1 Key Laboratory of the Ministry of Education of Unconventional Oil and Gas Development,2 Shandong Key Laboratory of oilfield chemistry China University of Petroleum East China,Qingdao
At present, more and more attention has been paid to the efficient development of unconventional oil and gas resources. Fracturing is an effective method for unconventional oil and gas development, and the performance of fracturing fluid determines the fracturing effect. For the traditional water-based fracturing fluid, it is easy to cause water-sensitive damage to reservoir. Carbon dioxide fracturing fluid has become a new direction of unconventional oil and gas development research due to its non-aqueous components. However, due to the low viscosity of pure carbon dioxide fracturing fluid, which seriously affects the fracturing effect, it is imperative to find a suitable thickener to improve the viscosity of carbon dioxide fracturing fluid. Based on the literature research, this paper studies the structure and performance characteristics of four kinds of carbon dioxide thickeners including surfactant, hydrocarbon polymer, fluoropolymer and siloxane polymer, and summarizes the current research status of carbon dioxide fracturing fluid thickening from two aspects of thickening mechanism and thickening performance. Finally, the characteristics of various thickeners are summarized and suggestions for future research directions are put forward.