Prospect of shale gas evaluation in view of measurement techniques development of coal seam gas content

It was introduced in this paper the development process of coal seam gas content measurement techniques, the experimental modeling results of methane escaping and desorption in coal cores, as well as the application conditions and constraints for the present coal seam gas content measurement standards. During the sampling, atmospheric exposure and sealing desorption phases of coal cores, the conditions and mechanisms for gas escaping and desorption were various. Uncertainty and risk remained when coal core gas loss estimation method was applied in shales. The basic studies of gas escaping and desorption in shale cores during the above-mentioned three phases should be focused on. Shale gas was classified into three types: gas in drilling fluids, gas exposed and escaped, and gas remained in cores. Some proposals were made as followed to set up a new measurement techniques standard of gas content in shales: developing detection devices for gas in drilling fluids, and establishing rapid detection and calculation methods for gas in drilling fluids combined with comprehensive logging data; improving the existing core desorption gas and residual gas measurement technology, and establishing a rapid determination method for core residual gas; exploring for the detection or calculation method for exposed and escaped gas based on desorbed gas tests.