阅读说明：本技术 一种适用于高温地热用环保低腐蚀型阻垢剂及其制备方法 (Environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal and preparation method thereof ) 是由 石彦平 李智 李子硕 杨现禹 蔡记华 于 2021-06-29 设计创作，主要内容包括：本发明提供一种适用于高温地热用环保低腐蚀型阻垢剂及其制备方法,该阻垢剂包括：顺丁烯二酸酐4～6％、丙烯酸8～12％、2-丙烯酰胺基-2-甲基丙磺酸4～6％,次亚磷酸钠2～4％、十二烷基硫酸钠0.2～0.3％、过硫酸铵3～5％、聚环氧琥珀酸20～25％。本发明提供的耐高温环保型低腐蚀阻垢剂适于高温地热井中抑制碳酸钙垢生成,能够有效阻缓抑制碳酸钙垢的生成,具有良好的抗温缓蚀性能,并且该耐高温环保型低腐蚀阻垢剂对环境友好,易于降解。(The invention provides an environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal and a preparation method thereof, and the scale inhibitor comprises: 4-6% of maleic anhydride, 8-12% of acrylic acid, 4-6% of 2-acrylamido-2-methylpropanesulfonic acid, 2-4% of sodium hypophosphite, 0.2-0.3% of sodium dodecyl sulfate, 3-5% of ammonium persulfate and 20-25% of polyepoxysuccinic acid. The high temperature resistant environment-friendly low-corrosion scale inhibitor provided by the invention is suitable for inhibiting the generation of calcium carbonate scale in a high-temperature geothermal well, can effectively inhibit the generation of the calcium carbonate scale, has good temperature resistant corrosion inhibition performance, is environment-friendly and is easy to degrade.)

1. An environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal heat is characterized in that: the method comprises the following steps: 4-6% of maleic anhydride, 8-12% of acrylic acid, 4-6% of 2-acrylamido-2-methylpropanesulfonic acid, 2-4% of sodium hypophosphite, 0.2-0.3% of sodium dodecyl sulfate, 3-5% of ammonium persulfate, 20-25% of polyepoxysuccinic acid and water, wherein the percentages are percentages of raw materials by mass.

2. The environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal use according to claim 1, wherein: the weight percentage of the maleic anhydride is 4%, the weight percentage of the acrylic acid is 10%, the weight percentage of the 2-acrylamide-2-methylpropanesulfonic acid is 5%, the weight percentage of the sodium hypophosphite is 4%, the weight percentage of the sodium dodecyl sulfate is 0.2%, the weight percentage of the ammonium persulfate is 3% is 4%, and the weight percentage of the polyepoxysuccinic acid is 20%.

3. The environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal use according to claim 1, wherein: the mass percent of the maleic anhydride is 5%, the mass percent of the acrylic acid is 12%, the mass percent of the 2-acrylamido-2-methylpropanesulfonic acid is 6%, the mass percent of the sodium hypophosphite is 2%, the mass percent of the sodium dodecyl sulfate is 0.3%, the mass percent of the ammonium persulfate is 3%, and the mass percent of the polyepoxysuccinic acid is 23%.

4. The environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal use according to claim 1, wherein: the mass percent of the maleic anhydride is 6%, the mass percent of the acrylic acid is 8%, the mass percent of the 2-acrylamide-2-methylpropanesulfonic acid is 4%, the mass percent of the sodium hypophosphite is 3%, the mass percent of the sodium dodecyl sulfate is 0.4%, the mass percent of the ammonium persulfate is 5%, and the mass percent of the polyepoxysuccinic acid is 25%.

5. The preparation method of the environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal heating according to any one of claims 1 to 4, characterized by comprising the following steps: the method comprises the following steps:

s1, weighing a certain amount of Maleic Anhydride (MA) and Acrylic Acid (AA), putting into a three-neck flask, and heating to 50-50 ℃ in a water-bath constant-temperature magnetic stirrer;

s2, adding Sodium Dodecyl Sulfate (SDS) and sodium hypophosphite (NaH)₂PO₂) Heating the solution to 80-90 ℃, adding 2-acrylamide-2-methyl propanesulfonic Acid (AMPS) and initiator ammonium persulfate, wherein the initiator is dropwise added in 20-40min by using a constant pressure funnel, keeping the reaction at a constant temperature for 1-3h, and cooling to room temperature to obtain a light yellow transparent solution product;

s3, pouring the product obtained in the step S2 into absolute ethyl alcohol to precipitate a copolymer, filtering, and drying in a drying oven at 50-70 ℃ to obtain a purified product, so as to obtain the scale inhibitor suitable for the high-temperature geothermal well;

s4, mixing the scale inhibitor of the high-temperature geothermal well obtained in the step S3 with polyepoxysuccinic acid according to the mass ratio of 1: 1 to obtain the environment-friendly low-corrosion scale inhibitor suitable for high-temperature terrestrial heat.

