Application of ionic liquid polymeric microsphere in oil field scale control process

The formation of mineral scale is a persistent and expensive problem in the oil and gas industry. In order to minimize the formation of scale deposits, threshold scale inhibitor treatment is a common practice in the oil industry. In this work, a new process have been attempted to solve the oilfield scaling problem encapsulating forms of chemicals (Kondo, 1979) that can interact with oilfield brine solution without losing the active ingredient. The primary advantage of loaded ionic liquid in microspheres is the ability to avoid its loss and make easier the recovery of the crystal formed at the microsphere surface. A Membrane process coupled with phase inversion technique has been successfully applied for the preparation of ionic liquid microsphere (ILMC). The technique yielded porous, spongy, spherical spheres of dimension of about 1000 μm diameter with smooth surface. This investigation evaluates the ionic liquid (IL) microsphere efficiency in high temperature brine solution. Ionic liquid microsphere efficiency was measured through chemical screening tests, dynamic tube block method and also through electrochemical techniques. Electrochemical studies are also supports in evaluating the scale inhibition efficiency of ionic liquid microsphere, using static and dynamic tests. Scale inhibition efficiency (82%) has been achieved using 25 wt% 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6] microsphere at lab scale level. The inhibition mechanism and morphology of the scale have also been studied through scanning electron microscopy (SEM) and EDX analysis. All experimental results encouraged the usage of [BMIM][PF6] ionic liquid loaded microsphere in oil wells.