Research and Application of the CO2 Dry Fracturing Technology

CO2 dry fracturing technology utilizes waterless and harmless liquid CO2 as sand-carrying fracturing fluid. Conventional water-based fracturing fluid causes major damage to reservoirs due to intrusion of large amount of water, greatly impacting the stimulation effects of water-sensitive reservoirs. In contrast, CO2 dry fracturing technology realizes waterless fracturing, achieves the purpose of being nearly harmless to the formation, and can augment production and energy in a sound manner. This paper studies the rock-breaking mechanism of the technology, its functions of changing reservoir fluid properties, and its application effects home and abroad, presenting its technological advantages and a promising application future. CO2 dry fracturing technology is an important technical means to improve the development effects of unconventional oil and gas reservoirs thanks to its strong rock-breaking ability, excellent fluidity, and tendency to form complex shear fractures. The application home and abroad shows obvious production enhancement and a large amount of water saved. Despite some room for improvement, the technology is a new one worth spreading and application. It has satisfied the construction requirements of energy conservation, emission reduction, environmental protection, high efficiency and production enhancement, and hence is of great significance to the clean and efficient development of strongly water-sensitive and strongly water-locked unconventional oil and gas reservoirs.