长宁-威远地区筇竹寺组和五峰组-龙马溪组页岩储层特征对比及含气性控制因素研究

Shale gas has become one of the most important unconventional energy resources.Two sets of typic typical organic-rich shale including Qiongzhusi Formation and Wufeng-Longmaxi Formation which developed in Changning-Weiyuan region, There are great potentials of shale gas resource in these two sets of organic-rich shales. Shale gas exploration progress quickly in Changning-Weiyuan region，But the understanding for the enriched rule of shale gas remains unclear. organic-rich shale is the reservoir space of shale gas, The study of reservoir characterization is key in shale gas enrichment regularity.further more, there are differences for Shale gas production capacity between in Qiongzhusi Formation and Wufeng-Longmaxi Formation, differences for between in Changningarea and Weiyuan area as well. Therefore, This proposal aims to disclose the reservoir characteristics of Qiongzhusi Formation and Wufeng-Longmaxi Formation,that contains Organic geochemical, mineralogical composition, physical, pore type, pore structure, gas content. reservoir characterization of shale is compared between in different structure locations and different formations,to reseach the parameters of the coupling relationship among in these key parameters,and then discuss controlling factors of shale gas, to establish evaluation criterion of key parameters, The results from this research may provide theoretical supports for us to explore and evaluate shale gas resource in Changning-Weiyuan region.

页岩气已成为重要的非常规接替能源。长宁-威远地区下古生界发育笻竹寺组和五峰组-龙马溪组两套典型的富有机质页岩，且页岩气资源潜力巨大。长宁-威远区块页岩气勘探进展较快，但对页岩气富集规律的研究严重滞后。富有机质页岩是页岩气的储集场所，储层特征研究是揭示页岩气富集规律的关键之一。另外，研究区笻竹寺组和五峰组-龙马溪组页岩气产能存在差异，长宁地区和威远地区两种不同构造位置的页岩产能也存在差异。因此，本申请试图结合地层、沉积相和岩相划分等基础地质研究，研究长宁-威远地区笻竹寺组和五峰组-龙马溪组页岩储层特征，包括有机地化特征、矿物组分特征、物性特征、孔隙类型、孔隙结构特征和含气性特征；对比川西南不同构造位置（盆内和盆缘）、不同层位（笻竹寺组和五峰组-龙马溪组）页岩储层特征差异，研究各参数之间的耦合关系，进而探讨页岩含气性控制因素，建立关键参数的评价标准，为页岩气勘探井位布署提供理论依据和技术支持。

筇竹寺组和五峰组-龙马溪组是中国南方页岩气最具开采价值和潜力的地层，而这两套地层在四川盆地勘探开发最成功的地区是长宁、威远和焦石坝地区，但两套地层同时开采且具有商业价值的是长宁和威远地区。因次，对比研究长宁和威远地区筇竹寺组和五峰组-龙马溪组页岩储层特征具有重要意义。. 首先，项目分别研究了筇竹寺组和五峰组-龙马溪组的地层、沉积、地化、矿物、物性、孔隙结构和含气性特征。其次，分别对比不同构造位置同一地层的储层特征进行对比，明确筇竹寺组和五峰组-龙马溪组长宁和威远地区横向展布特征，认为筇竹寺组储层威远地区好于长宁地区，且威远地区筇一2亚段好于筇一1亚段，长宁地区则是筇一1亚段更好，长宁地区五峰组-龙马溪组优质页岩储层厚度大于威远地区，且长宁地区均质性较强，而威远地区非均质性较强；以威201井和宁208井为例，对同一构造位置（同井）筇竹寺组和五峰组-龙马溪组储层特征对比，明确同一地区纵向上不同层位之间差异，研究表明五峰组-龙马溪组页岩储层品质优于筇竹寺组。最后，通过含气性控制因素研究，表明含气性受“相源、储层和保存”三元联控，其中相源是基础，储层是核心，保存是关键。