An anti-corrosion and scale inhibition composition, an anti-corrosion and scale inhibitor, and a preparation method and application thereof

Abstract

The application belongs to the technical field of corrosion protection of oil and gas wells and gathering pipelines, and specifically discloses a kind of corrosion and scale inhibition composition, corrosion and scale inhibitor and its preparation method and application. The corrosion and scale inhibition composition comprises: 40-50 parts by weight of mercapto benzimidazole derivative, 10-20 parts by weight of synergist, 8-15 parts by weight of compound auxiliary agent, 3-8 parts by weight of surfactant, appropriate amount of alkaline pH regulator and appropriate amount of solvent. The composition of the application has excellent corrosion and scale inhibition performance, and the components are compatible, without precipitation, flocculation and other phenomena, and the problem of decomposition of active ingredients during use, showing excellent stability and corrosion and scale inhibition synergistic effect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of corrosion protection of oil and gas wells and gathering pipelines, and particularly discloses a corrosion and scale inhibition composition, a corrosion and scale inhibitor, and a preparation method and application thereof. BACKGROUND

[0002] In the development of oil and gas fields, the corrosion problem of wells and gathering pipelines is particularly prominent. With the advancement of the mining process, the synergistic effect of chlorine ions, dissolved oxygen and CO2 and other media in the formation water and produced liquid, combined with the local corrosion environment formed under the scale layer, leads to an increase in the risk of pipeline perforation leakage, not only increasing the maintenance cost, but also easily causing safety production accidents. Although the current corrosion inhibitor has developed from the early chromate to high-efficiency products such as organic amine and imidazoline, and the scale inhibitor has also been upgraded from inorganic polyphosphate to multi-component systems such as organic phosphonic acid and polyepoxysuccinic acid, both of them still have significant defects in actual application. Especially when the corrosion inhibitor and the scale inhibitor are used in combination, the precipitation, flocculation and other phenomena often occur due to the conflict of the action mechanism or the chemical reaction of the components, which leads to a decrease of more than 30% in the corrosion inhibition efficiency and a decrease of more than 40% in the scale inhibition and dispersion ability, seriously affecting the application effect on site. In addition, the stability of some combined systems is insufficient under high temperature and high salt conditions, and the effective components of the medicament are prone to decomposition and failure, which is difficult to meet the protection requirements of complex oil and gas reservoirs. SUMMARY

[0003] In view of the above problems in the prior art, the application provides a corrosion and scale inhibition composition, a corrosion and scale inhibitor, and a preparation method and application thereof. Through molecular structure design, the application regulates the functional group matching and interface charge action of the corrosion inhibitor and the scale inhibitor, and develops a corrosion and scale inhibition composite system with excellent compatibility and significant synergistic effect, thereby effectively breaking through the compatibility technical bottleneck in the current combined use.

[0004] In a first aspect, the application provides a corrosion and scale inhibition composition, which comprises 40-50 parts by weight of a mercapto-benzimidazole derivative, 10-20 parts by weight of a synergist, 8-15 parts by weight of a combined agent, 3-8 parts by weight of a surfactant, an appropriate amount of an alkaline pH regulator and an appropriate amount of a solvent; wherein the mercapto-benzimidazole derivative has a structure shown in formula (I).

[0005]

[0006] Formula (I);

[0007] M is a monovalent metal, the synergist is at least one of molybdate, zinc salt, silicate, acetylenic alcohol or imidazoline derivative, the imidazoline derivative is at least one of imidazoline quaternary ammonium salt, imidazoline amide or imidazoline ketone; and the combined agent is at least one of organic phosphonic acid, polycarboxylic acid, polycarboxylate, amino-carboxyl complexing agent or amino acid corrosion inhibitor.

[0008] In some embodiments, M is any one of the Group IA metals. In some embodiments, M is sodium or potassium.

[0009] In some embodiments, the method for preparing the mercaptobenzimidazole derivative comprises: reacting 2-mercaptobenzimidazole with chlorosulfonic acid and phosphorus oxychloride in the presence of a solvent, an antioxidant, and an inert atmosphere, and adjusting the pH of the reaction product to 7-9 with a basic pH adjuster.

[0010] In some embodiments, the method for preparing the mercaptobenzimidazole derivative comprises: Step 1: reacting 2-mercaptobenzimidazole with chlorosulfonic acid in the presence of a first solvent, an antioxidant, and an inert atmosphere, adding water to the reaction solution, allowing the layers to separate, removing the lower layer, and adjusting the pH to 7-9 with a basic pH adjuster to obtain 2-mercaptobenzimidazole-5-sulfonate; the first solvent is at least one of acetone, methanol, ethanol, ethyl acetate, or butanone, the antioxidant is at least one of ascorbic acid, glutathione, thioethanol, β-mercaptoethanol, dithiothreitol (DTT), iodoacetamide, tris(2-carboxyethyl)phosphine (TCEP), or sodium sulfite, the temperature of the first reaction is 30-50°C, and the reaction time is 30-50 min; the molar ratio of 2-mercaptobenzimidazole, the first solvent, the antioxidant, chlorosulfonic acid is 1:(0.1-0.3):(0.003-0.01):(1.0-1.5). Step 2: reacting 2-mercaptobenzimidazole-5-sulfonate with phosphorus oxychloride in a second solvent and an inert atmosphere, and adjusting the pH to 7-8 with a basic pH adjuster; the second solvent is a Pd(OAc)2 and pyrrolidinyl phosphine ligand solution in anhydrous DMSO, the temperature of the second reaction is 100°C, and the reaction time is 11-13 h; the molar ratio of 2-mercaptobenzimidazole-5-sulfonate, the second solvent, phosphorus oxychloride is 1:(0.01-0.1):(2.0-3.0).

