Synthesis And Application Of AMPS/NVP/DAC/AM Quaternary Copolymer Fluid Loss Agent

Synthesis and performance evaluation of a polymer drilling fluid loss additive was studied in this paper.Redox method was adopted in the synthesis of quaternary copolymerization and the monomers were AM,AMPS,NVP,AMPS.The effect of reaction condition on fluid loss was studied and the property evaluation including anti-temperature,anti-salt,inhibition,compatibility were tested in this paper.Single factor test was studied to find the best polymer synthesis conditions based on the evaluation of freshwater mud fluid loss.For the more,the orthogonal experiment was also designed based on the result of single factor experiment.The specific effects including reaction temperature,pH value,the amount of initiator,monomer ratio and the substrate concentration was studied in a orthogonal experiment of 5 factors 4 level.The result of best synthesis conditions were dosage of the initiator was 0.3%,60? of reaction temperature,substrate concentration of 40%,the pH value of 9 and a monomer ratio of(AMPS + AM)/NVP/DAC is 6.6/0.5/0.5.The target product can be sure from the IR analysis.The optimum reaction conditions were determined by orthogonal experiment in a high temperature.The polymer synthesized according to the condition would be tested for its fluid loss ability.It was found that with the polymer increasing,the fluid loss effect would strengthen.When respectively added 1.5%polymer in fresh water,salt water,compound brine,and saturated salt water,the fluid loss were 5.6ml,9.7ml,16.1ml,20.9ml.At 200? for 16h,the fluid loss would apparently increase.The fluid loss at 180? was the same as that at room temperature,which indicated that the polymer could resist 180 ?.Rheological property test showed that,with the polymer added into the system,the plastic viscosity of and yield value of the drilling mud would obviously increase.When added 1.5%,the YP would be 12Pa,which increased its carrying capability.In the inhibitory test,rolling shale recovery was adopted and the result showed that when the polymer was added 0.6%by monomer,the recovery rate could reach 80%,secondary rolling recovery could be 75.3%.Furthermore,the polymer has other excellent property including anti-calcium salt.When added 1.5%polymer by mass into fresh water system which 2%CaSO4 had been added,the fluid loss was still lower than 10ml.More than that,when added 1.5%polymer by mass into fresh water system which 20%NaCl had been added,the fluid loss was still lower than 10ml.Compared with four products used in Xinjiang oilfield,the polymer is better at fluid loss controlling,viscosity increasing and anti-temperature.Furthermore,the polymer could be work well with often used mud system.When added 0.6%polymer by mass in the systems,the loss of the fluid didn't change after 16h burn-in at 100°C,API was lower than 5mL.