Deep Profile Synthesis, Characterization And Evaluation Of The Particles

Particulate as the in-depth performance controller is a absorbent, which will exhibit the viscoelasticity, strength, and water-keep ability after it fully swells, what's important is that the gel is good enough to salt tolerance and temperature resistance, easy to be constructed and hard to damage the non-disposed reservoirs. The hydrophilic character can change the volume of gel under the different reservoirs; the three-dimensional configuration can exhibit the strength which can form jam resulting in the fluid diversion; the gel can hold the reversibility after the change of exterior pressure. Taking advantage of these characters and the variety of reservoirs' pressure, the in-depth performance control would be easily realized. Two particulates were synthesized in this paper by inverse suspension polymerization and the technics of polymerization and evaluation were studied, the results are the following:Using Span60 as dispersant; the hexamethylene as oil-phase; NMBA as cross-linker; superphosphate Potassium as the initiator; the organic in-depth performance control particulate and the composite particulate were synthesized. Using the gel swelling multiple and viscoelasticity as index, the stability of inverse suspension polymerization and the basic character of in-depth performance control particulate were investigated, the result showed the polymerization system and the particulate-forming ability were very well when the ratio of oil and water was 5:1; the neutralization was 80%; the amount of dispersant was 4.5%; assistant-dispersant was 1%; the temperature of starting-polymerization was 60℃; the stirring speed was 350rpm. The optimum of polymerization : dispersant 5.5%; initiator 1.017‰; cross-linker 1.017‰; AMPS 8%; crylic acid 11.2%; acrylonitrile 5%; neutralization 81%, the absorption amount of particulate is more than 63g/g; 63g/g and 74g/g in case of 15x10⁴mg/L NaCI, 4.5×10³mg/L MgCI₂ and 1.5×10³mg/L FeCI₃ solution, respectively. Viscoelastic index was IV. The composite particulate containing 30% clay was superior to organic particulate in absorption amount and strength.IR and DTA show that the two particulates are good enough to temperature resistance, the starting degrade temperature was 135℃ and 165℃, even at 500℃ the residual was 41.88% and 54.93% respectively. However, the ordinary absorbent resin' residual was37.105%. SEM and XRD confirm the clay-polymer composite particulates are compounded in the range of micron scale in the clay-polymer dispersant system.The applied evaluations show that the average diameter of particulate is77.76|jm with 2.16% standard windage; the two particulates exhibit good dilatability in case of 20x104mg/L NaCI solution; rate of water retention( 150 days) was 90% at 80°C; the viscoelasticity of paniculate enhances whit the temperature increasing, especially above 120°C the viscoelasticity has no difference between the two particulate; it holds good injectivity, driving performance and plug; the toughness index was 1.116; through the diffluence experiments the performance controllabilities are 85.7%, 98.7%. 86.1%, 98.1% when the penetrability grades were 4.05 and 15.0, respectively by performance control of two particulates; the average EOR efficiency is 15%.