Pore Network Modeling of Polymer Flooding and Retention for Increased Oil Production (#1942)

Authors

Zuñiga Arenas, Gregory Luis Guillermo

Abstract

The oil industry plays an important role as a source of energy for Peru’s development. Oil production in Peru comes from mature basins such as the Talara basin in the northwest of the country. Increasing the productive life of fields at low cost is of vital importance, especially in situations where the price of oil is very low (less than $40 per barrel). To increase the recovery factor, Enhanced Oil Recovery (EOR) must be applied, and the selection of the technique to be applied depends on multiple parameters, such as reservoir and economic profitability. Currently, oil reservoirs in Peru are mature and marginal, with an average oil recovery factor of 24%. This makes it necessary to apply different techniques that are economical to increase the recovery factor, such as water injection. Currently, water injection is a widely applied technique worldwide, as it is simple, safe, effective and economical to increase the recovery factor. Polymer injection is a variant of the water injection technique that has gained importance in recent years, but the mechanism that makes the recovery factor increase possible has not yet been explained. The objective of this research work is to model the fluid flow behavior in water injection using the pore network model in OpenPNM, which will allow characterizing the fluid flow and salinity transport in each pore and throat by adding polymers to the injection water. Thus, a new physical model was proposed to include the effects of polymer addition by increasing the viscosity of the non-wetting fluid. This took into account the effects of shear and concentration changes due to polymer retention in porous media. In this way, fractional flow curves were obtained for the water-oil and polymer-oil system. Due to the change in the mobility of these systems, it was possible to measure the change in the critical saturation due to the change in viscosities. Finally, it is expected that the pore network models can be used to evaluate the viability of various enhanced recovery processes in mature fields such as those in Peru