Technical Field

The invention relates to the technical field of scale inhibitors, in particular to an environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal heating and a preparation method thereof.

Background

Geothermal energy is used as a novel clean green energy source, and the potential and development value of the development at present and in the future are paid more and more attention at home and abroad. However, the geothermal well contains a large amount of cations such as calcium ions and the like which react with anions such as carbonate ions, bicarbonate ions and the like in the solution to generate calcium carbonate scale deposits in the exploitation process, so that the aquifer and the water conveying well pipe are blocked. Meanwhile, the scale can accelerate the corrosion of the metal well pipe, and the corrosion product and the scale are accompanied simultaneously to accelerate the blockage of the water inlet channel. Therefore, the addition of the scale inhibitor has important significance.

However, many studies on scale inhibitors are based on industrial circulating cooling water systems, and the upper limit of the water temperature of the system is lower than 100 ℃. The bottom temperature of the geothermal well is similar to the temperature of the stratum and is higher than 100 ℃, for example, the bottom temperature of a certain well in the Tibetan sheep eight well is as high as 162 ℃. Generally, the scale inhibitor can greatly reduce the scale inhibition and inhibition effect on calcium carbonate scale at high temperature, and the corrosion to pipes is intensified at high temperature, so that the development of the scale inhibitor for the geothermal well has important significance in high-temperature conditions.

Disclosure of Invention

In order to solve the problems that the scale inhibition effect of the traditional scale inhibitor on calcium carbonate scale is poor and the corrosion of a pipe can be aggravated under a high-temperature environment, the invention provides an environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal use, which comprises 4-6% of maleic anhydride, 8-12% of acrylic acid, 4-6% of 2-acrylamido-2-methylpropanesulfonic acid, 2-4% of sodium hypophosphite, 0.2-0.3% of sodium dodecyl sulfate, 3-5% of ammonium persulfate, 20-25% of polyepoxysuccinic acid and water, wherein the percentages are percentages of raw material mass.

Further, the mass percent of the maleic anhydride is 4%, the mass percent of the acrylic acid is 10%, the mass percent of the 2-acrylamido-2-methylpropanesulfonic acid is 5%, the mass percent of the sodium hypophosphite is 4%, the mass percent of the sodium dodecyl sulfate is 0.2%, the mass percent of the ammonium persulfate is 4%, and the mass percent of the polyepoxysuccinic acid is 20%.

Further, the maleic anhydride accounts for 5% by mass, the acrylic acid accounts for 12% by mass, the 2-acrylamido-2-methylpropanesulfonic acid accounts for 6% by mass, the sodium hypophosphite accounts for 2% by mass, the sodium dodecyl sulfate accounts for 0.3% by mass, the ammonium persulfate accounts for 3% by mass, and the polyepoxysuccinic acid accounts for 23% by mass.

Further, the mass percent of the maleic anhydride is 6%, the mass percent of the acrylic acid is 8%, the mass percent of the 2-acrylamido-2-methylpropanesulfonic acid is 4%, the mass percent of the sodium hypophosphite is 3%, the mass percent of the sodium dodecyl sulfate is 0.4%, the mass percent of the ammonium persulfate is 5%, and the mass percent of the polyepoxysuccinic acid is 25%.

The invention also provides a method for preparing the scale inhibitor, which comprises the following steps:

s1, weighing a certain amount of Maleic Anhydride (MA) and Acrylic Acid (AA), putting into a three-neck flask, and heating to 50-50 ℃ in a water-bath constant-temperature magnetic stirrer;

s2, adding Sodium Dodecyl Sulfate (SDS) and sodium hypophosphite (NaH)₂PO₂) Heating the solution to 80-90 ℃, adding 2-acrylamide-2-methyl propanesulfonic Acid (AMPS) and initiator ammonium persulfate, wherein the initiator is dropwise added in 20-40min by using a constant pressure funnel, keeping the reaction at a constant temperature for 1-3h, and cooling to room temperature to obtain a light yellow transparent solution product;

s3, pouring the product obtained in the step S2 into absolute ethyl alcohol to precipitate a copolymer, filtering, and drying in a drying oven at 50-70 ℃ to obtain a purified product, so as to obtain the scale inhibitor suitable for the high-temperature geothermal well;

s4, mixing the scale inhibitor of the high-temperature geothermal well obtained in the step S3 with polyepoxysuccinic acid according to the mass ratio of 1: 1 to obtain the environment-friendly low-corrosion scale inhibitor suitable for high-temperature terrestrial heat.

