SHEN Naimin, ZHANG Lianfeng, LI Junjie, et al. Optimization of alternating injection with multiple rounds of gel and polymer in B238 Block[J]. Petroleum Reservoir Evaluation and Development, 2021, 11(6): 878-883. DOI: 10.13809/j.cnki.cn32-1825/te.2021.06.012.
In order to improve the current situation of serious water channeling and the poor development effect during the water flooding development of B238 Block in Xiaermen Oilfield
and further to enhance the oil recovery efficiency
the numerical simulation method has been carried out to systematically study the parameters optimization of the multi-stage slug injection system after polymer flooding and the differential adjustment of polymer injection concentration based on laboratory experiments. It is found that the combined small slug with multiple rounds is more effective than the large slug with less rounds. The main slug which increases EOR most is composed of 0.08 PV (polymer)+0.02 PV(gel)+0.06 PV(polymer)+0.02 PV(gel)+0.06 PV(polymer)+0.02 PV(gel)+0.06 PV(polymer)+0.02 PV(gel)+0.06 PV(polymer) and the EOR value is 7.92 %. When the polymer concentration adjustment range of injection wells is 20 %
that is
the concentration is adjusted to 420 mg/L
EOR reaches the inflection point. And with the continuous increase of polymer concentration adjustment range
the increase of oil recovery shows a downward trend. It shows that the gel system and polymer alternating injection method have the potential to further develop remaining oil
and provide some technical reference for the development of similar reservoirs.