库车坳陷阿瓦特地区巴西改组构造变形与油气成藏特征  

Structural Deformation and Hydrocarbon Accumulation Characteristics of Baxigai Formation in Awat Area,Kuqa Depression

作　　者：王莹莹 桂丽黎[2,3] 鲁雪松[2,3] 刘汇川[1] 莫涛[4] 周慧 姜林[2,3] WANG Yingying;GUI Lili;LU Xuesong;LIU Huichuan;MO Tao;ZHOU Hui;JIANG Lin(School of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China;Key Laboratory of Basin Structure and Hydrocarbon Accumulation,CNPC,Beijing 100083,China;Research Institute of Exploration and Development,Tarim Oilfield Company,PetroChina,Korla,Xinjiang 841000,China)

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油勘探开发研究院,北京100083 [3]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 [4]中国石油塔里木油田分公司勘探开发研究院,新疆库尔勒841000

出　　处：《新疆石油地质》2024年第6期631-641,共11页Xinjiang Petroleum Geology

基　　金：国家自然科学基金(42172164,42472216,42472181);中国石油科技开发项目(2023ZZ0206);中国石油前瞻性基础性技术攻关项目(2021DJ0105)。

摘　　要：库车坳陷前陆冲断带构造变形主要发生在喜马拉雅运动中—晚期,前人确定了盐上浅层褶皱构造变形的启动时间,但对盐下冲断构造变形与油气成藏时间的研究缺少绝对定年的约束。以库车坳陷阿瓦特地区为例,利用岩相学观察、方解石U-Pb定年、流体包裹体分析等资料,分析阿瓦特地区下白垩统巴西改组储集层成岩作用、方解石脉体形成时间及油气成藏过程,确定了阿瓦特地区巴西改组构造变形和油气成藏时间。结果表明:阿瓦特地区巴西改组储集层发育2期方解石,早期方解石胶结物形成年龄为(98.0±14.0)Ma,晚期方解石脉体形成年龄为(3.7±1.0)Ma,代表了盐下冲断构造变形时间;方解石脉体中发育1期油包裹体和1期气包裹体,通过流体包裹体均一温度、埋藏史和热史,推断油充注时间为4.0—3.0 Ma,天然气充注时间为3.0—1.0 Ma,早期油藏经历了上新世晚期气洗改造,形成现今的凝析气藏。The structural deformation in the foreland thrust belt of the Kuqa depression mainly occurred during the middle-late Himalayan orogeny.Previous studies primarily identified the initiation timing of shallow postsalt fold deformation,but had no absolute dating con⁃straints on the subsalt thrust deformation and the timing of hydrocarbon accumulation.Taking the Awat area in the Kuqa depression as an example,using the data from petrographic observations,calcite U⁃Pb dating,and fluid inclusion analysis,the diagenesis,formation timing of calcite veins,and hydrocarbon accumulation process of the Lower Cretaceous Baxigai formation reservoirs were investigated,and the timing of structural deformation and hydrocarbon accumulation in the Awat area was determined.The research results show that two periods of calcite were developed in the Baxigai formation in the Awat area.The early calcite cement formed at(98.0±14.0)Ma,while the late calcite veins formed at(3.7±1.0)Ma,reflecting the time of subsalt thrust deformation.Oil inclusions and gas inclusions of different periods were identified in the calcite veins.Based on the homogenization temperatures of the fluid inclusions,burial history and thermal history,it is inferred that the oil charging occurred at 4.0-3.0 Ma,and gas charging at 3.0-1.0 Ma.The early oil reservoir underwent reworking of gas washing in the late Pliocene,forming the current condensate gas reservoir.

关 键 词：塔里木盆地 库车坳陷 阿瓦特地区 构造变形 流体包裹体 油气成藏期次 成藏模式 

分 类 号：TE122.14[石油与天然气工程—油气勘探]