Synthesis and Performance Evaluation of High-Temperature and High-Salinity Tolerance Polymer Microspheres

Various technical problems are currently encountered in using regular plugging agents. The performance of this agent in terms of high temperature and salinity tolerance is poor. The cross-linking reaction time is difficult to control and the valid period of the operation measures is short. This study system of deep profile control and water shutoff was researched for high-temperature and high-salinity reservoirs. The microstructure of divinylbenzene-co-acrylamide microspheres were designed according to the principle of deep profile control and water shutoff. Scanning electron microscopy tests, showed that the interior of the microspheres was hollow and that the shell had a nanoporous structure. The basic performance of the microspheres was evaluated, including high temperature thermal stability, injection and plugging ability and plugging effect at 115 degrees C. Results showed that after 180 days, the microspheres did not appear to be carbonized. The residual resistance coefficient of the injection experiment was greater than 2. Only microsphere plugging slug was used. The amplitude of enhanced oil recovery reached 7 %. Domestic oil field tests showed that, by increasing the amount of oil by 5.11 t each day after profile control, the general water percentage decreased from 64.11 % to 32.08 %.