Desulfurizing agent for acidification of sulfur-containing reservoir and preparation method thereof

Abstract

The invention discloses a desulfurizing agent for acidizing a sulfur-containing reservoir, which is prepared from the following components in percentage by volume: 20 to 30 percent of compound complex iron reagent, 15 to 20 percent of amine reagent, 5 to 15 percent of activating agent and 35 to 60 percent of solvent water, and the sum of the volume contents of the components is 100 percent. The desulfurizing agent for acidification of the sulfur-containing reservoir solves the problems that in the prior art, the compatibility of a desulfurizing agent and other reagents in the acidification process is poor, and the acting effect is affected. The invention further discloses a preparation method of the desulfurizing agent for acidification of the sulfur-containing reservoir.

Description

Technical Field

[0001] This invention belongs to the technical field of desulfurizing agents for petrochemicals, and relates to desulfurizing agents for acidizing sulfur-containing reservoirs. This invention also relates to the preparation method of the above-mentioned desulfurizing agents. Background Technology

[0002] Hydrogen sulfide (H2S) not only endangers human life but also causes serious environmental pollution and severe corrosion damage to metal equipment. H2S is generated in many stages of oilfield development, production, and transportation, including drilling, well completion, acid fracturing, and gathering and transportation.

[0003] Water injection wells and source wells contain a certain amount of sulfate-reducing bacteria, leading to the formation of ferrous sulfide scale deposits in surface pipelines and underground. Acidification is a common method for pipeline descaling, but the process generates a large amount of H2S. The H2S generated during acid washing of surface water injection pipelines or reverse desulfurization processes in acidized wells not only causes pipeline corrosion and reduces descaling efficiency but also poses risks to human health and environmental damage. Therefore, descaling agents, corrosion inhibitors, and desulfurizing agents must be applied during acidification to achieve descaling, prevent pipeline corrosion, and remove H2S generated during the acidification process. However, the compatibility of desulfurizing agents with other reagents in the acidification process directly affects the effectiveness of these functional reagents. Therefore, developing desulfurizing agents for acidification that do not affect the effectiveness of descaling agents, corrosion inhibitors, and other functional reagents is crucial.

[0004] Chinese patent document CN1166003337A discloses a method for preparing a triazine desulfurizing agent for crude oil; Chinese patent document CN117567357A discloses a liquid high-temperature resistant iron ion stabilizer for acidification and its preparation method; Chinese patent document CN116875289A discloses a method for preparing and applying an acidification corrosion inhibitor for oil fields; Chinese patent document CN116640262B discloses a thickener for acidification and its synthesis method. However, the existing desulfurizing agent-related technologies disclosed in Chinese patent documents are mostly for the preparation of desulfurizing agents, without considering the compatibility of desulfurizing agents with other reagents in the acidification process. Summary of the Invention

[0005] The purpose of this invention is to provide a desulfurizing agent for acidizing sulfur-containing reservoirs, which solves the problem in the prior art of poor compatibility between the desulfurizing agent and other reagents in the acidizing process, thus affecting the effectiveness of the action.

[0006] Another object of the present invention is to provide a method for preparing a desulfurizing agent for acidizing sulfur-containing reservoirs.

[0007] The technical solution adopted in this invention is a desulfurizing agent for acidizing sulfur-containing reservoirs, which is composed of the following components by volume percentage: 20-30% compounded iron complex reagent, 15-20% amine reagent, 5-15% activator, and 35-60% solvent water, with the total volume content of the above components being 100%.

[0008] The compound ferric chelate reagent is obtained by dissolving ferric salt, ferrous salt, sorbitol, hexadecyltrimethylammonium chloride, sulfosalicylic acid, ethylenediaminetetraacetic acid, and ethanolamine in purified water.

[0009] In the compound iron complex reagent, pure water is used as the solvent, and the mass fraction of ferric salt is 0.5-1.5%, the mass fraction of ferrous salt is 6-15%, the mass fraction of sorbitol is 0.8-2.5%, the mass fraction of hexadecyltrimethylammonium chloride is 0.1-1%, the mass fraction of sulfosalicylic acid is 3-12%, the mass fraction of ethylenediaminetetraacetic acid is 1-5%, and the mass fraction of ethanolamine is 1-10%.

