Boron-resistant salt-tolerant polymer suspension emulsion and preparation method thereof

Abstract

The invention discloses an anti-boron salt-tolerant polymer suspension emulsion and a preparation method thereof, and relates to the technical field of suspension emulsions. The preparation method comprises the following steps: firstly, reacting 1, 3-bis (dimethylamino)-2-propanol with oxalyl chloride monoallyl ester to prepare double-bond modified tertiary amine when preparing the boron-resistant and salt-resistant polymer suspension emulsion; reacting the double-bond modified tertiary amine with propane sultone to prepare an amphoteric monomer; reacting the double-bond modified tertiary amine with 1-bromodecane to prepare a hydrophobic monomer; the preparation method comprises the following steps: copolymerizing acrylamide, maleic acid, an amphoteric monomer and a hydrophobic monomer to prepare modified polyacrylamide; and mixing the modified polyacrylamide, the slurry preparation soil, the polyacrylonitrile ammonium salt, the organic silanol, the emulsified paraffin and the boron inhibitor with water to prepare the boron-resistant and salt-resistant polymer suspension emulsion. The boron-resistant and salt-resistant polymer suspension emulsion prepared by the invention has the advantages of salt resistance, temperature resistance, good filtrate loss reduction performance and boron resistance.

Description

Technical Field

[0001] The invention relates to the technical field of suspension emulsions, in particular to a boron-proof and salt-resistant polymer suspension emulsion and a preparation method thereof. Background Art

[0002] As we all know, oil development operations have entered a phase of exploring for oil in deepwater, deep formations, and increasingly complex strata. This presents increasing challenges and places significantly higher demands on drilling, completion, workover, production, and oilfield wastewater treatment technologies. Drilling fluid, the lifeblood of drilling, plays an undeniable role in oil development operations. It carries cuttings, stabilizes the wellbore, cools the drill bit, and provides drag reduction and lubrication. However, the challenge facing drilling fluid technology is ensuring wellbore stability. Wellbore instability during development operations can have numerous adverse effects, significantly hindering the normal progress of drilling operations.

[0003] Statistics show that among the many factors contributing to wellbore instability, the majority of wellbore collapses are related to shale instability. Nearly 75% of the formations encountered during drilling are mud shale, leading some to refer to wellbore stability issues during drilling as mud shale instability. Mud shale is a fine-grained rock with very small pores, a high clay content, and is generally saturated with formation water, resulting in extremely low permeability. These characteristics significantly impact wellbore stability.

[0004] Suspension emulsion drilling fluid is formulated with an environmentally friendly, positively charged drilling fluid treatment agent, cationic emulsion polymer, emulsified paraffin, an organosilanol main agent, and other auxiliary agents. Through charge neutralization and the bridging effect of long-chain polymers, this drilling fluid significantly reduces the specific surface area and negative charge of clay, essentially eliminating the clay's water sensitivity. This effectively inhibits the expansion, dispersion, and migration of clay particles, stabilizing the clay. Combined with emulsified paraffin, it creates a synergistic effect of forming an extremely low-permeability shielding zone near the wellbore, reducing potential damage to the reservoir from filtrate and harmful solids, thereby preventing wellbore collapse and protecting the oil and gas formations.

[0005] Amphoteric polyelectrolytes, or polyampholytes, are polymers with both positively and negatively charged groups on their molecular chains. Because they carry both positive and negative charges on their chains after ionization, amphoteric polyelectrolytes possess excellent solubility, salt tolerance, acid and alkali resistance, crosslinking, and adsorption properties, making them widely used in the oil and gas extraction industry. Due to their unique structure, zwitterionic polymers can be used in combination with both anionic and cationic polymers. As drilling fluid treatment agents, zwitterionic polymers not only reduce fluid loss and viscosity, but also exhibit strong inhibitory properties, providing filtration and flocculation properties. Therefore, the use of suspensory emulsions and amphoteric polyelectrolytes in drilling fluids can effectively improve wellbore stability. Furthermore, in high-salt environments such as the deep sea, salt-gypsum deposits, and highly mineralized formation water, the suspensory emulsion also needs to be salt-tolerant to avoid demulsification failure caused by high salinity. Summary of the Invention

