Sulfonyl crown ether neutral scale remover for oil and gas well as well as preparation method and application of scale remover

Abstract

The invention belongs to the technical field of oilfield chemistry, and particularly relates to a sulfonic crown ether neutral scale remover for an oil and gas well as well as a preparation method and application of the sulfonic crown ether neutral scale remover. The sulfonyl crown ether neutral scale remover for the oil and gas well comprises the following components in parts by weight: 5-15 parts of sulfonyl crown ether chelating agent; 1-2 parts of a scale inhibitor; 2 to 3 parts of a surfactant; 1-4 parts of a pH buffer solution; the total amount is 100 parts, and the balance is water. The neutral descaling agent provided by the invention has the advantages of strong descaling capability, no corrosion to equipment, no pollution to the environment and the like, and can be used for removing most of insoluble scales.

Description

Technical Field

[0001] The present invention belongs to the technical field of oilfield chemistry, and particularly relates to a sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells, a preparation method thereof, and an application thereof. Background Art

[0002] At present, oil and gas fields have entered the middle and late stages of development, and water injection technology is required for crude oil production. After a large amount of water injection, due to factors such as changes in pressure, temperature, and incompatibility of formation water, pipeline scaling often occurs, causing great losses to production and irreversible damage to the environment.

[0003] According to the composition and formation mechanism of different scales, many related oilfield scale removal technologies have emerged. Among them, chemical scale removal technology has received extensive attention due to its high scale removal efficiency and wide application range. The main chemical scale removal technologies include acid washing technology, indirect scale removal technology, and chelating agent scale removal technology. Acid scale inhibitors have the advantages of low cost and high scale removal efficiency, but they are only applicable to some scale substances that are easily soluble in acid, and their application range is relatively limited. The indirect scale removal technology converts insoluble scales into scales that are easily soluble in acid, and then removes them through acid washing and chelating agents. However, this method has a complex process, high cost, and few implementation cases. Chelating agent scale removal has good scale removal effects on most scale substances, and the waste liquid after treatment is environmentally friendly. It is a new type of environmentally friendly scale inhibitor. The main mechanism is to form more stable complexes with scale-forming metal ions through multiple coordination bonds of the chelating agent. Among them, macrocyclic crown ethers have received extensive attention because they can remove insoluble scales such as silicates. Therefore, synthesizing a high-efficiency and inexpensive macrocyclic crown ether chelating agent has become the main development direction of future oilfield scale removal. Summary of the Invention

[0004] To solve the deficiencies of the prior art, the present invention provides a sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells, a preparation method thereof, and an application thereof. The neutral scale inhibitor provided by the present invention has the advantages of strong scale removal ability, no corrosion to equipment, and no pollution to the environment, and can be used to remove most insoluble scales.

[0005] The technical solution provided by the present invention is as follows:

[0006] A sulfonic acid group crown ether chelating agent having the structure shown in formula (Ⅰ):

[0007]

[0008] In the above technical solution, part of the polyethylene glycol chain in the crown ether is first replaced by an aromatic ring to obtain an aryl crown ether, which has a stronger coordination ability with metal ions and forms a more stable complex. The lone pair electrons of N and O atoms in the sulfonic acid group crown ether chelating agent form coordination bonds with Ca 2+ , Mg 2+ , Ba2+ , Sr 2+ The empty orbitals of metal ions are complementary to form a stable supramolecular structure, forming a dense, stable and uniform monolayer film on the metal surface. The supramolecular film can not only play the role of anti-corrosion and anti-scaling, but also has the function of cleaning oil stains. Finally, the introduction of sulfonic acid groups enhances the water solubility and high temperature resistance of the crown ether.

[0009] The present invention also provides a preparation method of the above-mentioned sulfonic acid group crown ether chelating agent, and the synthesis route is as follows:

[0010]

[0011] The preparation method of the above-mentioned sulfonic acid group crown ether chelating agent specifically includes the following steps:

[0012] 1) Weigh 1,10-phenanthroline-3,8-diol, tetraethylene glycol mono-OTs, potassium carbonate powder and sodium iodide according to the molar ratio of 1:(2.3-2.5):(4.5-4.7):(33.0-35.0), and add them and the solvent acetonitrile into the reaction flask respectively. Heat to 80-90 °C, reflux for 10-12 h, filter, spin dry, obtain a dark yellow oily initial product, dissolve it in dichloromethane, filter by suction, wash, and obtain a black oily substance a, where the mass ratio of the solvent acetonitrile to the total amount of reactants is equal;

