Pmas Polymer Synthesis, Characterization And Study On Gelling Properties

In recent years,polyacrylamide and its derivatives are widely used in the oil industry for EOR,which becomes an important method to enhance oil recovery.This kind of polymer has good viscosity effect and flocculation efficiency,but they are also sensitive to salt and have poor shear stability and poor thermal stability.Focusing on the characters of polymers using in oilfields at present and the design of the copolymer structure,we have developed a new kind of anion temperature-tolerant and salt-resistant polymer PMAS,and has conducted the research to its gelling properties.In the laboratory,the things as follows have been done;(1)after designing the molecular structure,using AM,AA and AMPS as monomers,the polymer PMAS was synthesized by water solution copolymerization.The optimum condition was attained by the method of onefold and orthogonal test and the fuzzy mathematics method;the monomer total concentration is 21wt%,the initiator concentration is 0.04wt%,the AMPS content is 15mol%, the AA content is 8.5mol%,the pH is 6.5.(2)The structure of polymer PMAS was characterized by FTIR,which showed PMAS polymer is synthesized by the three monomer. The intrinsic viscosity of PMAS polymer is 13.05 dL/g and its molecular weight is 7.67×10⁶, and the morphology was studied by scanning electron microscopy.(3)The temperature and salt resistance and thermal stability of PMAS polymer solution have been studied.It showed that in the condition of 80℃and 5×10⁴ mg/L salinity,the viscosity maintenance rate of the PMAS polymer solution was above 80% after 30 days.Compared PMAS polymer with Daqing and hengju,PMAS solution viscosity retension rate is at 10～30 percentage point higher than Daqing and hengju solutions.(4)We have studied the gelling properties of polymer PMAS and ZS and inspected the factors such as polymer concentration,crosslinking agent concentration,temperature,salinity on the gelling properties of polymer.When the temperature is 80～95℃and salinity is 12000 mg/L,the gelling properties of polymer are perfect.The long-term thermal stability of the gel G_PMAShave been inspected.The gel can maintain long-term stability in 80℃,After four months the viscosity retention rate was 81.2%; and in 95℃the stabilization time went up to three months and the viscosity retention rate was 78.5%.(5)We have studied the microscopic structure of the gel G_PMASthrough the scanning electron microscopy.And the properties of weak gel G_PMASwere evaluated through core-flow experiments.The results show that polymer PMAS has good shearing resistance,temperature and salt tolerance and thermal stability,so it is able to meet the application requirements of the oilfield to enhances oil recovery.And gel G_PMAShas high gel strength,perfect thermal stability and it has high residual resistance factor in the rock.With good ability of fluidity-control and stratum-block,it can be a blocking agent for controlling water and increasing oil and to enhance the water drive efficiency.