Core Leak-off tests are commonly used to ascertain the ability of a drilling fluid to seal permeable rock under downhole conditions. Unfortunately, these tests are expensive and require a long time to set up. To monitor fluid invasion trends and to evaluate potential treatments for reducing fluid invasion on location, a simpler screening test is highly desirable. The Capillary Suction Time (CST) Test has been used since the 1970's as a fast, yet reliable, method for characterizing fluid filterability and the condition of colloidal materials in water treatment facilities and drilling fluids. For the latter, it has usually been applied …
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Main Title:
Topical Report: Task 1.4 Correlation of Capillary Suction Time with Leak-Off Behavior
Description
Core Leak-off tests are commonly used to ascertain the ability of a drilling fluid to seal permeable rock under downhole conditions. Unfortunately, these tests are expensive and require a long time to set up. To monitor fluid invasion trends and to evaluate potential treatments for reducing fluid invasion on location, a simpler screening test is highly desirable. The Capillary Suction Time (CST) Test has been used since the 1970's as a fast, yet reliable, method for characterizing fluid filterability and the condition of colloidal materials in water treatment facilities and drilling fluids. For the latter, it has usually been applied to determine the state of flocculation of clay-bearing fluids and to screen potential shale inhibitors. In this work, the CST method was evaluated as a screening tool for predicting relative invasion rates of drilling fluids in permeable cores. However, the drilling fluids examined--DRILPLEX, FLOPRO, and APHRON ICS--are all designed to generate low fluid loss and give CST values that are so high that fluid invasion comes to be dominated by experimental artifacts, such as fluid evaporation. As described in this work, the CST procedure was modified so as to minimize such artifacts and permit differentiation of the fluids under investigation.
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Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.
Hoff, Tatiana & Growcock, Fred.Topical Report: Task 1.4 Correlation of Capillary Suction Time with Leak-Off Behavior,
report,
December 17, 2004;
Houston, Texas.
(https://digital.library.unt.edu/ark:/67531/metadc889689/:
accessed October 9, 2026),
University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu;
crediting UNT Libraries Government Documents Department.