摘要
长期以来,东海陆架盆地西湖凹陷中央反转带存在“大构造、小油气藏”的勘探局面。从中央反转带断裂发育演化特征、油气运聚成藏地质条件和油气分布规律为切入点,结合油气地球化学分析、盆地模拟、物源及成岩作用分析等资料,综合分析研究了中央反转带大中型油气田形成条件及控藏机制。研究结果表明:中央反转带具有近源、垂向、大跨度、晚期成藏特征,纵向上发育三套成藏组合,其中中下组合是油气聚集的主要场所,在油气成藏关键时刻中下组合已进入不稳定充注段。中央反转带油气成藏条件基本类似,油气富集程度主要受控于储层充注临界条件和晚期E—W向断层下倾末端之间的“储保耦合”窗。“储保耦合”窗是已探明大中型油气田发育的主要场所,该窗之上油气成藏规模小而散,该窗之下油气充注困难。受物源、断层活动强度等因素控制,“储保耦合”窗从南往北逐渐变宽导致中央反转带油气聚集规模往北逐渐变大。“十二五”以来,以“储保耦合”窗思想为指导在中央反转带中北部重新部署勘探共发现了近10×108m3油当量的三级地质储量。本文研究成果对东海陆架盆地西湖凹陷油气富集规律的认识和勘探方向选择具有重要的指导和借鉴意义。
For a long time,the central inversion belt of Xihu sag in the East China Sea basin has been characterized by “large structure and small oil and gas reservoirs”. Based on the development and evolution characteristics of structural faults,geological conditions of hydrocarbon migration and accumulation,and oil and gas distribution in the central inversion belt,combined with geochemistry,basin simulation,provenance and diagenesis,a comprehensive analysis was conducted on the formation conditions and reservoir control mechanism of large and medium-sized oil and gas fields in the central inversion belt.The results show that the central inversion belt has the characteristics of near-source,vertical migration,long-span and late hydrocarbon accumulation,and three sets of reservoir-forming assemblages are developed vertically. The middle-lower assemblage is the main place for hydrocarbon accumulation,and the middle-lower assemblage has entered the unstable hydrocarbon charging period at the critical time of hydrocarbon accumulation.The hydrocarbon accumulation conditions in the central inversion belt are basically similar,and the degree of hydrocarbon enrichment is mainly controlled by “reservoir-conservation coupling” window between the hydrocarbon charging critical condition and the down dip end of late E-W trending faults. The “reservoir-conservation coupling” window is the main place for the development of proven large and medium-sized oil and gas fields. The hydrocarbon accumulation scale above the window is small and scattered,and the hydrocarbon charging under the window is difficult. Controlled by provenance,intensity of fault activity and other factors,the “reservoir-conservation coupling” window gradually widens from south to north,resulting in increasing scale of hydrocarbon accumulation in the central inversion belt. Since the Twelfth Five-Year Plan,under the guidance of the idea of “reservoir-conservation coupling” window,a total of three-level geological reserves of nearly 10×10 8m 3 oil
作者
刘金水
邹玮
李宁
覃军
刘洋
LIU Jinshui;ZOU Wei;LI Ning;QIN Jun;LIU Yang(CNOOC China Limited,Shanghai Branch,Shanghai 200335,China)
出处
《中国海上油气》
CAS
CSCD
北大核心
2019年第3期11-19,共9页
China Offshore Oil and Gas
基金
“十三五”国家科技重大专项“东海深层低渗-致密天然气勘探开发技术(编号:2016ZX05027)”
中海石油(中国)有限公司科技联合攻关项目“宁波27-1构造再评价关键问题攻关(编号:2018OT-KT-KY-LH-01)”部分研究成果
关键词
控藏机制
储保耦合
成藏组合
不稳定充注
大中型油气田
西湖凹陷
hydrocarbon accumulation control mechanism
reservoir-conservation coupling
reservoir-forming assemblage
unstable hydrocarbon charging
large and medium-sized fields
Xihu sag
