Introduction Potassium chloride (KCl) is a commodity chemical frequently used in the hydraulic fracturing industry. A common misconception is that all KCl sources are the same in composition. Most KCl used in industry is non-reagent grade and is coated with anti-caking agents to prevent clumping in humid environments, such as offshore Gulf of Mexico (GOM). Not all suppliers use the same anti-caking agents, and some agents can affect fracturing fluid properties, which can delay operations – a significant economic issue when the rig costs $750,000 daily plus deferred cost of oil production. Herein we present a recount of two Gulf of Mexico case histories in which differences in anti-caking agents resulted in potential problems with fracturing fluids. Experimental The first case was resolved by developing laboratory procedures including gas chromatography-mass spectrometry (GC-MS) to analyze and evaluate the quality of the KCl used in our fracturing operations, and the effects of specific KCl coatings on fracturing fluids. As a part of this work, KCl anti-caking agents from several vendors were analyzed and the results revealed that the KCl coatings vary, depending on the manufacturer, and more importantly, those with amine functional groups can affect rheology profiles for fracturing fluids. The second case involved a recurrence of the original problem, which was solved with minimal pre-job delay because of the laboratory quality assurance testing procedures. Conclusions This work describes the disparity in fracturing fluid test results between two laboratories in the first case, the the efforts to determine the cause, and efficient pre-job testing for the subsequent Gulf of Mexico operation. It further explains the anti-caking agent identification process that has since been added to the quality control testing and evaluation process for KCl.

What’s the “rub” with your salt: A case history of quality assurance for potassium chloride

249th National Meeting (2015)

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