摘要
川东-鄂西地区志留系受加里东运动抬升剥蚀仅残留中下统地层。利用大量的地震、钻井、野外露头等资料,对该区进行层序地层学的分析和研究。在层序地层单元划分和对比的基础上,将川东南志留系地层划分出8个三级层序,其中下志留统龙马溪组2个(SSQ1-SSQ2)、小河坝组2个(SSQ3-SSQ4)、中志留统韩家店组4个(SSQ5-SSQ8),发育滨海、陆棚2类沉积体系。在层序格架下分析并介绍了各类沉积体系在该区的亚相类型及其平面展布。在对各方面资料分析研究的基础上,总结出该区的层序充填特征。通过层序地层划分对比及有利沉积相带研究,指出发育于小河坝期三级层序SSQ3高水位体系域,横向上分布于在武隆-石柱以及五科1井-奉节等地的小河坝组砂岩,具有良好的生储盖组合条件,应为勘探目标优选层位,有望为川东-鄂西下古生界油气资源的勘测工作打开新的局面。
Because of uplifting by Caledonian movement,most of the Silurian had been denuded and only its Middle-Lower series remained in Eastern Sichuan-Western Hubei. On the basis of the comprehensive study cores and log wells and outcrops,8 sequences and 2 system tracts were divided by use of sequence stratigraphic method,there are two sequences( SSQ1 ~ SSQ2) in the Lower Silurian Longmaxi Formation,two sequences( SSQ3 ~ SSQ4)in Xiaoheba Formation,four sequences( SSQ5 ~ SSQ8) in middle Silurian Hanjiadian Formation. Two depositional systems of coastal and shelf were developed. Under the sequence stratigraphic framework,various types of sedimentary system of sub-facies with their characteristics and planar distribution in this area were analysied and introduced,on all aspects of data analysis and summing up sequence filling characteristics of this area. Through the division and correlation of sequence stratigraphy and study favorable sedimentary facies,Pointed out that the third sequence SSQ3 highstand systems tract developed in the Xiaoheba age. The horizontal distribution in the Wulongshizhu and Wuke 1 well-Fengjie and other places of the Xiaoheba formation sandstone,it have good source-reservoir-caprock assemblages conditions and should be preferred for the exploration target layer. It is expected to open a new investigation situation of exploring Eopaleozoic oil and gas resources in the Eastern Sichuan-Western Hubai.
出处
《科学技术与工程》
北大核心
2016年第11期13-21,共9页
Science Technology and Engineering
基金
国家自然科学基金项目(41362008、U0933605)
江西省教育厅科技项目(GJJ14475)联合资助
关键词
川东-鄂西
志留系
层序地层
沉积体系
小河坝组
the Eastern Sichuan-Western Hubai
Silurian
sequence stratigraphy
depositional system the Xiaoheba formation