干酪根催化加氢热解技术在白云凹陷油源分析中的应用  

Application of kerogen catalytic hydropyrolysis technology in oil source analysis of Baiyun Sag

作　　者：陈聪 龙祖烈 朱俊章 熊永强[3] 杨兴业 蒋文敏 CHEN Cong;LONG Zu-lie;ZHU Jun-zhang;XIONG Yong-qiang;YANG Xing-ye;JIANG Wen-min(CNOOC China Ltd Shenzhen,Shenzhen 518054,China;CNOOC Deepwater Development,Shenzhen 518054,China;State Key for Laboratory of Organic Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,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 [2]中海石油深海开发有限公司,广东深圳518054 [3]中国科学院广州地球化学研究所有机地球化学国家重点实验室,广东广州510640

出　　处：《地球化学》2021年第6期579-590,共12页Geochimica

基　　金：“十三五”国家科技重大专项项目(2016ZX05026-003-006)。

摘　　要：针对白云凹陷钻遇文昌组及恩平组泥岩受油基或烃水基泥浆污染严重,无法准确界定源岩生烃潜力与母质类型,导致研究区烃源潜力尚待落实;油藏原油及气藏凝析油成熟度跨度大且遭受次生改造严重,应用生物标志物浓度法在判别该区原油、凝析油成因及主力油源岩可靠性差的问题,本次研究采用干酪根催化加氢热解技术,从催化加氢热解产物及原油和凝析油正构烷烃单体碳同位素组成特征进行分析,获取泥浆污染烃源岩样品原始地球化学信息,判识原油及凝析油成因及来源。研究表明,白云凹陷发育半深湖相、浅湖相及海相或海侵泥岩,文昌组半深湖相源岩为非藻类勃发湖盆型泥岩,正构烷烃单体碳同位素值分布在-33‰~-30‰之间,文昌组、恩平组浅湖相源岩沉积环境及生源构成整体相似,正构烷烃单体碳同位素值主体分布在-30‰~-28‰之间,但文昌组与恩平组泥岩在高碳数部分正构烷烃单体同位素组成上具有一定差异性,海相/海侵泥岩分布于恩平组,以具有重的碳同位素组成为特征,正构烷烃单体碳同位素值分布于-28‰~-25‰之间;白云凹陷不同区带油藏原油及气藏凝析油正构烷烃单体碳同位素组成特征具有高度的一致性,指示为浅湖相成因来源,文昌组浅湖相源岩可能为其主力油源岩,半深湖相及海相或海侵泥岩基本无成藏贡献。As mudstones of Wenchang and Enping formations in Baiyun Sag are heavily polluted by oil-based or hydrocarbon-bearing water-based mud, it is difficult to accurately define the hydrocarbon generation potential and parent material type of the source rocks. Therefore, the hydrocarbon potential of the study area is yet to be determined. Notably, crude oil and gas condensate in the reservoirs have a large maturity range and are influenced by secondary alteration. These factors decrease the reliability of the biomarker concentration method in identifying crude oil, condensate, and source origin in the area. In this study, both the kerogen catalytic hydropyrolysis and stable carbon isotopes of monomeric hydrocarbons experiments were performed to obtain the original geochemical information of the source rock samples polluted by mud;thus, identifying the origin of crude oil and condensate.The results show that the semi-deep lacustrine, shallow lacustrine, and marine or transgressive mudstones were developed in Baiyun Sag. The semi-deep lacustrine source rocks of the Wenchang Formation are non-algal blooming lake basin type mudstones. The stable carbon isotopic values of n-alkanes are distributed in the range of approximately-33‰ to-30‰. The sedimentary environment and source composition of shallow lacustrine source rocks in the Wenchang and Enping formations are similar. The stable carbon isotopic values of n-alkanes are mainly distributed in the range of approximately-30‰ to-28‰ The marine or transgressive mudstones are distributed in the Enping formation that is characterized by heavy carbon isotopic composition. The carbon isotopic values of n-alkanes vary from-28‰ to-25‰. The carbon isotopic compositions of n-alkanes in crude oil and gas condensate in different areas are highly consistent, indicating the contribution of the shallow lake mudstone.The shallow lacustrine source rocks of the Wenchang Formation may be the main source of rocks in the Baiyun Sag. The semi-deep lacustrine and marine or transgressi

关 键 词：催化加氢热解 正构烷烃 单体碳同位素 藻类勃发 白云凹陷 

分 类 号：P593[天文地球—地球化学]