[0010] The amine reagent is any one of triethanolamine, triethylamine hydrochloride, dodecylamine, tetradecylamine, hexadecylamine, polyacrylamine, diethylene glycolamine, and dihydroxyethylmethylamine.

[0011] The activator is any one of monoazine compounds, diazine compounds, or triazine compounds.

[0012] The second technical solution adopted in this invention is a method for preparing a desulfurizing agent for acidizing sulfur-containing reservoirs, which is implemented according to the following steps: Step 1: Prepare the compound iron complex reagent; Step 2: Measure the following components in order of volume percentage: 20-30% compound iron complex reagent, 15-20% amine reagent, 5-15% activator, and 35-60% solvent water. The total volume content of the above components should be 100%. Then add the compound iron complex reagent, amine reagent, and activator to the solvent water and stir at 25-80℃ for 10-120 min to obtain the desulfurizing agent for acidizing sulfur-containing reservoirs.

[0013] Step 1 is as follows: Step 1.1: Add ferric salts and ferrous salts to pure water and stir at 30-60℃ until the solids are completely dissolved to obtain system A; Step 1.2: Sorbitol, hexadecyltrimethylammonium chloride, and sulfosalicylic acid are added sequentially to system A, and the mixture is stirred at room temperature until completely dissolved to obtain system B; Step 1.3: Add ethylenediaminetetraacetic acid to system B and stir at 70-100℃ until completely dissolved to obtain system C; Step 1.4: Add ethanolamine dropwise to system C and stir at 40-80℃ to obtain a brownish-black complexed iron reagent. The stirring time in step 1.4 is 0.5-3 hours.

[0014] In the compound iron complex reagent, pure water is used as the solvent, and the mass fraction of ferric salt is 0.5-1.5%, the mass fraction of ferrous salt is 6-15%, the mass fraction of sorbitol is 0.8-2.5%, the mass fraction of hexadecyltrimethylammonium chloride is 0.1-1%, the mass fraction of sulfosalicylic acid is 3-12%, the mass fraction of ethylenediaminetetraacetic acid is 1-5%, and the mass fraction of ethanolamine is 1-10%.

[0015] Ferrous salts are ferric chloride, and ferrous salts are ferrous sulfide heptahydrate.

[0016] The beneficial effects of this invention are: The desulfurizing agent of this invention has good compatibility with current acid systems and will not cause secondary pollution. After using the desulfurizing agent of this invention, the commonly used acid washing hydrochloric acid, hydrochloric acid and fluoroboric acid, and hydrochloric acid and polyhydrogen acid systems in oil fields have no significant effect on the corrosion rate of N80 test pieces and no significant effect on the dissolution rate of scale samples.

[0017] The desulfurizing agent of this invention has a short preparation cycle, mild process conditions, low equipment requirements, and simple operation, making it suitable for large-scale production. The desulfurization rate of the prepared desulfurizing agent can reach over 90%, providing technical support for safe and efficient construction of acid washing of high sulfur scale on ground pipelines and acid fracturing to remove hydrogen sulfide gas from high sulfur reservoirs. Detailed Implementation

[0018] The present invention will now be described in detail with reference to specific embodiments.

[0019] Example 1 The technical solution adopted in this invention is a desulfurizing agent for acidizing sulfur-containing reservoirs, which is composed of the following components by volume percentage: 20-30% compounded iron complex reagent, 15-20% amine reagent, 5-15% activator, and 35-60% solvent water, with the total volume content of the above components being 100%.

[0020] The compound ferric chelate reagent is obtained by dissolving ferric salt, ferrous salt, sorbitol, hexadecyltrimethylammonium chloride, sulfosalicylic acid (SSA), ethylenediaminetetraacetic acid (EDTA), and ethanolamine in purified water.

[0021] In the compound iron complex reagent, pure water is used as the solvent, and the mass fraction of ferric salt is 0.5-1.5%, the mass fraction of ferrous salt is 6-15%, the mass fraction of sorbitol is 0.8-2.5%, the mass fraction of hexadecyltrimethylammonium chloride is 0.1-1%, the mass fraction of sulfosalicylic acid is 3-12%, the mass fraction of ethylenediaminetetraacetic acid is 1-5%, and the mass fraction of ethanolamine is 1-10%.

