北部湾盆地涠西南凹陷涠洲11-4—涠洲11-4N油田油气运聚的源控特征  

Source rock controlling effects on hydrocarbon migration and accumulation of Weizhou11-4& Weizhou11-4N oil fields in Weixi′nan Sag,Beibuwan Basin

作　　者：刘诗局 高岗[1] 徐新德 周肖肖 刘凤妍[3] 甘军 梁刚 Liu Shi-ju;Gao Gang;Xu Xin-de;Zhou Xiao-xiao;Liu Feng-yan;Gan Jun;Liang Gang(State Key Laboratory of Oil and Gas Resources and Exploration/School of Earth Sciences,China University of Petroleum,Beijing102249,China;Zhanjiang Branch of CNOOC Ltd.,Zhanjiang524057,China;Exploration&Development Research Institute,PetroChina Huabei Oilfield Company,Renqiu062552,China)

机构地区：[1]中国石油大学(北京)地球科学学院/油气资源与探测国家重点实验室,北京102249 [2]中海石油(中国)有限公司湛江分公司,广东湛江524057 [3]华北油田分公司勘探开发研究院,河北任丘062552

出　　处：《天然气地球科学》2019年第9期1312-1318,共7页Natural Gas Geoscience

基　　金：“十三五”国家科技重大专项“南海西部海域低渗油藏勘探开发关键技术”(编号:2016ZX05024-006)资助

摘　　要：基于原油生物标志化合物分析,对原油类型进行了划分,明确了北部湾盆地涠洲11-4油田与涠洲11-4N油田的原油类型分布特征及其油气运聚差异性。研究区原油分为A和B两类,前者成熟度高,主要来自流二段底部油页岩,后者成熟度低,主要来自流二段上部与流一段泥岩。A类原油在凹陷边缘构造高部位的涠洲11-4油田新近系角尾组与凹陷内构造低部位涠洲11-4N油田下部的流三段均有分布,而B类原油主要分布在涠洲11-4N油田上部的涠洲组和流一段。原油空间类型与烃源岩分布关系表明,A类原油主要在流二段下部的流三段成藏或沿流三段砂体侧向向构造高部位运移成藏;B类原油主要在凹陷内通过断裂近距离垂向运移成藏。这指示了成熟度较低的烃源岩生成的油气主要在凹陷内近距离运聚成藏,而A类原油主要在流二段底部油页岩附近与凹陷边缘的构造高部位运聚成藏。Based on the biomarker analysis,crude oil types are divided into type A and type B.Type A oil has a higher maturity and came from oil shale in the Second member of the Liushagang Formation,and type B oil has a lower maturity and derived mainly from mudstones in the upper part of the 2 ndmember and 1 stmember of the Liushagang Formation.Type A oil was distributed both in the Neogene Jiaowei Formation of the WZ11-4 oil field located in the high structural position of the sag margin and in the 3 rdmember of the Liushagang Formation of the WZ11-4 N oil field in low structural position in sag.Type B oil was distributed mainly in the Weizhou and the 1 stmember of the Liushagang Formation of the WZ11-4 N oil field.Spatial distribution relation of crude oil types and source rocks indicates that type A oil was accumulated chiefly in the 3 rdmember of the Liushagang Formation and high structural position in the margin of sag.Type B oil migrated vertically along faults and accumulated in the sag.This indicates that the crude oil coming from lower mature source rock accumulates mainly in sag,with a close migration distance,while type A oil accumulates chiefly in the reservoirs nearby the bottom oil shale layer of the 2 ndmember of the Liushagang Formation and in high structural positions in sag margin.

关 键 词：涠西南凹陷 涠洲11-4油田 涠洲11-4N油田 油气运聚 原油类型 

分 类 号：P618.13[天文地球—矿床学]