珠江口盆地惠州26-6油气田有效气源岩分析  

Analysis of effective gas source rocks of HZ26-6 oil and gas field in Pearl River Mouth Basin

作　　者：朱俊章 石创 黄玉平 杨兴业 史玉玲 张小龙 ZHU Junzhang;SHI Chuang;HUANG Yuping;YANG Xingye;SHI Yuling;ZHANG Xiaolong(Shenzhen Branch of CNOOC Ltd.,Shenzhen 518054,China)

机构地区：[1]中海石油(中国)有限公司深圳分公司,广东深圳518054

出　　处：《天然气地球科学》2022年第11期1723-1733,共11页Natural Gas Geoscience

基　　金：中国海洋石油集团总公司“十四五”重大科技项目“陆缘裂谷盆地深层/超深层油气成藏条件与成藏机制研究——珠江口盆地珠一坳陷”(编号:KJGG2022-0403);中海石油(中国)有限公司综合科研项目“南海东部大中型天然气田勘探潜力与突破方向”(编号:KJZH-2021-0003-00)联合资助.

摘　　要：位于珠江口盆地的惠州26-6构造在中生界古潜山及古近系获得油气勘探重大突破,是该盆地古潜山及恩平组—文昌组凝析气勘探的首个规模发现。为进一步指导浅水富油区天然气勘探,应用天然气生成及分子碳同位素动力学技术,对惠州26-6油气田三级层序格架下的有效气源岩层进行系统研究。结果表明:惠州26洼文昌组六段(文六段)+五段(文五段)半深湖—深湖亚相烃源岩为惠州26-6油气田古潜山储层提供大量天然气,文五段半深湖—深湖亚相烃源岩为文昌组—恩平组储层提供一定量天然气,文昌组四段(文四段)半深湖—深湖亚相烃源岩为文昌组—恩平组提供少量天然气,上文昌组(文三段)和恩平组烃源岩基本不提供天然气;该气田属于阶段性累积聚气,成藏时间较晚,有效充注成藏期在10~0 Ma之间,目前仍处于有效充注阶段。这一新认识对于珠江口盆地富油区天然气勘探具有重要的指导意义。HZ26-6 structure, located in Pearl River Mouth Basin, has made a major breakthrough in oil and gas exploration in Mesozoic buried hills and Paleogene, which is the first large-scale discovery of condensate gas exploration in the buried hills, Enping Formation and Wenchang Formation of the basin. In order to further guide natural gas exploration in shallow water oil-rich areas, the effective gas source rocks under the third-order sequence framework of HZ26-6 oil and gas field were systematically studied by using the natural gas generation and molecular carbon isotope dynamics. The results show that the deep lacustrine source rocks of Wenchang Ⅵ formation and Wenchang Ⅴ formation in Huizhou 26 Sag provide a large amount of natural gas for the buried hill reservoirs of HZ26-6 oil and gas field, the deep lacustrine source rocks in Wenchang V formation provide a certain amount of natural gas for the reservoirs of Wenchang Formation and Enping Formation, the deep lacustrine source rocks in Wenchang Ⅳ formation provide a small amount of natural gas for Wenchang Formation and Enping Formation, and the source rocks of upper Wenchang Formation(Wenchang Ⅲ Formation) and Enping Formation basically do not provide natural gas. The gas field belongs to staged cumulative gas accumulation, and the reservoir formation time is relatively late. The effective filling and reservoir formation period is 10-0Ma. At present, it is still in the effective filling stage. This new understanding has important guiding significance for natural gas exploration in oil-rich areas of Pearl River Mouth Basin.

关 键 词：珠江口盆地 惠州26洼 惠州26-6油气田 天然气生成及分子碳同位素动力学 有效气源岩 

分 类 号：P618.13[天文地球—矿床学]