[0022] The amine reagent is any one of triethanolamine, triethylamine hydrochloride, dodecylamine, tetradecylamine, hexadecylamine, polyacrylamine, diethylene glycolamine, and dihydroxyethylmethylamine.

[0023] The activator is any one of monoazine compounds, diazine compounds, or triazine compounds.

[0024] Example 2 The preparation method of the desulfurizing agent for acidizing sulfur-containing reservoirs of the present invention is carried out according to the following steps: Step 1, preparing the compound iron complex reagent, specifically: Step 1.1: Add ferric salts and ferrous salts to pure water and stir at 30-60℃ until the solids are completely dissolved to obtain system A; Step 1.2: Sorbitol, hexadecyltrimethylammonium chloride, and sulfosalicylic acid are added sequentially to system A, and the mixture is stirred at room temperature until completely dissolved to obtain system B; Step 1.3: Add ethylenediaminetetraacetic acid to system B and stir at 70-100℃ until completely dissolved to obtain system C; Step 1.4: Add ethanolamine dropwise to system C and stir at 40-80℃ to obtain a brownish-black complexed iron reagent. The stirring time in step 1.4 is 0.5-3 hours. In the preparation of the iron complex reagent, pure water is used as the solvent, and the mass fraction of ferric salt is 0.5-1.5%, the mass fraction of ferrous salt is 6-15%, the mass fraction of sorbitol is 0.8-2.5%, the mass fraction of hexadecyltrimethylammonium chloride is 0.1-1%, the mass fraction of sulfosalicylic acid is 3-12%, the mass fraction of ethylenediaminetetraacetic acid is 1-5%, and the mass fraction of ethanolamine is 1-10%. Step 2: Measure the following components in order of volume percentage: 20-30% compound iron complex reagent, 15-20% amine reagent, 5-15% activator, and 35-60% solvent water. The total volume content of the above components should be 100%. Then add the compound iron complex reagent, amine reagent, and activator to the solvent water and stir at 25-80℃ for 10-120 min to obtain the desulfurizing agent for acidizing sulfur-containing reservoirs.

[0025] Example 3 Based on Example 2, the preparation method of the desulfurizing agent for acidizing sulfur-containing reservoirs is carried out according to the following steps: Step 1: Add ferric chloride and ferrous sulfide heptahydrate to 100 g of purified water and stir at 45°C for 10 min until the solids are completely dissolved to obtain system A. Add sorbitol, hexadecyltrimethylammonium chloride, and SSA sequentially to system A and stir at room temperature until completely dissolved to obtain system B. Add 2.3% EDTA to system B and stir at 90°C until completely dissolved to obtain system C. Add ethanolamine dropwise to system C and stir at 60°C for 2 h to obtain a brownish-black complex iron reagent. The composition of the complex is as follows: ferric chloride 1.01%, ferrous sulfide heptahydrate 9.22%, sorbitol 1.25%, hexadecyltrimethylammonium chloride 0.34%, sulfosalicylic acid 6.8%, ethylenediaminetetraacetic acid 2.3%, and ethanolamine 5.21%. Step 2: Measure each raw material by volume percentage, and add 24wt% of compound complex iron reagent, 16wt% of amine reagent and 7wt% of activator to solvent water in sequence. After stirring at 25℃ for 20 min, a desulfurizing agent for acidizing sulfur-containing reservoirs is obtained. The evaluation method and result comparison of the effect of the desulfurizing agent prepared in this embodiment on the scale dissolution rate of acid solution are as follows: 25wt% (10 mL) of descaling agent and 3wt% (30 mL) of desulfurizing agent were added to 0.5 g of scale sample. The scale dissolution rate of the acid solution and the desulfurization efficiency of the desulfurizing agent were tested at 25℃. The influence of the desulfurizing agent on the scale dissolution effect of the acid solution was analyzed and compared, and the desulfurization effect was evaluated. The experimental results are shown in Table 1. The results show that the addition of the desulfurizing agent provided in this embodiment does not affect the scale dissolution rate of the acid solution system. At the same time, the acid solution does not affect the desulfurization efficiency of the desulfurizing agent, and the acid solution and desulfurizing agent have good compatibility.

