Research on reasonable depressurization rate in initial stage of exploitation to coal bed methane
Abstract：Taking advantage of the rock mechanical analysis approach,the theoretical research and discussion referring to the depressurization rate under the different stress state of coal rock around a borehole in the initial stage of exploitation was carried out,and the mechanical analysis model about the control to the depressurization rate was built,and the upper limit values of the reasonable depressurization rate in the process of exploitation were determined with considering the practical engineering test data in Hancheng.Meanwhile,the variation of the upper limit values against the depth of the reservoirs was given according to the research to several wells data.The results show that the upper limit values are linear increasing with the depth of the reservoirs,and mechanical characters of coal rock have a greater effect on the reasonable depressurization rate.Thus,it can be achieved to make the permeability rise or maintain at a high level by controlling the change of the depressurization rate of the bottom hole pressure.
Keywords：coal bed methaneinitial stage of exploitationdepressurization ratepermeabilitybottom hole pressure
Publication Date：2011-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)