Abstract: Accurate detection of gaseous hydrocarbon content of drilling fluid is one of means for discovering and evaluating the shows of oil and gas. However, the viscosity of drilling fluid greatly affects the detection result. With the help of high-temperature and highpressure rotary simulator for drilling fluid, the degassing experiments of different viscosity drilling fluid are conducted, regressing the degassing efficiency chart and equations of the different viscosity drilling fluid, including establishing the coefficient-corrected chart and equations. By them, the real-time calibration of the volume fraction of the gaseous hydrocarbon in drilling fluid can be made at the well site, being good for timely discovery and exact evaluation of the shows of oil and gas.

Key words: drilling fluid, viscosity, degassing efficiency, affection, coefficient correction