra-deep reef-bank lithologic gas reservoirs in the Upper Permian Changxing Formation in Yuanba area, Northeastern Sichuan Basin

范小军 彭俊 李吉选 陈丹 李凤 邓金花 黄勇 缪志伟

Fan Xiaojun Peng Jun Li Jixuan Chen Dan Li Feng Deng Jinhua Huang Yong Miao Zhiwei

为明确川东北元坝长兴组礁滩储层裂缝特征，通过对多口井长兴组储层裂缝特征的精细刻画和构造、生烃、成岩、孔隙等演化作用的动静态研究指出，裂缝纵向上主要发育于长兴组二段，平面分布非均质性较强，各井区差异性较大，构造相对高部位的裂缝较发育；裂缝类型可细化为3大类、11小类，主要发育3期裂缝，同时建立了典型裂缝标准识别图版及分类评价指标体系；裂缝形成主要受构造、埋藏及溶蚀等作用控制。缝-孔动态配置则表现为裂缝与有效孔隙网状交错配置形成有效储集空间或构建网状立体输导体系，其中第二、第三期缝-孔配置较第一期更好，对储层储渗性能和产能有积极贡献作用。认为元坝长兴组西北部为油气有利富集区。

In order to understand the fracture characteristics of reef-bank reservoir in the Changxing Formation in Yuanba area,northeastern Sichuan Basin,this paper finely described the fractures of the Changxing Formation in many wells,and also studied the tectonic evolution,hydrocarbon generation,diagenesis and the porosity evolution.Vertically,the fractures are mainly distributed in the 2 Member of Changxing Formation.While laterally,they show strong heterogeneity in distribution,with heterogeneity being different in different blocks.Fractures are relatively well developed on structural high.The fractures can be divided into 3 types and 11 subtypes developed mainly in 3 stages.We established the classification evaluation index system and the standard identification chart of typical fractures.The formation of fractures is mainly controlled by the tectonic evolution,burial and dissolution.The dynamic fracture-pore assemblages of the 2 and 3 stages are better than that of the 1 stage.These assemblages form effective storage space or reticular carrier systems and make a positive contribution to the reservoir property and productivity.The comprehensive analysis indicates that the Changxing Formation in the northwestern Yuanba area is favorable for enrichment of oil/gas.

10.11743/ogg20140410