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The knowledge of the relationship between the molecular structure of surfactants and their ability to form a single phase solution for water and oil has been expanded enormously over the last two decades, primarily because the use of microemulsion solutions for EOR are promising. The qualitative trends and sensitivities between the characteristic of microemulsion solutions and the phase behavior of mixtures of oil, water and surfactants are often obtained from experiment. The experiments are simple but laborious especially when it often involves a wide range of surfactant choice. In this paper, we demonstrate a complementing molecular chemistry modeling method to assist in reducing the huge experimental test matrix in shortlisting promising surfactants for a chemical EOR design. Application of molecular chemistry modeling for optimal microemulsion formation in chemical EOR application is a niche technology within the oil and gas industry. The modeling approach used in our simulation is based on the physical chemistry of an optimal microemulsion interface which is planar with zero surface tension and torque. The approach is implemented using the framework of Dissipative Particle Dynamics (DPD) technique. The simulation system comprises of oil, brine and surfactant in the form of coarse-grain (CG) beads. Atomistic parameters for both bonded and non-bonded CG beads are determined to simulate the molecular interactions within the system. This setup enables the computation of surface tension and torque as a function of the distance across the interface. Optimal salinity for for-mation of optimal microemulsion is determined from the profile of torque versus salinity at zero torque. The simulation results for various surfactants are compared with optimal salinity determined experimen-tally. The simulation results are in good agreement with the experimental data.

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Fines and sand capturing inside the separator is one of the methods to prevent solids carry over. Currently, there are ongoing studies to identify the suitable method to agglomerate the produced solids. Generally, heavier solids would be denser and easily settled at the bottom of the vessel, hence no solids carry over issues. Produced solids can be consisting of natural solids and/or artificial solids. Several types of polymers have been evaluated based on its agglomeration performance, rheology and compatibility as an approach to establish suitable particle size to minimize sand free rate. The procedures involved include bottle test experiments coupled with particle size distribution (PSD) analysis via Laser Particle Size Analyzer (LPSA). The materials used in the experiments are glass beads with sizes of 50µm and 100µm, synthetic water (0.1M NaCl), a cationic polymer and an anionic polymer. Both polymers have high molecular weight which is known to provide good agglomeration capacity. For each experiment, a 5g of glass bead was placed together with 90mL of synthetic water in a 100mL measuring cylinder. The system was then tested using three polymer system; i) a single cationic polymer system, ii) a single anionic polymer system and iii) a combination of both cationic and anionic polymer system. Light agitation was applied on each, PSD was evaluated and results compared to those of the untreated samples. The improvement of particle size distribution was observed for all three systems. The results will be discussed further in the paper. The novelty of this research is the application of the sand agglomeration mechanism towards surface sand capturing via separator.