Study On Enhanced Oil Recovery Technology After Polymer Flooding

At present, enhanced oil recovery mainly depend on chemical flooding in China, one of the higher proportion is polymer flooding. However there are still many remaining oil exist after polymer flooding. In order to maintain the sustainable development of the petroleum industry in China, there is an urgent need to study further enhanced oil recovery techniques and methods after polymer flooding.This paper researches the reservoir parameters (reservoir vertical heterogeneity, large pore, vertical permeability, average reservoir permeability, reservoir thickness, reservoir rhythmic, crude oil viscosity, oil temperature), polymer nature (residual resistance coefficient, accessible pore volume coefficient, absorption), polymer parameters (injection timing, polymer dosage, polymer concentration, injection rate), well pattern and well spacing on the effect of polymer flooding through the establishment of the polymer flooding concept model. And based on outputs than inputs, polymer concentration, polymer dosage and the injection rate of these three factors are orthogonal optimization by the use of orthogonal design method, thus, the best polymer flooding program has been got. Then, in the analysis of remaining oil distribution after the polymer flooding, the influencing factors and the parameter optimization of the second polymer, cross-linked polymer flooding and polymer surfactant flooding are studied after polymer flooding. At last,the enhanced oil recovery technology after polymer flooding are optimized by comparing the best programs of the second polymer, crosslinked polymer injection and polymer surfactant flooding technology. The results showed that crosslinking polymer flooding are better enhanced oil recovery technology after polymer flooding.