镇北地区前侏罗纪古地貌特征与油气富集规律研究

Characteristics of pre-Jurassic palaeogeomorphology and hydrocarbon accumulation regularity in Northern Zhenyuan Area

曾传富 田景春 张涛 刘哲 王峰

成都理工大学油气藏地质及开发工程国家重点实验室，四川 成都 610059 成都理工大学沉积地质研究院，四川 成都 610059 中国石油长庆油田公司勘探部，陕西 西安 710018

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China Exploration Department of Changqing Oilfield Company, PetroChina, Xi′an 710018, China

综合运用钻井岩心、测井及测试分析等资料，采用地层厚度印模法，恢复了鄂尔多斯镇北地区前侏罗纪古地貌形态，在此基础上，对前侏罗纪古地貌形态与中下侏罗统砂体展布特征及油气成藏关系进行了探讨。研究表明：镇北地区前侏罗纪发育高地、古河谷、斜坡、河间丘、古阶地等5种古地貌单元；下侏罗统富县组—延10段辫状河沉积沿古河谷发育，深切河谷为油气提供了良好的运移通道和储集空间，为古地貌控制明显的斜坡￣河流相成藏模式；经过早期的填平补齐，延9期发育三角洲沉积，油气多在有效储盖配置的构造高部位聚集成藏，为河间丘￣三角洲前缘成藏模式。

Comprehensive use of drilling, core, logging and test analysis data, Northern Zhenyuan Area′s pre-Jurassic palaeogeomorphology was reconstructed by the method of formation thickness impression. Based on this, the relationship between the pre-Jurassic palaeogeomorphology and the distribution features of the middle and lower Jurassic sandstone and hydrocarbon accumulation are discussed. Research shows that: five palaeogeomorphic patterns in Northern Zhenyuan Area developed, highland, incised valley, slope, mound, ancient terrace; the braided river deposits of the lower Jurassic Fuxian Formation Yan 10 developed along the ancient valley, deep valley provided good migration channel and storage space for oil and gas, the slope-river phase accumulation model developed, which was controlled by palaeogeomorphology obviously; after an early filling up, delta deposit  developed during the Yan 9 period, oil and gas usually accumulated in the high part of the structure, where there are effective reservoirs. Generally, mound-delta front phase accumulation model formed.

10.6056/dkyqt201503001