The technical scheme provided by the invention has the beneficial effects that: (1) the environment-friendly low-corrosion scale inhibitor for high-temperature geothermal heat has obvious scale inhibition capacity, and can effectively reduce the generation of calcium carbonate scale; (2) the environment-friendly low-corrosion scale inhibitor for high-temperature geothermal heat provided by the invention can still maintain excellent scale inhibition capability at the temperature of 150 ℃; (3) the environment-friendly low-corrosion scale inhibitor for high-temperature geothermal energy provided by the invention is matched with polyepoxysuccinic acid, so that the corrosion to carbon steel type metal pipes can be obviously reduced, a corrosion inhibitor is not required to be added, and the cost is reduced; (4) the raw material monomer used by the environment-friendly low-corrosion scale inhibitor for high-temperature geothermal is easy to biodegrade and is environment-friendly.

Drawings

FIG. 1 is a reaction schematic diagram of the environment-friendly low-corrosion scale inhibitor for high-temperature geothermal heat.

FIG. 2 is a comparative graph of the scale inhibition performance evaluation on calcium carbonate scale of different examples of the environmentally-friendly low-corrosion scale inhibitor for high-temperature geothermal use according to the present invention and a comparative example.

FIG. 3 is a comparative graph showing the morphological influence of the environmentally-friendly low-corrosion scale inhibitor for high-temperature geothermal application on the formation of calcium carbonate scale.

FIG. 4 is a comparison of the corrosion resistance of the high temperature resistant environment-friendly low corrosion scale inhibitor of examples 1-3 and deionized water to a metal coupon.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be further described with reference to the accompanying drawings.

The embodiment of the invention provides an environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal heat, which comprises the following formula components: 4-6% of maleic anhydride, 8-12% of acrylic acid, 4-6% of 2-acrylamido-2-methylpropanesulfonic acid, 2-4% of sodium hypophosphite, 0.2-0.3% of sodium dodecyl sulfate, 3-5% of ammonium persulfate, 20-25% of polyepoxysuccinic acid and the balance of water; the percentage of each raw material is mass percentage.

The preparation method of the environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal heat comprises the following steps:

s1, weighing a certain amount of Maleic Anhydride (MA) and Acrylic Acid (AA), putting the maleic anhydride and the acrylic acid into a three-neck flask, and putting the three-neck flask into a water bath constant-temperature magnetic stirrer to heat to 55 ℃.

S2, adding Sodium Dodecyl Sulfate (SDS) and sodium hypophosphite (NaH)₂PO₂) Heating the solution to 85 ℃, and adding 2-acrylamide-2-methylpropanesulfonic Acid (AMPS) and initiator ammonium persulfate. Wherein the initiator is dripped in 30min by using a constant pressure funnel. Keeping the reaction constant temperature for reaction for 2h, and then cooling to room temperature to obtain a light yellow transparent solution product.

And S3, pouring the product into absolute ethyl alcohol to precipitate the copolymer, filtering and drying in a drying box at 60 ℃ to obtain a purified product, thus obtaining the scale inhibitor suitable for the high-temperature geothermal well.

S4, mixing the obtained scale inhibitor of the high-temperature geothermal well with polyepoxysuccinic acid according to the proportion of 1: 1 to obtain the environment-friendly low-corrosion scale inhibitor suitable for high-temperature terrestrial heat.

Referring to fig. 1, the action mechanism of the environment-friendly low-corrosion scale inhibitor for high-temperature geothermal heat of the present invention is as follows: the reaction of the invention is mainly through aqueous solution free radical polymerization, a sulfonic acid group is introduced through maleic anhydride and acrylic acid introduced polycarboxylic acid groups, 2-acrylamide-2-methylpropanesulfonic acid is introduced through 2-acrylamide-2-methylpropanesulfonic acid at different temperatures, and a phosphonic acid group, a carboxylic acid group, a sulfonic acid group and a phosphonic acid group are introduced through sodium hypophosphite, so that the crystal lattice distortion effect can be effectively generated when calcium carbonate is crystallized, calcium carbonate can be effectively dispersed and is difficult to aggregate and crystallize, and meanwhile, the temperature resistance of the scale inhibitor can be improved, so that the generation of calcium carbonate scale can be effectively inhibited at high temperature. The polyepoxysuccinic acid is combined with cation in the solution through chelation, so that the generation of calcium scale is further inhibited. Meanwhile, a compact film is generated on the surface of the pipe, so that the corrosion medium in the solution can be effectively prevented from diffusing to the surface of the metal, and the corrosion of the pipe is prevented. The anionic surfactant introduced in the synthesis process can effectively change the appearance of calcium carbonate scale, and the scale inhibitor is synergistically enhanced to further inhibit the generation of calcium carbonate scale.

