Phosphino-polycarboxylic acid modified inhibitor nanomaterial for oilfield scale control: transport and inhibitor return in formation media†
Abstract
Mineral scale deposition is a major threat to the oil and gas industry. Scale threat is conventionally controlled by injecting a scale inhibitor chemical into oil production systems. Scale inhibitor nanomaterials are an alternative to the conventional inhibitor products. This study evaluates the transport and inhibitor return properties of the phosphino-polycarboxylic acid (PPCA) modified scale inhibitor nanomaterial with both PPCA and phosphonate constituents. The objective is to expand the use of this type of inhibitor nanomaterial in the delivery of scale inhibitor into formation for oilfield scale control. Electrolyte content and the sonication method have been investigated for their roles in nanomaterial transport in formation medium. It has been shown that the nanofluid electrolyte content can considerably impact the nanomaterial transport in terms of breakthrough level, deposition towards formation surfaces and inhibitor solid phase distribution. It is evident that an increase in electrolyte content can reduce the transportability of the nanomaterial. Consequently, the deposition tendency and also inhibitor solid phase distribution can be influenced as well. Furthermore, it shows that sonication treatment can result in a change in particle size with varied transportability. Laboratory squeeze simulation studies have been conducted to compare the squeeze lifetime of inhibitor nanomaterial against conventional pills. It is evident that the nanomaterial outperformed the conventional pills, with an extended squeeze lifetime. Overall, the transport studies and squeeze simulations suggest that the prepared inhibitor nanomaterial has the potential for application in the oilfield to control the scale deposition threat.