[0006] The purpose of the present invention is to provide a boron-proof and salt-resistant polymer suspension emulsion and a preparation method thereof, so as to solve the problems existing in the prior art.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: A boron-proof and salt-resistant polymer suspension emulsion is prepared by mixing modified polyacrylamide, slurry preparation soil, polyacrylonitrile ammonium salt, organosilanol, emulsified paraffin, and a boron-proof agent with water; The modified polyacrylamide is prepared by copolymerizing acrylamide, maleic acid, amphoteric monomers, and hydrophobic monomers; The amphoteric monomer is prepared by reacting a double-bond modified tertiary amine with propane sultone; The hydrophobic monomer is prepared by reacting a double-bond modified tertiary amine with 1-bromodecane; The double-bond modified tertiary amine is prepared by reacting 1,3-bis(dimethylamino)-2-propanol with monoallyl oxalyl chloride.

[0008] As an optimization, the slurry preparation soil is bentonite.

[0009] As an optimization, the anti-boron agent is a mixture of one or more of gypsum, potassium carbonate, Glauber's salt, potassium chloride, oxidized asphalt, sulfonated asphalt, cationic modified asphalt, emulsified asphalt, trichloromethylsilane, silicone fluoride and its modified preparations, ethylene oxide-propylene oxide copolymer, propylene oxide-polystyrene copolymer, polyvinyl alcohol, polypropylene alcohol, humic acid amide, potassium humate, and humic acid silicon.

[0010] A method for preparing a boron-proof and salt-resistant polymer suspension emulsion comprises the following preparation steps: (1) 1,3-bis(dimethylamino)-2-propanol and chloroform were mixed, triethylamine was added dropwise, hydroquinone was added, and the mixture was stirred. A 30 wt% chloroform solution of monoallyl oxalyl chloride was added dropwise in an ice-water bath, and the mixture was reacted for 10-12 hours. The mixture was heated and the reaction was continued for 10-12 hours. Sodium acetate was added and the reaction was continued for 20-24 hours. The mixture was filtered and the filtrate was dried by rotary evaporation. The mixture was extracted, washed, concentrated, and purified to obtain a double-bond modified tertiary amine. (2) Mixing the double-bond modified tertiary amine, hydroquinone, and acetone, adding dropwise 40 wt% propane sultone acetone solution, heating for reaction, filtering, washing, and drying to obtain an amphoteric monomer; (3) mixing a double-bond modified tertiary amine, 1-bromodecane, hydroquinone, potassium iodide, and acetonitrile, heating for reaction, rotary evaporation, recrystallization, and freeze drying to obtain a hydrophobic monomer; (4) acrylamide, maleic acid, emulsifier, and pure water are mixed, the pH is adjusted, and under a nitrogen atmosphere, an amphoteric monomer, a hydrophobic monomer, and an initiator are added, heated for reaction, naturally cooled, chopped, washed, dried, granulated, ground, and sieved to obtain modified polyacrylamide; (5) The formula of components by mass is as follows: slurry soil, 3%~5%; polyacrylonitrile ammonium salt, 0.5%~0.8%; organosilanol, 1%~1.5%; emulsified paraffin, 2%~3%; modified polyacrylamide, 0.3%~0.4%; anti-boron agent, 0.5%~2%; the balance is water; the slurry soil is prehydrated in 10 times the mass of water for 24 hours, and then polyacrylonitrile ammonium salt, organosilanol, emulsified paraffin, modified polyacrylamide, anti-boron agent and the remaining water are added, and stirred at 800~1000 rpm for 2~3 hours at room temperature to prepare a boron-proof and salt-resistant polymer suspension emulsion.

