Research On Profile Control And Flooding Technology Of Polymer Microsphere In G6 Block Of Jiangsu Oilfield

Polymer microsphere technology is a new type of profile control and flooding technology developed in recent years.It is suitable for deep polymer microsphere profile control and flooding test because of the large medium and low permeability water flooding reserves and the remaining oil recoverable reserves in Jiangsu Oilfield.Research and evaluate the feasibility and adaptability of this technology in Jiangsu Oilfield,which has great significance on the development of medium and low permeability water flooding reservoirs.There are three polymer microspheres in the basic performance evaluation in this paper,named YG-5,YG-E and ST-2.The following laboratory experiments were carried out:visual observation of the stability of microsphere dispersion system;analysis of the size and size distribution of polymer microspheres during expansion by laser particle size analyzer and transmission electron microscopy;measurement of oil-water interfacial tension of polymer microspheres by interfacial tensiometer;and investigation of the shear of expanded microspheres by rheometer.The shear stability,the change of viscosity of polymer microspheres with thermal expansion days,the migration and plugging performance of three kinds of polymer microspheres,the plugging performance and oil displacement efficiency of polymer microspheres in different stages of parallel sand filling pipe model were studied.Through the above series of evaluations,YG-5 have good solubility,low interfacial tension,good shear resistance and thermal stability,strong plugging ability after expansion.Under the condition of poor permeability,YG-5 microspheres can effectively plug high permeability layer and push the fluid into low permeability layer and improve displacement efficiency.The effect is to improve the overall recovery of the parallel model.It is suitable for injection in Oilfield formation and is selected as field implementation system.At the same time,on the basis of summarizing the laboratory research experience,a preliminary evaluation system for the performance of microspheres in Jiangsu Oilfield is established,and the principle of well selection of microspheres is formulated.According to this principle,G6-38 fault block G6 is selected as the field profile control and displacement well group,and the construction scheme is optimized and implemented according to the actual working condition parameters of the well group.From the result analysis,the production decline rate of the well group decreased from 2.17%to 1.07%monthly,the precipitation was 179 m~3,and the oil increase was 305 tons.