[0011] In some embodiments, the molar ratio of Pd(OAc)2 to pyrrolidinyl phosphine ligand in the second solvent is 1:2. In some embodiments, the pyrrolidinyl phosphine ligand is (2S,4S)-4-diphenylphosphino-2-(diphenylphosphinomethyl)-N-tert-butoxycarbonyl-pyrrolidine, (7-azabenzotriazol-1- yloxy)tripyrrolidinophosphonium hexafluorophosphate, 1H-benzotriazol-1-yloxytris(1- pyrrolidinyl)phosphine hexafluorophosphate, or tris(1-pyrrolidinyl)phosphine oxide, with CAS numbers 61478-28-2, 156311-83-0, 128625-52-5, and 6415-07-2, respectively.

[0012] In some embodiments, step 1 further comprises a step of purifying the 2-mercapto- benzimidazole-5-sulfonate salt, comprising: using water and a C1-C3 halogenated alkane as the extraction and back-extraction agent, completely dissolving the crude product, and after standing for phase separation, removing the lower layer solution.

[0013] In some embodiments, step 2 further comprises a step of purifying the reaction product, comprising: extracting with a C1-C3 halogenated alkane, evaporating, and drying.

[0014] In some embodiments, the molybdate salt is at least one of sodium molybdate, ammonium molybdate, or potassium molybdate.

[0015] In some embodiments, the zinc salt is at least one of zinc chloride or zinc sulfate.

[0016] In some embodiments, the silicate salt is at least one of sodium silicate or potassium silicate.

[0017] In some embodiments, the acetylenic alcohol contains 1-2 OH functional groups, and the number of carbon atoms of the acetylenic alcohol is 3-6. In some embodiments, the acetylenic alcohol is at least one of propargyl alcohol, butynediol, hexynol, or methylbutynol.

[0018] In some embodiments, the organophosphonic acid is at least one of hydroxyethylidene diphosphonic acid (HEDP), polyaminopolylether methylene phosphonic acid (PAPEMP), or diethylenetriamine pentamethylene phosphonic acid (DTPMPA).

[0019] In some embodiments, the polycarboxylic acid is at least one of polyacrylic acid or polyepoxysuccinic acid.

[0020] In some embodiments, the polycarboxylate salt is at least one of sodium polyacrylate or sodium polyepoxysuccinate.

[0021] In some embodiments, the aminocarboxylate complexing agent is at least one of diethylenetriamine pentaacetic acid or ethylenediamine tetraacetic acid.

[0022] In some embodiments, the amino acid-based corrosion inhibitor is sodium polyaspartate.

[0023] In some embodiments, the surfactant is at least one of an alkyl benzene sulfonate, an alkyl sulfate, a Tween, an alcohol ether phosphate, or a betaine-type surfactant. In some embodiments, the surfactant is at least one of a C10-C18 alkyl benzene sulfonate sodium, a C10-C18 alkyl sulfate sodium, a Tween 20-80, an alcohol ether phosphate, or a cocamidopropyl betaine.

[0024] In some embodiments, the alkaline pH regulator is at least one of an ammonium chloride-ammonia mixed solution, sodium acetate, ammonia, a carbonate of an alkali metal, or an alkali metal hydroxide. In some embodiments, the content of the alkaline pH regulator is 0.3-0.8 parts by weight.

[0025] In some embodiments, the solvent is water. In some embodiments, the content of the solvent is 6-40 parts by weight.

[0026] In a second aspect, the present application provides an inhibitor and scale inhibitor prepared by using the aforementioned composition.

[0027] In a third aspect, the present application provides a preparation method of the aforementioned inhibitor and scale inhibitor, comprising: mixing the mercaptobenzimidazole derivative with part of the solvent first, and then mixing the mercaptobenzimidazole derivative with the synergist, the compounding aid, the alkaline pH regulator, and the remaining solvent.

[0028] In a fourth aspect, the present application provides an application of the aforementioned composition or inhibitor and scale inhibitor in corrosion protection of oil and gas wells and gathering pipelines.

[0029] In a fifth aspect, the present application provides an oilfield water corrosion and scale inhibition method, comprising: contacting the aforementioned composition or inhibitor and scale inhibitor with the oilfield water, wherein the addition amount of the composition or inhibitor and scale inhibitor is 3-5%.

