渤中22-1构造碳酸盐岩储层岩溶识别及影响因素

Karst Identification and Influencing Factors on Carbonate Reservoir in Bozhong 221 Buried Hill Structure

以渤中22-1潜山构造为研究目标,通过岩芯、薄片、成像测井等资料,研究潜山碳酸盐岩储层基础特征、岩溶识别及影响因素。结果表明,研究区岩性主要为白云岩类、灰岩类及过渡岩类,储集空间以溶蚀孔、洞、缝为主,平均孔隙度为4.1%,储层主要受沉积相、裂缝作用和岩溶作用的控制。沉积微相影响溶蚀程度,研究区发育局限台地相和开阔台地相,其中,台内滩微相和云质瀉湖微相基质孔隙发育,有利于溶蚀作用发生;构造作用形成的断裂、裂缝系统改善储集空间,是岩溶的先期通道;多期岩溶作用是储层形成的关键,通过岩芯和成像测井对科2井岩溶结构进行识别,表生岩溶影响深度达不整合面以下180 m。受岩溶旋回控制,发育有4个垂直渗流—水平潜流带,水平潜流带物性最好,为优质储层发育带。

The basic characteristics,karst identification and influencing factors of carbonate reservoir in buried hill were studied by means of core,thin section,imaging logging and other data.The results show that the lithology of the study area is mainly dolomite,limestone and transition rock.The reservoir space is dominated by dissolution holes,holes and fractures with an average porosity of 4.1%.The reservoir is mainly controlled by sedimentary facies,fractures and karsts.The sedimentary microfacies influence the dissolution degree,and the restricted platform facies and open platform facies are developed in the study area,among which the in-platform beach microfacies and cloud lagoon microfacies matrix pores are developed,which are conducive to the occurrence of dissolution.The improvement of reservoir space by fault and fracture system formed by tectonics is the early channel of karst.Karstification is the key to the formation of reservoirs.The karst structure in Well Ke2 was identified by core and imaging logging,and the influence depth of epigenic karst reaching 180 m below the unconformity surface.Under the control of karst cycle,there are four vertical percolation-horizontal subsurface flow zones,and the best physical property is the horizontal subsurface flow zone,which is a high-quality reservoir development zone.