CO_2切槽定向致裂机理实验研究

Directional Fracturing Caused by Carbon Dioxide

基于CO_2致裂理论和实践,结合切槽定向爆破方法,提出了CO_2切槽定向致裂技术,定性分析了CO_2切槽定向致裂机理,开展了CO_2切槽定向致裂实验。结果表明:在CO_2致裂过程中,切槽产生了应力集中和孔壁裂纹抑制2个力学效应,再加切槽对裂纹方向的引导作用,在三者共同影响下,使裂纹沿着设计方向起裂和扩展,从而实现CO_2致裂裂纹的定向控制。

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.