[0011] As an optimization, the double bond modified tertiary amine in step (1) is calculated by weight: 3-4 parts of 1,3-bis(dimethylamino)-2-propanol and 15-20 parts of chloroform are mixed evenly, and 2.28-3.04 parts of triethylamine are added dropwise at 7-8 ml / min at 200-300 r / min at room temperature, and then 0.016-0.018 parts of hydroquinone are added, and stirred at 200-300 r / min at room temperature for 20-30 minutes, and then transferred to an ice water bath, and 200-3 00r / min, 10.67~14.22 parts of 30wt% chloroform solution of monoallyl oxalyl chloride was added dropwise at 2~3ml / min, and the reaction was carried out at 200~300r / min for 10~12h at room temperature. The mixture was heated to 35~40℃ and the reaction was continued for 10~12h. 1~1.2 parts of sodium acetate was added and the reaction was continued for 20~24h. The mixture was filtered and the filtrate was dried by rotary evaporation. The filtrate was dissolved with dichloromethane, washed and extracted with saturated sodium chloride aqueous solution, and the organic phase was concentrated and purified to obtain the product.

[0012] As an optimization, the amphoteric monomer in step (2) is calculated by weight, and 3-4 parts of double-bond modified tertiary amine, 0.01-0.012 parts of hydroquinone, and 25-30 parts of acetone are mixed evenly. At room temperature, 7.8-10.4 parts of 40 wt% propane sultone acetone solution are added dropwise at 3-5 ml / min at 200-300 r / min. The mixture is reacted at 50-55°C and 300-400 r / min for 18-20 hours. The mixture is filtered and washed 3-4 times with a mixed solution of acetone and ether in a volume ratio of 1:1. The mixture is vacuum dried at 50-60°C for 8-10 hours.

[0013] As an optimization, the hydrophobic monomer in step (3) is prepared by uniformly mixing 5-6 parts of double-bond modified tertiary amine, 10.27-12.33 parts of 1-bromodecane, 0.015-0.017 parts of hydroquinone, 0.3-0.4 parts of potassium iodide, and 25-30 parts of acetonitrile in parts by mass, reacting at 40-45°C and 300-400 r / min for 20-24 h, rotary evaporation to remove the solvent, dissolving with ethanol, recrystallizing with methyl tert-butyl ether, and freeze-drying to obtain the product.

[0014] As an optimization, the modified polyacrylamide in step (4) is prepared by uniformly mixing 8-10 parts of acrylamide, 1.63-2.04 parts of maleic acid, 1.5-1.6 parts of emulsifier, and 20-25 parts of pure water, adjusting the pH to 7-8, adding 5-6.26 parts of amphoteric monomer, 2.46-3.08 parts of hydrophobic monomer, and 0.015-0.016 parts of initiator under a nitrogen atmosphere, reacting at 75-80°C and 300-400 r / min for 10-12 h, naturally cooling to room temperature, chopping, washing with anhydrous ethanol 4-5 times, vacuum drying at 60-65°C for 8-10 h, granulating and grinding with a high-speed crusher, and passing through a 120-mesh sieve to obtain the obtained product.

[0015] As an optimization, the model of the emulsifier in step (4) is OP-10.

[0016] As an optimization, the initiator in step (4) is one of azobisisobutyramidine hydrochloride and azobisisobutyronitrile.

[0017] Compared with the prior art, the present invention has the following beneficial effects: When preparing the boron-proof and salt-resistant polymer suspension emulsion, the present invention comprises the following steps: firstly reacting 1,3-bis(dimethylamino)-2-propanol with monoallyl oxalyl chloride to obtain a double-bond modified tertiary amine; reacting the double-bond modified tertiary amine with propane sultone to obtain an amphoteric monomer; reacting the double-bond modified tertiary amine with 1-bromodecane to obtain a hydrophobic monomer; copolymerizing acrylamide, maleic acid, the amphoteric monomer and the hydrophobic monomer to obtain a modified polyacrylamide; and adding water to the modified polyacrylamide, slurry preparation soil, polyacrylonitrile ammonium salt, organosilanol, emulsified paraffin and a boron-proof agent to mix to obtain the boron-proof and salt-resistant polymer suspension emulsion.

