MA Y Z, WANG M, MA R Y, et al.Microscopic characteristics and influencing factors of coal-measure shale gas reservoirs in marine-continent transitional facies： Take the Y2 well in the mid-eastern Qinshui Basin as an example[J].Journal of Henan Polytechnic University(Natural Science) ,2023,42(5):80-92.

doi:10.16186/j.cnki.1673-9787.2020110075

Received:2020/11/24

Revised:2020/12/09

Published:2023/09/25

Microscopic characteristics and influencing factors of coal-measure shale gas reservoirs in marine-continent transitional facies： Take the Y2 well in the mid-eastern Qinshui Basin as an example

MA Yuanzhen1, WANG Meng2,3, MA Ruying1, DAI Xuguang3, XIE Weidong4, LI Jiamin1

1.College of Geology and Mining Engineering，Xinjiang University，Urumqi  830046，Xinjiang，China;2.Low Carbon Energy Institute，China University of Mining and Technology，Xuzhou  221008，Jiangsu，China;3.School of Resources and Geosciences，China University of Mining and Technology，Xuzhou  221116， Jiangsu，China;4.College of Resources，China University of Geosciences（Wuhan），Wuhan  430074，Hubei，China

Abstract:In order to explore the microscopic characteristics and their influencing factors of the coal-measure shale gas reservoirs in the mid-eastern Qinshui Basin，the microscopic pore structure in the shales of the Shanxi and Taiyuan formations from the Y2 well was acquired by means of organic geochemistry test，SEM test，bulk-rock and clay mineral XRD，high pressure mercury injection，and low temperature N2 adsorption analysis.The results showed that：（1）The organic matter in the shale was type Ⅲ（humic），and the total organic carbon（TOC）content was relatively high，with an average value of 1.79%，which had experienced a long and complex thermal evolution history.（2）Intragranular，intergranular，and organic matter pores and micro-cracks were mainly developed in the shales，and a large number of intergranular and intragranular pores were presented in clay minerals and quartz.（3）Based on two-dimensional SEM image analysis，the fractal dimension of the shale pore fracture morphology was between 2.34 and 2.51，and the heterogeneity was moderate.（4）The high-pressure mercury intrusion and N2 adsorption experiments were mainly aided to reveal the distribution patterns of the macropores and mesopores in the shales.Mesopore was the main pore type in the shales，which had great influence on pore volume and pore specific surface area.The volume and specific surface area of the mesopores were positively correlated with the total organic carbon content（TOC） and quartz content，and negatively correlated with the vitrinite reflectance（R_O）.（5）The illite content in clay minerals had a positive effect on the pore volume and specific surface area，but the present of kaolinite was not conducive to it.This research results had a theoretical guiding significance for the exploration of coal measures shale gas there.

Key words:coal-measure shale gas reservoir;pore characteristics;fractal characteristics;microscropic characteristics and influencing factors;mid-eastern Qinshui Basin

海陆过渡相煤系页岩气储层微...以沁水盆地中东部Y2井为例_马元稹.pdf