西藏伦坡拉盆地古近系牛堡组烃源岩预测与评价  

Preliminary Prediction and Evaluation of Source Rocks in the Lunpola Basin,Tibet,China

作　　者：刘一茗[1] 叶加仁[1] 曹强[1] 刘中戎[2] 杨宝林[1] Liu Yiming Ye Jiaren Cao Qiang Liu Zhongrong Yang Baolin(Key Laboratory of Tectonics and Petroleum Resources of the Ministry of Education, China University of Geosciences , Wulmn 430074, China The Tibetan Projects Department of the SINOPEC Exploration Company, Chengdu 610041, China)

机构地区：[1]中国地质大学构造与油气资源教育部重点实验室,湖北武汉430074 [2]中国石化勘探分公司青藏项目部,四川成都610041

出　　处：《地球科学（中国地质大学学报）》2017年第4期601-612,共12页Earth Science-Journal of China University of Geosciences

基　　金：国家科技重大专项(No.2016ZX05024002-003);中国石化勘探分公司项目(No.G0800-14-KK-169)

摘　　要：伦坡拉盆地是西藏地区唯一获工业性油气流的盆地,油气勘探前景广阔,但其勘探和研究程度均较低,对古近系牛堡组烃源岩的发育状况认识不清,制约了盆地油气资源潜力评价和勘探选区.通过研究钻井、测井及相关化验测试等资料,利用测井多参数回归和盆地数值模拟等方法技术,分析了牛堡组主要亚段有机质丰度、类型及其展布等特征,模拟重建了烃源岩的热成熟演化历史,实现了对伦坡拉盆地牛堡组烃源岩的早期综合评价.研究表明:伦坡拉盆地古近系牛堡组烃源岩发育,并以牛二段中亚段分布最广、厚度最大,在蒋日阿错凹陷最厚在400m以上,其中优质烃源岩(TOC>1.0%)最厚可达170m;牛堡组总体上属较好级别的烃源岩,其中牛二段上亚段较好-优质烃源岩所占比例最高,牛二段中亚段次之;牛堡组烃源岩有机质类型以Ⅰ型和Ⅱ_1为主;有机质成熟度总体呈中西部高、东部低的趋势,牛二段中亚段烃源岩现今多处于中-晚期生油阶段,牛二段上亚段和牛三段下亚段烃源岩现今多处于早期生油阶段.牛二段中亚段烃源岩为伦坡拉盆地主力烃源岩,蒋日阿错凹陷为最重要的生烃凹陷.As the only one basin which oil has come to the industrial standard in Tibet,it is believed that the Lunpola basin extend into rich-oil area,but exploration and investigation activities were limited,so that the development of Niubao Formation,palaeogene,is not clear,which not only limited the evaluation of oil and gas,but also the exploration strategy.Based on the drilling,logging and related laboratory test data,an integrated approach involving the logging regression equation model and basin modeling technique was used to investigate the distribution of source rock,organic matter abundance and types in main period of Niubao Formation,and to reconstruct the source rock thermal evolution history,so an evaluation system for source rocks was presented in Lunpola basin.The following conclusions can be drawn：the Lunpola basin is riched by the source rocks of Niubao Formation,and the middle of the second member of Niubao Formation is widely distributed with large thickness,the date indicates that the source rock thickness in Jiangriacuo sag can reach above 400 m,what＇s more,the thickness of excellent source rocks（TOC〉1.0%）can reach more than 170m;in general,the type of source rocks of Niubao Formation is good,with highest proportion of good-excellent source rock in the upper of the second member of Niubao Formation and lower proportion in the middle of the second member of Niubao Formation;parent material types of source rocks in Niubao Formation are mainly mixed type of typeⅡ_1-Ⅰand have oil-prone characteristic;the maturities of organic matters are mainly high inthe midwest and low in the east,the results indicate that the middle of the second member of Niubao Formation is middle and late mature,the upper of the second member of Niubao Formation and the bottom of the third member of Niubao Formation are immature to early mature to present-day.Therefore,in Lunpola basin,the middle of the second member of Niubao Formation is major source rock and Jiangriacuo sag is the most important hydrocarbon generatin

关 键 词：牛堡组 烃源岩评价 有机质丰度 盆地模拟 伦坡拉盆地 石油地质 

分 类 号：P618[天文地球—矿床学]