垦西油田的井下腐蚀与化学防腐蚀

Downhole Corrosion and Corrsoion Inhibition by Using Chemical at Kenxi Oil Field of Shengli

垦西油田井下金属设备腐蚀严重 ,检泵周期短 ,严重影响油田生产。对典型油井的产出水、产出气及注入水的成份进行了分析 ,判定主要腐蚀因素是溶解的和气态的H2 S及游离CO2 气体 ,既有地层水腐蚀 ,也有气体腐蚀。合成并评价了油井缓蚀剂GS 1 (膦甲基化的有机酸酰胺溶液 ,有效成份含量 4 0 % ) ,加量为 50mg/L时 ,无论在模拟油田污水中 ,还是油井采出液中 ,对N80钢、A3钢的缓蚀率均在 80 %以上 ,优于现用的两种缓蚀剂。在垦西油田1 2口油井中 ,每日从油套环空加入GS 1 2 5kg ,使检泵周期由 1 .5— 3个月延长到 6— 8.5个月以上。简介了GS 1的合成方法。

Severe corrosion of downbole installations of oil wells at Kenxi Oil Field, Gudao, Shengli, led to shortening of the working duration of downhole pumps after maintenance and exerted negative influence on the oil production. The composition of the produced water and the natural gas associated with the produced crude oil from two presentative wells and of the injection water is determined and it is ascertained that the main corrosion factors are shown to be the dissolved in brine and the gaseous hydrogen sulfide and the gaseous free carbon dioxide. A phosphorylmethylated fatty acid amide is prepared and evaluated as corrosion inhibitor GS 1(40% solution) GS 1 at use level 50 mg/L decreases the corrosion rates of carbon steel A3 and N80 in the simulation and oilfield produced waters by >80%. Introducing 25 kg of GS 1 through annulus into the producing wells every day leads to reducing the working time of the downhole pumps after maintenance from 1.5-3 to 6-8.5 months. The synthesis of GS 1 is described briefly.