Study Of Treatment Measures On Scale Forming In Oilfield

Scaling is a very common problem in the oilfield, and brings serious harm to theoilfield production. The scaling of the oil wells and pipelines is one of the important issuesencountered in the oilfield development process, constraints the normal production andgathering transportation of crude oil, and increases the cost of crude oil production, so it hasbrought greater economic losses to the oilfield. Scaling phenomenon is a common problemfaced by the oilfield water flooding, and so far, is still an unresolved global problem.A novel quadripolymer scale inhibitor is prepared from maleic anhydride (MA),epoxy succinic acid sodium(ESAS), acrylamide(AM) and sodium vinyl sulfonate(SAS), andthe polymerization is initiated by persulfate ammonium. The study determined the optimalsynthesis conditions for scale inhibitors by orthogonal test, and investigated scale inhibitorsdosage, systematic pH value and temperature on the scale inhibitor anti-scaling properties.The results show that the optimal conditions of synthesis as follows: the mass ratio ofinitiator to total monomer is15%, the monomer's mole ratio ofn(MA):n(ESAS):n(AM):(SAS) is1:1:0.6:1, the reaction temperature is90℃, and thereaction time is3h. Under the optimum conditions, determining the inhibition rate of the ofcopolymer is more than90%, and the scaling effect is good.A quadripolymer scale inhibitor as ASAE is prepared from acrylic acid (AA), sodiumvinyl sulfonate(SAS), acrylamide(AM) and epoxy succinic acid sodium(ESAS).Thepolymerization is initiated by persulfate ammonium in aqueous solution. The best syntheticconditions of the quadripolymer was determined through an orthogonal test, and itsproperties had been evaluated. The optimal conditions of synthesis as follows: the reactiontemperature is80℃; the monomer's mole ratio of n(AA):n(SAS):n(AM):(ESAS) is1:1:0.6:1.2; the mass ratio of initiator to total monomer is15%, and the reaction time is3h.Under the optimum conditions, the inhibition rate of the of copolymer is86.72%, and thescaling effect is very good.A terpolymer scale inhibitor is prepared from epoxy succinic acid sodium (ESAS),acrylamide (AM) and sodium vinyl sulfonate (SAS), and the polymerization is initiated bypersulfate ammonium. Its structure is characterized by infrared spectroscopy, and the resultsshow that the synthetic product is the target product. Research into the best syntheticconditions through an orthogonal test as follows: the reaction temperature is90℃, thereaction time is3.5h, the mass ratio of persulfate ammonium to total monomer is12.5%,and the monomer's mole ratio of n(ESAS):n(AM):n(AS) is1.2:0.6:1.The synthetic product to calcium carbonate scale has a better inhibition performance, and the inhibition rate canamount to88.07%.Open the ultrasonic anti-scaling device, while the aqueous solution of pretreatment iswarming, for water quality processing.Single ultrasound, dual ultrasound, and withoutultrasonic experiments as the research objects, the study researched the anti-scaling effect ofultrasonic measures. Before and after joining the scale inhibitors, through chemical titrationmethod, measured change rule of the easy scaling ion.The results show that, in the role ofultrasound, ultrasonic radiant energy can restrain the change direction of microcrystalline tocalcium carbonate compounds, that is, it can inhibit the speed of the microcrystallinegrowth into calcium carbonate compounds, thereby preventing scaling; in the role ofultrasonic, the scaling materials on the wall can be shaken off, so that it will be able toachieve the the antiscale purpose; under the same conditions, single ultrasonic's effect isstronger than the dual ultrasound's.