[0030] The present application has the following beneficial effects:

[0031] The composition provided by the present application has the following advantages: (1) A specific structure mercaptobenzimidazole derivative is specially added, which contains three key functional groups of mercapto group, sulfonic acid group, and phosphoric acid group. The mercapto group has strong coordination ability and is easy to form a chemical adsorption passivation film (such as Fe-S bond) with the metal surface. The phosphoric acid group can complex calcium and magnesium ions in the solution, improve the application range and salt tolerance of the system, and still maintain good corrosion and scale inhibition effect in oilfield water with different divalent salt ion contents. The chelation effect enhances the passivation film, and the derivative has the ability to repair the passivation film, so as to ensure the compactness and durability of the film. The presence of the sulfonic acid group significantly improves the water solubility and dispersibility of the derivative. (2) By compounding the derivative with the synergist, the compounding aid, and the surfactant and performing suitable weight ratio, the system has excellent corrosion and scale inhibition performance, good compatibility of each component, no precipitation, flocculation, and other phenomena, and no decomposition of the effective component during use, which shows excellent stability and corrosion and scale inhibition synergistic effect. DETAILED DESCRIPTION

[0032] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are some of the embodiments of the present application but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application. The specific conditions not mentioned in the embodiments are carried out according to the conventional conditions or the conditions recommended by the manufacturers. The reagents or instruments not mentioned by the manufacturers are all conventional products that can be purchased in the market.

[0033] Embodiment 1: An inhibitor and scale inhibitor, the preparation method is as follows:

[0034] Step 1: Preparation of mercaptobenzimidazole derivative

[0035]

[0036] S11, 2-mercaptobenzimidazole and ethanol are added to a flask, a small amount of glutathione is added, stirred and ice bathed to 5℃, a sufficient amount of nitrogen is continuously introduced at the bottom of the solution, and an appropriate amount of chlorosulfonic acid is slowly added dropwise through a constant pressure dropping funnel, and the molar ratio of 2-mercaptobenzimidazole, ethanol, glutathione and chlorosulfonic acid is 1:0.2:0.005:1.3. After the dropwise addition is completed, it is heated to 40℃ and kept at 40℃ for 40 min, then the solution is transferred to a separatory funnel, a small amount of water is added and shaken thoroughly, and it is left to stand at room temperature for 40 min to make it completely layered, then the lower layer solution is taken and the pH is adjusted to 7-9 with sodium hydroxide to obtain a crude product. Water and dichloroethane are used as extraction and back-extraction agents to completely dissolve the crude product, and after standing and layering, the lower layer solution is taken to obtain sodium 2-mercaptobenzimidazole-5-sulfonate.

[0037] S12, Pd(OAc)2 / (2S,4S)-4-diphenylphosphino-2-(diphenylphosphino methyl)-N-tert-butoxycarbonyl-pyrrolidine is dissolved in anhydrous DMSO according to a molar ratio of 1:2, ultrasonic treatment is performed for 10 min to form a uniform liquid to obtain a solvent. The dried sodium 2-mercaptobenzimidazole-5-sulfonate is added to a three-necked flask, stirred to completely dissolve, a sufficient amount of argon is continuously introduced at the bottom of the solution, and POCl3 is slowly added dropwise through a constant pressure dropping funnel, and the molar ratio of sodium 2-mercaptobenzimidazole-5-sulfonate, solvent and POCl3 is 1:0.05:2.5. The dropwise addition speed is controlled (0.5 mL / h), and the system temperature is maintained ≤30℃. After the dropwise addition is completed, the system is programmed to heat to 100℃ for 2 h and kept at 100℃, and the stirring is kept intense for 12 h, then an appropriate amount of ice water is slowly added, the pH is adjusted to 7-8 with saturated sodium bicarbonate, the product is extracted with dichloromethane as an extraction agent, the upper layer solution is collected and evaporated and dried to obtain a mercaptobenzimidazole derivative (2-mercapto-4-(phosphoryloxy)benzimidazole-5-sulfonic acid trisodium salt).

[0038] Step 2: Preparation of corrosion and scale inhibitor

[0039] S21, the following weight proportions of each component are taken: 40 parts by weight of mercaptobenzimidazole derivative, 10 parts by weight of sodium molybdate, 8 parts by weight of hydroxyethylidene diphosphonic acid, 3 parts by weight of sodium dodecyl benzene sulfonate, 0.3 parts by weight of ammonium chloride-ammonia mixed solution, and 38.7 parts by weight of water.

[0040] S22, the mercaptobenzimidazole derivative and a small amount of water are mixed and stirred uniformly; sodium molybdate, hydroxyethylidene diphosphonic acid, and sodium dodecyl benzene sulfonate are sequentially added to the solution and stirred uniformly; then the remaining water and the ammonium chloride-ammonia mixed solution are added to adjust the pH to 8-9, to obtain the corrosion and scale inhibitor.

[0041] Example 2: A corrosion and scale inhibitor, prepared by the following method:

[0042] Step 1: Preparation of mercaptobenzimidazole derivative

[0043] S11, 2-mercaptobenzimidazole and acetone are added to a flask, a small amount of ascorbic acid is added, stirred and ice-bathed to 10°C, and a sufficient amount of nitrogen is continuously introduced at the bottom of the solution, and an appropriate amount of chlorosulfonic acid is slowly added dropwise through a constant pressure funnel, and the molar ratio of 2-mercaptobenzimidazole, acetone, ascorbic acid, and chlorosulfonic acid is 1:0.1:0.01:1.0. After the dropwise addition is completed, it is heated to 40°C and kept at 40°C for 40 min, then the solution is transferred to a separatory funnel, a small amount of water is added and shaken thoroughly, and it is left to stand at room temperature for 40 min to completely separate the layers, and the lower layer solution is taken and the pH is adjusted to 7-9 with sodium hydroxide to obtain the crude product. Water and dichloroethane are used as extraction and back-extraction agents to completely dissolve the crude product, and after standing and separating the layers, the lower layer solution is taken to obtain 2-mercaptobenzimidazole-5-sodium sulfonate.

