Injection of Polymer for Improved Sweep Efficiency in High Temperature High Salinity Carbonate Reservoirs: Linear X-Ray Aided Flood Front Monitoring

Abstract

Polymer flooding is one of the most commonly used techniques to improve oil recovery; however its application is dependent on the technical and economic feasibility along with the knowledge of the risks involved. The presented work is focused on quantifying the uncertainties affecting the mobility of injected fluid in polymer flooding along with a sensitivity analysis of influential parameters. Initially, a coreflooding experiment on carbonate core sample is performed using partially hydrolyzed polyacrylamide, SAV 10 under high temperature high salinity conditions. The coreflood apparatus is aided with linear X-ray in order to record real time saturations for the entire length of core sample in addition to the pressure and production data. The experimental data are then history matched using commercial software to generate relative permeability curves and to optimize polymer slug size and initiation time. The optimized model is then used as a reference and a coredflood is conducted on the optimized conditions i.e. slug size and initiation time. The recovery obtained from the experimental run is compared with the simulation results. Polymer viscosity, adsorption on the rock surface and mechanical degradation are some of the other parameters included in the study. The optimum polymer flooding scenario established in this study is injection of 0.1 PV of polymer after 0.3 PV water injection. Encouraging results are obtained at the optimized conditions resulting in an overall recovery factor of 84% and early injection of polymer also helped to delay the breakthrough time. The small slug size resulted in low adsorption and residual residual factor for the optimized case is found to be 1.73.

Experimental investigation of polymer flooding with low-salinity preconditioning of high temperature–high-salinity carbonate reservoir

“…The cumulative oil recovery from volumetric production and in situ saturation was 62% and 64%, respectively. This margin error is expected from the laboratory data and could be as a result of inaccuracy when taking manual readings (Hashmet et al 2017b).…”

“…This is an advanced technology that gives better understanding of fluids performances as well as level of capillary end effect. Core flood experiments were also conducted by Hashmet et al (2017b) to study the effectiveness of a HPAM base polymer on oil recovery in HTHS carbonate reservoirs. Results of the experiments showed that the polymer was effective in enhancing the mobility ratio and was able to produce more oil (Hashmet et al 2017b).…”

“…Core flood experiments were also conducted by Hashmet et al (2017b) to study the effectiveness of a HPAM base polymer on oil recovery in HTHS carbonate reservoirs. Results of the experiments showed that the polymer was effective in enhancing the mobility ratio and was able to produce more oil (Hashmet et al 2017b). The experiments were conducted with the aid of a linear X-ray core flood system to record the ISSM data.…”

Updated Perceptions on Polymer-Based Enhanced Oil Recovery toward High-Temperature High-Salinity Tolerance for Successful Field Applications in Carbonate Reservoirs

“…Xu et al [ 59 ] observed that the degree of polymer adsorption increases with increasing brine salinity (e.g., NaCl concentration) [ 59 ]. Also, even though the xanthan bio-polymer is capable of tolerating very high salinity conditions, it is afflicted with issues of poor injectivity and bio-degradation [ 60 , 61 , 62 , 63 ].…”

Recovery Observations from Alkali, Nanoparticles and Polymer Flooding as Combined Processes

“…Generally, most researchers believe that polymers do not contribute to enhancing oil recovery, but assist in increasing the ultimate recovery [ 28 ]. Some others propose that polymers can contribute to EOR by improving the sweep efficiency [ 29 , 30 ]. Lately, polymers have been used in synergetic applications with other cEOR techniques such as alkali and/or nanoparticle injection seeking to improve R–F/F–F interactions [ 18 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ].…”