Simulation and Determination of Optimal Variables for Increased Oil Recovery Potential of Surfactant Polymer Flooding

Abstract

Enhanced oil recovery methods have been largely discussed in the petroleum industry. Many new techniques are being tested to grapple the situation of high recovery with the least expenditure. As the petroleum industry is striving for it, the EOR process of surfactant polymer flooding is quickly gaining traction. However, testing new technologies directly itself is a costly affair. Our study aims at simulating and understanding the effects of surfactant flooding in subsurface conditions using a Fluent module. The research was conducted to alleviate the inputs of the industry by providing them faster oil recovery while viably dealing with cost-effectiveness. For simulation studies, a 2-D replica of sand packed bed core {8.49 cm×3.66 cm} is created. The core is modeled for porosity and the average permeability. Physio-chemical properties of anionic natural surfactant extracted from Madhuca longifolia {Mahua} oil and PHPA {Partially Hydrolyzed polyacryl amide} polymer has been exclusively used in the simulations. Eulerian multiphase model is used for studying the volume of oil swept out of the core by introducing the water and surfactant + polymer slug. The simulation results were influenced by the control mechanism and parameters like inlet velocity of the fluids and gauge pressure, porosity and permeability of the core sample supported by appropriate boundary conditions. Taking the retarding effects of turbulence, and shear and tear caused on the rocks in the reservoir into consideration an optimum set of values for velocity and pressure are selected for maximal recovery. The results indicate that with a small change in parameters a huge change in breakthrough point is observed. Breakthrough indicates the starting time for the production of the primary phase present within the core. On plotting an oil volume fraction v/s flow timeline chart we could observe the quantitative dependence of breakthrough time over different variables. The plots suggested that on increasing the conventional velocity 25%, an unexpected high decrease in breakthrough time is observed for the core under consideration. Moreover, a 25% rise in pressure resulted in a substantial increase in the recovery of oil in minimal time. These results show that the velocity has a more significant impact on the breakthrough total recovery of oil in minimal time. Since, the core is a smaller scale representative of a whole reservoir, the recovery of oil is expected to enhance significantly during actual flooding. The study extends to simulating the flow in varying subsurface conditions as well as on different material reservoirs alleviating our in-depth knowledge of breakthrough behavior within different cores as well. The exhaustive study of parameters on faster breakthrough accedes with the motive of the industry of improved recovery incurring a minimum cost.

Optimization of Polymer Flooding Using Genetic Algorithm

“…The current method that has received much attention is chemical EOR [1][2][3], one of which is polymer flooding. Increasing the viscosity value due to polymer flooding will increase the fluid mobility ratio to a more reasonable value [4][5], thereby significantly increasing the recovery factor [6].…”