[0044] S12, Pd(OAc)2 / (7-azabenzotriazol-1-yl)oxy)tripyrrolidinophosphonium hexafluorophosphate was dissolved in anhydrous DMSO in a 1:2 molar ratio, ultrasonic treatment for 10 min to form a homogeneous liquid, and the solvent was obtained. After drying, 2-mercaptobenzimidazole-5-sulfonic acid sodium was added to a three-necked flask, stirred until completely dissolved, and sufficient argon was continuously introduced at the bottom of the solution. POCl3 was slowly added through a constant pressure dropping funnel, and the molar ratio of 2-mercaptobenzimidazole-5-sulfonic acid sodium, solvent, and POCl3 was 1:0.03:2.0. The dropping speed was controlled (0.5 mL / h), and the system temperature was maintained at ≤30℃. After the completion of the dropping, the system was programmed to heat to 100℃ for 2h and kept constant, and 12 h of stirring was maintained. An appropriate amount of ice water was slowly added, and the pH was adjusted to 7~8 with saturated sodium bicarbonate. The product was extracted with dichloromethane as the extracting agent, and the upper solution was collected and evaporated and dried to obtain the mercapto benzimidazole derivative (2-mercapto-4-(phosphoryloxy) benzimidazole-5-sulfonic acid trisodium salt).

[0045] Step 2: Preparation of corrosion and scale inhibitor

[0046] S21, the components were taken in the following weight proportions: mercapto benzimidazole derivative 45 parts by weight, ammonium molybdate 15 parts by weight, polyamino polyether based methylidene phosphonic acid 12 parts by weight, Tween 20 5 parts by weight, sodium acetate 0.5 parts by weight, and water 22.5 parts by weight.

[0047] S22, the mercapto benzimidazole derivative and a small amount of water were mixed and stirred uniformly; ammonium molybdate, polyamino polyether based methylidene phosphonic acid, and Tween 20 were sequentially added to the solution and stirred uniformly; then the remaining water and sodium acetate were added to adjust the pH to 8~9, and the corrosion and scale inhibitor was obtained.

[0048] Example 3: A corrosion and scale inhibitor, the preparation method is as follows:

[0049] Step 1: Preparation of mercapto benzimidazole derivative

[0050] S11, 2-mercaptobenzimidazole and ethanol were added to a flask, a small amount of thioethanol was added, stirred and ice bathed to 8℃, and sufficient nitrogen was continuously introduced at the bottom of the solution. An appropriate amount of chlorosulfonic acid was slowly added through a constant pressure dropping funnel, and the molar ratio of 2-mercaptobenzimidazole, ethanol, thioethanol, and chlorosulfonic acid was 1:0.3:0.01:1.5. After the completion of the dropping, it was heated to 40℃ and kept constant for 40 min. The solution was transferred to a separatory funnel, a small amount of water was added and shaken thoroughly, and it was left to stand at room temperature for 40 min to completely separate the layers. The lower solution was taken and the pH was adjusted to 7~9 with sodium hydroxide to obtain the crude product. Water and dichloroethane were used as the extraction and back extraction agents, the crude product was completely dissolved, and after standing and separating the layers, the lower solution was taken to obtain 2-mercaptobenzimidazole-5-sulfonic acid sodium.

[0051] S12, Pd(OAc)2 / 1H-benzotriazole-1-oxyl tri(1-pyrrolidinyl)phosphonium hexafluorophosphate was dissolved in anhydrous DMSO in a 1:2 molar ratio, ultrasonic treatment for 10 min to form a homogeneous liquid, and a solvent was obtained. Dry 2-mercapto benzimidazole-5-sulfonic acid sodium was added to a three-necked flask with the solvent, stirred until fully dissolved, and sufficient argon was continuously introduced at the bottom of the solution. POCl3 was slowly added through a constant pressure dropping funnel, and the molar ratio of 2-mercapto benzimidazole-5-sulfonic acid sodium, solvent, and POCl3 was 1:0.1:3.0. The dropping speed was controlled (0.5 mL / h), and the system temperature was maintained at ≤30°C. After the completion of the dropping, the system was programmed to heat to 100°C for 2 h and kept constant, and 12 h of stirring was maintained. An appropriate amount of ice water was slowly added, and the pH was adjusted to 7-8 with saturated sodium bicarbonate. The product was extracted with dichloromethane as the extracting agent, and the upper solution was collected and evaporated and dried to obtain the mercapto benzimidazole derivative (2-mercapto-4-(phosphoryloxy) benzimidazole-5-sulfonic acid trisodium salt).

[0052] Step 2: Preparation of the corrosion and scale inhibitor

[0053] S21, the components were taken in the following weight proportions: mercapto benzimidazole derivative 50 parts by weight, potassium molybdate 20 parts by weight, diethylene triamine penta (methylene phosphonic acid) 15 parts by weight, alcohol ether phosphate 8 parts by weight, ammonia 0.8 parts by weight, and water 6.2 parts by weight.

