A Review of the Status of Foam Applications in Enhanced Oil Recovery

Foam has been used for controlling gas mobility during injection processes in order to mitigate the adverse effects of low gas viscosity, reservoir heterogeneity and gravity override. In addition, foam has also been employed in near-wellbore production, matrix acidizing stimulation, hydraulic fracturing, gas shut-off and water shut-off. The optimization of these operations requires a good understanding of the physical characteristics of foam and its behavior under reservoir conditions. Despite numerous experimental and theoretical studies on foam and some field applications reported in the literature, there is no comprehensive literature survey detailing the knowledge and experience gained through the application of foam. The aim of this paper is to present a critical review of the literature available on the use of foam injection for enhanced oil recovery. An extensive appraisal of the current status of foam application in EOR methods is a useful way of presenting advantages, shortcomings and limitations of the process as well as supplementary advances. Special attention has been given to the review of new research topics, such as the use of foam as a mobility control agent. Advances in more efficient foaming agents, additives and boosters are discussed. Moreover, in depth analysis of field applications of foam in EOR projects show that the main problems encountered during field-scale foam applications are related to foam stability, foam compatibility, as well as adsorption of the injected chemicals onto the rock surface. To address this, we discuss the evolution of the pilot field application and the reasons for inconsistency between laboratory results and field scale performance.