[0013] 2) Weigh a, triethylamine, 4-dimethylaminopyridine and p-toluenesulfonyl chloride in dichloromethane according to the molar ratio of 1:(4.5-5.5):(0.18-0.22):(2.1-2.5) (preferably 1:5:0.2:2.3). Slowly add p-toluenesulfonyl chloride under ice bath conditions. Weigh a certain amount of a, triethylamine and a catalytic amount of 4-dimethylaminopyridine and dissolve them in dichloromethane. Slowly add p-toluenesulfonyl chloride under ice bath conditions, stir at room temperature until a flocculent precipitate is formed, dilute, adjust the pH of the aqueous phase to neutral with hydrochloric acid, extract, concentrate under reduced pressure, and then perform column chromatography separation with ethyl acetate: petroleum ether as the eluent to obtain a black oily substance b;

[0014] 3) Under a nitrogen atmosphere, weigh compound b and 1,10-phenanthroline-3,8-diol according to the molar ratio of 1.0:(1.0-1.2), and load them and acetonitrile into a constant pressure dropping funnel respectively. Then slowly add them into the reaction flask containing potassium carbonate powder, a catalytic amount of sodium iodide and acetonitrile solvent. Heat to 80-90 °C, react for 12-14 h, cool, filter by suction, spin dry to obtain a solid powder, then dissolve it in dichloromethane, filter by suction, wash, concentrate under reduced pressure, and perform column chromatography separation with ethyl acetate: petroleum ether to obtain a yellow product c, where the mass ratio of acetonitrile to the total amount of reactants is equal;

[0015] 4) Weigh 1.0 g of c and dissolve it in 80 mL of anhydrous dichloromethane. Slowly add 10 mL of chlorosulfonic acid under ice bath conditions. After reacting for 2.5 - 3.5 h, add 30 mL of water and 5 mL of saturated tetramethylammonium hydroxide aqueous solution. Concentrate under low pressure, continue to add 20 mL of sodium perchlorate aqueous solution, ultrasonicate, let it stand for liquid separation, filter by suction, and obtain pure compound d, namely the sulfonic acid group crown ether chelating agent, after recrystallization.

[0016] Based on the above technical solution, a sulfonic acid group crown ether chelating agent can be prepared. Moreover, this method itself has the characteristic of being easy to implement.

[0017] The present invention also provides a sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells, which comprises the following components in parts by weight: 5 - 15 parts of the above-mentioned sulfonic acid group crown ether chelating agent; 1 - 2 parts of scale inhibitor; 2 - 3 parts of surfactant; 1 - 4 parts of pH buffer; the total is 100 parts, and the rest is water.

[0018] The above technical solution uses the sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells in combination with a scale inhibitor and a surfactant. The water solubility of the dirt dispersed by the sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells is stronger. At the same time, based on the continuous chelating ability of the sulfonic acid group crown ether chelating agent, it can perform persistent decontamination, thereby achieving deeper scale removal.

[0019] Specifically, the scale inhibitor is selected from the combination of sodium polyacrylate and copolymer of maleic anhydride, and the weight ratio of sodium polyacrylate to copolymer of maleic anhydride is (50 - 60):(20 - 30).

[0020] Specifically, the surfactant is sorbitan fatty acid ester.

[0021] Specifically, the pH buffer is a mixed solution of ammonium chloride and ammonia water, sodium acetate.

[0022] In the above technical solution, using a pH buffer to stabilize the pH of the scale inhibitor at 7 - 8 to maintain a slightly neutral state can not only promote the chelating effect of the chelating agent, but also make it have lower corrosion performance compared with acidic scale inhibitors, and will not cause harm to the formation.

[0023] Preferably, the pH buffer is a mixed solution of ammonium chloride and ammonia water with a mass ratio of 1:1.

[0024] The present invention also provides a preparation method of a sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells, comprising the following steps: Add water into a reaction kettle according to the formula amount, and successively add a sulfonic acid group crown ether chelating agent, a scale inhibitor, a surfactant, and half of the total amount of pH buffer solution. Heat up to 80-90 °C, stir for 30-60 min, then add the remaining pH buffer solution in batches. Measure the pH of the system during the process. Stop adding the pH buffer solution when the pH of the system reaches 7-8. Continue to stir for 25-35 min, then stop and cool down to obtain the sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells.

[0025] The present invention also provides the application of the sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells, which is used to remove inorganic scale plugs in oil and gas wells under the conditions of 80-180 °C.

[0026] The sulfonic acid group crown ether neutral scale inhibitor provided by the present invention has the advantages of excellent performance, high scale removal efficiency, green environmental protection, etc., and its own properties are stable. It is particularly suitable for removing inorganic scale plugs in oil and gas wells under medium and low temperature (80-180 °C) conditions.