[0054] S22, the mercapto benzimidazole derivative and a small amount of water were mixed and stirred uniformly. Potassium molybdate, diethylene triamine penta (methylene phosphonic acid), and alcohol ether phosphate were sequentially added to the solution and stirred uniformly. The remaining water and ammonia were then added to adjust the pH to 8-9, and the corrosion and scale inhibitor was obtained.

[0055] Example 4: A corrosion and scale inhibitor was prepared as follows:

[0056] Step 1: Preparation of the mercapto benzimidazole derivative

[0057] S11, 2-mercapto benzimidazole and methanol were added to a flask, a small amount of thioethanol was added, and stirring and ice bath were performed until the temperature reached 5°C. Sufficient nitrogen was continuously introduced at the bottom of the solution, and an appropriate amount of chlorosulfonic acid was slowly added through a constant pressure dropping funnel. The molar ratio of 2-mercapto benzimidazole, methanol, thioethanol, and chlorosulfonic acid was 1:0.2:0.01:1.0. After the completion of the dropping, the solution was heated to 40°C and kept constant for 40 min. The solution was transferred to a separatory funnel, a small amount of water was added, and stirring was performed until the solution was fully separated. The lower solution was taken, and the pH was adjusted to 7-9 with sodium hydroxide to obtain the crude product. Water and dichloroethane were used as the extraction and back-extraction agents, and the crude product was fully dissolved. After the solution was separated, the lower solution was taken, and 2-mercapto benzimidazole-5-sulfonic acid sodium was obtained.

[0058] S12, Pd(OAc)2 / 1H-benzotriazole-1-oxyl tri(1-pyrrolidinyl)phosphonium hexafluorophosphate was dissolved in anhydrous DMSO in a 1:2 molar ratio, and ultrasonic treatment was performed for 10 min to form a uniform liquid to obtain a solvent. After drying, 2-mercapto benzimidazole-5-sulfonic acid sodium was added to a three-necked flask, stirring was performed until complete dissolution, sufficient argon was continuously introduced at the bottom of the solution, and POCl3was slowly added dropwise through a constant pressure dropping funnel, the molar ratio of 2-mercapto benzimidazole-5-sulfonic acid sodium, the solvent, and POCl3being 1:0.01:2.0. The dropping speed was controlled (0.5 mL / h), and the system temperature was maintained at ≤30°C. After the completion of dropping, the system was subjected to programmed temperature increase to 100°C for 2 h and constant temperature, and stirring was maintained for 12 h. An appropriate amount of ice water was slowly added, saturated sodium bicarbonate was used to adjust the pH to 7-8, the product was extracted using dichloromethane as an extracting agent, the upper solution was collected and evaporated and dried to obtain a mercapto benzimidazole derivative (2-mercapto-4-(phosphoryloxy) benzimidazole-5-sulfonic acid trisodium salt).

[0059] Step 2: Preparation of the corrosion and scale inhibitor

[0060] S21, the components were taken in the following weight proportions: 40 parts by weight of mercapto benzimidazole derivative, 15 parts by weight of zinc sulfate, 15 parts by weight of hydroxyethylidene diphosphonic acid, 3 parts by weight of cocamidopropyl betaine, 0.4 parts by weight of sodium carbonate, and 26.6 parts by weight of water.

[0061] S22, the mercapto benzimidazole derivative and a small amount of water were mixed and stirred uniformly; the zinc sulfate, hydroxyethylidene diphosphonic acid, and cocamidopropyl betaine were sequentially added to the solution and stirred uniformly; then the remaining water and sodium carbonate were added to adjust the pH to 8-9 to obtain the corrosion and scale inhibitor.

[0062] Example 5: A corrosion and scale inhibitor, the preparation method being as follows:

[0063] Step 1: Preparation of a mercapto benzimidazole derivative

[0064] S11, 2-mercapto benzimidazole and ethanol were added to a flask, glutathione was added, stirring was performed and ice bath was used to maintain the temperature at 5°C, sufficient nitrogen was continuously introduced at the bottom of the solution, and an appropriate amount of chlorosulfonic acid was slowly added dropwise through a constant pressure dropping funnel, the molar ratio of 2-mercapto benzimidazole, ethanol, glutathione, and chlorosulfonic acid being 1:0.1:0.01:1.4. After the completion of dropping, heating was performed to 40°C, constant temperature was maintained for 40 min, the solution was transferred to a separatory funnel, a small amount of water was added and fully shaken, and the solution was left to stand at room temperature for 40 min to completely separate the layers, the lower layer solution was taken, and sodium hydroxide was used to adjust the pH to 7-9 to obtain a crude product. Water and dichloroethane were used as extraction and back-extraction agents, the crude product was completely dissolved, and after the solution was left to stand to separate the layers, the lower layer solution was taken to obtain 2-mercapto benzimidazole-5-sulfonic acid sodium.

