A composite scale dissolution and scale prevention method for downhole coalbed methane

A technology for coalbed methane wells and scale dissolution, applied in chemical instruments and methods, earthwork drilling, wellbore/well components, etc., can solve the problems of unrelieved scaling and cathodic protectors that cannot fully achieve the protection effect, and achieve good results The effect of the scale dissolution effect

Active Publication Date: 2021-11-16
XI'AN PETROLEUM UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the performance of electrochemical corrosion on the upper, middle and lower parts of the pipe string is different, and the ideal protection effect cannot be fully achieved by using a cathodic protector, and the scaling situation is not alleviated

Method used

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  • A composite scale dissolution and scale prevention method for downhole coalbed methane
  • A composite scale dissolution and scale prevention method for downhole coalbed methane
  • A composite scale dissolution and scale prevention method for downhole coalbed methane

Examples

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Effect test

Embodiment 1

[0023] This embodiment provides a composite scale dissolving agent for downhole coalbed methane, including the following components: 80 parts of main agent, 18 parts of iron ion stabilizer, and 2 parts of corrosion inhibitor;

[0024] Among them, the main agent of scale dissolution is hydrochloric acid with a mass fraction of 16%; the iron ion stabilizer is citric acid and acetic acid in a ratio of 1:2 by mass; the corrosion inhibitor is polyaspartic acid and cycloalkylimidazoline It is compounded with urotropine according to the mass ratio of 1:3:6;

[0025] Preparation steps of the coalbed methane downhole composite scale-dissolving agent: at room temperature, add the main scale-dissolving agent, iron ion stabilizer, and corrosion inhibitor into the beaker in sequence according to the recipe amount and stir evenly to obtain the coalbed methane downhole composite scale-dissolving agent.

Embodiment 2

[0027] This embodiment provides a composite scale dissolving agent for downhole coalbed methane, including the following components: 87 parts of main agent, 12 parts of iron ion stabilizer, and 1 part of corrosion inhibitor;

[0028] Among them, the main agent for dissolving scale is hydrochloric acid with a mass fraction of 18%; the iron ion stabilizer is a mixture of citric acid and acetic acid in a mass ratio of 1:2; The product is compounded according to the mass ratio of 1:3:6;

[0029] Preparation steps of the coalbed methane downhole composite scale dissolving agent: at room temperature, add the main scale dissolving agent, iron ion stabilizer, and corrosion inhibitor to the beaker in sequence according to the formula amount and stir evenly to obtain the coalbed methane downhole composite scale dissolving agent;

Embodiment 3

[0031] This embodiment provides a composite scale dissolving agent for downhole coalbed methane, including the following components: 90 parts of main agent, 7 parts of iron ion stabilizer, and 3 parts of corrosion inhibitor;

[0032] Among them, the main agent of scale dissolution is hydrochloric acid with a mass fraction of 20%; the iron ion stabilizer is citric acid and acetic acid in a ratio of 1:2 by mass; the corrosion inhibitor is composed of polyaspartic acid and cycloalkylimidazoline It is compounded with urotropine according to the mass ratio of 1:3:6;

[0033] Preparation steps of the coalbed methane downhole composite scale dissolving agent: at room temperature, add the main scale dissolving agent, iron ion stabilizer, and corrosion inhibitor to the beaker in sequence according to the formula amount and stir evenly to obtain the coalbed methane downhole composite scale dissolving agent;

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Abstract

The invention relates to the technical field of downhole descaling of coal bed methane, in particular to a method for compound dissolving and anti-scaling downhole of coal bed methane. The composite scale-dissolving agent of the invention is composed of a scale-dissolving main agent, an iron ion stabilizer and a corrosion inhibitor, wherein the main agent is a hydrochloric acid solution, the iron ion stabilizer is a compound of citric acid and acetic acid, and the corrosion inhibitor is composed of a polymer Aspartic acid, cycloalkylimidazoline and urotropine are compounded; the anti-scaling agent is prepared by mixing polyepoxysuccinic acid, aminotrimethylene phosphoric acid and hydrolyzed polymaleic anhydride, and dissolving in water. The scale dissolving agent of the present invention can effectively remove the downhole calcium carbonate scales produced by the use of jet pump for coalbed methane drainage and production, and does not corrode the pipe string and does not produce secondary precipitation.

Description

technical field [0001] The invention relates to the technical field of downhole descaling of coal-bed methane, in particular to a composite scale-dissolving and anti-scaling method for downhole coal-bed methane. Background technique [0002] In the process of artificially lifting coalbed methane by using jet pumps, problems such as scaling and corrosion gradually appeared in the center pipe of the downhole string, the pump working cylinder and the reinjection water pipe. The main components of the scale are calcium carbonate and magnesium carbonate. Dirt. Due to the widespread use of jet pumps in drainage sites, scaling problems are widespread and becoming more and more serious. Scaling and corrosion of downhole equipment will reduce the pump efficiency of the jet pump, which cannot meet the requirements of conventional drainage and pressure reduction, and has a great impact on the normal and continuous drainage of coalbed methane. gas production. If scaling occurs in the...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): E21B37/06C02F5/14
CPCC02F5/14E21B37/06
Inventor 唐长久盖洁超唐颖
Owner XI'AN PETROLEUM UNIVERSITY
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