Patent ID: 6543276
Filing Date: 2003-04-08
Classification: G01N

Abstract:
A method for testing the effectiveness or reaction time of a breaker fluid in breaking a filter cake on sides of a borehole penetrating a subterranean formation, said method comprising:(a) obtaining an apparatus comprising a filter medium and the capability of facilitating formation of a repeatable and uniform filter cake on a filter medium under dynamic or static conditions and of allowing monitoring of fluid passing through said filter medium; (b) positioning a drilling mud in said apparatus capable of forming a filter cake on said filter medium of said apparatus under imposed-shear and differential pressure conditions; (c) forming a filter cake on said filter medium while controlling imposed-shear and differential pressure conditions; (d) substituting said breaker fluid for said drilling mud in said apparatus; and (e) monitoring the amount of breaker fluid that passes through said filter medium under, static conditions over time and determining the instantaneous rate of filtration.