[0065] S12, Pd(OAc)2 / (7-azabenzotriazol-1-yl oxy) tripyrrolidinophosphonium hexafluorophosphate was dissolved in anhydrous DMSO in a 1:2 molar ratio, ultrasonic treatment for 10 min to form a homogeneous liquid, and the solvent was obtained. After drying, 2-mercaptobenzimidazole-5-sodium sulfonate was added to a three-necked flask, stirred until completely dissolved, and a sufficient amount of argon was continuously introduced at the bottom of the solution. POCl3 was slowly added through a constant pressure dropping funnel, and the molar ratio of 2-mercaptobenzimidazole-5-sodium sulfonate, solvent, and POCl3 was 1:0.08:2.2. The dropping speed was controlled (0.5 mL / h), and the system temperature was maintained ≤30℃. After the addition was completed, the system was programmed to heat to 100℃ for 2h and kept constant, and 12h of vigorous stirring was maintained. An appropriate amount of ice water was slowly added, the pH was adjusted to 7~8 with saturated sodium bicarbonate, the product was extracted with dichloromethane as the extractant, the upper solution was collected and evaporated, and dried to obtain a mercaptobenzimidazole derivative (2-mercapto-4-(phosphoryloxy) benzimidazole-5-sulfonic acid trisodium salt).

[0066] Step 2: Preparation of corrosion and scale inhibitor

[0067] S21, the components were taken in the following weight proportions: mercaptobenzimidazole derivative 50 parts by weight, imidazoline lauryl acid quaternary ammonium salt 10 parts by weight, polyaspartic acid sodium 10 parts by weight, sodium dodecyl sulfate 8 parts by weight, sodium hydroxide 0.6 parts by weight, and water 21.4 parts by weight.

[0068] S22, the mercaptobenzimidazole derivative and a small amount of water were mixed and stirred uniformly; imidazoline lauryl acid quaternary ammonium salt, polyaspartic acid sodium, and sodium dodecyl sulfate were added to the solution in sequence and stirred uniformly; then the remaining water and sodium hydroxide were added to adjust the pH to 8~9, and a corrosion and scale inhibitor was obtained.

[0069] Example 6 A corrosion and scale inhibitor was prepared by the following method:

[0070] Step 1: Preparation of mercaptobenzimidazole derivative

[0071] S11, 2-mercaptobenzimidazole and ethyl acetate are added to a flask, dithiothreitol is added, stirring and ice bath to 5℃, continue to pass a sufficient amount of nitrogen at the bottom of the solution, slowly drop a proper amount of chlorosulfonic acid through the constant pressure funnel, the molar ratio of 2-mercaptobenzimidazole, ethyl acetate, dithiothreitol, chlorosulfonic acid is 1:0.3:0.005:1.0. After the completion of drop, heated to 40℃, constant temperature 40 min, the solution is transferred to a separatory funnel, add a little water to shake thoroughly, room temperature for 40 min, make it completely layered, take the lower solution with sodium hydroxide to adjust the pH to 7~9, obtain the crude product. Using water and dichloroethane as extraction and back extraction agent, completely dissolved the crude product, after standing and layering, take the lower solution, that is, 2-mercaptobenzimidazole-5-sulfonic acid sodium is obtained.

[0072] S12, Pd(OAc)2 / tris(1-pyrrolidinyl)phosphine oxide is dissolved in anhydrous DMSO according to 1:2 molar ratio, ultrasonic treatment for 10 min to form a homogeneous liquid, get the solvent. Dry 2-mercaptobenzimidazole-5-sulfonic acid sodium and solvent are added to a three-necked flask, stirring to dissolve thoroughly, continue to pass a sufficient amount of argon at the bottom of the solution, slowly drop POCl3 through the constant pressure drop funnel, the molar ratio of 2-mercaptobenzimidazole-5-sulfonic acid sodium, solvent, POCl3 is 1:0.05:2.5. Control the drop speed (0.5 mL / h), maintain the system temperature ≤30℃. After the completion of drop, the system is programmed to 100℃ for 2h and constant temperature, keep stirring for 12 h, slowly add a proper amount of ice water, adjust the pH to 7~8 with saturated sodium bicarbonate, use dichloromethane as extraction agent to extract the product, collect the upper solution and evaporate, dry, get mercaptobenzimidazole derivative (2-mercapto-4-(phosphoryloxy) benzimidazole-5-sulfonic acid trisodium salt).

[0073] Step 2: preparation of corrosion and scale inhibitor

[0074] S21, take the following weight ratio of each component: mercaptobenzimidazole derivative 40 parts by weight, zinc chloride 10 parts by weight, polyacrylic acid 15 parts by weight, sodium dodecyl sulfate 8 parts by weight, potassium hydroxide 0.5 parts by weight, water 26.5 parts by weight.

[0075] S22, mix mercaptobenzimidazole derivative and a small amount of water, stir evenly; add zinc chloride, polyacrylic acid, sodium dodecyl sulfate to the solution in turn and stir evenly; then add the remaining water and potassium hydroxide to adjust the pH to 8~9, get the corrosion and scale inhibitor.

[0076] Example 7, a kind of corrosion and scale inhibitor, the preparation method is as follows:

[0077] Step 1: preparation of mercaptobenzimidazole derivative

[0078] S11, 2-mercaptobenzimidazole and ethyl acetate are added to a flask, glutathione is added, stirred and ice bathed to 5℃, a sufficient amount of nitrogen is continuously introduced at the bottom of the solution, an appropriate amount of chlorosulfonic acid is slowly added dropwise through a constant pressure funnel, and the molar ratio of 2-mercaptobenzimidazole, ethyl acetate, glutathione and chlorosulfonic acid is 1:0.2:0.005:1.3. After the dropwise addition is completed, it is heated to 40℃ and kept at 40℃ for 40 min. The solution is transferred to a separatory funnel, a small amount of water is added and shaken thoroughly, and it is allowed to stand at room temperature for 40 min to completely separate the layers. The lower layer is taken and the pH is adjusted to 7-9 with sodium hydroxide to obtain the crude product. Water and dichloroethane are used as extraction and back-extraction agents to completely dissolve the crude product. After standing and separating the layers, the lower layer is taken to obtain sodium 2-mercaptobenzimidazole-5-sulfonate.

