Patent ID: 7117734
Filing Date: 2006-10-10
Classification: E21B

Abstract:
1. A method for estimating a formation fluid mobility, comprising: performing a pretest using a formation tester disposed in a formation penetrated by a borehole, the pretest comprising a drawdown phase and a buildup phase; collecting data points representing pressures in a pretest chamber of the formation tester as a function of time during the drawdown phase and the buildup phase; determining an estimated formation pressure from the data points; determining an area bounded by a line passing through the estimated formation pressure and curves interpolating the data points during the drawdown phase and the buildup phase; and estimating the formation fluid mobility from the area, a volume extracted from the formation during the pretest, a radius of the formation testing probe, and a shape factor that accounts for the effect of the borehole on a response of the formation testing probe.