| 摘要: |
| 以"沉积控相,相控储层"为研究思路,基于野外露头剖面实测与室内实验测试,以及前人的研究成果,探讨渝东北地区上奥陶统五峰组-下志留统龙马溪组沉积环境对页岩气储层的控制作用。研究表明,渝东北地区五峰组-龙马溪组富有机质泥页岩主要发育于滞留浅海陆棚相中,沉积中心页岩厚度可达70~80m,有机碳含量(TOC)最高可达7.56%,平均3.09%。静水缺氧还原沉积环境岩石类型主要以富含有机质的含碳质含粉砂泥(页)岩、含碳质含硅质泥(页)岩、含硅质泥(页)岩、含碳质泥(页)岩、含粉砂泥(页)岩及硅质泥(页)岩为主。页岩矿物成分以石英(平均达62.76%)和黏土矿物(平均达22.61%)为主。缺氧还原环境下沉积的大量黄铁矿形成的黄铁矿晶间孔、黏土矿物层间微孔隙、有机质生烃形成的微孔隙以及脆性矿物控制形成的微裂缝为页岩气提供了良好的储集空间。沉积环境控制的储层发育特征的研究可为页岩展布、有机质丰度、储集空间及其之后有利区评价等研究提供基础。 |
| 关键词: 沉积环境 页岩气 储层特征 渝东北地区 五峰组-龙马溪组 |
| DOI： |
| 附件 |
| 投稿时间：2015-09-10修订日期：2015-10-13 |
| 基金项目:国家自然科学基金(41030315)资助 |
|
| Controls of sedimentary environments on shale gas reservoirs: A case study of the Wufeng and Longmaxi Formations in northeastern Chongqing |
| YANG Yu-ning, WANG Jian, XIONG Guo-qing |
(1. Chengdu University of Technology, Chengdu 610059, Sichuan, China;
2. Sichuan Zhongcheng Coalfield Geophysical Exploration Engineering Co., Ltd., Chengdu 610072, Sichuan, China;
3. Key Laboratory of Sedimentary Basins and Oil and Gas Resources, Ministry of Land and Resources, Chengdu 610081, Sichuan, China) |
| Abstract: |
| The controls of sedimentary environments on shale gas reservoirs in the Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation in northeastern Chongqing are treated in this study on the basis of field investigation, laboratory data and previous results of research. The organic-rich shales occur mostly in the stagnant neritic shelf environment, and have a thickness of 70-80 m at the depositional center. The organic carbon contents amount to 7.56%, with an average of 3.09%. The rock types in the static anoxic environment include organic-rich carboniferous-silty mudstones and shales, carboniferous-siliceous mudstones and shales, siliceousbearing mudstones and shales, carboniferous mudstones and shales, silty mudstones and shales, and siliceous mudstones and shales. The mineral compositions in the shales contain quartz (62.76% in average) and clay minerals(22.61% in average). The intergranular pores in pyrite created in the anoxic-reduction environments, interlayer micropores in clay minerals, micropores created by hydrocarbon generation in organic matter, and microcracks created by brittle minerals have provided excellent reservoir spaces for the shale gas. The study of reservoir characteristics in sedimentary environments will offer some thoughts on the shale distribution, organic matter abundance, reservoir spaces and evaluation of favourable areas in future shale gas exploration and development. |
| Key words: sedimentary environment shale gas reservoir characteristics northeastern Chongqing Wufeng and Longmaxi Formations |
