Physical Simulation Study On ASP Flooding Adaptability Of Low Permeability Reservoir In XB Block

In this paper,physical simulation experiments were conducted to analyze the adaptability of weak alkali ternary flooding technology in blocks with characteristics of such reservoirs by taking XB block as the research object for low-permeability sandstone reservoirs and according to geological development characteristics and production dynamic data.Affected by sedimentary environment and heterogeneity,XB block is characterized by prominent plane contradictions,increased invalid water flooding,high recoverable reserves and limited water flooding EOR.Therefore,it is necessary to further optimize oil flooding mode and seek EOR technology.Therefore,it is necessary to explore chemical flooding to improve oil recovery based on the current situation of low permeability oil fields.Through the comparative analysis of the polymer rheological property,viscosity enhancement,shear resistance,salt resistance,stability,alkali resistance,temperature resistance and reservoir compatibility of the weak alkali ternary composite system,the medium-component polymer was screened out;Petroleum sulfonate was selected as the surfactant by comparing and analyzing the compatibility of the surfactant with formation water,the properties of salt resistance and divalent ion,emulsification,static and static adsorption,stability,oil displacement and injection;Through the ternary compound system chemical concentration and dosage of optimization in the experimental study,XB block ternary flooding injection system was confirmed as the following: front slug(polymer“zhongfen” in 15 mpa·s)0.015 PV + ternary main slug(0.3% petroleum sulfonate,1.0% sodium carbonate,polymer “zhongfen”in 15 mpa·s)0.105 PV + ternary vice slug(0.1%petroleum sulfonate,0.8% sodium carbonate,polymer in 15 mpa·s)0.075 PV + post slug(polymer “zhongfen” in 15 mpa·s)0.055 PV.By conducting parallel core flooding experiments with different permeability ranges,the upper limit of permeability range is determined to be 4.Through the injection rate optimization experiment of the asp system,the optimal rate of the optimized asp flooding is 0.1ml/min.Through the experiment of slug combination optimization of asp system,it is concluded that the alternative injection of main slug can get better displacement effect than the whole injection of asp flooding,and the chemical flooding has the highest recovery efficiency and the best oil displacement effect when the injection times are 3?4 times.According to the analysis of experimental results,the average enhanced recovery rate of weak alkali ternary flooding in XB block is about15%?20%,which can effectively improve the recovery degree of XB block.The conclusion of this paper has a certain guiding role for the implementation of weak alkali ternary flooding in XB block and similar low permeability reservoirs.