Patent ID: 9109433
Filing Date: 2015-08-18
Classification: E21B,G01F,G01N,G01V

Abstract:
1. A method of detecting a gas influx event in a borehole fluid during a drilling operation, comprising: generating acoustic pulses over a time period using an acoustic transducer disposed in a borehole; obtaining measurements of acoustic velocity of the acoustic pulses through borehole fluid over the time period at an acoustic sensor disposed in a borehole; obtaining measurements of temperature of the borehole fluid over the time period at a temperature sensor disposed in the borehole; determining a difference between a curve derived from the measurements of acoustic velocity and a curve derived from the measurements of temperature over the time period; and detecting the gas influx event when the acoustic velocity changes over the time period and the difference between the curve derived from the measurements of acoustic velocity and the curve derived from measurements of temperature is substantially constant during the time period.