The Effect Of Magnetic Field On The Scaling Of Oilfield Wastewater And The Study Of Scaling Inhibition Methods

Scaling usually result in some consequences in oil production system, such as formation damage, pipe plug, corrosion, and even affect the oilfield production. Therefore, anti scaling is very necessary. Chemical anti-scaling method which can achieve a high ratio of anti-scaling is used commonly in oilfield, but the high cost, complicated operation and contaminated the environment. Magnetic anti-scaling method is a physical anti-scaling method in oilfield, the virtue of which is low cost, simple maintenance, easy to install management and without environmental pollution. For the virtue of chemical and magnetic anti-scaling method, this paper proposed an combination of two anti-scaling methods to reduce the costs and pollution in a better inhibiting efficiency.The study of magnetic scale-inhibition show that magnetization had little effect on calcium sulfate scaling when two incompatible water was mixed firstly then be magnetized. But when two incompatible water was magnetized firstly then be mixed, it can reduce calcium sulfate scaling more up than 35% on coupon, and more up than 60% in pipelines in unit time. Magnetization have little effect on the calcium carbonate scaling.The experiments of chemical scale inhibitions show that the number of 3,4,25 scale inhibitions can effectively prevent calcium sulfate, and the inhibition rate could reach 85%; the number of 2,4,25 scale inhibitions can effectively prevent calcium carbonate scaling, and the inhibition rate could reach 70%; the number of 8,21 scale inhibitions can effectively prevent Barium Sulfate scaling, and the inhibition rate could reach 90%; Citric acid can prevent the scaling of iron compounds.The study of the combination of chemical and magnetic anti-scaling show that magnetization can imporve the effect of chemical anti-scaling. In static tests, magnetization can imporve the effect of scale inhibitor in 5% to 24%. In dynamic tests, magnetization can imporve the effect of scale inhibitor about 24% on coupon and more up than 75% in pipelines.