Numerical study on crack propagation of CO2 fracturing in tight sandstone reservoir considering fluid-solid-temperature coupling

Abstract

Tight sandstone has a tight structure and low natural production capacity, usually requiring the use of fracturing technology to achieve industrial production. Supercritical CO2 fracturing has attracted much attention due to its clean and efficient properties. In this paper, using the principles of damage mechanics, the crack propagation law during supercritical CO2 fracturing was studied by using numerical methods. The influence of different factors on the fracture propagation patterns is analyzed. Results indicate that supercritical CO2 fracturing can form complex fracture distribution patterns. This mode is divided into three different stages: slow fracture propagation, rapid fracture propagation, and rigid fracture propagation. In addition, highly heterogeneous formations generate more secondary fractures but limit their expansion.