[0026] Table 1

[0027] The evaluation method and result comparison of the influence of the desulfurizing agent prepared in this embodiment on the corrosion inhibition effect of the corrosion inhibitor are as follows: 25 wt% (10 mL) of descaling agent, 2 wt% (0.2 mL) of corrosion inhibitor, and 3 wt% (30 mL) of desulfurizing agent were added to 0.5 g of scale sample. The corrosion rate of the N80 sample in 10% hydrochloric acid and the desulfurization efficiency of the desulfurizing agent were tested at 70℃. The influence of the desulfurizing agent on the corrosion inhibition effect of the corrosion inhibitor was analyzed and compared, and the desulfurization effect was evaluated. The experimental results are shown in Table 2. The results show that the addition of the desulfurizing agent of this invention has no significant effect on the ketone-aldehyde-amine condensate corrosion inhibitor and the Mannich base corrosion inhibitor, and these two corrosion inhibitors also have no significant effect on the desulfurization efficiency of the desulfurizing agent. The desulfurizing agent has good compatibility with these two commonly used corrosion inhibitors.

[0028] Table 2

[0029] Example 4 The preparation method of the desulfurizing agent for acidizing sulfur-containing reservoirs is carried out according to the following steps: Step 1: Add ferric chloride and ferrous sulfide heptahydrate to 100 g of purified water and stir at 45°C for 10 min until the solids are completely dissolved to obtain system A. Add sorbitol, hexadecyltrimethylammonium chloride, and SSA sequentially to system A and stir at room temperature until completely dissolved to obtain system B. Add 2.3% EDTA to system B and stir at 90°C until completely dissolved to obtain system C. Add ethanolamine dropwise to system C and stir at 60°C for 2 h to obtain a brownish-black complex iron reagent. The composition of the complex is as follows: ferric chloride 1.01%, ferrous sulfide heptahydrate 9.22%, sorbitol 1.25%, hexadecyltrimethylammonium chloride 0.34%, sulfosalicylic acid 6.8%, ethylenediaminetetraacetic acid 2.3%, and ethanolamine 5.21%. Step 2: Measure each raw material by volume percentage, and add 20wt% of compound complex iron reagent, 16wt% of amine reagent and 7wt% of activator to the solvent water in sequence. After stirring at 45℃ for 120 min, a desulfurizing agent for acidizing sulfur-containing reservoirs is obtained.

[0030] The evaluation method and result comparison of the influence of the desulfurizing agent prepared in this embodiment on the scale dissolution rate of the descaling agent are as follows: 25 wt% (10 mL) of descaling agent and 3 wt% (30 mL) of desulfurizing agent were added to 0.5 g of scale sample. The scale dissolution rate of the descaling agent and the desulfurization efficiency of the desulfurizing agent were tested at 25℃. The influence of the desulfurizing agent on the scale dissolution effect of the descaling agent was analyzed and compared, and the desulfurization effect was evaluated. The experimental results are shown in Table 3. The results show that adding the desulfurizing agent provided in this embodiment does not affect the scale dissolution rate of the acid system. At the same time, the acid does not affect the desulfurization efficiency of the desulfurizing agent. The acid and desulfurizing agent have good compatibility.

[0031] Table 3

[0032] The evaluation method and result comparison of the influence of the desulfurizing agent prepared in this embodiment on the corrosion inhibition effect of the corrosion inhibitor are as follows: 25 wt%, 10 mL of descaling agent, 2 wt%, 0.2 mL of corrosion inhibitor, 3 wt%, and 30 mL of desulfurizing agent were added to 0.5 g of scale sample. The corrosion rate of N80 test piece by 10% hydrochloric acid and the desulfurization efficiency of the desulfurizing agent were tested at 70℃. The influence of the desulfurizing agent on the corrosion inhibition effect of the corrosion inhibitor was analyzed and compared, and the desulfurization effect was evaluated. The experimental results are shown in Table 4. The results show that the addition of the desulfurizing agent of the present invention has no significant effect on the ketone-aldehyde-amine condensate corrosion inhibitor and the Mannich base corrosion inhibitor, and these two corrosion inhibitors also have no significant effect on the desulfurization efficiency of the desulfurizing agent. The desulfurizing agent has good compatibility with these two commonly used corrosion inhibitors.

