IJRRAS 23 (2) ● May 2015 www.arpapress.com/Volumes/Vol23Issue2/IJRRAS_23_2_04.pdf 107 COMPARISON OF DIFFERENT NUMERICAL TECHNIQUES FOR THE DEVELOPMENT OF A SIMULATOR OF SURFACTANT ASSISTED ENHANCED OIL RECOVERY PROCESS Kamilu Folorunsho Oyedeko 1 & Alfred Akpoveta Susu 2 1 Department of Chemical & Polymer Engineering, Lagos State University, Epe, Lagos, Nigeria 2 Department of Chemical Engineering, University of Lagos, Lagos, Nigeria E-mail:kfkoyedeko@yahoo.com; alfredasusu222@hotmail.com ABSTRACT In this work, a simulator is designed for enhanced oil recovery process for surfactant assisted water flooding. The system being investigated consists of three components (petroleum, water and surfactant) and two-phases (aqueous and oleic). The model equations are characterized by a system of non-linear, partial, differential equations: the continuity equation for the transport of each component, Darcy’s equation for the flow of each phase and algebraic equations. The simulator incorporates first order effects, with scope to accommodate two or three dimensions, two fluid phases and one adsorbent phase and four other components. The numerical methods used in the solution of the model equations are the orthogonal collocation, finite difference, and coherence theory techniques. Matlab computer programs were used for the numerical solution of the model equations. The results of the orthogonal collocation solution were compared with those of finite difference and coherence solutions. The results indicate that the concentration of surfactants for orthogonal collocation show more features than the predictions of the coherence solutions and the finite difference, offering more opportunities for further understanding of the physical nature of the complex problem. Also, comparison of the orthogonal collocation solution with computations based on finite difference and coherence theory methods offers possible explanation for the observed differences especially between the methods and the two different reservoirs they represent. Keywords: Simulator Design; Multidimensional, Multiphase and Multicomponent system; Surfactant Flooding; Finite Difference Method; Orthogonal Collocation Technique; Coherence Theory Method. 1. INTRODUCTION The depleting world oil reserve can be conservatively managed through the use of tertiary production techniques known as Enhanced Oil Recovery procedures. Although production capacity can be enhanced through the primary and secondary recovery methods, bringing new fields online is very expensive and recovery from existing fields by conventional methods will not fully provide the necessary relief for global oil demand. On an average, only about a third of the original oil in place can be recovered by the primary and secondary methods. The rest of the oil is trapped in reservoir pores due to surface and interfacial forces. This trapped oil can be recovered by reducing the capillary forces that prevent the oil from flowing within the pores of reservoir rock and into the well bores. Due to high oil prices and declining production in many regions around the globe, the possible application of advance technologies for further oil recovery, called “Enhanced Oil Recovery“(EOR) has become more attractive. The technology of EOR involves the injection of a fluid or fluids or materials into a reservoir to supplement the natural energy present in a reservoir, where the injected fluids interact with the reservoir rock/oil/brine system to create favourable conditions for maximum oil recovery. Surfactants are injected for this purpose to decrease the interfacial tension between oil and water in order to mobilize the oil trapped after secondary recovery by water flooding. In a surfactant flood, a multi-component multiphase system is involved. The theory of multi-component, multiphase flow has been presented by several authors. The surfactant flooding is a form of chemical flooding process and is represented by a system of nonlinear, partial differential equations: the continuity equation for the transport of the components and Darcy’s equation for the phase flow.