[0018] First, 1,3-bis(dimethylamino)-2-propanol reacts with allyl oxalyl chloride to produce a compound with a di-tertiary amine structure and a double bond. The di-tertiary amine structure facilitates the subsequent introduction of a dicationic structure, greatly improving the coverage of the cations. At the same time, the introduced double bond enables it to effectively participate in the copolymerization of polyacrylamide. At the same time, the two adjacent acyl groups in allyl oxalyl chloride have good hydrogen bonding, effectively improving the performance of fluid loss reduction.

[0019] Secondly, propane sultone undergoes a ring-opening reaction with the tertiary amine group on the double-bond modified tertiary amine to form an amphoteric betaine structure, while also introducing a sulfonic acid group. Due to its own structure, the sulfonic acid group has good salt resistance. At the same time, the amphoteric structure with both anions and cations has a significant "anti-polyelectrolyte effect", which also effectively improves the salt resistance. 1-Bromodecane undergoes a quaternization reaction with the double-bond modified tertiary amine to form a quaternary ammonium cation while introducing a long carbon chain. The hydrophobic monomer with a long carbon chain gives it some of the properties of an emulsifier. At the same time, the hydrophobic association effect makes the formed suspended emulsion have good stability and greatly improves the effect of reducing fluid loss.

[0020] Finally, acrylamide, maleic acid, amphoteric monomers, and hydrophobic monomers are copolymerized to form a modified polyacrylamide with an amphoteric structure and a low content of long carbon chain structure, which improves the salt resistance and filtration loss reduction performance. The prepared modified polyacrylamide is mixed with slurry soil, polyacrylonitrile ammonium salt, organosilanol, emulsified paraffin, boron inhibitor, and pure water to form a suspended emulsion system. This system has good application prospects in drilling fluids. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] The raw materials used in all the following examples and comparative examples are as follows: Slurry preparation soil: bentonite, purchased from Dongzheng Chemical Co., Ltd., Shangnan County, Shaanxi Province; Polyacrylonitrile ammonium salt: model NH4-HPAN, purchased from Dongzheng Chemical Co., Ltd., Shangnan County, Shaanxi Province; Organosilanol: model DS-302, purchased from Henan Longxiang Petroleum Additives Co., Ltd. Emulsified paraffin: Model RHJ-1, purchased from Henan Longxiang Petroleum Additives Co., Ltd. Emulsifier: OP-10; Initiator: azobisisobutylamidine hydrochloride; Boron inhibitor: potassium carbonate.