[0033] Table 4

[0034] Example 5 The preparation method of the desulfurizing agent for acidizing sulfur-containing reservoirs is carried out according to the following steps: Step 1: Add ferric chloride and ferrous sulfide heptahydrate to 100 g of purified water and stir at 45°C for 10 min until the solids are completely dissolved to obtain system A. Add sorbitol, hexadecyltrimethylammonium chloride, and SSA sequentially to system A and stir at room temperature until completely dissolved to obtain system B. Add 2.3% EDTA to system B and stir at 90°C until completely dissolved to obtain system C. Add ethanolamine dropwise to system C and stir at 60°C for 2 h to obtain a brownish-black complex iron reagent. The composition of the complex is as follows: ferric chloride 1.01%, ferrous sulfide heptahydrate 9.22%, sorbitol 1.25%, hexadecyltrimethylammonium chloride 0.34%, sulfosalicylic acid 6.8%, ethylenediaminetetraacetic acid 2.3%, and ethanolamine 5.21%. Step 2: Measure each raw material by volume percentage, and add 30wt% of the compounded complex iron reagent, 20wt% of the amine reagent, and 7wt% of the activator to the solvent water in sequence. After stirring at 65℃ for 20 min, a desulfurizing agent for acidizing sulfur-containing reservoirs is obtained. The evaluation method and result comparison of the influence of the desulfurizing agent prepared in this embodiment on the scale dissolution rate of the descaling agent are as follows: 25 wt% (10 mL) of descaling agent and 3 wt% (30 mL) of desulfurizing agent were added to 0.5 g of scale sample. The scale dissolution rate of the descaling agent and the desulfurization efficiency of the desulfurizing agent were tested at 25℃. The influence of the desulfurizing agent on the scale dissolution effect of the descaling agent was analyzed and compared, and the desulfurization effect was evaluated. The experimental results are shown in Table 5. The results show that adding the desulfurizing agent provided in this embodiment does not affect the scale dissolution rate of the acid system. At the same time, the acid does not affect the desulfurization efficiency of the desulfurizing agent. The acid and desulfurizing agent have good compatibility.

[0035] Table 5

[0036] The evaluation method and result comparison of the influence of the desulfurizing agent prepared in this embodiment on the corrosion inhibition effect of the corrosion inhibitor are as follows: 25 wt%, 10 mL of descaling agent, 2 wt%, 0.2 mL of corrosion inhibitor, 3 wt%, and 30 mL of desulfurizing agent were added to 0.5 g of scale sample. The corrosion rate of N80 test piece by 10% hydrochloric acid and the desulfurization efficiency of the desulfurizing agent were tested at 70℃. The influence of the desulfurizing agent on the corrosion inhibition effect of the corrosion inhibitor was analyzed and compared, and the desulfurization effect was evaluated. The experimental results are shown in Table 6. The results show that the addition of the desulfurizing agent of the present invention has no significant effect on the ketone-aldehyde-amine condensate corrosion inhibitor and the Mannich base corrosion inhibitor, and these two corrosion inhibitors also have no significant effect on the desulfurization efficiency of the desulfurizing agent. The desulfurizing agent has good compatibility with these two commonly used corrosion inhibitors.

[0037] Table 6

[0038] Example 6 The preparation method of the desulfurizing agent for acidizing sulfur-containing reservoirs is carried out according to the following steps: Step 1: Add ferric chloride and ferrous sulfide heptahydrate to 100 g of purified water and stir at 45°C for 10 min until the solids are completely dissolved to obtain system A. Add sorbitol, hexadecyltrimethylammonium chloride, and SSA sequentially to system A and stir at room temperature until completely dissolved to obtain system B. Add 2.3% EDTA to system B and stir at 90°C until completely dissolved to obtain system C. Add ethanolamine dropwise to system C and stir at 60°C for 2 h to obtain a brownish-black complex iron reagent. The composition of the complex is as follows: ferric chloride 1.01%, ferrous sulfide heptahydrate 9.22%, sorbitol 1.25%, hexadecyltrimethylammonium chloride 0.34%, sulfosalicylic acid 6.8%, ethylenediaminetetraacetic acid 2.3%, and ethanolamine 5.21%. Step 2: Measure each raw material by volume percentage, and add 24 wt% of the compounded complex iron reagent, 20 wt% of the amine reagent, and 7 wt% of the activator to the solvent water in sequence. After stirring at 80°C for 20 min, a desulfurizing agent for acidizing sulfur-containing reservoirs is obtained. The evaluation method and result comparison of the influence of the desulfurizing agent prepared in this embodiment on the scale dissolution rate of the descaling agent are as follows: 25 wt% (10 mL) of descaling agent and 3 wt% (30 mL) of desulfurizing agent were added to 0.5 g of scale sample. The scale dissolution rate of the descaling agent and the desulfurization efficiency of the desulfurizing agent were tested at 25℃. The influence of the desulfurizing agent on the scale dissolution effect of the descaling agent was analyzed and compared, and the desulfurization effect was evaluated. The experimental results are shown in Table 7. The results show that adding the desulfurizing agent provided in this embodiment does not affect the scale dissolution rate of the acid system. At the same time, the acid does not affect the desulfurization efficiency of the desulfurizing agent. The acid and desulfurizing agent have good compatibility.

