东海西湖凹陷海陆过渡型油气成熟度恢复方法及应用  

Maturity recovery of oil and gas from marine-continental source rock and its application of Xihu Sag,East China Sea

作　　者：丁飞 李宁 刁慧 于仲坤 王皖丽 余箐 DING Fei;LI Ning;DIAO Hui;YU Zhongkun;WANG Wanli;YU Qing(Shanghai Branch of CNOOC(China)Ltd.,Shanghai 200335,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335

出　　处：《海洋地质前沿》2024年第12期41-49,共9页Marine Geology Frontiers

基　　金：“十四五”全国油气资源评价项目“中海油矿业权区及周边空白区油气资源评价”(QGYQZYPJ2022-3);“十三五”国家科技重大专项“东海盆地天然气资源潜力评价”课题(2016ZX05027001);中国海洋石油有限公司重大科技专项“东海西湖凹陷大中型气田勘探方向及关键技术研究”(KJZX-2023-0101)。

摘　　要：海陆过渡相煤系烃源岩岩性多样,油气成熟度恢复难度大,影响油气源判别。以东海西湖凹陷为例,通过烃源岩镜质体反射率、饱和烃和芳香烃色谱-质谱及热模拟天然气碳同位素分析等手段,建立了油和天然气成熟度恢复方法,计算了油、气成熟度,明确了油气来源。结果显示,油成熟度主要分布于0.8%~1.0%,为成熟油;天然气成熟度主要分布于1.0%~2.0%,属于成熟—高熟气;同层段油及天然气成熟度存在差异,且垂向变化规律不同,揭示了油和天然气来源和成藏过程存在差别。综合分析认为,本区油主要来自斜坡次洼,环次洼带是油有利勘探区;天然气主要来自凹陷主洼,自主洼向斜坡带均为天然气有利区带,勘探潜力大。The lithology of marine-continental transitional coal source rocks is complex and changeable,and the maturity recovery of oil and gas is difficult.Taking an oil and gas field of Xihu Sag as an example,the recovery method of oil and gas maturity is established by means of vitrinite reflectance of source rock,chromatographic mass spectrometry of saturated hydrocarbon and aromatic hydrocarbon and carbon isotope analysis of thermally simulated natural gas.The maturity of oil and gas is calculated and the source of oil and gas is clarified.The results show that oil maturity is mainly distributed between 0.8% and 1.0%,which is mature oil.The maturity of natural gas is mainly distributed between 1.0% and 2.0%,belonging to mature-high mature gas.The maturity of oil and natural gas in the same interval is different,which reveals the difference in the source and accumulation process of oil and natural gas.Based on the thermal evolution history of source rocks,it is considered that the oil in this area mainly comes from the slope sub-depression,and the ring sub-depression zone is the favorable exploration area.Natural gas mainly comes from the main depression of the sag,and the slope zone is a favorable zone for natural gas,with great exploration potential.

关 键 词：海陆过渡相 烃源岩 油气成熟度 油气来源 西湖凹陷 

分 类 号：P618.13[天文地球—矿床学] P736[天文地球—地质学]