[0027] The beneficial effects of the present invention:

[0028] The present invention uses 4,7-dihydroxy-1,10-phenanthroline hydrochloride and tetraethylene glycol mono-OTs as raw materials to prepare a sulfonic acid group crown ether chelating agent, which meets the requirements of green environmental protection. This compound contains a macrocyclic crown ether and multiple sulfonic acid groups. Among them, the crown ether group has strong chelating ability and scale dissolution ability, and can form strong complexation with main scale-forming metal ions such as Ca 2+ , Mg 2+ , Ba 2+ , Sr 2+ in water, effectively preventing these ions from combining with scale-forming anions to form insoluble scales; and has good inhibition and elimination effects on sediments, can effectively destroy the lattice order of sediments to make them loose and then be stably dispersed. The introduction of sulfonic acid groups can effectively inhibit the scale formation process of calcium phosphate, prevent the generation of insoluble calcium gels, effectively disperse iron oxide, stabilize zinc, and is not easy to form colloid, thereby improving the temperature resistance performance of the scale inhibitor. The main function of the scale inhibitor is to prevent the deposition of smaller scale particles, play a dispersing role, and prevent the scaling of scale-forming cations. Oily substances and waxes are often attached to the surface of dirt, and these substances are hydrophobic, making the surface of the dirt not easily wetted by water. After adding a surfactant, the water droplets on the surface of the dirt are easily dispersed, greatly reducing the surface tension of the dirt and achieving the purpose of wetting. Description of the Drawings

[0029] Figure 1 is the hydrogen spectrum diagram of the sulfonic acid group crown ether chelating agent provided by the present invention. Detailed Embodiments

[0030] The principles and features of the present invention will be described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0031] Example 1

[0032] The novel scale inhibitor of this example includes 15 parts of sulfonic acid group crown ether chelating agent; 2 parts of scale inhibitor; 3 parts of surfactant; 4 parts of pH buffer; the rest is water.

[0033] Among them, the chemical structure of the sulfonic acid group crown ether chelating agent is shown in formula (Ⅰ):

[0034]

[0035] By weight, the scale inhibitor includes, by weight, 50 parts of sodium polyacrylate and 30 parts of maleic anhydride copolymer. The surfactant is sorbitan fatty acid ester. The pH buffer solution includes a 1:1 mixed solution of ammonium chloride - ammonia water.

[0036] The synthesis method of the sulfonic acid group crown ether chelating agent in this example is as follows:

[0037]

[0038] The specific synthesis method of the sulfonic acid group crown ether chelating agent includes:

[0039] Under a nitrogen atmosphere, 1.0 mol of 1,10-phenanthroline-3,8-diol, 2.5 mol of tetraethylene glycol mono-OTs, 4.6 mol of potassium carbonate powder, 34.0 mol of sodium iodide and acetonitrile solvent were successively added to a reaction flask, heated to 90 °C, refluxed for 12 h, filtered, and rotary evaporated to obtain a dark yellow oily initial product. It was dissolved in dichloromethane, suction filtered, and washed to obtain a black oily substance a. 1.0 mol of a, 5.0 mol of triethylamine, and 0.2 mol of 4-dimethylaminopyridine were dissolved in dichloromethane. Under an ice bath condition, 2.3 mol of p-toluenesulfonyl chloride was slowly added, stirred at room temperature until a flocculent precipitate was formed, diluted, the pH of the aqueous phase was adjusted to neutral with hydrochloric acid, extracted, concentrated under reduced pressure, and then column chromatographed with an eluent of ethyl acetate: petroleum ether (v:v = 2:1) to obtain a black oily substance b. Under a nitrogen atmosphere, 1.0 mol of compound b, 1.2 mol of 1,10-phenanthroline-3,8-diol, and acetonitrile were charged into a constant pressure dropping funnel. 12.7 mol of potassium carbonate powder, a catalytic amount of sodium iodide, and acetonitrile solvent were mixed and dissolved in a reaction flask, heated to 80 °C, slowly added dropwise, refluxed for 12 h, cooled, suction filtered, and rotary evaporated to obtain a solid powder. It was then dissolved in dichloromethane, suction filtered, washed, concentrated under reduced pressure, and column chromatographed with an eluent of ethyl acetate: petroleum ether (v:v = 1.5:1) to obtain a yellow product c. 1.0 g of c was dissolved in anhydrous dichloromethane. Under an ice bath condition, chlorosulfonic acid was slowly added. After reacting for 4 h, an appropriate amount of water and aqueous tetramethylammonium hydroxide were added, concentrated under reduced pressure, an aqueous sodium perchlorate solution was continuously added, sonicated, allowed to stand for phase separation, and then suction filtered to obtain a crude product of compound d. After recrystallization with a mixed solvent of ethanol: water = 1:1, 0.75 g of pure compound d was obtained with a yield of 75%. 1 HNMR(400MH Z , D 2 O): δ 9.46 (s, 4H), 8.05 (d, 4H), 3.85 (s, 8H), 3.40 (s, 8H), 3.36 (dd, 16H).

