塔中83井区表生岩溶缝洞体系中油气的差异运聚作用  

Differential hydrocarbon migration and entrapment in the karstified carbonate reservoir:A case study of Well TZ83 block of the central Tarim uplift zone

作　　者：向才富[1,2] 王建忠[1,2] 庞雄奇[1,2] 姜振学[1,2] 刘洛夫[1,2] 李素梅[1,2] 

机构地区：[1]中国石油大学油气资源与探测国家重点试验室,北京102249 [2]中国石油大学资源与信息学院盆地中心,北京102249

出　　处：《地学前缘》2009年第6期349-358,共10页Earth Science Frontiers

基　　金：国家重点基础研究发展计划"973"项目(2006CB202308);国家科技重大专项(2008ZX05008-004-012)

摘　　要：叠合盆地海相碳酸盐岩介质油气运聚机理是油气勘探必须解决的关键科学问题之一,选择代表性储层介质进行系统油气运聚作用分析有利于为解决这一关键科学问题提供范例。塔中83井区鹰山组储层是典型的表生岩溶缝洞体系储层,油气主要分布在岩溶体系的水平潜流带中,油水关系复杂,油水界面倾斜。本区原油和天然气性质参数在NE向断层与NW向断层的交汇部位异常高,而随着远离断层交汇部位逐渐降低,并顺构造脊有规律的降低,说明断层交汇部位是本区油气的注入点,而油气运移的主输导通道沿本区的鼻状构造展布。这一认识为系统分析表生岩溶缝洞体系油气运聚机理奠定了地质基础。基于碳酸盐岩表生岩溶的相关研究成果,建立了表生岩溶缝洞体系的基本模型。在分析油气在表生岩溶缝洞体系运聚过程的基础上,认为复杂缝洞体系中油气的差异运聚原理是产生这种现象的关键。油气运移过程受储层含水程度控制,油气总是首先将临近充注点的孔隙或缝洞充满后,才能继续向远处运移,并沿油气运移路径顺次充满远处的孔洞缝体系。所形成的油气水分布规律受储层含水程度,储层中能导致油气侧向运移的侧向联通通道、局部缝洞单元与侧向联通通道的关系及其油气溢出点和晚期气侵强度的联合控制。岩溶缝洞体系中油气运聚过程及其所形成的油气分布规律对叠合盆地下构造层碳酸盐岩油气勘探具有重要的启发,油气勘探不仅要通过地球物理方法识别优质储层发育的部位,还应该尽量描述优质储层的孔洞缝结构,结合油气运移方向和主输导通道的空间展布规律指导油气勘探。The mechanism of hydrocarbon migration and entrapment occurring in complex carbonate pore-fissure-fracture reservoirs is a key problem for effective hydrocarbon exploration and development of the lower part of an overlapped basin.The production,gas/oil ratio and the composition of crude oils and natural gas in the TZ83 Well block are high at the intersection point of the NE and NW-strike fault and decrease gradually along the ridge of the structure.A basic model of the pore-fissure-fracture system is built based on the achievements in the research on carbonate karstification.The processes of the hydrocarbon migration and entrapment in this system are analyzed,which indicates that an understanding of the complexity of differential hydrocarbon migration is a key to interpreting this phenomenon.Hydrocarbon must charge the nearest compartment until it can migrate further away to charge other compartments on its pathway in the complex pore-fissure-fracture system.As a result,gas is enriched near the hydrocarbon injection point and drives away the oil which is enriched in compartments farther from the injection point;and the complex gas-oil-water relationship is controlled by the lateral connected networks.Thus,we indicate that the fault intersection point is the injection point of the oil and gas and that the main pathway system is distributed along the ridge of the structure.The theory of differential hydrocarbon migration in the pore-fissure-fracture system suggests that（1）in hydrocarbon exploration,the structure of the fissure-fractures system should be described first,then the special distribution of gas-oil-water is predicted according to the main charging point and the main pathway system;and that（2）the exploration should be confined to the hydrocarbon charging point and the main pathway systems.An exploration area should not be abandoned merely due to the failure in some wells.

关 键 词：差异运聚 表生岩溶 缝洞单元 碳酸盐岩 叠合盆地 塔中 

分 类 号：P618.13[天文地球—矿床学]