Volume 46: Energy Transitions toward Carbon Neutrality: Part IX

Study on high pressure imbibition characteristics of ultra-deep carbonate rocks based on nuclear magnetic resonance method Beidong Wang, Shenglai Yang, Jiangtao Hu, Sishi Lin, Qiaoling Wang, Lufei Bi

Abstract

In dengsi gas reservoir, Anyue gas field, Sichuan Basin, It’s diagenetic process of ultra-deep carbonate sedimentation is complex. At present, the structural characteristics of the pore throat are not enough. In this paper, I use the real reservoir core of the gas reservoir as the research object, and study the types and characteristics of the pore throat of the reservoir by using the method of cast thin section analysis and nuclear magnetic resonance testing.Studying the nuclear magnetic resonance spectroscopy characteristics of the three types of pore cores after different pressure imbibition of saturated water. The results show that the main peaks of T2 spectrum of pore type I, II and III cores are distributed around 1-10ms, 10-100ms and 1ms, and the high-speed conductivity of fractures can improve the overall imbibition degree of pore type II cores. Increasing saturation pressure has the greatest effect on the imbibition saturation degree of pore type II cores, and the best effect on the cores with permeability between 0.001-0.01mD. Because it is difficult for water to enter the pore type III core with too low permeability, the influence of increasing saturation pressure on the pore type III core is low. The research can provide a theoretical basis for the study of water invasion mechanism in the production process of target gas reservoir and the drainage gas production in the later stage.

Keywords Carbonate rock, Nuclear magnetic resonance, Imbibition