REDUCING POLYMER ADSORPTION DURING CHEMICAL ENHANCED OIL RECOVERY IN UZEN FIELD

Abstract

This research investigated the potential of nanomaterials and alkaline in diminishing polymer adsorption on terrigenous rock formations. Polymer injection has been examined as a tertiary recovery technique in the Uzen field, which has favorable reservoir characteristics for this technology implementation. Nonetheless, the occurrence of polymer adsorption can considerably limit the usefulness of the method, reducing the permeability of the layers and the viscosity of the injection fluid, and consequently decreasing the oil recovery. Therefore, polymer adhesion may be adjusted by modifying the system's chemical and physical properties using nanoparticles. In particular, silica nanoparticles are widely employed due to their large surface area and ability to connect with polymeric chains. In addition, alkali can improve the repelling forces between the polymer and minerals by making the rock surface more negative. This research aimed to determine the influence of silica nanoparticles and lye on HPAM-based ASP3 polymer adsorption at the interface of Uzen rock. It was investigated by performing tests on static and dynamic adsorption. The first step was to evaluate different concentrations of polymers and nanoparticles by zeta potential measurement in order to achieve stable chemical conditions. ASP3 (2500 ppm) – SiO2 (0.1 wt. %) and ASP3 (2500 ppm) – NaOH (0.03%) solutions were utilized for the static adsorption tests, showing a noticeable influence on adsorption reduction. It should be highlighted that alkali was less efficient in prolonged durations, such as 24 and 36 hours. When silicon dioxide was applied for dynamic adsorption studies, the adsorption of ASP3 was decreased by around 18%. At the same time, alkali was ineffective in reducing the polymer's dynamic adsorption, leading to a 5% increase in adsorption. Polymer-nanoparticle flooding as an enhanced oil recovery technique was successful, achieving a total recovery factor of around 96%, where incremental recovery was 5% higher than only the polymer injection case. Ultimately, it is recommended that the project plan for the Uzen field can be improved in consideration of the findings of the study.