摘要
上奥陶统五峰组-下志留统龙马溪组为鄂西地区重要的页岩气勘探目的层。为更好地实现研究区域页岩气的勘探与开发,利用黄陵背斜周缘调查井及实测地层剖面资料,对五峰组-龙马溪组岩石地层、有机地球化学、储层物性、含气性等方面进行了综合分析。研究表明:目的层纵向上可以分为五峰组硅质岩段、五峰组观音桥灰岩段、龙马溪组下部黑色炭质页岩段、龙马溪组上部灰黑色炭质页岩夹粉砂岩段。目的层埋深多为1000~3000m,厚度具有由南向北、由东向西逐渐增大的趋势。研究区TOC含量多为1.16%~2.99%,平均为2.10%。黄陵背斜西南缘TOC含量比东缘高,五峰组TOC含量最高,龙马溪组上部含量最低。五峰组-龙马溪组以石英矿物和黏土矿物为主,脆性矿物含量高,页岩储层为低孔特低渗孔隙类型;孔隙类型以有机质孔隙及粒间孔隙为主,地层由下至上表现出有机质条带、有机质孔隙及黄铁矿数量逐渐减少的趋势。含气性特征研究表明,黄陵背斜西南缘含气性稍微好于东缘地区,含气量与TOC值呈现较好的正相关性,五峰组含气性最好,龙马溪组上部较差;北北东向新华断裂带附近页岩气含气性较差,而北西向断裂带附近页岩气含气性较好。研究结果可为黄陵背斜周缘页岩气调查井的部署提供理论依据。
The Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation is considered as a major shale gas exploration interval in western Hubei.In order to better realize the shale gas exploration and development in this area,the lithostratigraphy,organic geochemistry,reservoir and gas-bearing properties of the Wufeng-Longmaxi Formations were comprehensively analyzed based on the surveying well data and the measured stratigraphic profiles in the periphery of Huangling Anticline.Research shows that the target stratum can be divided into 5 intervals,including Wufeng Formation siliceous rock interval,Wufeng Formation Guanyinqiao limestone interval,black carbonaceous shale interval of the Longmaxi Formation,and the gray-black carbonaceous shale interval interbedded with siltstone of the upper Longmaxi Formation.The target interval is generally buried in a depth of 1 000~3 000 m,and the corresponding thickness increases from south to north and from east to west.The TOC content in the study area is mostly 1.16%~2.99% with 2.10% on average.The TOC content in the southwestern edge of the Huangling Anticline is higher than that in the eastern edge.The Wufeng Formation shows the maximum TOC content and the upper Longmaxi Formation shows the minimum TOC content.The Wufeng-Longmaxi Formations with high brittle mineral content are dominated by quartz minerals and clay minerals,and the shale gas reservoirs are characterized by low porosity and ultra-low permeability.The reservoir pore space is mainly contributed by organic pore and intergranular pore.The reservoirs show a gradually decreasing trend of organic matter strip,organic pore and pyrite from bottom to top.The oil-bearing properties illustrates that the gas-bearing properties of the southwestern edge is slightly better than that of eastern edge.There is a favorable positive correlation between the gas content and TOC.The Wufeng Formation shows the maximum gas content and the upper Longmaxi Formation shows a poor gas content.The NNE Xinhua fault zone shows a poor gas content and the NW fault zone shows a better gas content.This research could provide certain theoretical basis for the deployment of shale gas surveying well in the periphery of the Huangling Anticline.
作者
许露露
张焱林
陈程
周向辉
温雅茹
Xu Lulu;Zhang Yanlin;Chen Cheng;Zhou Xianghui;Wen Yaru(Hubei Geological Survey Shale Gas Center,Wuhan,Hubei 430034,China)
出处
《特种油气藏》
CAS
CSCD
北大核心
2019年第5期26-32,共7页
Special Oil & Gas Reservoirs
基金
湖北省国土资源厅项目“湖北省页岩气勘查区块评价优选”(HBCZ-17060223-170397)
湖北省地质局科研项目“鄂西地区构造特征与页岩气保存条件研究”(KJ2019-3)联合资助
关键词
储层特征
含气性特征
页岩气
五峰组-龙马溪组
黄陵背斜
鄂西
reservoir properties
gas-bearing properties
shale gas
Wufeng-Longmaxi Formation
Huangling Anticline
western Hubei
