高校地质学报2018，Vol.24Issue(2)：273-284,12.DOI:10.16108/j.issn1006-7493.2017105
川南地区筇竹寺组页岩微观孔隙结构特征及其影响因素
Characteristics of Microscopic Pore Structures and Its Influencing Factors of the Qiongzhusi Formation Shales in the Southern Sichuan Basin
摘要
Abstract
Microscopic pore structures of shale are an important factor influencing the storage capacity of shale gas reservoirs. To evaluate the reservoir properties of the Lower Cambrian Qiongzhusi Formation shales in the southern Sichuan Basin, we investigate genetic types of microscopic pores,characteristics of pore structures and its influencing factors in this paper,based on the data from core and drilling samples. Multiple methods were applied, including scanning electron microscopy, field emission scanning electron microscopy with argon ion polishing,image J2x software analysis,low-temperature CO2and N2adsorption,and high-pressure mercury injection experiments.Results show that the porosity of the Qiongzhusi Formation shales ranges from 0.25％ to 5.80% with an average of 2.49%.Multiple genetic types of pores are present in the shales,with the inter-granular pores being dominant and the intra-granular pores, organic matter pores and micro-cracks being subdominant. The total surface porosity of the microscopic pores in the shales ranges from 3.58% to 5.92%. The total pore volume of the shales ranges from 2.86×10-3to 12.55×10-3mL/g, and the total specific surface area ranges from 2.727 to 21.992 m2/g.Their pore-size distribution mainly occurs in three ranges:0.30～1.00 nm,2.5～4.7 nm and 55～70 nm.Micropores(<2 nm)and mesopores(2～50 nm)are the main reservoir storage space for shale gas.Types of pore structure are mainly circular pores,wedge-shaped pores,parallel-plate pores and mixed pores.The porosity and total specific surface area of the shales show positive correlations with TOC and abundance of brittle minerals.The micropore volume and specific surface area of shales show positive correlations with TOC.The porosity,total pore volume and specific surface area of shales show negative correlations with Ro and abundance of clay minerals.关键词
页岩气储层/孔隙类型/孔隙结构/筇竹寺组页岩/川南地区Key words
shale gas reservoir/pore type/pore structure/the Qiongzhusi Formation shale/Southern Sichuan Basin分类
天文与地球科学引用本文复制引用
王哲,李贤庆,祁帅,姚素平,王飞宇..川南地区筇竹寺组页岩微观孔隙结构特征及其影响因素[J].高校地质学报,2018,24(2):273-284,12.基金项目
国家重点基础研究计划"973"课题(2014CB239102 （）
2012CB214702) （）
国家科技重大专项课题(2016ZX05007-003) （2016ZX05007-003）
国家自然科学基金项目(41572125) （41572125）
国土资源部公益性=业科研专项基金项目(201311022)联合资助 （201311022）
