The production of excess water during oil recovery creates not only a major technical problem but also an environmental and cost impact. This increasing problem has forced oil companies to reconsider methods that promote an increase in oil recovery and a decrease in water production. Many techniques have been applied over the years to reduce water cut, with the application of chemicals being one of them. Chemicals such as polymer gels have been widely and successfully implemented in several oil fields for conformance control. In recent years, the application of foam and emulsions for enhanced oil recovery projects has been investigated and implemented in oil fields, but studies have shown that they can equally act as conformance control agents with very promising results. In this paper, we present a comprehensive review of the application of polymer gel, foam and emulsion for conformance control. Various aspects of these chemical-based conformance control methods such as the mechanisms, properties, applications, experimental and numerical studies and the parameters that affect the successful field application of these methods have been discussed in this paper. Including the recent advances in chemical-based conformance control agents has also been highlighted in this paper.

The rapid advancements in the computational abilities of numerical simulations have attracted researchers to work on the area of reactive transport in porous media to improve the hydrocarbon production processes from mature reservoirs. In the hydrology community, reactive transport is well developed where the main research focuses on studying the movement of groundwater and contaminants in aquifers, and quantifying the effect of chemical reactions between the rocks and water. Recently, great efforts have been made to adapt similar models for petroleum applications where multiphase flow is experienced in the subsurface reservoirs. In such systems, thermodynamic and chemical equilibrium is key in establishing an accurate description of the states of the fluids existing in the reservoir. This paper presents a detailed and comprehensive review on the concepts of geochemical modeling, and how it can be mathematically adapted to petroleum multiphase flow problems in porous media. We introduce key physical concepts outlining the treatment of chemical reactions in experimental trials and then explain in detail how a network of chemical reactions can be modeled mathematically for numerical simulation applications. The steps of characterizing the physical behavior of the fluid flow—through a set of governing equations by either natural or molar variables formulations, and the methodology to simplify and incorporate the numerical algorithms into an existing reservoir simulation scheme are shown as well. We finally present two numerical cases from the literature to highlight the key variations between the different variable formulations and comment on the advantages and disadvantages of each approach.