The Development of Potassium Cellulosic Polymers and Their Contribution to the Inhibition of Hydratable Clays

Abstract

ABSTRACT Water-base fluids with inhibitive properties require, as primary components, proper exchangeable ions and effective water soluble polymers; Potassium based drilling fluids formulated with optimized levels of KCl, KOH and water soluble polymers such as sodium carboxymethylcelluloses (CMC), polyanionic celluloses (PAC), partially hydrolized polyacrylamides (PHPA) and modified starches have been investigated by many authors. The field preparation of potassium based drilling fluids generally requires a high level of potassium to counteract the negative effect of sodium on hydratable clays. As a matter of fact nowadays the oilfield industry shows a growing interest in the use of sodium free, potassium based chemicals, examples of which are potassium lignite, potassium asphalt sulphonates and KOH. This paper introduces a new class of polymers, potassium carboxymethylcellulose and potassium polyanionic cellulose, and demonstrates their contribution to the formulation of inhibitive fluids.