Directional Fracturing Caused by Carbon Dioxide

Based on the theory and practice of carbon dioxide fracturing, combined with the pre-notched directional fracture, the carbon dioxide pre-notched directional fracturing technique was proposed. The mechanism and experiment of carbon dioxide pre-notching directional fracturing technique was studied. The results show that during the process of carbon dioxide fracturing, the pre-notched hole produces two mechanical effects of a strong tensile stress area around notch and a compression stress area around non-notching direction, as well guiding effect on the crack direction. Under the combined action of these three effects, the cracks initiate and propagate along the pre-notched direction, and the directional control of the cracks made by carbon dioxide is achieved.