层序格架中富有机质页岩发育模式及差异分布:以上扬子下寒武统为例  

Sedimentary Model and Distribution of Organic-Rich Shale in the Sequence Stratigraphic Framework:A Case Study of Lower Cambrian in Upper Yangtze Region

作　　者：刘忠宝 杜伟[3] 高波[3] 胡宗全[3] 张钰莹[4] 吴靖 冯动军[3] 

机构地区：[1]页岩油气富集机理与有效开发国家重点实验室,北京100083 [2]中国石化页岩油气勘探开发重点实验室,北京100083 [3]中国石化石油勘探开发研究院,北京100083 [4]中国石油大学(华东)非常规油气与新能源研究院,山东青岛266580

出　　处：《吉林大学学报（地球科学版）》2018年第1期1-14,共14页Journal of Jilin University：Earth Science Edition

基　　金：国家重大科技专项(2016ZX05060;2016ZX05061);中国石油化工股份有限公司科技部项目(P15114)~~

摘　　要：以岩石地层分区多、名称复杂多变的上扬子下寒武统为例,并以高分辨率层序地层学理论为指导,通过露头、岩心、钻(测)井及岩矿测试等资料综合研究,识别出6个层序划分依据、5种沉积旋回叠加组合样式,认为页岩层系中层序界面厘定困难,不同级次沉积旋回的识别是层序划分的关键。以此为依据,结合研究区构造、岩相、有机碳含量等研究,建立了等时层序地层格架及其富有机质页岩的沉积发育模式,并以层序为单元,开展了富有机质页岩分布的精细编图。富有机质页岩主要发育于不同级次的海侵-海退作用早期,不同地区时空分布特征差异明显:四川盆地内部富有机质页岩主要分布在资阳-长宁一线近南北向带状展布的区域,其受基底断裂早寒武世多幕堑垒式活动控制,纵向上发育4套富有机质页岩段;四川盆地之外鄂西—渝东、黔北、黔东南及宜昌等地区主要受早寒武世早期上升洋流作用控制,以下部层序发育大套富有机质页岩段为特征。今后应考虑不同地区富有机质页岩的时空分布特点,进行页岩气勘探与开发部署。Taking the lithostratigraphy complicated Lower Cambrian in the Upper Yangtze region as an example,guided by the theory of high resolution sequence stratigraphy,based on the outcrop,rock core,thin section and drill data,we identified 6 standards to divide sequence stratigraphy and 5 sedimentary cycles of combination style.The interface of shale sequence stratigraphy is difficult to identify,and the recognition of different grades of depositional cycle is the key factor.Based on the above,combined with the study of tectonics,lithofacies and organic carbon content,we established isochronous sequence stratigraphic framework and sedimentary model of rich organic shales,and carried out fine mapping of organic shale distribution based on the sequence units.The organic-rich shales are developed mainly in the early different grade of transgressive-regressive periods.The distribution of organic-rich shales in the different areas is varied.The organic-rich shales distribute mainly in ZiyangChangning area in the Sichuan basin.There are four sets of organic-rich shales controlled by the polytectonic basement rift.A large set of organic-rich shales are developed in the western Hubei-eastern Chongqing,north-southeastern Guizhou and Yichang areas controlled by Early Cambrian upward flow of ocean currents.The distribution characteristics of organic-rich shales should be taken into consideration for shale gas exploration and exploitation.

关 键 词：页岩 层序地层 筇竹寺组 牛蹄塘组 下寒武统 上扬子地区 四川盆地 

分 类 号：TE121[石油与天然气工程—油气勘探]