[0040] Example 2

[0041] The novel scale inhibitor in this example comprises 6 parts of sulfonic acid group crown ether chelating agent; 2 parts of scale inhibitor; 3 parts of surfactant; 4 parts of pH buffer; the balance is water. By weight ratio, the scale inhibitor comprises, by weight ratio, 50 parts of sodium polyacrylate and 30 parts of maleic anhydride copolymer. The surfactant is sorbitan fatty acid ester. The pH buffer comprises a 1:1 mixed solution of ammonium chloride - ammonia water. The sulfonic acid group crown ether chelating agent in this example is the same as that in Example 1.

[0042] A synthesis method of a sulfonic acid group crown ether chelating agent, comprising:

[0043] Under a nitrogen atmosphere, 1.0 mol of 1,10-phenanthroline-3,8-diol, 2.3 mol of mono-OTs tetraethylene glycol, 4.6 mol of potassium carbonate powder, 34.0 mol of sodium iodide and acetonitrile solvent were successively added to a reaction flask, heated to 90 °C, refluxed for 12 h, filtered, and the solvent was evaporated to dryness to obtain a dark yellow oily initial product. It was dissolved in dichloromethane, filtered by suction and washed to obtain a black oily substance a. 1.0 mol of a, 5.0 mol of triethylamine and 0.2 mol of 4-dimethylaminopyridine were weighed and dissolved in dichloromethane. Under an ice bath condition, 2.3 mol of p-toluenesulfonyl chloride was slowly added, stirred at room temperature until a flocculent precipitate was formed, diluted, the pH of the aqueous phase was adjusted to neutral with hydrochloric acid, extracted, concentrated under reduced pressure, and then column chromatographed with an eluent of ethyl acetate: petroleum ether (v:v = 2:1) to obtain a black oily substance b. Under a nitrogen atmosphere, 1.0 mol of compound b, 1.0 mol of 1,10-phenanthroline-3,8-diol and acetonitrile were charged into a constant pressure dropping funnel. 12.7 mol of potassium carbonate powder, a catalytic amount of sodium iodide and acetonitrile solvent were dissolved in a reaction flask, heated to 90 °C, slowly added dropwise, refluxed for 14 h, cooled, filtered by suction, and the solvent was evaporated to dryness to obtain a solid powder. It was then dissolved in dichloromethane, filtered by suction, washed, concentrated under reduced pressure, and column chromatographed with an eluent of ethyl acetate: petroleum ether (v:v = 1.5:1) to obtain a yellow product c. 1.0 g of c was weighed and dissolved in anhydrous dichloromethane. Under an ice bath condition, chlorosulfonic acid was slowly added, reacted for 4 h, an appropriate amount of water and an aqueous solution of tetramethylammonium hydroxide were added, concentrated under reduced pressure, an aqueous solution of sodium perchlorate was added, sonicated, allowed to stand for liquid separation, and then filtered by suction to obtain a crude product of compound d. It was recrystallized with a mixed solvent of ethanol: water = 1:1 to obtain pure compound d.

[0044] The preparation method of the novel neutral detergent in this example is the same as that in Example 1.

[0045] Example 3

[0046] The novel detergent in this example comprises 15 parts of a sulfonic acid group crown ether chelating agent; 2 parts of a scale inhibitor; 2 parts of a surfactant; 4 parts of a pH buffer; and the balance is water. By weight ratio, the scale inhibitor comprises, by weight ratio, 50 parts of sodium polyacrylate and 30 parts of a copolymer of maleic anhydride. The surfactant is sorbitan fatty acid ester. The pH buffer comprises a 1:1 mixed solution of ammonium chloride - ammonia water.

