松辽盆地开鲁凹陷构造特征及其有利区预测——基于重力异常资料  

Structural characteristics and oil-gas favorable areas of Kailu Sag in Songliao Basin--Based on gravity data

作　　者：袁禹涵 张金功[1,2] 袁炳强 薛健 姚天星 YUAN Yuhan;ZHANG Jingong;YUAN Bingqiang;XUE Jian;YAO Tianxing(Department of Geology,Northwest University,Xi’an,710069;State Key Laboratory of Continental Dynamics,Northwest University,Xi’an,710069;School of Earth Sciences and Engineering,Xi’an Shiyou University,Xi’an,710065;Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xi’an Shiyou University,Xi’an,710065)

机构地区：[1]西北大学地质学系,西安710069 [2]西北大学大陆动力学国家重点实验室,西安710069 [3]西安石油大学地球科学与工程学院,西安710065 [4]陕西省油气成藏地质学重点实验室,西安710065

出　　处：《地质论评》2023年第5期1628-1638,共11页Geological Review

基　　金：中石化石油勘探开发研究院研究项目“松辽盆地南部重力资料连片处理解释”的成果。

摘　　要：开鲁凹陷位于松辽盆地西南部,油气前景优良,但研究程度较低。前人主要针对凹陷内次级构造单元进行研究,而对凹陷整体构造和基底特征缺乏研究。为了研究凹陷构造特征,预测油气有利区,笔者等基于重力资料,综合地质、地震等前人相关研究成果,推测了该区的断裂构造;应用Parker法和相关分析法计算了盆地的基底深度;并对凹陷进行了次级构造单元划分及油气有利区预测。研究结果表明:开鲁凹陷重力场特征宏观上表现为由西北向东南重力高和重力低呈条带状相间分布;反映了凹陷内突起与断陷亦由西北向东南相间分布。凹陷内断裂发育,其边界主要受近SN向、EW向及两组NE向断裂控制。开鲁凹陷可进一步划分为8个次级构造单元,各次级构造单元之间以断裂为界。凹陷内新生界、中生界白垩系、侏罗系发育。开鲁凹陷西部清河—苇莲苏断陷带内的平安地断阶,东部茫汉断陷中的茫汉南西缓坡带,南部奈曼旗断陷等区域,油气地质条件良好,为油气有利区。Kailu sag is located in the southwest of Songliao basin with good oil and gas geological conditions,whereas its research degree is low.The study is mainly focused on the secondary structural units in the sag,the research is lacked on the overall structure and basement characteristics of the sag.In order to study the structural characteristics of the Kailu Sag and predict the favorable oil and gas areas,the paper is based on the gravity data and the previous research results such as geology and seismic data.After that,the paper identifies and infers the fault structure system of the study area combined with the actual geological background of the study area and previous relevant research results.To improve the accuracy of the basement depth by using gravity data of the basin,the basement depth was calculated by Parker’s method and the correlation analysis method,combined with reference to previous related research results.According to the interpretation results of gravity data and related data above,predicting reasonably the favorable oil and gas areas.The results show that the gravity characteristics of Kailu Sag are macroscopically the distribution of high and low gravity from northwest to southeast,which reflect the alternative distribution of protuberance and fault depression in the sag from northwest to southeast.Kailu Sag has complex faults and the boundary of the sag is mainly controlled by near SN,EW and two groups of NE faults.The Kailu sag can be further divided into 8 secondary structural units,which are bounded by fracture.The Cenozoic,Mesozoic Cretaceous and Jurassic developed in the sag.The petroleum geology condition in Ping’an fault terrace in Qinghe—Weiliansu fault depression zone in western sag,gentle slope belt in Manghan fault depression in eastern sag and Nanaimanqi fault depression in southern sag are outstanding,which make it a favorable hydrocarbon area.

关 键 词：重力异常 断裂构造 基底特征 油气有利区 开鲁凹陷 松辽盆地 

分 类 号：P618.13[天文地球—矿床学] P631.1[天文地球—地质学]