塔河油田岩溶型碳酸盐岩缝洞结构研究

塔北隆起奥陶系碳酸盐岩经过上亿年的岩溶作用形成了纵横交错的溶洞和裂缝,成为复杂的储集体,位于该隆起中心部位的塔河油田就是在这样的储集体内发现了上十亿吨的石油储量。针对缝洞成因及其空间展布问题,通过对现代岩溶和古岩溶的地质考察,精细分析研究区地质、测井和地震等资料,提出表层岩溶带、渗流岩溶带和径流岩溶带划分方案,并且定义出每个岩溶带缝洞成因类型及其发育特征,建立缝洞结构模式;同时分析不同岩溶带缝洞充填物性质,为岩溶型碳酸盐岩储集空间描述和预测提供了理论依据。

Investigation of fracture-cave constructions of karsted cabonate reservoirs of Ordovician in Tahe Oilfield, Tarim Basin

The fracture-cave reservoir in Ordovician carbonates was formed by karstification in middle Paleozoic in Tahe Oilfield. It is one of the most complicated reservoirs in the world. Investigation of modern and ancient karstsand comprehensive interpretation on geological, well-logging and seismic data reveal that there are three zones (i.e. epikarst zone, vadose karst zone, and runoff karst zone) in the fracture-cave systems. Fracture-cave structure models were established for each zone to characterize the features and mechanism of fracture and cave in Ordovician carbonates in Tahe Oilfield. The filling materials in the different zones of fracture-cave system were discussed. In conclusion, the study may help to describle and predict fracture-cave reservoir in karsted carbonates.