[0047] Under a nitrogen atmosphere, 1.0 mol of 1,10-phenanthroline-3,8-diol, 2.5 mol of mono-OTs tetraethylene glycol, 4.6 mol of potassium carbonate powder, 34.0 mol of sodium iodide and acetonitrile solvent were successively added to a reaction flask. It was heated to 80 °C and refluxed for 10 h, filtered, and the solvent was evaporated to dryness to obtain a dark yellow oily initial product. It was dissolved in dichloromethane, filtered by suction and washed to obtain a black oily substance a. 1.0 mol of a, 5.0 mol of triethylamine and 0.2 mol of 4-dimethylaminopyridine were dissolved in dichloromethane. Under an ice bath condition, 2.3 mol of p-toluenesulfonyl chloride was slowly added. It was stirred at room temperature until a flocculent precipitate was formed, diluted, and the pH of the aqueous phase was adjusted to neutral with hydrochloric acid, extracted, concentrated under reduced pressure, and then column chromatographed with an eluent of ethyl acetate: petroleum ether (v:v = 2:1) to obtain a black oily substance b. Under a nitrogen atmosphere, 1.0 mol of compound b, 1.2 mol of 1,10-phenanthroline-3,8-diol and acetonitrile were placed in a constant pressure dropping funnel. 12.7 mol of potassium carbonate powder, a catalytic amount of sodium iodide and acetonitrile solvent were dissolved in a reaction flask, heated to 90 °C, slowly added dropwise, and refluxed for 14 h. After cooling, it was filtered by suction and the solvent was evaporated to dryness to obtain a solid powder. It was then dissolved in dichloromethane, filtered by suction, washed, and concentrated under reduced pressure. Column chromatography was carried out using ethyl acetate: petroleum ether (v:v = 1.5:1) to obtain a yellow product c. 1.0 g of c was dissolved in anhydrous dichloromethane. Under an ice bath condition, chlorosulfonic acid was slowly added and reacted for 4 h. An appropriate amount of water and an aqueous solution of tetramethylammonium hydroxide were added, concentrated under reduced pressure, and an aqueous solution of sodium perchlorate was continuously added. After ultrasonic treatment and standing for phase separation, it was filtered by suction to obtain a crude product of compound d, which was recrystallized with a mixed solvent of ethanol: water = 1:1 to obtain pure compound d.

[0048] The novel neutral detergent in this example is the same as that in Example 1.

[0049] Example 4

[0050] The novel detergent in this example includes 6 parts of sulfonic acid group crown ether chelating agent; 1 part of scale inhibitor; 2 parts of surfactant; 1 part of pH buffer; the rest is water. According to the weight part ratio, the scale inhibitor includes 50 parts of sodium polyacrylate and 30 parts of maleic anhydride copolymer according to the weight part ratio. The surfactant is sorbitan fatty acid ester. The pH buffer includes a 1:1 mixed solution of ammonium chloride - ammonia water. The sulfonic acid group crown ether chelating agent in this example is the same as that in Example 1.

[0051] Under a nitrogen atmosphere, 1.0 mol of 1,10-phenanthroline-3,8-diol, 2.3 mol of mono-OTs tetraethylene glycol, 4.6 mol of potassium carbonate powder, 34.0 mol of sodium iodide, and acetonitrile solvent were successively added to a reaction flask. The mixture was heated to 80 °C and refluxed for 12 h, then filtered and rotary evaporated to obtain a dark yellow oily initial product. The product was dissolved in dichloromethane, filtered with suction and washed to obtain a black oily substance a. 1.0 mol of a, 5.0 mol of triethylamine, and 0.2 mol of 4-dimethylaminopyridine were dissolved in dichloromethane. Under an ice bath condition, 2.3 mol of p-toluenesulfonyl chloride was slowly added. The mixture was stirred at room temperature until a flocculent precipitate formed, diluted, and the pH of the aqueous phase was adjusted to neutral with hydrochloric acid. Then, it was extracted and concentrated under reduced pressure. Column chromatography separation was performed using an eluent of ethyl acetate: petroleum ether (v:v = 2:1) to obtain a black oily substance b. Under a nitrogen atmosphere, 1.0 mol of compound b, 1.0 mol of 1,10-phenanthroline-3,8-diol, and acetonitrile were placed in a constant pressure dropping funnel. 12.7 mol of potassium carbonate powder, a catalytic amount of sodium iodide, and acetonitrile solvent were dissolved in a reaction flask. The temperature was raised to 90 °C, and the mixture was slowly added dropwise and refluxed for 14 h. After cooling, it was filtered with suction and rotary evaporated to obtain a solid powder. The solid powder was then dissolved in dichloromethane, filtered with suction, washed, and concentrated under reduced pressure. Column chromatography separation was performed using an eluent of ethyl acetate: petroleum ether (v:v = 1.5:1) to obtain a yellow product c. 1.0 g of c was dissolved in anhydrous dichloromethane. Under an ice bath condition, chlorosulfonic acid was slowly added and reacted for 4 h. Appropriate amounts of water and aqueous tetramethylammonium hydroxide were added, and it was concentrated under low pressure. An aqueous sodium perchlorate solution was continuously added, and it was ultrasonicated. After standing and separating layers, it was filtered with suction to obtain a crude product of compound d. Recrystallization was performed using a mixed solvent of ethanol: water = 1:1 to obtain pure compound d.

[0052] The preparation method of the novel neutral detergent in this example is the same as that in Example 1.

