EVALUATION OF THE INTERACTIONS BETWEEN OILFIELD CHEMICALS AND RESERVOIR ROCKS

Sand failure and production occurs when the formation stress exceeds the strength of the formation which is derived majorly from the natural material that cements the sand grain and cohesive forces. This study investigates the effects of scale inhibitor, biocide and corrosion inhibitor on the geomechanical strength of reservoir rocks (carbonate and sandstone). Integration of geomechanical, petrophysical and analytical techniques is used to establish the failure effects of the interaction of these chemicals on the geomechanical strength of reservoir rocks and failure mechanisms resulting from such interaction. The results confirm that chemical adsorption, dissolution, precipitation and ionic substitution reactions took place between the oilfield chemicals and the formation rocks leading to weakening of the reservoir grain fabrics and reduction in unconfined compressive strength (UCS) which in turn causes sand failure.