银额盆地哈日凹陷火成岩发育特征及其成藏作用  

Development characteristics of igneous rocks and its role in hydrocarbon accumulation in Hari Sag,Yingen-Ejinaqi Basin

作　　者：白晓寅 韩长春 贺永红 任来义 马芳侠 陈治军 刘护创 BAI Xiaoyin;HAN Changchun;HE Yonghong;REN Laiyi;MA Fangxia;CHEN Zhijun;LIU Huchuang(Research Institute of Shaanxi Yanchang Petroleum(Group)Co.Ltd,Xi’an 710075,China)

机构地区：[1]陕西延长石油(集团)有限责任公司研究院,西安710075

出　　处：《岩性油气藏》2018年第6期18-26,共9页Lithologic Reservoirs

基　　金：陕西延长石油(集团)有限责任公司科技攻关项目"银额盆地延长探区基本石油地质特征研究与勘探方向分析"(编号:ycsy2015kyA-06)资助

摘　　要：哈日凹陷是银额盆地北部的小型断陷,勘探程度较低,岩性复杂,火成岩广泛发育。为明确研究区火成岩的发育特征及其对油气成藏的影响,开展了火成岩矿物特征分析、锆石U-Pb年代学研究、地震相分析以及火成岩的发育期次和喷发模式等研究工作,并结合勘探实践,分析了哈日凹陷火山活动对油气成藏的影响。结果表明:(1)研究区发育火山角砾岩、凝灰岩、玄武岩、英安岩、安山岩等多种类型的火成岩,地震反射特征主要表现为丘状杂乱地震相、锥状地震相、平行板状地震相等3种类型;(2)通过火成岩锆石定年和地震相综合研究,晚古生代以来研究区发育3期火山活动,分别为晚二叠世、早白垩世巴音戈壁期和苏红图期,其中前两期为中心式喷发模式,后一期为典型的裂隙式喷发模式;(3)多期火山活动和持续的岩浆热液活动促进了研究区烃源岩有机质的快速成熟及储集层的白云石化作用;(4)与烃源岩有着良好匹配关系且气孔和微裂缝较发育的火成岩是油气勘探的有利区。该研究成果可为深入了解研究区火成岩特征及下一步油气勘探部署提供指导作用。The Hari Sag is a small fault depression in northern Yingen-Ejinaqi Basin,with low exploration degree,complex lithology and widely developed igneous rocks.In order to further clarify the development characteristics of igneous rock and their influences on hydrocarbon accumulation in the study area,the mineral characteristics,zircon U-Pb chronology,seismic facies,development period and eruption model of igneous rocks were studied,and the influences of volcanic activities on hydrocarbon accumulation in Hari Sag were analyzed in combination with exploration practice.The results show that:(1)There are many types of igneous rocks developed in the study area such as volcanic breccia,tuff,basalt,dacite and andesite.The seismic reflection characteristics are mainly manifested in three types of mainly mound-like seismic facies,cone-shaped seismic facies and parallel plate-like seismic facies.(2)According to the comprehensive study of zircon dating and seismic facies of igneous rocks,there are three stages of volcanic activity in the study area since Late Paleozoic,which are Late Permian,Early Cretaceous Bayingobi Formation and Suhongtu Formation,and the first two stages are central eruption mode,while the latter is typical cracked eruption model.(3)Multi-stage volcanic activity and continuous magmatic hydrothermal activity promoted the rapid maturation of organic matters in source rocks and dolomitization of reservoirs.(4)Igneous rocks with good matching relationship with source rocks and pore and micro-fracture developed are favorable areas for oil and gas exploration.The research results will provide guidance for understanding the characteristics of igneous rocks and the next step of oil and gas exploration and deployment.

关 键 词：火成岩 锆石定年 发育期次 喷发模式 油气成藏 哈日凹陷 银额盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]