[0053] Example 5

[0054] The novel detergent in this example includes 9 parts of sulfonic acid group crown ether chelating agent; 2 parts of scale inhibitor; 2 parts of surfactant; 3 parts of pH buffer; and the rest is water. According to the weight ratio, the scale inhibitor includes 50 parts of sodium polyacrylate and 30 parts of maleic anhydride copolymer according to the weight ratio. The surfactant is sorbitan fatty acid ester. The pH buffer includes a 1:1 mixed solution of ammonium chloride - ammonia water. The sulfonic acid group crown ether chelating agent in this example is the same as that in Example 1.

[0055] A synthesis method of a sulfonic acid group crown ether chelating agent includes:

[0056] Under a nitrogen atmosphere, 1.0 mol of 1,10-phenanthroline-3,8-diol, 2.4 mol of mono-OTs tetraethylene glycol, 4.6 mol of potassium carbonate powder, 34.0 mol of sodium iodide, and the solvent acetonitrile were successively added to a reaction flask. It was heated to 80 °C, refluxed for 12 h, filtered, and rotary evaporated to obtain a dark yellow oily initial product, which was dissolved in dichloromethane, filtered by suction, and washed to obtain a black oily substance a. 1.0 mol of a, 5.0 mol of triethylamine, and 0.2 mol of 4-dimethylaminopyridine were weighed and dissolved in dichloromethane. Under an ice bath condition, 2.3 mol of p-toluenesulfonyl chloride was slowly added, and it was stirred at room temperature until a flocculent precipitate was formed. It was diluted, the pH of the aqueous phase was adjusted to neutral with hydrochloric acid, extracted, concentrated under reduced pressure, and then column chromatographically separated with an eluent of ethyl acetate: petroleum ether (v:v = 2:1) to obtain a black oily substance b. Under a nitrogen atmosphere, 1.0 mol of compound b, 1.1 mol of 1,10-phenanthroline-3,8-diol, and acetonitrile were charged into a constant pressure dropping funnel. 12.7 mol of potassium carbonate powder, a catalytic amount of sodium iodide, and an acetonitrile solvent were weighed and dissolved in a reaction flask, heated to 80 °C, slowly added dropwise, and refluxed for 12 h. After cooling, it was filtered by suction and rotary evaporated to obtain a solid powder, which was then dissolved in dichloromethane, filtered by suction, washed, and concentrated under reduced pressure. Column chromatographic separation was carried out using ethyl acetate: petroleum ether (v:v = 1.5:1) to obtain a yellow product c. 1.0 g of c was weighed and dissolved in anhydrous dichloromethane. Under an ice bath condition, chlorosulfonic acid was slowly added, and the reaction was carried out for 4 h. An appropriate amount of water and an aqueous solution of tetramethylammonium hydroxide were added and concentrated under low pressure. An aqueous solution of sodium perchlorate was continuously added, ultrasonicated, allowed to stand and separate layers, and then filtered by suction to obtain a crude product of compound d, which was recrystallized with a mixed solvent of ethanol: water = 1:1 to obtain pure compound d.

[0057] The preparation method of the novel scale inhibitor in this example is the same as that in Example 1.

[0058] Example 6

[0059] The novel scale inhibitor in this example comprises 9 parts of a sulfonic acid group crown ether chelating agent; 2 parts of a scale inhibitor; 3 parts of a surfactant; 4 parts of a pH buffer; and the rest is water. According to the weight part ratio, the scale inhibitor comprises, according to the weight part ratio, 50 parts of sodium polyacrylate and 30 parts of a copolymer of maleic anhydride. The surfactant is sorbitan fatty acid ester. The pH buffer comprises a 1:1 mixed solution of ammonium chloride - ammonia water. The sulfonic acid group crown ether chelating agent in this example is the same as that in Example 1.

[0060] A synthesis method of a sulfonic acid group crown ether chelating agent, comprising:

