Study On Influencing Factors And Wax Control Technology Of Polymer Flooding Oil Wells In B301 Experimental Area

The phenomenon of wax formation in oil well will affect the internal oil flow channel and lead to blockage of the channel,which will seriously affect the normal production of oil well and reduce its output.If “wax blockage” occurs,the rod pumping system may encounter wax jam and other production failures,which will directly lead to the production of the well and affect the production efficiency and economic benefits of the oilfield.In this paper,the polymer flooding oil well in B301 test area is taken as the research object.Through laboratory experiment,theoretical calculation,numerical simulation and correlation analysis,the factors affecting the formation of wax in the wellbore of polymer flooding oil well in B301 test area and the corresponding anti-wax technology are systematically and deeply studied,so as to provide theoretical and technical basis for the efficient exploitation of polymer flooding oil well in this test area.In this paper,the wax formation rate of the produced liquid from 10 polymer flooding oil Wells in B301 test area was measured by a self-made dynamic simulation device.The wax breaking point,wax dissolving point and viscosity change of the produced liquid at different temperatures were measured by differential scanning calorimeter and Brinard rotary viscometer.The results show that 7 oil Wells have serious paraffin formation,and the paraffin formation rate is above 0.03g/d.3 oil Wells have light paraffin formation,which is consistent with the actual situation in the test area.The average wax analysis point of 10 polymer flooding Wells is 45.506℃,and the higher the wax analysis point is,the faster the wax formation rate of produced liquid is.The average wax dissolving point was 70.088℃,and the higher the wax dissolving point was,the worse the wax cleaning effect was.At the average reservoir temperature,the produced liquid viscosity is 8.774 m Pa·s,and the higher the produced liquid viscosity,the faster the wellbore wax formation rate.The effects of wax,gum,asphaltene,mechanical impurities,polymer content and wall temperature on the wax formation rate were analyzed by laboratory experiments.The numerical simulation model of wax formation in B46-53 oil well was established by Olga multiphase flow simulation software.Based on the model,the influences of velocity,water cut,production time and pressure on the thickness of wellbore wax formation profile were analyzed.Based on the results of laboratory experiment and numerical simulation,the correlation analysis model of each influencing factor was established by Pearson correlation coefficient method,and the correlation degree of each influencing factor to the wax formation velocity of wellbore was determined.Among them,polymer,wax,mechanical impurities,temperature and production time are positively correlated with the wax formation rate,and play a role in accelerating the wax formation.The velocity,moisture content and pressure were negatively correlated with the wax formation rate,which inhibited the wax formation.Based on the correlation between the influencing factors and the wax formation speed of the well shaft,the existing wax prevention technology was optimized,and the optimal SY-1solid wax prevention agent was used to measure the dissolution release rate and the wax prevention rate.The results show that the dissolution and release rate of SY-1 solid anti-wax agent is stable in the shaft of 10 polymer flooding Wells,and the anti-wax rate is all above 60%,which plays a good anti-wax effect and has certain economic benefits,and can be used as an effective anti-wax technology in this experimental area.