Abstract:
Since entering into the late development stage of high water cut, the main layers of Wenzhong oilfield have been watered seriously, and the remaining oil distributes highly scattered, which results in poor water driving effect. Influencing by high temperature and high salinity, conventional granular profile controlling and flooding agent is not suitable because of big diameter, invalidity of deep formation plugging and short validity period. Based on these situations, research on mechanism of gel microspheres for deep profile controlling and flooding was developed. A kind of cross-linked polymer gel in Nano-size was synthesized by using micro-emulsion polymerization method, which is distributed evenly in water, and could easily arrive at the injected formation and swelled slowly when meeting water. Due to these features, the goal of synchronous coordination of water plugging controlling and flooding can be meet, which means that a gel microspheres with high temperature and salinity resistance was established for deep profile controlling and flooding. This system was applied in 11 well groups in Blocks Wen10 and Wen25, and ‘PI+FD’ profile controlling and injection parameter comprehensive adjustment method was designed during the field operation process. Good results have been achieved with increasing 21.35×104 t of water driving reserve and 3 562 t oil production form corresponding wells.