[0023] Example 1: A method for preparing a boron-proof and salt-resistant polymer suspension emulsion, the method for preparing the boron-proof and salt-resistant polymer suspension emulsion comprising the following preparation steps: (1) By weight, 3 parts of 1,3-bis(dimethylamino)-2-propanol and 15 parts of chloroform were mixed evenly. At room temperature, 200 r / min and 7 ml / min were used to dropwise add 2.28 parts of triethylamine, and then 0.016 parts of hydroquinone were added. At room temperature, 200 r / min was used to stir for 30 min. Then, the mixture was transferred to an ice-water bath and 10.67 parts of a 30 wt% chloroform solution of monoallyl oxalyl chloride was added dropwise at 200 r / min and 2 ml / min. At room temperature, 200 r / min was used to react for 12 h. The mixture was heated to 35 ° C and continued to react for 12 h. 1 part of sodium acetate was added and continued to react for 24 h. The mixture was filtered and the filtrate was spin-dried. After dissolving the mixture with dichloromethane, the mixture was washed and extracted with a saturated sodium chloride aqueous solution. The organic phase was concentrated and purified to obtain a double-bond modified tertiary amine. (2) By weight, 3 parts of double-bond modified tertiary amine, 0.01 parts of hydroquinone, and 25 parts of acetone were mixed evenly, and 7.8 parts of 40 wt% propane sultone acetone solution were added dropwise at 3 ml / min at 200 r / min at room temperature. The mixture was reacted at 50°C and 300 r / min for 20 h, filtered, and washed three times with a mixed solution of acetone and ether in a volume ratio of 1:1. The mixture was vacuum dried at 50°C for 10 h to obtain an amphoteric monomer. (3) By weight, 5 parts of double-bond modified tertiary amine, 10.27 parts of 1-bromodecane, 0.015 parts of hydroquinone, 0.3 parts of potassium iodide, and 25 parts of acetonitrile were mixed evenly, reacted at 40°C and 300 r / min for 24 h, and the solvent was removed by rotary evaporation. The mixture was dissolved in ethanol and recrystallized with methyl tert-butyl ether, and then freeze-dried to obtain a hydrophobic monomer. (4) By weight, 8 parts of acrylamide, 1.63 parts of maleic acid, 1.5 parts of emulsifier, and 20 parts of pure water were mixed evenly, and the pH was adjusted to 7. Under a nitrogen atmosphere, 5 parts of amphoteric monomer, 2.46 parts of hydrophobic monomer, and 0.015 parts of initiator were added. The mixture was reacted at 75°C and 300 r / min for 12 h, and naturally cooled to room temperature. The mixture was chopped, washed with anhydrous ethanol 4 times, and vacuum-dried at 60°C for 10 h. The mixture was granulated and ground into powder using a high-speed crusher, and passed through a 120-mesh sieve to obtain modified polyacrylamide. (5) The formula of components by mass is as follows: slurry soil, 3%; ammonium polyacrylonitrile, 0.8%; organosilanol, 1%; emulsified paraffin, 3%; modified polyacrylamide, 0.3%; anti-boron agent, 0.5%; the balance is water; the slurry soil is prehydrated in 10 times the mass of water for 24 hours, and then ammonium polyacrylonitrile, organosilanol, emulsified paraffin, modified polyacrylamide, anti-boron agent and the remaining water are added, and stirred at 800 rpm for 3 hours at room temperature to prepare a boron-proof and salt-resistant polymer suspension emulsion.

