Pore Characteristics of the Upper Carboniferous Taiyuan Shale in Liaohe Depression

High pressure mercury, nitrogen adsorption, nano-CT, and scanning electron microscope with energy spectrum analysis were conducted on core shale samples for studying the characteristics of Taiyuan formation in the eastern uplift of Liaohe depression. The research results show that the shale gas reservoir pores are mainly open pores such as the wedge-shape pores and parallel-plate pores. By a genetic type, pores mainly include organic pore, pyrite crystal particle pore, illite intragranular pore, illite-smectite mixed layer intragranular pore, and feldspar dissolved pore. The micropore and mesopore play an important role in shale gas reservoir, and their surface area and pore volume are ۹.۵۶ m۲/g, ۰.۰۴۱۴ mL/g, ۹۷.۳%, and ۶۸.۸% respectively. The pores diameter presents a bimodal distribution with two main peaks at ۴۳ nm and ۶.۳۵ μm. Based on the nano-CT, the porosity is ۴.۳۶% and the permeability is ۲۰۴ nD. The brittle minerals played a supportive and protective role for the pores and controlled their spatial distribution.

کلیدواژه ها:

Liaohe ، Marine-continental Transitional Facies ، Taiyuan Formation ، Shale ، Pore