The formulation ratio and the implementation effect of the environment-friendly low-corrosion scale inhibitor suitable for high-temperature geothermal use provided by the invention are further described below with reference to specific examples and comparative examples.

In the following examples, maleic anhydride, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, and sodium hypophosphite were obtained from Shanghai Michelle chemical technology, Inc., sodium lauryl sulfate and ammonium persulfate were obtained from the national pharmaceutical group Chemicals, aminotrimethylene phosphonic acid, diethylenetriamine pentamethylene phosphonic acid, polymaleic anhydride, and polyepoxysuccinic acid were obtained from Shandong Yousol chemical technology, Inc.

Example 1:

4 percent of Maleic Anhydride (MA) and 10 percent of Acrylic Acid (AA) are weighed and put into a three-neck flask, and the three-neck flask is placed into a water bath constant temperature magnetic stirrer to be heated to 55 ℃. Then 0.2% Sodium Dodecyl Sulfate (SDS) and 4% sodium hypophosphite (NaH) were added₂PO₂) Then the solution is heated to 85 ℃, 5 percent of 2-acrylamide-2-methyl propane sulfonic Acid (AMPS) and 4 percent of ammonium persulfate solution of initiator are added. Wherein the initiator is dripped in 30min by using a constant pressure funnel. Keeping the reaction at constant temperature for reacting for 2h, cooling to room temperature to obtain a light yellow transparent solution product with the solid phase content of 23%, and reacting according to the following ratio of 1: 1, adding 23 percent of polyepoxysuccinic acid to obtain the environment-friendly low-corrosion scale inhibitor for high-temperature geothermal heating.

Example 2:

5 percent of Maleic Anhydride (MA) and 12 percent of Acrylic Acid (AA) are weighed and put into a three-neck flask, and the three-neck flask is placed into a water bath constant temperature magnetic stirrer to be heated to 55 ℃. Then 0.3% Sodium Dodecyl Sulfate (SDS) and 2% sodium hypophosphite (NaH) were added₂PO₂) Then the solution is heated to 85 ℃, and 6 percent of 2-acrylamide-2-methyl propane sulfonic Acid (AMPS) and 3 percent of ammonium persulfate solution of an initiator are added. Wherein the initiator is dripped in 30min by using a constant pressure funnel. Keeping the reaction at constant temperature for reacting for 2h, cooling to room temperature to obtain a light yellow transparent solution product with the solid phase content of 25%, and reacting according to the following ratio of 1: 1, adding 25 percent of polyepoxysuccinic acid to obtain the environment-friendly low-corrosion scale inhibitor for high-temperature geothermal heating.

Example 3:

6 percent of Maleic Anhydride (MA) and 8 percent of Acrylic Acid (AA) are weighed and put into a three-neck flaskAnd the mixture is placed in a water bath constant temperature magnetic stirrer to be heated to 55 ℃. Then 0.4% Sodium Dodecyl Sulfate (SDS) and 3% sodium hypophosphite (NaH) were added₂PO₂) Then the solution is heated to 85 ℃, 4 percent of 2-acrylamide-2-methyl propane sulfonic Acid (AMPS) and 5 percent of ammonium persulfate solution of initiator are added. Wherein the initiator is dripped in 30min by using a constant pressure funnel. Keeping the reaction at constant temperature for reacting for 2h, cooling to room temperature to obtain a light yellow transparent solution product with the solid phase content of 21%, and reacting according to the following ratio of 1: 1, adding 21 percent of polyepoxysuccinic acid to obtain the environment-friendly low-corrosion scale inhibitor for high-temperature geothermal heating.

Comparative example 1:

commercially available scale inhibitor aminotrimethylene phosphonic acid (ATMPA) (concentration 50%).

Comparative example 2:

the commercial scale inhibitor diethylenetriamine pentamethylene phosphonic acid (DTPMPA) (concentration 50%).

