Green silica scale inhibitors for Alkaline-Surfactant-Polymer flooding: a review

Abstract

Alkaline-Surfactant-Polymer flooding is a tertiary enhanced oil recovery (EOR) method designed to lower interfacial tension (IFT), water wet the formation, and decrease water mobility to produce residual oil. The ASP flood uses a combination of alkali, surfactant, and polymer to achieve these results. The use of these three fluid injection additives offers great synergistic effects in terms of oil recovery and sweep efficiency. Despite its popularity as a potentially cost-effective chemical flooding method, it is not without (its) problems, one of which is the excessive formation of silicate scales. Silicate scale is a very serious problem in the oil and gas industry; which forms in perforation holes, casing surface, tubing, and surface facilities. This study reviewed and assessed some of the inhibition techniques used in the industry with regard to handling oilfield scales in general and silicates scales in particular. Besides, the inhibitors with enhanced functionality in mitigating silicate scale also have been discussed. However, the conventional scale inhibitors used are facing restrictions world over, due to their ecotoxicity and non-biodegradability, which, therefore, has led to the call for green scale inhibition in the oil and industry. Green scale inhibitors are considered as alternative scale inhibitors due to their value-added benefits to the environment with respect to the methods of treating oilfield scales.