Volume 43: Energy Transitions toward Carbon Neutrality: Part VI

Pore structure characteristics of deep carbonate gas reservoir based on CT scanning Jiangtao Hu, Shenglai Yang, Xiangshang Zhao, Sishi Lin, Beidong Wang, Qiaoling Wang, Lufei Bi

Abstract

Carbonate gas reservoirs are rich in reserves, with various types of reservoirs, developed cross-scale porous media, and complex seepage mechanisms. In this paper, the natural cores of the fourth member of the Dengying Formation in the Anyue gas field were selected, CT scanning experiments were carried out, and digital cores were constructed. The plane pore characteristics, three-dimensional pore characteristics and pore and throat distribution frequency characteristics of the digital core are studied respectively.
The results of CT scanning show that: (1) the pore and throats of pore-type reservoirs are small, poor in connectivity, and the karst caves and fractures are underdeveloped, with low seepage capacity; (2) The pore and throats of cavity-type reservoirs are relatively large in size, with good connectivity, medium and small-sized karst caves and micro-fractures are widely developed, and the seepage capacity is good; (3) Fracture-cavity-type reservoirs have large pore and throats and good connectivity, and various-sized cavities and various types of fractures are widely developed in the reservoir, and the entire rock block area is full of Interconnected fracture-cavity network system with excellent seepage capacity.

Keywords Carbonate gas reservoirs, CT scanning, Pore structure characteristics, Fracture-cavity-type reservoirs