松辽盆地深层地质结构及致密砂砾岩气勘探  

Deep strata geologic structure and tight conglomerate gas exploration in Songliao Basin, East China

作　　者：赵泽辉[1,2] 徐淑娟[2] 姜晓华[2] 林畅松[1] 程宏岗[2] 崔俊峰[2] 贾丽[2] 

机构地区：[1]中国地质大学(北京)海洋学院 [2]中国石油勘探开发研究院廊坊分院

出　　处：《石油勘探与开发》2016年第1期12-23,共12页Petroleum Exploration and Development

基　　金：国家自然科学基金项目(40772075);国家重大科技专项(2011ZX05007)

摘　　要：基于全盆地野外露头、钻井、地震资料及地球化学分析数据,研究了松辽盆地深层地质结构特征、断陷基本地质规律、沙河子组致密气成藏地质条件及下步勘探方向。通过系统对比分析,明确盆地深层地质结构表现为下断上坳的双层结构,断陷期以断裂或地层超覆与隆(凸)起为界、由隆(凸)起相互间隔的断陷独立发育。与断陷形成演化相关的断裂可分为区域深大断裂、基底控陷断裂和洼内次级断裂3类,阐明了3类断裂在断陷群形成演化中的作用。结合区域构造和盆地演化特征分析,明确致密砂砾岩气、火山岩和基岩潜山等3大勘探领域,沙河子组致密砂砾岩气是目前最具勘探前景的战略新领域。在沙河子组基本石油地质特征分析基础上,提出砂砾岩是沙河子组碎屑岩储集层优势岩类,母岩成分、沉积结构、沉积相带及成岩作用是砂砾岩有利储集层主控因素。沙河子组气藏属典型自生自储型,发育岩性和构造两种气藏类型,陡缓两带有利沉积相带控制储集层展布、岩性圈闭形成及气藏规模,断陷内部次级断裂控制构造圈闭的形成及天然气的富集。通过综合评价优选出7个沙河子组致密砂砾岩气勘探最为现实的断陷。The geologic structure of deep formations, basic geologic pattern of fault depressions, geologic conditions of Shahezi Formation tight gas reservoir, and the exploration direction in the next step in the Songliao Basin are examined based on a comprehensive and comparative analysis of the outcrop, drilling, seismic and geochemical data. Systematic comparison analysis shows that the geologic structure of deep formations in the basin is characterized by a double-layer structure with fault depression in the lower layer and depression in the upper layer. In the deep fault depression （DFD） stage, fault depressions bounded by faults or onlaps and uplifts, developed independently. The faults related to the formation and evolution of the fault depressions can be divided into regional major faults, basement depression controlling faults and secondary faults in subsags, and their actions in the evolution of the fault depression groups are presented in the paper. Based on analysis of regional tectonics and basin evolution features, three exploration fields, tight conglomerate gas, volcanic rocks and basement buried hills are pointed out, and it is concluded the tight conglomerate gas in the Shahezi Formation is currently a new strategic field with the most promising exploration prospect. Based on comprehensive analysis of basic oil geologic features of Shahezi Formation, it is proposed that conglomerate is the main category of clastic reservoir in Shahezi Fromation, and parent rock composition, sedimentary structure and facies, and diagenesis are the main factors affecting the distribution of conglomerate reservoirs. Furthermore, the gas reservoirs in Shahezi Formation, all source and reservoir in one, include two types, lithologic and structural types. Favorable sedimentary facies belts in the gentle slope and steep slope control the distribution of the reservoirs, formation of lithologic traps and gas reservoir scale; while secondary faults in side fault depressions control the formation of structural traps and enrichm

关 键 词：松辽盆地 深层地质结构 白垩系 沙河子组 致密砂砾岩气'9勘探前景 

分 类 号：TE121.1[石油与天然气工程—油气勘探]