Mudcake Buildup and Invasion in Low Permeability Formations; Application to Permeability Determination by Measurement While Drilling


John T. Dewan, Dewan & Timko, Inc.,
Martin E. Chenevert, University of Texas

SPWLA 34th Annual Logging Symposium, June 13-16, 1993



In formations with permeabilities greater than a few md, mudcake forms so quickly after bit penetration that it takes over control of invasion rate within minutes or even seconds. Thereafter the rate of invasion is deter- mined entirely by the mudcake properties, not by the formation.