Research progress and prospects of CO₂ enhanced shale gas recovery and geologic sequestration

Petro-China Research Institute of Petroleum Exploration & Development, Beijing 100083, China

^* Corresponding author: author@e-mail.org

Abstract

CO₂ injection to strengthen shale gas development is a new technology to improve shale gas recovery and realize geologic sequestration. Many scholars have studied these aspects of this technology: mechanism of CO₂ displacement CH₄, CO₂ and CH₄ adsorption capacity, affecting factors of shale adsorption CO₂, CO₂ displacement numerical simulation, and supercritical CO₂ flooding CH₄ advantages. Research shows that CO₂ can exchange CH₄ in shale formations, improve shale gas recovery, on the other hand shale formations is suitable for CO₂ sequestration because shale gas reservoir is compact. The supercritical CO₂ has advantages such as large fluid diffusion coefficient, CO₂ dissolution in water to form carbonic acid that can effectively improve the formation pore permeability etc., so the displacement efficiency of supercritical CO₂ is high. But at present the technology study mainly focus on laboratory and numerical simulation, there is still a big gap to industrial application, need to study combined effect of influence factors, suitable CO₂ injection parameter in different shale gas reservoir, CO₂ injection risk and solutions etc.