Barium strontium calcium scale remover and preparation method thereof

Abstract

The invention provides a barium strontium calcium scale remover. The barium strontium calcium scale remover is prepared from, by weight, 20%-35% of a metal chelator, 10%-20% of a solubilizer, 0.5%-5% of a dispersing agent, 5%-15% of potassium hydroxide and 40%-60% of deionized water. Compared with the prior art, the barium strontium calcium scale remover has the good performance, can effectively remove organic composite scale such as barium sulfate, strontium sulfate and calcium sulfate, has the advantages of being high in scale removal efficiency, harmless to the natural environment, safe in use, non-corrosive to equipment and the like and has an important practical significance for increasing the oil and gas recovery rate.

Description

Technical field

[0001] Invention of the Invention The present invention relates to the field of oilfield chemical additives, in particular to a descaling agent for three types of inorganic composite scales, such as barium sulfate, strontium sulfate, and calcium sulfate for oilfields, and a preparation method thereof. Background technique

[0002] According to recent surveys in several oil fields, about 70-80% of oil wells are under high pressure during the drilling and completion process, and barite powder needs to be used to increase the density. Among barite powder, barium sulfate, strontium sulfate, and calcium sulfate are It cannot be removed by conventional pickling methods; in addition, some oil reservoirs themselves also contain barium sulfate, strontium sulfate, and calcium sulfate. These insoluble inorganic compound scales such as barium sulfate, strontium sulfate and calcium sulfate make the oil and gas reservoirs The damage caused the formation to be blocked, the water...

Examples

Embodiment 1

[0025] The formula of the descaling agent is: ethylenediaminetetraacetic acid sodium salt (EDTA-Na) is used as the metal chelating agent with a mass percentage of 30%, and OP-4, OP-15 and OP-40 ( In this embodiment, the mass ratio of the above three substances is 1:1:2, that is, the mass percentages are 5%, 5%, and 10% respectively. The above-mentioned ratio range can be adjusted according to actual use conditions.) The mass percentage is The 3% dispersant is a mixture of polyethylene wax and oxidized polyethylene wax (the mass ratio is 7:3, and the ratio range of the mass ratio can be adjusted accordingly according to the actual use), and the mass percentage is 7% hydrogen hydroxide Potassium, 40% by mass deionized water.

[0026] The preparation method of the descaling agent is as follows: first add deionized water, metal chelating agent, and potassium hydroxide into the reaction flask and stir uniformly, react at 60°C for 1 hour, add solubilizer and dispersant, stir uniformly,...

Embodiment 2

[0029] The formula of the descaling agent is: 20% by weight of the metal chelating agent aminotriacetic acid, and 10% by weight of the solubilizing agent to choose OP-9, OP-13, OP-30 (the quality of the above three substances in this embodiment The ratio is 1:1:2, and the above ratio range can be adjusted according to the actual use.) The mixture, the dispersant with 0.8% mass percentage is stearamide, the mass percentage is 10% strong alkali potassium hydroxide, the mass percentage It is 59.2% deionized water.

[0030] The preparation method of the descaling agent is as follows: first add deionized water, metal chelating agent and potassium hydroxide into the reaction flask and stir evenly, react at 60°C for 2h, add solubilizer and dispersant, stir evenly, and cool to room temperature to give a light yellow liquid.

[0031] The method of using the descaling agent is: take 10 grams of scale sample, keep the temperature at 80-90℃, keep stirring or shaking, take it out after 48h, fi...

Embodiment 3

[0033] The formula of the descaling agent is: the metal chelating agent with a mass percentage of 25% is diethylene triamine pentaacetic acid sodium salt (DTPA-Na), and the mass percentage is 15% with a solubilizer of OP-9, OP-15 (this In the embodiment, the mass ratio of the above two substances is 1:1:2, and the above ratio range can be adjusted according to the actual use.) Mixture, 0.5% by mass dispersant, select lipids, the lipids are stearin The mixture of acid monoglyceride and glyceryl tristearate (the mass ratio of the above two substances in this example is 2:1, and the above ratio range can be adjusted accordingly according to actual use), and the mass percentage is 12.5% ​​strong Alkali potassium hydroxide, deionized water with a mass percentage of 47%.

