A holistic approach to determine the enhanced oil recovery potential of hydroxyethylcellulose, tragacanth gum and carboxymethylcellulose

Abstract

Several polymers have been investigated for their potential as an enhanced oil recovery process. In general, polymer dispersion in an injection fluid increases its sweep efficiency and mobility ratio leading to an increase in oil recovery rate. Though, harsh reservoir heterogeneous environment, lowers performance of different polymers under high formation salinity and temperature. Therefore, to achieve a profitable operational decision to recover crude oil, the oil and gas industry relies heavily on predicting various enhanced oil recovery (EOR) fluid performance in advance. Decisions on such recovery strategies should be taken at the lab scale before practical field job planning. In this study, we propose a holistic approach for analyzing and assessing tragacanth gum (TGU), hydroxyethylcellulose (HEC), and carboxymethyl cellulose (CMC) potential as an EOR fluid in three stages of screening methods, depending on the criteria that are well-established in the literature. We perform a comprehensive study based on the polymer rheological characteristics as first stage examination, wettability alteration features as second stage examination, and evaluation of additional oil recovery potential using oil reservoir simulating bioreactors (ORSBs) in the final stage. We integrate all the practical screening principles involving the reservoir characteristics through this innovative approach. The first stage screening showed better rheological characteristics of HEC and TGU, and the existence of wettability alteration capacities in these polymers was observed during the second stage screening. The final stage demonstrated that both these polymers (HEC – 7.38% and TGU – 6.71% of Residual Oil in Place) had higher additional oil recovery potential than polyacrylamide polymer (5.83%), a widely used commercial EOR polymer.