Analysis of cavitation pressure difference during blowdown in CBM cavity completion

摘要

In the cavitation process of cavity completion, one of the most important steps is wellbore depressur-ization after injection, during which the pressure difference between pore pressure around the borehole and bottom pressure forms as a highly influential factor for wellbore cavitation. The laboratory simulation of cavity completion has been performed with water and air. By analyzing the change of pressure difference during cavitation with the water or air, the reason why air is better to create a cavity than water has been explained. Furthermore, the effect of pressure difference of adsorbed gases on wellbore cavitation has also been demonstrated.