Pore Connectivity of Deep Lacustrine Shale and its Effect on Gas-bearing Characteristics in the Songliao Basin:Implications from Continental Scientific Drilling  

作　　者：HAN Shuangbiao HUANG Jie WANG Chengshan CUI Jiayi 

机构地区：[1]College of Geoscience and Surveying Engineering,China University of Mining and Technology,Beijing 100083,China [2]State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Beijing 100083,China

出　　处：《Acta Geologica Sinica(English Edition)》2023年第5期1503-1522,共20页地质学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.42072168 and 41802156);the National Key R&D Program of China(Grant No.2019YFC0605405);the Fundamental Research Funds for the Central Universities(Grant Nos.2023ZKPYDC07 and 2022YQDC06)。

摘　　要：The lacustrine shale of deep Shahezi Formation in the Songliao basin has great gas potential,but its pore evolution,heterogeneity,and connectivity characteristics remain unclear.In this work,total organic carbon analysis,rock pyrolysis,X-ray diffraction field emission scanning electron microscopy,the particle and crack analysis system software,low-temperature nitrogen adsorption experiment,fractal theory,high-pressure mercury injection experiment and nuclear magnetic resonance experiment were used to study the Shahezi shale from Well SK-2.The result indicated that the organic pores in Shahezi shale are not developed,and the intergranular and intragranular pores are mainly formed by illitedominated clay.As the burial depth increases,the pore size and slit-shaped pores formed by clay decrease,and dissolved pores in the feldspar and carbonate minerals and dissolved fractures in the quartz increase.The pore evolution is affected by clay,compaction,and high-temperature corrosion.Based on the pore structure characteristics reflected by the pore size distribution and pore structure parameters obtained by multiple experimental methods,the pore development and evolution are divided into three stages.During stageⅠandⅡ,the pore heterogeneity of the shale reservoirs increases with the depth,the physical properties and pore connectivity deteriorate,but the gas-bearing property is good.In stageⅢ,the pore heterogeneity is the highest,its gas generation and storage capacity are low,but the increase of micro-fractures makes pore connectivity and gas-bearing better.

关 键 词：pore evolution pore connectivity gas-bearing deep shale Songliao basin 

分 类 号：P618.13[天文地球—矿床学] P634[天文地球—地质学]