塔里木盆地牙哈—英买力寒武系潜山区优质储层形成模式

Formation model of high-quality reservoirs within Cambrian buried hill in Yaha-Yingmaili area,Tarim Basin

碳酸盐岩潜山是国内外油气勘探的热点领域,为探讨长期抬升淋滤区多期岩溶的剥离问题,明确潜山优质储层形成演化模式,以塔里木盆地牙哈—英买力寒武系潜山为研究对象,在系统分析储层岩石类型、储集空间类型、储层物性特征的基础上,探讨储层主控因素,建立优质储层形成模式。研究发现:牙哈—英买力地区储层岩性以晶粒云岩、砂屑云岩为主;晶间溶孔、溶蚀孔洞等次生孔隙为主要储集空间;储层非均质性强。台内滩亚相储层物性明显优于潮坪—潟湖亚相,反映了原始沉积相带是储层发育的物质基础;提出前热液表生岩溶和后热液表生岩溶,总结了2类岩溶的识别标志并明确了研究区以前热液表生岩溶作用为主。最终,结合构造演化和成岩作用研究成果,建立了研究区优质储层形成模式,预测了储层平面分布。

Buried hill reservoir is one of the hottest areas of carbonate exploration in China and abroad.In order to recognize different stages of karstification,confirm formation model of high-quality reservoirs,YahaYingmaili block was chosen as an example and main controlling factors in this block were discussed based on the analysis of reservoir rock types,reservoir space types and reservoir physical property systematically.The results show that main reservoir rocks include crystalline dolostones and sandy dolostones and intercrystalline dissolved pores and vugs are the main reservoir space with high heterogeneity.Reservoir physical property of intraplatform shoal was better than that of tidal flat to lagoon dramatically and this reflects that the original facies was the fundamental factor of reservoir development.Meanwhile,pre-hydrotherm karstification and post-hydrotherm karstification were proposed.Furthermore,identifications of the two kinds of karstification were summarized and pre-hydrotherm karstification had a significance effect on reservoir quality.Finally,combined with the studies of tectonic evolution and diagenesis,formation model of high-quality reservoirs was established and reservoir distribution was predicted.