Study On The Synthesis Of Temperature Sensitive Polymer And Its Flocculation In Waste Drilling Fluid

More and more attention has been paid to environmental pollution and protection in the world.In the process of exploration and development of oil and gas resources,a series of pollution problems will inevitably occur,among which waste drilling fluid produced in the process of drilling is always the difficulty and key point of construction site treatment.Waste polysulfonate drilling fluid is a kind of typical waste drilling fluid system,which is difficult to deal with and has high content of pollutants.Its pollution to the environment is very serious.Therefore,it is imperative to carry out research on waste polysulfonate drilling fluid treatment technology.Flocculation technology is one of the key technologies that can effectively treat waste drilling fluid,and flocculant is the fundamental core of this technology.Therefore,the development of a new and efficient flocculant is the key to improve the treatment technology of waste drilling fluid.In this paper,the cationic temperature sensitive polymer PAA was synthesized by oxidation-reduction micelle polymerization with temperature sensitive monomer N,N-diethylacrylamide(DEAM),hydrophobic monomer(PB),hydrophilic monomer acrylamide(AM)and cationic monomer(PC)as polymerization monomers.The effects of initiator dosage,monomer concentration,monomer ratio,polymerization temperature,polymerization time and surfactant concentration on the product yield were studied by single factor experiment.The results show that when the monomer concentration is 30%,the mole ratio of AM: DEAM: PB: PC is 73:26:1:12,the polymerization temperature is 50?,the polymerization time is 12 hours,and the surfactant concentration is 4%,the yield of the cationic temperature sensitive polymer can reach 98%.The monomers of am,DEAM,PC and the temperature sensitive polymer PAA were characterized by FTIR.The results showed that some monomers took part in the reaction.Thermogravimetric analysis(TG)shows that the temperature sensitive polymer has good thermal stability.The phase transition temperature(LCST)of the temperature sensitive polymer was measured by UV spectrophotometer.The LCST of the temperature sensitive polymer was 40?.As the performance of drilling fluid is greatly affected by the content of submicron particles,during the research and development of flocculant,the flocculant should not only minimize the useful solid-phase flocculation of bentonite,but also realize the efficient flocculation of submicron poor soil such as kaolin in drilling fluid.In order to achieve the above purpose,the flocculation performance of bentonite suspension was studied as the useful solid phase of waste drilling fluid,and the light transmittance of supernatant after flocculation was taken as the measurement standard to investigate the effect of different flocculant concentration,flocculation temperature and p H on the flocculation performance.The results show that when the concentration of the flocculant is 200mg/L,the flocculation temperature is 45?,and the p H is 10,the transparency of the supernatant can reach the maximum.Kaolin suspension was used to simulate the poor solid phase of waste drilling fluid.The results showed that PAA flocculant had the best flocculation effect on the suspended particles when the concentration of flocculant was 90mg/L,the temperature of flocculation was 45?,the p H was 10.The mixed suspension of bentonite and kaolin was used as the simulated waste drilling fluid.The results showed that when the concentration of flocculant was 90mg/L,the flocculation temperature was 45 ?,and the p H was controlled to 10,the transparency of the supernatant after flocculation reached the maximum.Through the above experiments,it can be proved that PAA flocculant can realize the effective selective flocculation between bentonite and kaolin.Finally,PAA flocculant is applied to the real waste polysulfonate drilling fluid,and the supernatant of the broken waste polysulfonate drilling fluid is taken.Based on the transmittance of the supernatant after flocculation as the measurement standard,the effects of different flocculant concentration,flocculation temperature and p H on the flocculation performance are investigated.The results show that PAA flocculant has the best flocculation effect on small suspended particles when the concentration of flocculant is 230mg/L,flocculation temperature is 45 ?,p H is 10.The results show that the flocculation effect of PAA flocculant on the suspended solids in waste polysulfonate drilling fluid is basically the same as that of CPAM flocculant,but the temperature can promote the flocculation effect of PAA flocculant on waste drilling fluid,while CPAM flocculant for industry does not Effect.