Study On Fouling Mechanism And Slow Release Scale Inhibitor Of Oil Well In Jilin Oilfield

An oilfield in Jilin has entered the middle and late stages of oilfield exploitation.With the application of water injection,polymer flooding,ternary compound flooding and other technologies,the scaling problem of oil wells,oil production pipelines and gathering and transportation pipelines is becoming more and more serious.In order to reduce oilfield exploitation The loss caused by scaling in the process is based on the analysis of the quality of the produced fluid in an oil field in Jilin and the analysis of the composition of scale samples.The scaling mechanism of prediction and experimental analysis is used to analyze the scaling mechanism of the oil well.Aimed at the main control factors of scale formation,a slow-release scale inhibitor was studied.The main knowledge gained is as follows:1 By means of chemical analysis and XRD analysis,the composition of scale samples in oil wells is analyzed,the results of the study showed that the composition of scale samples in an oil field in Jilin was mainly calcium carbonate,an amorphous aluminosilicate mixture insoluble in hydrochloric acid,organic matter and ferric oxide.2 Analyze the produced water quality of an oil well in an oil field in Jilin,measure the ionic composition and content of produced water by atomic absorption spectrophotometry and titration,and predict the scaling tendency according to the composition.The results of the study showed that the water samples of the produced liquid were all weakly alkaline and the p H value was between 8.75 and 8.99.The content of Na⁺and Cl^-ions in the produced liquid was high,which easily caused electrochemical corrosion and caused the formation of rust.Although the concentration of calcium and magnesium ions in produced water is not high(Ca²⁺<60 mg/L,Mg²⁺<2 mg/L),due to the high concentration of bicarbonate ions（HCO₃^->1000 mg/L）,the scale of Ca CO₃ in oil wells,the trend is generally larger.At the same time,the produced liquid contains a large amount of micron-scale aluminosilicate suspension.The scaling mechanism of oil wells is speculated based on the prediction of scaling theory.Among them,the formation of calcium carbonate is the main controlling factor for scaling of oil wells in Jilin Oilfield.3 According to the water quality analysis results of the oil well produced in an oil field in Jilin,a simulated scaling solution was prepared.From the 10 common scale inhibitor monomers,scale inhibitor monomers with good inhibitory effect on calcium carbonate scale were selected as solids The active ingredient of scale inhibitor.The results showed that PASP,ATMP,HDTMPA and HEDP were used in the simulated scaling solution.When the scale inhibitor concentration is 4 ppm,the scale inhibition rate reaches more than 90%,and the temperature resistance is good.4 Carry out the optimal experiment of the slow-release scale inhibitor carrier,and finally determine the composition of the solid slow-release scale inhibitor by investigating the compatibility between the scale inhibitor monomer and the carrier,and pass the slow-release experiment and the scale inhibitor experiment Optimize the conditions of solid scale inhibitor synthesis.The results show that the solid scale inhibitor with polyaspartic acid as the active ingredient and transparent soap base as the carrier has the best scale inhibition effect when the mass ratio is 1:3.The prepared solid slow-release scale inhibitor 19 g releases 5h At this time,the scale inhibition rate simulated scale solution can reach 90.24%.