Comparative example 3:

the scale inhibitor, polymaleic anhydride (50% strength), is commercially available.

Comparative example 4:

the scale inhibitor polyepoxysuccinic acid is commercially available (concentration 40%).

(1) The scale inhibition performance of the environment-friendly low-corrosion scale inhibitor for high-temperature geothermal heat prepared in the examples 1 to 3 on calcium carbonate scale at high temperature is analyzed and evaluated:

experimental configuration simulation geothermal water with calcium ion concentration of 240mg/L and bicarbonate ion concentration of 732 mg/L. Adding 480mg/L of copolymer scale inhibitor into simulated geothermal water, reacting for 10 hours at the simulated geothermal temperature of 150 ℃, cooling to room temperature, and testing the content of calcium ions in the solution by using an EDTA method. The scale inhibition efficiency η was calculated according to the following formula, and the result is shown in fig. 2.

In the formula: rho₁: calcium ion concentration (mg/mL) after experiment of blank solution without adding scale inhibitor;

ρ₂: addingAfter the scale inhibitor is added, the calcium ion concentration (mg/mL) of the solution is tested;

0.240: the configuration before the experiment simulates the concentration (mg/mL) of calcium ions in geothermal water.

As can be seen from fig. 2, the environment-friendly low-corrosion scale inhibitor of the present embodiment can more effectively inhibit the generation of calcium carbonate scale at high temperature, and effectively avoid the disadvantage that the scale inhibition capability of the conventional scale inhibitor on calcium carbonate scale is obviously reduced at high temperature.

The morphology of the calcium carbonate scale formed in each case was observed by electron microscopy (SEM) (example 1 was used as an example). After the environment-friendly low-corrosion scale inhibitor is added, the formed structure of the calcium carbonate scale is changed from compact to loose; with the increase of the concentration of the added scale inhibitor, the loosening degree of the calcium carbonate scale is more obvious (as shown in figure 3), which shows that the generated environment-friendly low-corrosion scale inhibitor for high-temperature geothermal can effectively inhibit the generation of the calcium carbonate scale.

(2) The corrosion of the environment-friendly low-corrosion scale inhibitor prepared in the examples 1 to 3 on the drill rod under a high temperature condition is evaluated:

the experimental steps are carried out according to the oil and gas industry standard (SY/T5405-1996) of the people's republic of China, and the specific process is as follows:

taking out a carbon steel type standard corrosion test piece, measuring the size of the test piece by using a vernier caliper, putting the test piece into the simulated geothermal water containing the scale inhibitor in the embodiment 1-3, numbering the test piece, and recording the initial quality; and pouring the prepared simulated geothermal water containing the scale inhibitor into an aging kettle in sequence, and rolling for 24 hours at 150 ℃.

Recording the reaction starting time, taking out the test piece when the reaction reaches the preset time for 24h, immediately washing the test piece by absolute ethyl alcohol, scrubbing the test piece by a soft brush, wiping the surface of the test piece by filter paper, and photographing and comparing the test piece with the initial test piece after recording the quality; the corrosion rate v was calculated using the following formula_iThe results are shown in Table 3.

Corrosion rate v_iThe calculation formula of (2) is as follows:

in the formula: v. of_iMonolithic corrosion rate, g/(m)²H); t is reaction time h; m is₁Mass of the test piece before corrosion, g; m is₂G, the quality of the test piece after corrosion; a is the surface area of the test piece in mm². The surface area of the standard corrosion test piece of the experiment is 2800mm²。

TABLE 1 Corrosion Rate of standard test pieces of carbon steel type in simulated geothermal water containing scale inhibitor

As can be seen from Table 1, the simulated geothermal water containing the scale inhibitor in examples 1-3 has a lower corrosion rate on the carbon steel type corrosion test piece, which is significantly lower than the corrosion rate of the metal corrosion test piece in deionized water. FIG. 4 is a comparison between the corrosion of the high temperature resistant environment-friendly low corrosion scale inhibitor of examples 1-3 and deionized water on a metal test piece, and it can be seen from FIG. 4 that the surface of the carbon steel type standard corrosion test piece corroded by the simulated geothermal water working fluid containing the scale inhibitor of examples 1-3 is relatively complete, which shows that the simulated geothermal water containing the scale inhibitor of examples 1-3 has less damage to a pipe at the bottom of a well and has obvious corrosion inhibition effect without adding a corrosion inhibitor.

The features of the embodiments and embodiments described herein above may be combined with each other without conflict.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.