CN103194197B - 3,5-Dibromosalicylaldehyde-2-Pyridinecarboxylic hydrazide and application thereof - Google Patents

Abstract

The invention discloses a kind of inhibiter 3,5-Dibromosalicylaldehyde-2-Pyridinecarboxylic hydrazide and application thereof.The structural formula of 3,5-Dibromosalicylaldehyde-2-Pyridinecarboxylic hydrazide is:

Description

3,5-Dibromosalicylaldehyde 2-pyridinecarbohydrazide and its application

technical field

The invention belongs to the technical field of corrosion inhibitors, and in particular relates to 3,5-dibromosalicylaldehyde 2-picolyl hydrazide for preventing corrosion of carbon steel and its products in oil field aqueous solution.

Background technique

Most of the newly exploited oil fields in China are deep wells and ultra _- deep wells, and the corrosion factors in the wells are complex and _changeable . Equipment, downhole tools, gathering pipelines, etc. caused serious corrosion, which caused accidents such as casing perforation, drilling equipment failure, pipeline cracking, etc., and even endangered people's lives and property safety; according to the data obtained from the statistical analysis of relevant departments, The failure of 70% of petroleum equipment is related to corrosion; according to the data released by China Corrosion Association, China Petroleum Association, and China Chemical Industry Association, in the petroleum and petrochemical industry, the loss caused by corrosion accounts for 6% of the total output value of the industry; The cost of pipes is tens of billions, most of which are scrapped due to corrosion; adding corrosion inhibitors as a commonly used anti-corrosion technology has the characteristics of simple operation, quick effect, low cost, and strong applicability. It has been widely used and developed rapidly; 3,5 dibromosalicylaldehyde acetal 2-pyridine carbohydrazide contains C=N bond, both N atom with lone pair of electrons and π bond, so it is very easy on metal The surface is adsorbed to form a dense molecular film, showing good corrosion inhibition performance, and its application to prevent corrosion of carbon steel and its products in oilfield aqueous solution has not been reported.

Contents of the invention

The object of the present invention is to provide a corrosion inhibitor 3,5-dibromosalicylaldehyde acetal 2-pyridine carbohydrazide and its application.

The structural formula of 3,5 dibromosalicylaldehyde 2-pyridine carbohydrazide is:

.

The 3,5-dibromosalicylaldehyde 2-pyridinecarbohydrazide is applied to prevent corrosion of carbon steel and its products in oil field aqueous solution.

The 3,5-dibromosalicylaldehyde 2-pyridinecarbohydrazide of the present invention can prevent the corrosion of carbon steel and its products in the oil field water medium, and has the advantages of less dosage, good corrosion inhibition effect, strong applicability and simple synthesis And the advantages of non-toxic and harmless.

Detailed ways

Example:

(1) The structural formula of 3,5 dibromosalicylaldehyde 2-pyridinecarbohydrazide:

.

(2) The preparation method of 3,5 dibromosalicylaldehyde 2-pyridinecarbohydrazide is:

Dissolve 10 mmol (1.37 g) of 2-pyridinecarbohydrazide in 20 ml of absolute ethanol and add it to a three-necked flask with a volume of 100 ml. After dissolving with magnetic stirring in a water bath, add 10 mmol (2.8 g) dropwise. g) A solution prepared by dissolving 3,5-dibromosalicylaldehyde in 35 ml of absolute ethanol was refluxed at 70°C for 4 hours, a large amount of yellow precipitate was formed, cooled to room temperature, filtered, washed 5 times with absolute ethanol, and dried to obtain Yellow powder, that is, 3,5 dibromosalicylaldehyde 2-picolyl hydrazide (M.P. 264~269oC, yield 83.1%).

(3) Application of 3,5 dibromosalicylaldehyde 2-pyridinecarbohydrazide:

a. Prepare the carbon steel test piece: take Q235 carbon steel, the outer dimension is 5.0×1.0×0.2 cm, use 400#, 1000# and 1200# water-grinding sandpaper to polish until it is smooth, wipe the test piece with filter paper, and then put Soak in a container filled with acetone, dry the surface of the test piece with absorbent cotton, then soak it in absolute ethanol for 5 minutes, further degrease and dehydrate, take out the carbon steel test piece and dry it with a hair dryer, and place it in a desiccator in spare.

b. Preparation of simulated oilfield aqueous solution for experiment: Weigh 70 grams of sodium chloride, 6 grams of anhydrous calcium chloride, 4 grams of magnesium chloride, 0.58 grams of sodium sulfite, 0.48 grams of sodium bicarbonate and 1.5 grams of sodium sulfide, and dissolve them in 1 liter of water , stir and dissolve until the solution is clear, and then use nitrogen to drive oxygen for 4 hours, and then use a gas cylinder to inject carbon dioxide to saturation to obtain a simulated oilfield aqueous solution for the experiment (the solution was prepared on the day of the experiment).

c. Use weight loss experiment to study corrosion inhibition performance: take 6 beakers with the same specifications, add the simulated oil field aqueous solution prepared in step b in step (3) and 3,5 di Bromosalicylaldehyde condensate 2-picolyl hydrazide corrosion inhibitor, so that the concentration of the corrosion inhibitor in the simulated oilfield aqueous solution is 0 mg/L (blank control), 25 mg/L, 50 mg/L, 75 mg/L liter, 100 mg/liter and 125 mg/liter, then immerse the dry carbon steel test piece prepared by step a in step (3) in the simulated oilfield aqueous solution of the above-mentioned different concentrations of corrosion inhibitor (hang three parallel beakers in each beaker) Carbon steel test piece, the weight loss of each group of test pieces measured in the experiment is the average weight loss value of three parallel carbon steel test pieces in the beaker).

The specific operation steps of the weight loss test are carried out according to the national standard GB10124-88, and the corrosion rate ( V ) and corrosion inhibition rate ( IE) are calculated according to the following formula:

V =( W ₀ –W _t )/( S × t )

In the formula: V is the corrosion rate, the unit is g/( ^m2 ·hour); W ₀ and W _t are the mass of the sample before and after corrosion respectively, the unit is g; S is the working area of the test piece, The unit is ^m2 ; t is the corrosion test time, the unit is hour.

IE =[( W ₀ -W _t )/ W ₀ ]×100%

In the formula: IE is the corrosion inhibition efficiency, in %; W ₀ is the weight loss of the carbon steel test piece in the blank simulated oilfield aqueous solution, in grams; W _t is the carbon steel test piece in the simulated oilfield aqueous solution with different concentrations of corrosion inhibitors Tablet loss weight, in grams.

Table 1. Data of weight loss experiment

Claims (1)

1. an application for inhibiter 3,5-Dibromosalicylaldehyde-2-Pyridinecarboxylic hydrazide, is characterized in that described 3,5-Dibromosalicylaldehyde-2-Pyridinecarboxylic hydrazide is applied to and prevents carbon steel and goods thereof from corroding in oil-field water solution;

The structural formula of described 3,5-Dibromosalicylaldehyde-2-Pyridinecarboxylic hydrazide is:

。