Low Salinity Polymer Flooding: Effect on Polymer Rheology, Injectivity, Retention, and Oil Recovery Efficiency

Abstract

Synergism between different enhanced oil recovery (EOR) methods has always been a subject of paramount interest for oil industry as it led to the development of many successful EOR methods in the past. Low salinity water flooding is a recent development in the field of EOR, and polymer flooding is a conventional EOR technique that has been practiced for many decades. In this study, we have investigated the synergistic effects of low salinity water flooding and polymer flooding focusing on the effect of low salinity on polymer rheology, polymer solution injectivity, retention of polymer in the reservoir rock, and oil recovery efficiency of low salinity polymer flooding. The study is comprised of a multidimensional experimental approach including measurements of bulk rheology of polymer solutions prepared with brines of varying salinities, single phase displacement experiments for injectivity analyses, UV–visible and electron dispersive spectroscopy along with scanning electron microscopy for studying retention of polymer on the reservoir rock surface, and finally laboratory flooding experiments to demonstrate the oil recovery efficiency of low salinity polymer flooding synergy. The results obtained from this study show that low salinity water tremendously improves the polymer rheology that could greatly favor the oil recovery efficiency of the overall process. Low salinity water is also found to be a very impressive agent for improving displacement efficacy and the injectivity of a polymer solution. Finally, the results of enhanced oil recovery flooding experiments demonstrated that low salinity polymer flooding could significantly increase the oil recovery efficiency in comparison to either low salinity or conventional polymer flooding alone.

Study on Micro Production Mechanism of Corner Residual Oil after Polymer Flooding

“…For the remaining oil to flow out of the corner or for small oil droplets to break out under the action of the polymer solution to reduce the volume, the following two conditions must be satisfied [ 39 ]: the carrying force of the polymer on the crude oil must be greater than the cohesive force preventing the remaining oil from peeling off, and the centrifugal force of the crude oil rotation must be greater than the cohesive force that prevents the crude oil from peeling off. where θ is the angle between the carrying force and cohesive force, °; and F l , F 2 , and F 3 are the acting forces, N.…”

Artificial Neural Network to Forecast Enhanced Oil Recovery Using Hydrolyzed Polyacrylamide in Sandstone and Carbonate Reservoirs

“…Six prior investigations on both carbonate and sandstone core reservoir samples provided the raw data needed for modeling [ 25 , 26 , 27 , 28 , 29 , 30 ]. There were 847 data records in the gathered data sets, which were separated into three groups: training (70%), validating (15%), and testing data (15%).…”

Where is research on fossil fuels going in times of climate change? A perspective on chemical enhanced oil recovery

“…Regardless of classifications, LSWI has proven effective in sandstone reservoirs with high salinity connate water, already more than 20 years ago, but it has gained popularity only in more recent times. [60] It is generally accepted that the main mechanism of oil recovery is via wettability alteration, but other factors may be in play, depending on the types of oil and rock formation. [58,59] Moreover, the presence of certain type of ions instead of others, can reduce scaling phenomena and chemicals precipitation.…”

“…Low-salinity polymer flooding (LSP) has gained attention is recent times. [56,60] This can be considered a hybrid cEOR method, more of which will be discussed later.…”