Study And Evaluation Of Heat And Salt-resistant Viscosifying Displacement Diquid Dystem And Its Performance Evaluation

The conventional polymer flooding system is easy to degrade and cannot effectively maintain viscosity under high temperature and high salt conditions.The temperature and salt resistance of polymer systems are increased by means of addition,association and crosslinking.Based on the method of crosslinking,the weak crosslinking polymer system for oil displacement is formed to improve the high temperature resistance of the system.Selected by using orthogonal test method,type of heat-resistant SDPJ-1 oil displacement with weak crosslinked polymer system,determine the system a better recipe for 0.6%polyacrylamide+2%F crosslinking agent+0.025%C crosslinking agent+0.1%thiourea,monomer and system compatibility,select SDPJ-2 type heat resistance salt resistant oil displacement with weak crosslinked polymer system,determine the system the optimum formula is 0.6%polyacrylamide+2%F type crosslinking agent+0.025%C type crosslinking agent+16%AM monomer;The microstructure of the system was studied by means of environmental scanning electron microscopy.The results show that the selected SDPJ-1 and SDPJ-2 systems have good thermal stability,which is due to the addition of composite crosslinking agent to form a sphere-tree structure,which is conducive to improving the thermal stability of the polyacrylamide polymer system.Moreover,the SDPJ-2 system has good salt resistance,and the viscosity retention rate is 51.22%in simulated formation water aging of2.4×10~5mg/L for 45 days.The dynamic evaluation results show that the weak crosslinked polymer systems for SDPJ-1 and SDPJ-2 flooding have good injection and shear resistance properties.The visual displacement evaluation device was used to study the weak cross-linked polymer system for oil flooding with SDPJ-1 and SDPJ-2.