[0034] The preparation method of the descaling agent is as follows: first add deionized water, metal chelating agent, and potassium hydroxide into the reaction flask and stir evenly, react at 50℃ for 1.5h, add solubi...

Technical field

[0001] Invention of the Invention The present invention relates to the field of oilfield chemical additives, in particular to a descaling agent for three types of inorganic composite scales, such as barium sulfate, strontium sulfate, and calcium sulfate for oilfields, and a preparation method thereof. Background technique

[0002] According to recent surveys in several oil fields, about 70-80% of oil wells are under high pressure during the drilling and completion process, and barite powder needs to be used to increase the density. Among barite powder, barium sulfate, strontium sulfate, and calcium sulfate are It cannot be removed by conventional pickling methods; in addition, some oil reservoirs themselves also contain barium sulfate, strontium sulfate, and calcium sulfate. These insoluble inorganic compound scales such as barium sulfate, strontium sulfate and calcium sulfate make the oil and gas reservoirs The damage caused the formation to be blocked, the water...

Examples

Embodiment 1

[0025] The formula of the descaling agent is: ethylenediaminetetraacetic acid sodium salt (EDTA-Na) is used as the metal chelating agent with a mass percentage of 30%, and OP-4, OP-15 and OP-40 ( In this embodiment, the mass ratio of the above three substances is 1:1:2, that is, the mass percentages are 5%, 5%, and 10% respectively. The above-mentioned ratio range can be adjusted according to actual use conditions.) The mass percentage is The 3% dispersant is a mixture of polyethylene wax and oxidized polyethylene wax (the mass ratio is 7:3, and the ratio range of the mass ratio can be adjusted accordingly according to the actual use), and the mass percentage is 7% hydrogen hydroxide Potassium, 40% by mass deionized water.

[0026] The preparation method of the descaling agent is as follows: first add deionized water, metal chelating agent, and potassium hydroxide into the reaction flask and stir uniformly, react at 60°C for 1 hour, add solubilizer and dispersant, stir uniformly,...

Embodiment 2

[0029] The formula of the descaling agent is: 20% by weight of the metal chelating agent aminotriacetic acid, and 10% by weight of the solubilizing agent to choose OP-9, OP-13, OP-30 (the quality of the above three substances in this embodiment The ratio is 1:1:2, and the above ratio range can be adjusted according to the actual use.) The mixture, the dispersant with 0.8% mass percentage is stearamide, the mass percentage is 10% strong alkali potassium hydroxide, the mass percentage It is 59.2% deionized water.

[0030] The preparation method of the descaling agent is as follows: first add deionized water, metal chelating agent and potassium hydroxide into the reaction flask and stir evenly, react at 60°C for 2h, add solubilizer and dispersant, stir evenly, and cool to room temperature to give a light yellow liquid.

[0031] The method of using the descaling agent is: take 10 grams of scale sample, keep the temperature at 80-90℃, keep stirring or shaking, take it out after 48h, fi...

Embodiment 3

[0033] The formula of the descaling agent is: the metal chelating agent with a mass percentage of 25% is diethylene triamine pentaacetic acid sodium salt (DTPA-Na), and the mass percentage is 15% with a solubilizer of OP-9, OP-15 (this In the embodiment, the mass ratio of the above two substances is 1:1:2, and the above ratio range can be adjusted according to the actual use.) Mixture, 0.5% by mass dispersant, select lipids, the lipids are stearin The mixture of acid monoglyceride and glyceryl tristearate (the mass ratio of the above two substances in this example is 2:1, and the above ratio range can be adjusted accordingly according to actual use), and the mass percentage is 12.5% ​​strong Alkali potassium hydroxide, deionized water with a mass percentage of 47%.

[0034] The preparation method of the descaling agent is as follows: first add deionized water, metal chelating agent, and potassium hydroxide into the reaction flask and stir evenly, react at 50℃ for 1.5h, add solubi...