川西北龙门山冲断带北段油砂成藏特征及其主控因素  

Reservoir Forming Characteristics and Main Controlling Factors of Oil Sandstones in the Northern Longmen Mountain Thurst Zone of the Northwest of Sichuan

作　　者：孙晓猛[1] 许强伟[1] 王英德[1] 田景雄[1] 王书琴[1] 杜继宇[1] 

机构地区：[1]吉林大学地球科学学院,长春130026

出　　处：《吉林大学学报（地球科学版）》2010年第4期886-896,共11页Journal of Jilin University：Earth Science Edition

基　　金：国土资源部油气战略研究中心项目(2009GYXQ14);国家'973'计划项目(2009CB219305);'东北亚生物演化与环境教育部重点实验室';吉林大学'211'工程三期建设项目;2009年教育部基本科研业务经费('吉林大学创新团队发展计划')支持

摘　　要：野外实测地质大剖面和室内综合研究表明:龙门山北段泥盆系平驿铺组和侏罗系沙溪庙组是两个最重要的含油砂地层,它们呈北东向带状展布,组成两条区域性油砂带。两条油砂带在区域构造位置上分别与矿山梁—天井山—二郎庙冲断背斜亚带和下寺—金子山—青林口山前带叠置。两条构造-地层带的构造样式分别制约了两条油砂带的成藏方式和成藏过程,反映了油砂带与区域构造-地层带之间具有密切的成因关系。根据龙门山北段油砂特征以及区域构造-地层带对油砂带形成与分布的控制作用,首次将龙门山北段划分出2条区域性油砂成矿带,即矿山梁—天井山—二郎庙油砂成矿带和金子山—青林口—厚坝油砂成矿带。研究区油砂烃源岩具有多层位特征,油源十分丰富。泥盆系平驿铺组和侏罗系沙溪庙组具有良好的储层物性,为油气的聚集提供了有利的储集空间。各种不同的构造类型对油砂、沥青脉的成藏方式起着重要的控制作用。矿山梁—天井山—二郎庙油砂成矿带中印支期形成的褶皱与高孔隙度中、粗砂岩的良好配置、金子山—青林口—厚坝油砂成矿带中印支期形成的逆冲断层在喜山期重新活动以及喜山期形成的节理发育带与高孔隙度中、粗砂岩的良好配置是油砂储层形成的主控因素。喜山期侏罗系沙溪庙组地层的构造掀斜、山前剥蚀、断裂输导和上覆泥岩封盖以及泥盆系平驿铺组隆升剥蚀是油砂得以形成和保存的必要条件。在综合研究的基础上建立了龙门山北段油砂成藏模式。According to large geological profiles of field survey and synthetic studies indoor, It was thought that Devonian Pingyipu Formation and Jurassic Shaximiao Formation in the Northern Longmen Mountain are two most important oil sandstone strata, which spread zonally towards north east and make of two regional oil sandstone zones. This two regional oil sandstone zones overlay Kuangshanliang, Tianjingshan and Erlangmiao thrust anticline subzone and Xiasi, Jinzishan and Qinglinkou foreland zone in the regional structural location respectively. Different structural styles restrict reservoir forming mode and process of different oil sandstone zones,which shows that there is a close genetic relationship between oil sandstone zones and regional structural-stratigraphic zones. Because oil sandstone characteristics and regional structural-stratigraphic zones control oil sandstones formation and distribution in the northern Longmen Mountain,it was first thought that the northern Longmen Mountain can be divided into two regional oil sandstone metallogenic zones, namely Kuangshanliang, Tianjingshan and Erlangmiao oil sandstone metallogenic zone and Jinzishan, Qinglinkou and Houba oil sandstone metallogenic zone. The multizone is characteristic of source rocks of oil sandstone in study area,where is abundant in oil source. Devonian Pingyipu Formation and Jurassic Shaximiao Formation contain better reservoir physicality, which provides a favorable reservoir space for oil gas accumulation. Different structural types play important controlling role in accumulation mode of the oil sandstone and asphalt vein. Some following better configurations are main controlling factors of oil sandstone reservoir, one is that of Indosinianfolds and high-porosity, medium-coarse sandstone in Kuangshanliang, Tianjingshan and Erlangmiao oil sandstone metallogenic zone, and another one is that of Indosinian thrust faults reactivated in Himalayan and developed joint zone formed in Himalayan and high-porosity medium-coarse sandstone in Jinzishan, Qingl

关 键 词：龙门山 冲断带 构造-地层带 平驿铺组 沙溪庙组 油砂 成藏特征 

分 类 号：P618.13[天文地球—矿床学]