Scaling Mechanism And Testing Of The Efficiency Of Scale Inhibitor

During the process of the EOR, amount of alkali is used into crude oil to enhance the oil recovery, that made more serious scaling of the oil field facilities and pipelines, hidered oil transportation and normal production, and caused huge economic losses in the oil field. Therefore, scaling inhibitors of oil field water play an important role in oil field production. Nowadays, scale inhibitor is the most commonly used chemical antiscale method in the oil field.This paper found that the percent of Calcium carbonate is very large in all of the oil field scale, and the hard-cleared silicate has a certain percent by analysed the scale sample in a certain work area of DaQing oil field. Aim at the scale's ingredients and water's characters, and choose five common-used scale inhibitors (MH-1,MH-2,MH-3,TW-1,TW-2)with different structure. An experimental research on calcium carbonate and silica scale inhibition behavior of siple and associative scale inhibitor was carried out by using a static experimental method and the analog water which has the similar mineralization ingredient with this block.This paper chose harsh environment with higher temperature (50℃-90℃) and higher PH (>10)to investigate the function of original scale inhibitors. The experimental results of calcium carbonate scal's experiment showed that when the temperature is 70℃and the heating time is 10h, MH-2's scale inhibiting rate can be best and as high as 94.22% with the concentration 40 mg/L;MH-2 with the concentration 20 mg/L and TW-2 with the concentration 20 mg/L,this proportion's scale inhibiting rate can reach 97.19% after formulation. This proportion has good temperature endurance and longresidualaction, and be appropriate for practical manufacture.This paper had made a small change in the silica scale inhibition experiment that we used the ascorbic acid instead of 1-amino-2-naphthol-4-sufonic acid as deoxidizer. The experimental results in silica scale inhibition showed that when the temperature is 70℃and the heating time is 10h, silicon content is only 0.06445mg in blank solution. according to the experimental result, the best scaling inhibitor MH-2 can made the silicon content increase to 0.08124mg with the concentration 40 mg/L;MH-2 with the concentration of 20 mg/L and TW-1 with the concentration 20 mg/L,MH-2 with the concentration of 20 mg/L and TW-2 with the concentration 20 mg/L,can make the silicon content rise up to 0.08662mg and 0.08628mg after they associatived. and these two formulas both have good temperature endurance and longresidualaction.