Experimental investigation of corrosion inhibiting effect by compound corrosion inhibitor.

according to the occurrence of corrosion and scaling of pump rod and tubing in Cha 19 Block of Huabei Oilfield, the main influential factors of corrosion and scaling were analyzed. Several corrosion inhibitors were combined to improve the corrosion inhibiting effect. Based on the optimization of single corrosion inhibitor, two kinds of water solubility corrosion inhibitor, CY03 (polyether) and CY05 (imidazoline) were combined with 1:1 proportion. The corrosion inhibiting rate of combined corrosion inhibitor was 5% higher than that of single inhibitor under the same overall concentration. At the same time, the combined corrosion inhibitor has good compatibility with scale inhibitor such as HEDP, ATMP and PBTCA. The selected corrosion and scale inhibitor owns more than 75% corrosion inhibiting rate and 95% scale inhibiting rate. The total iron level of the water in oil wells decreased from 2.0 mg/L to 0.1～0.5 mg/L when this type of inhibitor was added in June,2005. The average pump inspecting period was prolonged from 140d to 300d, and good scale and corrosion inhibiting capability has been acquired.