[0079] S12, Pd(OAc)2 / tris(1-pyrrolidinyl)phosphine oxide is dissolved in anhydrous DMSO at a molar ratio of 1:2, ultrasonically treated for 10 min to form a homogeneous liquid to obtain a solvent. Dry sodium 2-mercaptobenzimidazole-5-sulfonate is added to a three-necked flask, stirred until completely dissolved, and a sufficient amount of argon is continuously introduced at the bottom of the solution. POCl3 is slowly added dropwise through a constant pressure dropping funnel, and the molar ratio of sodium 2-mercaptobenzimidazole-5-sulfonate, solvent and POCl3 is 1:0.1:3.0. The dropwise addition rate is controlled at 0.5 mL / h, and the system temperature is maintained at ≤30℃. After the dropwise addition is completed, the system is programmed to heat to 100℃ over 2 h and kept at this temperature, and the stirring is maintained for 12 h. An appropriate amount of ice water is slowly added, the pH is adjusted to 7-8 with saturated sodium bicarbonate, and the product is extracted with dichloromethane as an extraction agent. The upper layer is collected and evaporated and dried to obtain a mercaptobenzimidazole derivative (trisodium 2-mercapto-4-(phosphoryloxy)benzimidazole-5-sulfonate).

[0080] Step 2: Preparation of corrosion and scale inhibitor

[0081] S21, the components are taken in the following weight proportions: mercaptobenzimidazole derivative 45 parts by weight, sodium silicate 15 parts by weight, polyacrylic acid sodium 8 parts by weight, sodium dodecyl sulfate 3 parts by weight, sodium hydroxide 0.4 parts by weight, and water 28.6 parts by weight.

[0082] S22, the mercaptobenzimidazole derivative and a small amount of water are mixed and stirred until uniform. Sodium silicate, polyacrylic acid sodium and sodium dodecyl sulfate are added to the solution in sequence and stirred until uniform. The remaining water and sodium hydroxide are then added to adjust the pH to 8-9 to obtain the corrosion and scale inhibitor.

[0083] Example 8, a corrosion and scale inhibitor, is prepared as follows:

[0084] Step 1: Preparation of mercaptobenzimidazole derivative

[0085] S11, 2-mercaptobenzimidazole and ethanol were added to a flask, sodium sulfite was added, stirred and ice bathed to 5℃, sufficient nitrogen was continuously introduced at the bottom of the solution, and an appropriate amount of chlorosulfonic acid was slowly added dropwise through a constant pressure funnel, and the molar ratio of 2-mercaptobenzimidazole, ethanol, sodium sulfite and chlorosulfonic acid was 1:0.3:0.01:1.3. After the dropwise addition was completed, it was heated to 40℃ and kept at 40℃ for 40 min, then the solution was transferred to a separatory funnel, a small amount of water was added and shaken thoroughly, and it was allowed to stand at room temperature for 40 min to completely separate the layers, then the lower layer was taken and the pH was adjusted to 7~9 with sodium hydroxide to obtain the crude product. Water and dichloroethane were used as extraction and back-extraction agents to completely dissolve the crude product, and after standing and separating the layers, the lower layer was taken to obtain sodium 2-mercaptobenzimidazole-5-sulfonate.

[0086] S12, Pd(OAc)2 / 1H-benzotriazole-1-oxyl tris(1-pyrrolidinyl)phosphonium hexafluorophosphate was dissolved in anhydrous DMSO in a molar ratio of 1:2, ultrasonically treated for 10 min to form a homogeneous liquid to obtain a solvent. Dry sodium 2-mercaptobenzimidazole-5-sulfonate was added to a three-necked flask, stirred until completely dissolved, and sufficient argon was continuously introduced at the bottom of the solution. POCl3 was slowly added dropwise through a constant pressure dropping funnel, and the molar ratio of sodium 2-mercaptobenzimidazole-5-sulfonate, solvent and POCl3 was 1:0.05:2.5. The dropwise addition rate was controlled at 0.5 mL / h, and the system temperature was maintained at ≤30℃. After the dropwise addition was completed, the system was programmed to heat to 100℃ over 2 h and kept at this temperature, and the stirring was maintained for 12 h. An appropriate amount of ice water was slowly added, the pH was adjusted to 7~8 with saturated sodium bicarbonate, and the product was extracted with dichloromethane as an extraction agent. The upper layer was collected and evaporated and dried to obtain a mercaptobenzimidazole derivative (2-mercapto-4-(phosphoryloxy)benzimidazole-5-sulfonic acid trisodium salt).

[0087] Step 2: Preparation of corrosion and scale inhibitor

[0088] S21, the components were taken in the following weight proportions: mercaptobenzimidazole derivative 45 parts by weight, propargyl alcohol 10 parts by weight, diethylenetriamine pentaacetic acid 10 parts by weight, sodium dodecyl sulfate 7 parts by weight, sodium hydroxide 0.6 parts by weight, and water 27.4 parts by weight.