[0061] Under a nitrogen atmosphere, 1.0 mol of 1,10-phenanthroline-3,8-diol, 2.3 mol of mono-OTs tetraethylene glycol, 4.6 mol of potassium carbonate powder, 34.0 mol of sodium iodide, and the solvent acetonitrile were successively added to a reaction flask. It was heated to 90 °C and refluxed for 10 h, filtered, and the solvent was evaporated to dryness to obtain a dark yellow oily initial product. It was dissolved in dichloromethane, filtered by suction, and washed to obtain a black oily substance a. 1.0 mol of a, 5.0 mol of triethylamine, and 0.2 mol of 4-dimethylaminopyridine were dissolved in dichloromethane. Under an ice bath condition, 2.3 mol of p-toluenesulfonyl chloride was slowly added. It was stirred at room temperature until a flocculent precipitate was formed, diluted, and the pH of the aqueous phase was adjusted to neutral with hydrochloric acid, extracted, concentrated under reduced pressure, and then column chromatographed with an eluent of ethyl acetate: petroleum ether (v:v = 2:1) to obtain a black oily substance b. Under a nitrogen atmosphere, 1.0 mol of compound b, 1.0 mol of 1,10-phenanthroline-3,8-diol, and acetonitrile were placed in a constant pressure dropping funnel. 12.7 mol of potassium carbonate powder, a catalytic amount of sodium iodide, and an acetonitrile solvent were mixed and dissolved in a reaction flask, heated to 80 °C, slowly added dropwise, and refluxed for 12 h. After cooling, it was filtered by suction, the solvent was evaporated to dryness to obtain a solid powder, which was then dissolved in dichloromethane, filtered by suction, washed, concentrated under reduced pressure, and column chromatographed with ethyl acetate: petroleum ether (v:v = 1.5:1) to obtain a yellow product c. 1.0 g of c was dissolved in anhydrous dichloromethane. Under an ice bath condition, chlorosulfonic acid was slowly added and reacted for 4 h. An appropriate amount of water and an aqueous solution of tetramethylammonium hydroxide were added, concentrated under low pressure, and an aqueous solution of sodium perchlorate was continuously added. After ultrasonic treatment and standing for phase separation, it was filtered by suction to obtain a crude product of compound d, which was recrystallized with a mixed solvent of ethanol: water = 1:1 to obtain pure compound d.

[0062] The preparation method of the novel scale inhibitor in this example is the same as that in Example 1.

[0063] Example 7

[0064] The difference from Example 1 is that the novel scale inhibitor in this example includes 15 parts of sulfonic acid crown ether chelating agent; 1 part of scale inhibitor; 3 parts of surfactant; 4 parts of pH buffer; and the rest is water. By weight, the scale inhibitor includes, by weight, 50 parts of sodium polyacrylate and 30 parts of maleic anhydride copolymer.

[0065] Example 8

[0066] The difference from Example 1 is that the novel scale inhibitor in this example includes 14 parts of sulfonic acid crown ether chelating agent; 2 parts of scale inhibitor; 3 parts of surfactant; 2.5 parts of pH buffer; and the rest is water. By weight, the scale inhibitor includes, by weight, 60 parts of sodium polyacrylate and 20 parts of maleic anhydride copolymer.

[0067] Example 9

[0068] The difference from Example 1 is that the novel scale inhibitor in this example includes 15 parts of sulfonic acid group crown ether chelating agent; 2 parts of scale inhibitor; 3 parts of surfactant; 4 parts of pH buffer; and the rest is water. By weight, the scale inhibitor includes, by weight, 60 parts of sodium polyacrylate and 20 parts of copolymer of maleic anhydride.

[0069] Example 10

[0070] The difference from Example 1 is that the novel scale inhibitor in this example includes 9 parts of sulfonic acid group crown ether chelating agent; 2 parts of scale inhibitor; 2 parts of surfactant; 3 parts of pH buffer; and the rest is water. By weight, the scale inhibitor includes, by weight, 60 parts of sodium polyacrylate and 20 parts of copolymer of maleic anhydride.

[0071] Example 11

[0072] The difference from Example 1 is that the novel scale inhibitor in this example includes 10 parts of sulfonic acid group crown ether chelating agent; 2 parts of scale inhibitor; 3 parts of surfactant; 2 parts of pH buffer; and the rest is water. By weight, the scale inhibitor includes, by weight, 60 parts of sodium polyacrylate and 20 parts of copolymer of maleic anhydride.

[0073] Comparative Example 1

[0074] In Comparative Example 1, by weight, the novel scale inhibitor includes 15 parts of sulfonic acid group crown ether chelating agent; 3 parts of surfactant; 4 parts of surfactant; 4 parts of pH buffer; and the rest is water. The preparation method of the sulfonic acid group crown ether chelating agent and the scale inhibitor is the same as that in Example 1.

[0075] Comparative Example 2

[0076] In Comparative Example 2, by weight, the novel scale inhibitor includes 16 parts of sulfonic acid group crown ether chelating agent; 3 parts of scale inhibitor; 5 parts of pH buffer; and the rest is water. The composition of the scale inhibitor is the same as that in Example 1, and the preparation method of the sulfonic acid group crown ether chelating agent and the scale inhibitor is the same as that in Example 1.

[0077] Comparative Example 3

[0078] In Comparative Example 3, by weight, the novel scale inhibitor includes 13 parts of comparative crown ether chelating agent, and the structural formula (Ⅱ) is as follows, 2 parts of scale inhibitor, 3 parts of surfactant, 4 parts of pH buffer solution; and the rest is water. The composition of the scale inhibitor is the same as that in Example 1, and the preparation method of the crown ether chelating agent is as follows:

[0079]

[0080] The composition components of the novel scale inhibitors in Examples 1 to 11 and Comparative Examples of the present application and the scale dissolution rate test results for calcium carbonate scale and barium sulfate scale taken from a certain oilfield site are shown in Table 1. The experiments were carried out under the conditions of low temperature 80 °C and 180 °C respectively.