[0039] Table 7

[0040] The evaluation method and result comparison of the influence of the desulfurizing agent prepared in this embodiment on the corrosion inhibition effect of the corrosion inhibitor are as follows: 25wt%, 10 mL of descaling agent, 2wt%, 0.2 mL of corrosion inhibitor, 3wt%, and 30 mL of desulfurizing agent were added to 0.5 g of scale sample. The corrosion rate of N80 test piece by 10% hydrochloric acid and the desulfurization efficiency of the desulfurizing agent were tested at 70℃. The influence of the desulfurizing agent on the corrosion inhibition effect of the corrosion inhibitor was analyzed and compared, and the desulfurization effect was evaluated. The experimental results are shown in Table 8. The results show that the addition of the desulfurizing agent of the present invention has no significant effect on the ketone-aldehyde-amine condensate corrosion inhibitor and the Mannich base corrosion inhibitor, and these two corrosion inhibitors also have no significant effect on the desulfurization efficiency of the desulfurizing agent. The desulfurizing agent has good compatibility with these two commonly used corrosion inhibitors.

[0041] Table 8

[0042] Comparative Example 1 To compare the desulfurization effect of the embodiments of the present invention and the effect on the corrosion inhibition effect of the corrosion inhibitor, a commercially available triazine desulfurizer was used as the desulfurizer of Comparative Example 1.

[0043] The evaluation method and results of the effect of triazine desulfurizer on the scale dissolution rate of descaling agent in this comparative example are as follows: 25 wt%, 10 mL of descaling agent, and 3 wt%, 30 mL of triazine desulfurizing agent were added to 0.5 g of scale sample. The scale dissolution rate of the descaling agent and the desulfurization efficiency of the desulfurizing agent were tested at 25℃. The influence of the desulfurizing agent on the scale dissolution effect of the descaling agent was analyzed and compared, and the desulfurization effect was evaluated. The experimental results are shown in Table 9. The results show that, under the same component ratio and evaluation conditions, if the desulfurizing agent is replaced with commercially available triazine desulfurizing agent, the scale dissolution rate is lower than that without desulfurizing agent. The desulfurization efficiency is significantly affected by the acid solution. In the 6% hydrochloric acid + 2.5% fluoroboric acid system, the desulfurization efficiency is only 48.94%, which does not meet the requirements for the use of desulfurizing agent in the production site. It can be seen that the compatibility between the desulfurizing agent and the acid solution is poor.

[0044] Table 9

[0045] The evaluation method and results of the comparative example of the effect of triazine desulfurizer on the corrosion inhibition effect of corrosion inhibitor are as follows: 25wt%, 10 mL of descaling agent, 2wt%, 0.2 mL of corrosion inhibitor, 3wt%, and 30 mL of triazine desulfurizer were added to 0.5 g of scale sample. The corrosion rate of N80 specimens by 10% hydrochloric acid and the desulfurization efficiency of the desulfurizer were tested at 70℃. The influence of the desulfurizer on the corrosion inhibition effect of the corrosion inhibitor was analyzed and compared, and the desulfurization effect was evaluated. The experimental results are shown in Table 10. The results show that the addition of triazine desulfurizer has a significant effect on ketone-aldehyde-amine condensate corrosion inhibitors and Mannich base corrosion inhibitors, with a significant increase in corrosion rate. This indicates that the addition of desulfurizer accelerates metal corrosion, and the corrosion inhibitor cannot play its role. The desulfurization efficiency of triazine desulfurizer is also reduced in the presence of corrosion inhibitor, indicating that the presence of corrosion inhibitor affects the desulfurization efficiency of desulfurizer. Therefore, triazine desulfurizer has poor compatibility with these two commonly used corrosion inhibitors.