[0089] S22, the mercaptobenzimidazole derivative and a small amount of water were mixed and stirred until uniform; propargyl alcohol, diethylenetriamine pentaacetic acid and sodium dodecyl sulfate were added to the solution in sequence and stirred until uniform; then the remaining water and sodium hydroxide were added to adjust the pH to 8~9 to obtain the corrosion and scale inhibitor.

[0090] Comparative Example 1

[0091] The difference between this comparative example and Example 2 is that the mercaptobenzimidazole derivative is replaced by imidazoline quaternary ammonium salt laurate.

[0092] Comparative Example 2

[0093] The present comparative example differs from Example 2 in that the mercaptobenzimidazole derivative is removed.

[0094] Comparative Example 3

[0095] The present comparative example differs from Example 2 in that the mercaptobenzimidazole derivative is replaced with the 2-mercaptobenzimidazole-5-sulfonic acid sodium prepared in step S11.

[0096] The corrosion and scale inhibitors prepared in the present application, Examples 1-8 and Comparative Examples 1-3, were measured for corrosion inhibition rate and scale inhibition rate according to the current standards of the oil and gas industry, SY / T 5273-2014 “Performance Index and Evaluation Method for Corrosion Inhibitors for Oilfield Produced Water Treatment” and SY / T 5673-2020 “General Technical Conditions for Scale Inhibitors for Oilfields”, and the results are shown in Table 1.

[0097] Table 1. Results of corrosion inhibition rate and scale inhibition rate determination

[0098]

[0099] The results show that the corrosion inhibition rates of the samples prepared in each example of the present application are all above 95%, and the scale inhibition rates are all above 91%, which are significantly better than the corrosion inhibition rates (67.6%, 48.3%, 78.3%) and scale inhibition rates (63.6%, 50.9%, 68.1%) of the comparative examples, indicating that the corrosion and scale inhibition performance of the samples of the present application is excellent.

[0100] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

Claims

1. An corrosion and scale inhibition composition characterized in that, The composition comprises: The composition comprises: The mercapto-benzimidazole derivative has a structure shown in formula (I); Formula (I); M is a monovalent metal; The synergist is at least one of molybdate, zinc salt, silicate, acetylenic alcohol or imidazoline derivative, the imidazoline derivative is at least one of imidazoline quaternary ammonium salt, imidazoline amide or imidazoline ketone; The complexing agent is at least one of organic phosphonic acid, polycarboxylic acid, polycarboxylic acid salt, amino-carboxyl complexing agent or amino acid corrosion inhibitor.

2. The corrosion and scale inhibition composition as claimed in claim 1, wherein, M is any one of IA group metal; And / or, the molybdate is at least one of sodium molybdate, ammonium molybdate or potassium molybdate; And / or, the zinc salt is at least one of zinc chloride or zinc sulfate; And / or, the silicate is at least one of sodium silicate or potassium silicate; And / or, the acetylenic alcohol contains 1-2 OH functional groups, and the number of carbon atoms of the acetylenic alcohol is 3-6; And / or, the organic phosphonic acid is at least one of hydroxyethylidene diphosphonic acid, polyamino polyether methylidene phosphonic acid or diethylene triamine penta-methylidene phosphonic acid; And / or, the polycarboxylic acid is at least one of polyacrylic acid or polyepoxysuccinic acid; And / or, the polycarboxylic acid salt is at least one of sodium polyacrylate or sodium polyepoxysuccinate; And / or, the amino-carboxyl complexing agent is at least one of diethylene triamine pentaacetic acid or ethylenediamine tetraacetic acid; And / or, the amino acid corrosion inhibitor is polyaspartic acid sodium.

3. The corrosion and scale inhibition composition as claimed in claim 2, wherein M is sodium or potassium; And / or, the acetylenic alcohol is at least one of propargyl alcohol, butynediol, hexynol or methyl butynol.

4. The corrosion and scale inhibition composition as claimed in claim 1, wherein, The surfactant is at least one of alkyl benzene sulfonate, alkyl sulfate, Tween, alcohol ether phosphate or betaine surfactant.

5. The corrosion and scale inhibition composition as claimed in claim 4, wherein, The surfactant is at least one of C10-18 alkyl benzene sulfonate sodium, C10-18 alkyl sulfate sodium, Tween 20-80, alcohol ether phosphate or cocamide propyl betaine.

6. The corrosion and scale inhibition composition as claimed in claim 1, wherein, The basic pH regulator is at least one of ammonium chloride-ammonia mixed solution, sodium acetate, ammonia, alkali metal carbonate or alkali metal hydroxide; And / or, the solvent is water; And / or, the content of the basic pH regulator is 0.3-0.8 parts by weight; And / or, the content of the solvent is 6-40 parts by weight.

7. A process for the preparation of the corrosion and scale inhibiting composition as claimed in any one of claims 1 to 6, characterized in that, The preparation method comprises: mixing the mercapto-benzimidazole derivative with the synergist, the complexing agent, the surfactant, the basic pH regulator and the solvent.

8. The application of the corrosion and scale inhibition composition in any one of claims 1-6 in corrosion protection of oil and gas wells and gathering pipelines.

9. An oilfield water corrosion and scale inhibition method, characterized in that, The method comprises: contacting the corrosion and scale inhibition composition in any one of claims 1-6 with oilfield water.

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