High temperature acidified corrosion inhibitor for oil passageway containing Cr

Abstract

The invention relates to a high-temperature acidizing inhibiter containing a Cr oil pipe. A main agent A comprises the following compositions by weight portion: 25 to 35 portions of quinoline quaternary ammonium salt or quinoline derivate quaternary ammonium salt, 5 to 10 portions of potassium iodide, and 40 to 60 portions of organic solvent methanol or formaldehyde. An addition agent B comprises the following compositions by weight portion: 30 to 50 portions of Mannich base, 15 to 35 portions of propiolic alcohol, 5 to 15 portions of chromic chloride, and 20 to 35 portions of formaldehyde. During use, the proportion of A to B is 2-1.5:1 according to the weight portions, in an environment of 15 percent HCl+3 percent HF mud acid and 20 percent hydrochloric acid, inhibitions to super 13Cr at 100 DEG C, 120 DEG C and 140 DEG C all accord with acidizing standard requirement; and according to SY / T5405-1996 acidizing inhibiter performance test method and evaluating indicator, corrosion velocity of the inhibiter is lower than 40g / m<2>h at 140 DEG C. The inhibiter achieves the requirement of primary standard, and solves the problem of acidizing corrosion of Cr-contained steel in a high-temperature oil well.

Description

technical field [0001] The invention relates to a high-temperature acidification corrosion inhibitor used for Cr-containing oil pipes of petroleum and natural gas oil wells. Background technique [0002] In a high-temperature simulation environment, when acidifying Cr-containing pipes, after using carbon steel high-temperature acidification corrosion inhibitor, the local corrosion of the sample is very serious, and the minimum corrosion rate of hydrochloric acid at 80°C is 26.06g / (m2 h). There is a large area of ​​corrosion on the surface of the sample; the corrosion rate for soil acid is 100g / (m 2 h) above, far beyond the SY / T5405-1996 acidification corrosion inhibitor performance test method and evaluation index, the surface of the sample has a large area of ​​metal peeling, indicating that the acidification corrosion inhibitor for ordinary carbon steel has no effect on Cr-containing pipes Good corrosion inhibition effect. [0003] Commonly used acidifying corrosion inhi...

AI Technical Summary

Problems solved by technology

In a strong acid environment, a passivation film is easily formed on the surface of ordinary carbon steel, and the acidizing corrosion inhibitor prevents further corrosion of the carbon steel by the acid solution. After adding the ordinary carbon steel acidizing corrosion inhibitor, the corrosion rate of the Cr-containing material is accelerated, indicating that the commonly used The corrosion inhibition film formed by carbon steel acidizing corrosion inhibitor cannot prevent the acidizing corrosion of Cr-containing materials very well

[0004] In order to solve C0 2 Corrosion problem. Cr-containing pipes (such as super 13Cr, ordinary 13Cr, and 3-5Cr oil pipes) have been widely used in China. Traditional carbon steel corrosion inhibitors cannot effectively slow them down at high temperatures (well depths exceeding 5,000 meters). Corrosion; in order to solve the acid corrosion problem of Cr-containing materials, especially the acid corrosion problem of super 13Cr tubing, it is necessary to study a new acid corrosion inhibitor