Characterizing Natural-Fracture Permeability From Mud-Loss Data

Original SPE manuscript received for review 20 October 2009. Revised manuscript received for review 29 March 2010. Paper (SPE 139592) peer approved 25 May 2010. Summary Liétard et al. (1999, 2002) have provided important insight into the mechanism and prediction of transient-state radial mud invasion in the near-wellbore region. They provided type curves describing mud-loss volume vs. time that allow the hydraulic width of natural fractures to be estimated through a curve-matching technique. This paper describes a simpler and more direct method for estimating the hydraulic width by the solution of a cubic equation, with input parameters given by the well radius rw, the overpressure ratio p/ y, and the maximum mud loss volume (Vm)max.