塔河9区奥陶系储层特征与控制因素分析

通过对塔河油田9区多口井的钻井、测井、地震等资料的系统分析,结合岩心观察,薄片鉴定及地球化学分析研究,认为塔河9区奥陶系凝析气藏的产气层主要为一间房组,部分为鹰山组,岩石以泥晶灰岩为主,颗粒灰岩次之。储层基质物性较差,储集空间类型主要为溶洞、裂缝,孔隙型发育较少,储集层类型为裂缝-孔洞型、溶洞型及裂缝型3种。储集层的发育受控于局部构造、断裂和裂缝及岩溶作用。岩溶作用对储层的发育至关重要,构造高部位岩溶作用较强烈,储层较发育;平面上,断裂和裂缝系统为多期岩溶作用提供渗流通道,有利储集体主要沿断裂及断裂相切部位呈片状展布;纵向上有利储层主要位于奥陶系一间房组顶面以下0~60 m的砂屑灰岩段,受到正常潜水面的大气水岩溶作用控制。

Ordovician reservoir characteristics and controlling factors analysis of 9-area in Tahe oilfield

Through systematic drilling,well logging,seismic data analysis of 9-area in Tahe oilfield,combined with core observation,thin section identification and geochemical analysis,the gas-bearing layers of ordovician condensate gas reservoir of 9-area in Tahe oilfield is mainly from Yijianfang formation,part from Yingshan formation,with mainly micrite and secondly grain limestone.The physical property of reservoir matrix is poor and the main reservoir space types are mainly caves and cracks,the pore-types are less,and there are three reservoir types,namely crack-hole type,cavity type and crack type.The reservoir development is controlled by local structure,faulting,fracture and karstification.Karstification is essential to the reservoir development,and the karstification in structural high position is strong,with developed reservoirs.On the plane,the fracture and fracture systems can provide seepage channels for karstification,the favorable reservoir body presents plate shaped distribution along the fracture and the tangent place of the fracture.Vertically the favorable reservoirs are mainly located in calcarenite section 0~60 m below ordovician Yijianfang formation,and under atmospheric water karstification control of normal phreatic surface.