Status and prospects of coalbed methane reservoir fracturing

In order to deeply study the seam fracturing and to improve the fracturing effect of the seam, the paper summarized and analyzed the seam fracturing flu id, fracturing proppant, numerical simulation of the fractured cracks, crack monitoring and measuring, seam fracturing design and construction technique status.The Co mparison analysis showed that the activated water combined with the quartz sand would be the major combination mode of the coalbed methane fracturing in the shallo W depth seam.But with the depth increased and the geological complexity of the reservoir enhanced, the after fracturing effect of the major combination mode would be steadily poor. The application of the conventional two dimension and the pseudo-three-dimension crack simulation method would be limited to the seam and the optimiza tion should be conducted on the crack simulation method according to the geological features of the coal reservoir.The results of the multi crack monitoring method to t he seam showed that after the coal reservoir fractured, there would be three shape complicated crack and asymmetry network cracks combined with the through seam vertical cracks, vertical cracks and horizontal cracks.Mainly the activated water vertical fracturing, the hydraulic wave and fracturing and indirect fracturing and other m ulti fracturing techniques as the secondary fracturing technique and technology were discovered in China.Finally, an outlook on the seam fracturing was provided, thus on the premise of the low cost and high efficient environment protection, from a view of the fracturing mechanism to increase the seam reconstruction volume and to inc rease the desorption area, in combination with the coal and rock engineering geological features, the optimum fracturing material and the matched fracturing technology would provide the theoretical guide to the rational high efficient development of the coalbed methane.