Cyclic Characteristics of the Physical Properties of Key Strata in CBM Systems Controlled by Sequence Stratigraphy—An Example from the Gujiao Block  

作　　者：WANG Gang QIN Yong XIE Yiwei WANG Ziwei WANG Boyang WANG Qi ZHANG Xiaoyang 

机构地区：[1]Shangqiu Normal University.Shangqiu,Henan 476000,China [2]Shandong Provincial Key Laboratory of Depositional Mineralization&Sedimentary Mineral,Shandong University of Science and Technology,Qingdao,Shandong 266590,China [3]Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of the Ministry of Education,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China [4]Geology Section of the Xi Shan Coal Electricity Group,Taiyuan 030053,China [5]Xi'an Research Institute,China Coal Technology and Engineering Group Corp,Xi’an 710054,China

出　　处：《Acta Geologica Sinica(English Edition)》2020年第2期444-455,共12页地质学报（英文版）

基　　金：the National Natural Science Foundation of China(No.41672149 and No.41672146);the Key Project of the Natural Science Foundation of China(No.41530314);the Application Research Plan of Key Scientific Research Projects in Colleges and Universities of Henan Province(20B610006);Scientific Research Foundation of the Shandong Provincial Key Laboratory of Depositional Mineralization&Sedimentary Minerals;the Shandong University of Science and Technology(DMSM2017012);the National Science and Technology Major Project(2016ZX05044-002).

摘　　要：Multiple coal seams and interbedded rock assemblages formed in vertical progression due to the influence of multiple stages of sea level transgressions.Based on mercury injection experiment,low temperature liquid nitrogen experiment,porosity and permeability experiment and breakthrough pressure experiment,the vertical variation characteristics of coal-bearing strata in Gujiao block are explained in detail.The results of the mercury injection and low temperature liquid nitrogen experiments show that the pore structure characteristics fluctuate with increasing depth in the strata,with fewer micropores followed by transition pores.The BET specific surface area and average pore diameter of the Shanxi Formation are generally larger than those of the Taiyuan Formation.Due to the continuous cyclic sequence stratigraphy changes,the porosity,permeability,breakthrough pressure and breakthrough time of the samples show a certain cyclicity.Within the same sequence,the porosity is larger,and the permeability is smaller near the maximum flooding surface.Although the permeability of the sandstone samples is higher,the porosity is lower,and the breakthrough pressure and breakthrough times are greater.The strata in the study area formed in an oxidized environment that was affected by freshwater,and the pore structure of different lithologies is quite different.After the formation of sandstone,the intergranular pores generally underwent filling with secondary quartz,clay minerals and organic matter,resulting in low porosity and permeability.

关 键 词：coal-bearing STRATA SEQUENCES physical properties cycle Gujiao BLOCK 

分 类 号：P618.13[天文地球—矿床学] P539.2[天文地球—地质学]