库车坳陷秋里塔格构造带中东段油气充注期次及成藏模式  

Hydrocarbon charging stage and accumulation model in the middle-east section of Qiulitag Structural Belt, Kuqa Depression

作　　者：罗富文 柳少波[2] 卓勤功 鲁雪松[2] 张蔚 LUO Fuwen;LIU Shaobo;ZHUO Qingong;LU Xuesong;ZHANG Wei(School of Earth and Space Sciences,Peking University,Beijing 100142,China;PetroChina Key Laboratory of Basin Structure and Hydrocarbon Accumulation,PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China)

机构地区：[1]北京大学地球与空间科学学院,北京100142 [2]中国石油勘探开发研究院、中国石油天然气集团公司盆地构造与油气成藏重点实验室,北京100083

出　　处：《东北石油大学学报》2024年第1期26-38,85,I0003,共15页Journal of Northeast Petroleum University

基　　金：国家自然科学基金联合基金项目(U22B6002);中国石油天然气股份有限公司基础性前瞻性科学研究与技术开发项目(2021DJ0303)。

摘　　要：库车坳陷秋里塔格构造带新生界油藏勘探潜力大,古近系膏盐岩相变区储层砂岩厚度薄,油气成藏过程复杂。利用流体包裹体岩相学观察、激光拉曼光谱、包裹体测温、盆地模拟和储层定量荧光光谱等方法,分析古近系库姆格列木群盐间砂岩样品的烃充注相关流体记录,明确研究区油气充注期次和成藏模式。结果表明:古近纪末—中新世早期,中质油聚集于白垩系砂岩顶部;中新世中期,库姆格列木群砂岩储层第一期轻质油—凝析油充注发生于约14.2 Ma,以蓝绿色荧光包裹体组合为主,古油藏广泛分布;中新世晚期—上新世中期,构造挤压作用增强,逆冲断裂、构造裂缝导致古油藏大量散失;上新世晚期以来,随埋藏深度的增加,高纯度、厚层膏盐层封盖性逐渐恢复,砂岩储层第二期甲烷干气充注发生于约3.7 Ma,形成含甲烷包裹体组合,构成现今盐间砂岩气藏的基本油气特征,形成膏盐岩盖层与构造作用双重控制的油气成藏模式。该结果为秋里塔格构造带中东段进一步勘探提供依据。There is great exploration potential in Qiulitag Structural Belt,Kuqa Depression.In the Paleogene gypsum-salt phase transition zone,the reservoir sandstone thickness is thin and the process of hydrocarbon accumulation is complicated.In order to reveal the hydrocarbon charging stage and accumulation model,the fluid records about hydrocarbon in the intersalt thin sandstone of Kumugeliemu Group was studied by microscopic observation,Laser Raman spectroscopy,temperature measurement of inclusion,basin simulation,quantitative fluorescence spectroscopy of reservoir.The results show that:from the end of Paleogene to the Early Miocene,medium oil gathered on the top of Cretaceous sandstone;in the Middle Miocene,the charging of light oil-condensate occurred at 14.2 Ma,forming blue-green fluorescent inclusion assemblages and widely distributed paleo-oil reservoirs;between the Late Miocene and the Middle Pliocene,the ancient oil reservoirs were leaked by the development of thrust faults and structural fractures with the more intense tectonic compression;since the Late Pliocene,methane started charging at 3.7 Ma because of the recovering of gypsum-salt’s sealing property with the deeper burial in Kumugeliemu Group,which is purer and thicker.The inclusions with methane and intersalt sandstone gas reservoir also formed at this period.The oil-gas accumulation model controlled by the dual control of gypsum-salt caprock and tectonic action.The result provides a reference case for further exploration in the middle-east section of Qiulitag Structural Belt.

关 键 词：库车坳陷 秋里塔格构造带中东段 古近系 库姆格列木群 流体包裹体 油气充注期次 膏盐岩 成藏模式 

分 类 号：TE122.1[石油与天然气工程—油气勘探] P618.130.2[天文地球—矿床学]