[0081] Table 1

[0082]

[0083] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A sulfonic acid group crown ether chelating agent, Characterized in that, It has the structure shown in formula (Ⅰ):

2. A preparation method of the sulfonic acid group crown ether chelating agent according to claim 1, Characterized in that, It includes the following steps: 1) Weigh 1,10-phenanthroline-3,8-diol, tetraethylene glycol mono-OTs, potassium carbonate powder and sodium iodide according to the molar ratio of 1:(2.3~2.5):(4.5~4.7):(33.0~35.0), and add them and the solvent acetonitrile into the reaction flask respectively. Heat to 80~90℃, reflux for 10~12h, filter, spin dry, obtain a dark yellow oily initial product, dissolve it in dichloromethane, filter by suction, wash, and obtain a black oily substance a, wherein, the mass ratio of acetonitrile to the total amount of reactants is equal; 2) Weigh a, triethylamine, 4-dimethylaminopyridine and p-toluenesulfonyl chloride in dichloromethane according to the molar ratio of 1:(4.5~5.5):(0.18~0.22):(2.1~2.5). Slowly add p-toluenesulfonyl chloride under ice bath conditions, stir at room temperature until a flocculent precipitate is formed, dilute, adjust the pH of the aqueous phase to neutral with hydrochloric acid, extract, concentrate under reduced pressure, and then carry out column chromatography separation with ethyl acetate: petroleum ether as the eluent to obtain a black oily substance b; 3) Under the condition of nitrogen atmosphere, weigh compound b and 1,10-phenanthroline-3,8-diol according to the molar ratio of 1.0:(1.0~1.2), and load them and acetonitrile into a constant pressure dropping funnel respectively. Then slowly add them into the reaction flask containing potassium carbonate powder, catalytic amount of sodium iodide and acetonitrile solvent. Raise the temperature to 80~90℃, react for 12~14h, cool, filter by suction, spin dry to obtain a solid powder, then dissolve it in dichloromethane, filter by suction, wash, concentrate under reduced pressure, and carry out column chromatography separation with ethyl acetate: petroleum ether to obtain a yellow product c, wherein, the mass ratio of acetonitrile to the total amount of reactants is equal; 4) Weigh 1.0 g of c and dissolve it in 80 mL of anhydrous dichloromethane. Slowly add 10 mL of chlorosulfonic acid under ice bath conditions. After reacting for 2.5~3.5 h, add 30 mL of water and 5 mL of saturated tetramethylammonium hydroxide aqueous solution, concentrate under low pressure, continue to add 20 mL of sodium perchlorate aqueous solution, ultrasonicate, let it stand for stratification, filter by suction, and obtain pure compound d after recrystallization, that is, the sulfonic acid group crown ether chelating agent.

3. A sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells, Characterized in that, It includes the following components in parts by weight: 5~15 parts of the sulfonic acid group crown ether chelating agent according to claim 1; 1~2 parts of scale inhibitor; 2~3 parts of surfactant; 1~4 parts of pH buffer; the total amount is 100 parts, and the rest is water.

4. The sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells according to claim 3, Characterized in that: The scale inhibitor is selected from the combination of sodium polyacrylate and copolymer of maleic anhydride.

5. The sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells according to claim 4, Characterized in that: The weight ratio of the scale inhibitor sodium polyacrylate and copolymer of maleic anhydride is (50~60):(20~30).

6. The sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells according to claim 3, It is characterized in that: The surfactant is sorbitan fatty acid ester.

7. The sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells according to claim 3, It is characterized in that: The pH buffer solution is a mixed solution of ammonium chloride and ammonia water, and sodium acetate.

8. The sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells according to claim 7, It is characterized in that: The pH buffer solution is a mixed solution of ammonium chloride and ammonia water with a mass ratio of 1:

1.

9. A preparation method of the sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells according to any one of claims 3 to 8, It is characterized in that, It includes the following steps: according to the amounts in the formula, add water into a reaction kettle, and successively add a sulfonic acid group crown ether chelating agent, a scale inhibitor, a surfactant, and half of the total amount of the pH buffer solution. Heat up to 80-90°C, stir for 30-60 minutes, then add the remaining pH buffer solution in batches. Measure the pH of the system midway. When the pH of the system reaches 7-8, stop adding the pH buffer solution, continue to stir for 25-35 minutes, stop, cool down, and obtain the sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells.

10. An application of the sulfonic acid group crown ether neutral scale inhibitor for oil and gas wells according to any one of claims 3 to 8, It is characterized in that: It is used to remove inorganic scale plugs in oil and gas wells under the conditions of 80-180°C.

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