珠江口盆地AD15洼构造沉积演化控制下的油气运聚模式  

Oil and gas migration and accumulation model under the joint control of tectonic and sedimentary evolution in AD 15 Sag,Pearl River Mouth Basin

作　　者：吴浩武 黄峰 WU Haowu;HUANG Feng(Shenzhen Branch of CNOOC(China)Ltd.,Shenzhen 518000,China)

机构地区：[1]中海石油(中国)有限公司深圳分公司,深圳518000

出　　处：《海洋地质前沿》2024年第5期72-79,共8页Marine Geology Frontiers

基　　金：国家自然科学基金“琼东南盆地冷泉差异发育的流体动力学特征及其深部控制机理”(42076054)。

摘　　要：珠江口盆地是南海地区重要的油气产区,其中,AD15洼是重要的富生烃洼陷。但由于对复式油气藏认识有限,AD15洼未取得重大勘探进展。本文基于“源-汇-聚”的评价思路,针对AD15洼北部缓坡带,利用三维地震资料,结合测井资料及地化资料,开展了深入系统的油气运聚模式研究,得到以下认识:边界断裂差异演化控制了AD15富烃洼陷的形成,裂陷高峰期强烈断裂活动促使AD南部形成“连片湖盆”,沉降速率大,湖盆广而深,文昌组文四段、文三段时期大规模发育生烃潜力大的中深湖优质烃源岩。继承型流体运移构造脊控制油气主运聚方向,早、晚期断裂纵向差异性疏导与侧向砂体耦合组建了油气的接替立体输导模式。区域盖层控制下,油气沿构造脊高孔渗储层高效汇聚,则构建了AD15洼缓坡带“断-盖-脊”联控的油气长距离运聚成藏模式。上述研究对于研究区进一步深化油气勘探获取新的突破,具有一定的指导及借鉴意义。The Pearl River Mouth Basin is an important oil and gas producing area in the South China Sea,of which the AD 15 Sag is an important hydrocarbon-rich sag.However,due to limited understanding on the complexity of the oil and gas reservoirs,significant exploration progress has not been made in the AD 15 Sag.Based on the evaluation concept of"source,sink,accumulation",we conducted in-depth and systematic research on the oil and gas migration and accumulation in the northern gentle slope zone of AD 15 Sag using 3D seismic data,and combined them with logging and geochemical data.Result show that the differential evolution of boundary faults controlled the formation of the AD 15 Sag,and strong fault activity during the peak period of the depression promoted the formation of a"contiguous lake basin"in the areas to the south of the sag,with a large subsidence rate and a wide and deep lake basin.The middle-deep lake high-quality source rock with great potential for large-scale hydrocarbon generation during the 4th and 3rd members of the Wenchang Formation.The inherited fluid migration structural ridge controls the main migration and accumulation direction of oil and gas,and the coupling of longitudinal differential dredging of early and late faults and lateral sand bodies formed a series of three-dimensional transport of oil and gas.Under the control of regional caprocks,oil and gas efficiently converged in high porosity and permeability reservoirs along structural ridges,forming a fault-cap-ridge joint control model for longdistance oil and gas migration and accumulation in gentle slope zone of the AD 15 Sag.Therefore,this study provided a guidance and reference for further deepening oil and gas exploration and achieving new breakthroughs in the research area.

关 键 词：构造沉积演化 断裂差异 烃源岩特征 运聚模式 AD15洼 珠江口盆地 

分 类 号：P744.4[天文地球—海洋科学]