Early water breakthrough with high water cut through highly conductive thief zones is a prevalent problem in many water-flooded oil reservoirs. Smart polymers that are sensitive to temperature changes, also known as thermo-responsive polymers, e.g., polyethylene glycol (PEG) have great advantages over conventional polymers that can be exploited to solve the problem of conductive thief zones. Thus, this study aims at designing and synthesizing a thermo-responsive polymer using Gamma Ray Induced radiation to withstand high-temperature, high salinity reservoir conditions and to be economic and applicable for synthesis in Egypt. A combined use of polyacrylamide or polymeth-acrylamide together with the selected thermo-responsive polymer (PEG) could achieve a viscosity of about 2.8 cp at 90°C, 200000 ppm salinity with 3000 ppm polymer concentration. The thermo-gravimetric analysis as well as the viscosity temperature profiles, confirmed that the polymer composite can maintain its thermal stability up to 105°C. The FT-IR spectrum confirmed that the polymer components were well-blended with each other and produced a homogeneous polymer with enhanced characteristics.



Keywords: CEOR, Thermo-responsive polymers, LCST, Heterogeneous reservoirs, Gamma radiation.