Automatic shale gas content measurement technology

The manual drainage gas recovery method that is applied to measure the gas content on site can hardly meet the measurement requirements when the sampling density of shale reservoir is increased. In this paper, an automatic shale gas content measurement technology was developed. According to the constant-pressure level equilibrium principle of the liquid of the same height in U-tube under the equal atmospheric pressure, photoelectric non-contacting closed loop measurement and control method is adopted to measure the gas content of shale reservoir automatically and continuously at constant pressure and volume. Field application shows that the difference between the manual measurement and the automatic one of the samples from the adjacent well depth is only 0.03 m³/t. It is indicated that on-site automatic shale gas content measurement technology can take the place of manual drainage gas recovery method and can meet the requirements of on-site shale gas content measurement. By virtue of this technology, the labor intensity of field testers is reduced effectively. This technology is of higher precision and can evaluate shale gas content automatically and precisely. This technology has been successfully applied on site to measure the gas content of over 20 shale gas wells in the Sichuan Basin. It provides the vigorous data support for the construction of shale gas demonstration regions (Changning and Weiyuan) in the Sichuan Basin. This automatic measurement technology can be also applicable to CBM content measurement and continuous gas metering and testing.