摘要:
塔里木盆地奥陶系碳酸盐岩地层中蕴藏丰富的油气资源,多期次不同类型岩溶作用叠加改造是形成塔中古岩溶储层的主要动因,断裂是影响岩溶储层发育的重要因素。中古8井区加里东期发育北西-南东逆冲断裂带,海西期发育北东-南西向走滑断裂带,组成网状断裂系统。岩溶储层发育于鹰山组顶面0~120 m深度范围内,类型细分为:孔洞型、洞穴型、裂缝型和裂缝—孔洞型4种,以裂缝-孔洞型和孔洞型为主。加里东至海西期多期、多组断裂及伴生的裂缝网状系统形成良好的流体运移通道,促进缝洞系统的形成与埋藏溶蚀作用及内幕白云岩化的发生,改善了储层的储集性能,形成碳酸盐岩孔-洞-缝复合型储集体。
Abstract:
There are abundant oil and gas resources in the Ordovician carbonate formation of the Tarim ba-sin.The superposition and transformation in many episodes of different types of karst development are the main driving force of Tazhong ancient karst reservoirs.Faults are an important factor affecting karst reser-voirs.The Medieval No.8 wellblock is situated in a northwest-southeast trending thrust fault zone of the Caledonian period and a northeast-southwest trending strike-slip fault zone of the Hercynian period,which form a network system.The karst reservoirs developed in the subsurface from the top of Yingshan formation to 120 km depth,which are of hole type,cavity type,fissure type and fissure-hole type.Of these,the fis-sure-hole type and hole-type are dominant.The multi-episode faults and associated fissure network system of the Caledonian to Hercynian period serve as good migration channels for fluids,which promote the develop-ment of the fissure-hole system,burial dissolution and dolomitization,improving the performance of reser-voirs to become a complex combination of carbonate holes,cavities and cracks.
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