南堡凹陷二号断裂带古生界碳酸盐岩潜山岩溶模式  

Karst model of Paleozoic carbonate buried hill in No.2 fault zone of Nanpu Sag

作　　者：田晓平 张汶 周连德 沈孝秀 郭维 TIAN Xiaoping;ZHANGWen;ZHOU Liande;SHEN Xiaoxiu;GUOWei(TianjinBranchofCNOOCLimited,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《岩性油气藏》2021年第6期93-101,共9页Lithologic Reservoirs

基　　金：“十三五”国家科技重大专项“渤海油田高效开发示范工程”(编号:2016ZX05058)资助。

摘　　要：南堡凹陷古生界潜山为渤海海域重要的油气勘探和评价目标。为研究该构造二号断裂带古生界碳酸盐岩潜山岩溶模式,通过岩心观察、薄片鉴定、测井分析、构造演化、岩溶演化模式等研究,结合古地貌特征对各区块岩溶模式差异性进行了综合分析。结果表明:①岩溶储层岩性为灰岩和白云岩,具有双重孔隙介质特征,其基质孔隙连通性较差,裂缝在储集空间中起到关键作用。一方面可对微观孔隙进行沟通疏导,另一方面沿裂缝发育的溶蚀孔洞为重要的储集空间。②潜山岩溶储层主要经历了表生期岩溶作用和埋藏期胶结作用,其中表生期岩溶受印支—燕山早期逆冲褶皱作用影响,形成了现今构造格局和断裂系统,控制了岩溶储层的发育和分布,但燕山中晚期—喜山期的埋藏胶结为岩溶储层形成过程中的破坏作用,主要表现为地表水和地层水对早先形成的缝洞储集空间进行充填。③岩溶作用强度受古地貌和断裂控制。根据古地貌形态及岩溶作用强度划出岩溶高地、岩溶斜坡区和岩溶洼地,各区块间及同区块内岩溶储层发育程度差异主要是离断层远近、古地貌位置高低和斜坡陡缓的原因造成的。其中靠近断裂的古地貌斜坡缓坡带岩溶作用最强,保存条件最好,岩溶储层最为发育,为油气勘探的有利目标。该研究成果对碳酸盐岩潜山的油气勘探具有指导意义。The Paleozoic buried hill in Nanpu Sag is an important target for oil and gas exploration and evalua‐tion in Bohai Sea.In order to study the karst model of Paleozoic carbonate buried hill in No.2 fault zone of Nanpu Sag,based on core observation,thin section identification,logging analysis,structural evolution,karst evolu‐tion model,combined with paleogeomorphology characteristics,the differences of karst models in each block were comprehensively analyzed.The results show that:(1)the lithology of karst reservoir is limestone and dolomite,with the characteristics of dual pore medium.The connectivity of matrix pores is poor,and fractures play a key role in the reservoir space.They can communicate and dredge the micropores and dissolved pores developed along the fractures are important reservoir spaces.(2)The buried hill karst reservoir mainly experienced supergene karstification and burial cementation.The supergene karstification was affected by the Indosinian-Early Yan‐shanian thrust folding,forming the current structural pattern and fault system,controlling the development and distribution of karst reservoir.On the other hand,the burial cementation in the Middle-Late Yanshanian-Himalayan period is mainly manifested as the filling of the fracture cavity reservoir space formed earlier by surface water and formation water,which is the destructive effect in the process of karst reservoir formation.The intensity of karstification is controlled by paleogeomorphology and faults.According to the paleogeomorphic morphology and karstification intensity,karst Highlands,karst slope areas and karst depressions are divided.The differences in the development degree of karst reservoirs between different blocks and within the same block are mainly caused by the distance to the fault,the position of paleogeomorphology and the steep and gentle slope.(3)The intensity of karstification is controlled by paleogeomorphology and faults.According to the morphology of paleo geomorphology and the intensity of karstification,karst high

关 键 词：古地貌 岩溶模式 碳酸盐岩潜山 古生界 南堡凹陷 

分 类 号：TE122.1[石油与天然气工程—油气勘探]