Study On Core Simulation Of Chemical Increase Inject Agent For Polymer Injection Oil Well

At present,with the application of polymer injection technology is widely used,start-up pressure is high and injection quantity reducing are of common occurrence in Daqing oilfield.With injection pressure lifting,it doesn't establish effective pressure between oil and water wells that may cause more casings failure and oil well abandoning;the speed of solution injection is different,in order to keep pace,The middle and low reservoirs need to narrow spacing and increase investment.Although taken fracturing and other enhancing the polymer injection measures that easing conflicts between polymer injection amount is less and injection pressure is too high in a certain degree,it does not solve the problem of construction cost is high,increase note amount is low,validity period is short and other problems.A new type of less pollution,low cost,long validity period enhancing the polymer injection measures has fundamental significance.This paper focuses on the problems of injection pressure is too high and polymer injection amount is less in polymer flooding of Daqing oilfield.Through the analysis and discussion of essential component of the plugging in polymer injection,choosing effective oxidant and developing chemical increase inject agent for high concentration polymer flooding.The simulation experiment was carried out in lab and it was found that the HPAM was strongly adsorbed on the surface of the sand.Higher concentration will result in adsorbed amount bigger and reached saturation adsorption;bigger molecular weight will result in adsorbed layer thicker and adsorbance bigge.the adsorbance of different concentration of chemical increase inject agent is bigger along with longer time.The adsorbance reached saturation adsorption when the concentration of chemical increase note agent is greater than 0.25%and the adsorption time is over 40h.Through the indoor core simulation experiment,under different conditions that different permeability of core and different concentration and different molecular weight of HPAM,after 1PV oxidant and 1 PV 0.25%of chemical increase inject agent treatments,and after the follow-up into 5 PV polymer solution,depressurizing over 40%.Compared with the chemical agent in factory,the experiment of depressurization and enhancing the polymer injection with the higher concentration and bigger molecular weight of HPAM is better than chemical agent in factory.