Flowback technology after fracturing of CBM wells

There is no unified understanding on fracturing fluid flowback of CBM wells: either shut-in for pressure diffusion after a period of time to discharge or discharge in time. By means of analyzing the fracturing fluid, pressure and shut-in time, the CBM wells should be discharged in time after fracturing and suggested time control within 30 min. At the same time, according to the fracturing characteristics of CBM wells, such as the immediate settlement of proppants and the cementation between particles, the fracturing fluid flowback model is established. The calculation results show that in order to discharge the fracturing fluid timely and shorten the flowback time, it must begin with small choke and change a bigger choke or open flow latter during fracturing fluid flowback. The results provide an important theoretical basis for the quantitative selection of choke diameter in the fracturing fluid flowback design of CBM wells.