Study On Simulation Experiment And Estimate Model For Coalbed Methane Lost Gas Content

Coalbed methane content is one of the key parameters representing the coal reservoir characters. To get accurate coalbed methane content is very meaningful for coalbed methane exploratory development and preventing and curing coal mine gas. Aiming at that the estimate lost gas content is lower than the actual content in coal reservoir, as well as being short of testers and methods to examine current estimate methods. In this paper, the author has carried out coalbed methane high-pressure desorption simulation test with representative coal samples of different coal rank and size, making use of existing knowledge, technology and methods, such as theory of coal geology, coal petrography, coal chemistry and engineering mathematics , as well as high-pressure experiment technology. And then, high pressure desorption simulation test method has been worked out and lost gas content is measured actually. The simulation test results show the desorption law and effecting factors. It is concluded that the estimate lost gas contents by the USBM direct method are lower than measuring results in this simulation test. In the end, this paper has brought forward coalbed methane diffusion and desorption model during the coal coring procedure and deduced its analytical solution.