[0046] Table 10

Claims

1. A desulfurizing agent for acidizing sulfur-containing reservoirs, characterized in that, The composition by volume percentage is as follows: 20-30% compound iron complex reagent, 15-20% amine reagent, 5-15% activator, and 35-60% water solvent, with the total volume content of the above components being 100%.

2. The desulfurizing agent for acidizing sulfur-containing reservoirs according to claim 1, characterized in that, The compound ferric chelate reagent is obtained by dissolving ferric salt, ferrous salt, sorbitol, hexadecyltrimethylammonium chloride, sulfosalicylic acid, ethylenediaminetetraacetic acid, and ethanolamine in purified water.

3. The desulfurizing agent for acidizing sulfur-containing reservoirs according to claim 2, characterized in that, In the compound iron complex reagent, purified water is used as the solvent, and the mass fraction of ferric salt is 0.5-1.5%, the mass fraction of ferrous salt is 6-15%, the mass fraction of sorbitol is 0.8-2.5%, the mass fraction of hexadecyltrimethylammonium chloride is 0.1-1%, the mass fraction of sulfosalicylic acid is 3-12%, the mass fraction of ethylenediaminetetraacetic acid is 1-5%, and the mass fraction of ethanolamine is 1-10%.

4. The desulfurizing agent for acidizing sulfur-containing reservoirs according to claim 3, characterized in that, The amine reagent is any one of triethanolamine, triethylamine hydrochloride, dodecylamine, tetradecylamine, hexadecylamine, polyacrylamine, diethylene glycolamine, and dihydroxyethylmethylamine.

5. The desulfurizing agent for acidizing sulfur-containing reservoirs according to claim 4, characterized in that, The activator is any one of monoazine compounds, diazine compounds, or triazine compounds.

6. A method for preparing a desulfurizing agent for acidizing sulfur-containing reservoirs, characterized in that, The specific steps are as follows: Step 1: Prepare the compound iron complex reagent; Step 2: Measure the following components in order of volume percentage: 20-30% compound iron complex reagent, 15-20% amine reagent, 5-15% activator, and 35-60% solvent water. The total volume content of the above components should be 100%. Then add the compound iron complex reagent, amine reagent, and activator to the solvent water and stir at 25-80℃ for 10-120 min to obtain the desulfurizing agent for acidizing sulfur-containing reservoirs.

7. The method for preparing the desulfurizing agent for acidizing sulfur-containing reservoirs according to claim 6, characterized in that, Step 1 specifically involves: Step 1.1: Add ferric salts and ferrous salts to pure water and stir at 30-60℃ until the solids are completely dissolved to obtain system A; Step 1.2: Sorbitol, hexadecyltrimethylammonium chloride, and sulfosalicylic acid are added sequentially to system A, and the mixture is stirred at room temperature until completely dissolved to obtain system B; Step 1.3: Add ethylenediaminetetraacetic acid to system B and stir at 70-100℃ until completely dissolved to obtain system C; Step 1.4: Add ethanolamine dropwise to system C and stir at 40-80℃ for 0.5-3h to obtain a brownish-black compound iron reagent.

8. The method for preparing the desulfurizing agent for acidizing sulfur-containing reservoirs according to claim 7, characterized in that, The stirring time in step 1.4 is 0.5-3 hours.

9. The method for preparing the desulfurizing agent for acidizing sulfur-containing reservoirs according to claim 7, characterized in that, The compound iron complex reagent contains 0.5-1.5% ferric salt, 6-15% ferrous salt, 0.8-2.5% sorbitol, 0.1-1% hexadecyltrimethylammonium chloride, 3-12% sulfosalicylic acid, 1-5% ethylenediaminetetraacetic acid, and 1-10% ethanolamine.

10. The method for preparing the desulfurizing agent for acidizing sulfur-containing reservoirs according to claim 9, characterized in that, The trivalent ferric salt is ferric chloride, and the divalent ferric salt is ferrous sulfide heptahydrate.

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