[0024] Example 2: A method for preparing a boron-proof and salt-resistant polymer suspension emulsion, the method for preparing the boron-proof and salt-resistant polymer suspension emulsion comprising the following preparation steps: (1) By weight, 3.5 parts of 1,3-bis(dimethylamino)-2-propanol and 18 parts of chloroform were mixed evenly. At room temperature, 250 r / min and 7.5 ml / min were used to dropwise add 2.66 parts of triethylamine, and then 0.017 parts of hydroquinone were added. At room temperature, 250 r / min and stirred for 25 min. Then, the mixture was transferred to an ice-water bath and 250 r / min and 2.5 ml / min were used to dropwise add 12.44 parts of a 30 wt% chloroform solution of monoallyl oxalyl chloride. The mixture was reacted at room temperature and 250 r / min for 11 h. The mixture was heated to 38 ° C and continued to react for 11 h. 1.1 parts of sodium acetate was added and continued to react for 22 h. The mixture was filtered and the filtrate was spin-dried. After dissolving the mixture with dichloromethane, the mixture was washed and extracted with a saturated sodium chloride aqueous solution. The organic phase was concentrated and purified to obtain a double-bond modified tertiary amine. (2) By weight, 3.5 parts of double-bond modified tertiary amine, 0.011 parts of hydroquinone, and 28 parts of acetone were mixed evenly, and 9.1 parts of 40 wt% propane sultone acetone solution were added dropwise at 250 r / min at room temperature and 4 ml / min, and the mixture was reacted at 52°C and 350 r / min for 19 h. The mixture was filtered and washed three times with a mixed solution of acetone and ether in a volume ratio of 1:1, and dried in vacuo at 55°C for 9 h to obtain an amphoteric monomer. (3) By weight, 5.5 parts of double-bond modified tertiary amine, 11.3 parts of 1-bromodecane, 0.016 parts of hydroquinone, 0.35 parts of potassium iodide, and 28 parts of acetonitrile were mixed evenly, reacted at 42°C and 350 r / min for 22 h, and the solvent was removed by rotary evaporation. The mixture was dissolved in ethanol and recrystallized with methyl tert-butyl ether, and then freeze-dried to obtain a hydrophobic monomer. (4) By weight, 9 parts of acrylamide, 1.84 parts of maleic acid, 1.55 parts of emulsifier, and 22 parts of pure water were mixed evenly, and the pH was adjusted to 7.5. Under a nitrogen atmosphere, 5.63 parts of amphoteric monomer, 2.77 parts of hydrophobic monomer, and 0.0155 parts of initiator were added. The mixture was reacted at 78°C and 350 r / min for 11 h, and naturally cooled to room temperature. The mixture was chopped, washed with anhydrous ethanol 4 times, and vacuum-dried at 60°C for 9 h. The mixture was granulated and ground into powder using a high-speed grinder, and passed through a 120-mesh sieve to obtain modified polyacrylamide. (5) The formula of components by mass is as follows: slurry soil, 4%; polyacrylonitrile ammonium salt, 0.6%; organosilanol, 1.2%; emulsified paraffin, 2.5%; modified polyacrylamide, 0.35%; anti-boron agent, 1.2%; the balance is water; the slurry soil is prehydrated in 10 times the mass of water for 24 hours, and then polyacrylonitrile ammonium salt, organosilanol, emulsified paraffin, modified polyacrylamide, anti-boron agent and the remaining water are added, and stirred at 900 rpm for 2.5 hours at room temperature to prepare a boron-proof and salt-resistant polymer suspension emulsion.

[0025] Example 3: A method for preparing a boron-proof and salt-resistant polymer suspension emulsion, the method for preparing the boron-proof and salt-resistant polymer suspension emulsion comprising the following preparation steps: (1) By weight, 4 parts of 1,3-bis(dimethylamino)-2-propanol and 20 parts of chloroform were mixed evenly. At room temperature, 300 r / min and 8 ml / min were used to dropwise add 3.04 parts of triethylamine, and then 0.018 parts of hydroquinone were added. At room temperature, 300 r / min and stirred for 20 min. Then, the mixture was transferred to an ice-water bath and 300 r / min and 3 ml / min were used to dropwise add 14.22 parts of a 30 wt% chloroform solution of monoallyl oxalyl chloride. The mixture was reacted at room temperature and 300 r / min for 10 h. The mixture was heated to 40°C and continued to react for 10 h. 1.2 parts of sodium acetate were added and continued to react for 20 h. The mixture was filtered and the filtrate was spin-dried. The mixture was dissolved with dichloromethane and washed and extracted with a saturated sodium chloride aqueous solution. The organic phase was concentrated and purified to obtain a double-bond modified tertiary amine. (2) By weight, 4 parts of double-bond modified tertiary amine, 0.012 parts of hydroquinone, and 30 parts of acetone were mixed evenly, and 10.4 parts of 40 wt% propane sultone acetone solution were added dropwise at 5 ml / min at 300 r / min at room temperature. The mixture was reacted at 55°C and 400 r / min for 18 h, filtered, and washed four times with a mixed solution of acetone and ether in a volume ratio of 1:1. The mixture was vacuum dried at 60°C for 8 h to obtain an amphoteric monomer. (3) By weight, 6 parts of double-bond modified tertiary amine, 12.33 parts of 1-bromodecane, 0.017 parts of hydroquinone, 0.4 parts of potassium iodide, and 30 parts of acetonitrile were mixed evenly, reacted at 45°C and 400 r / min for 20 h, and the solvent was removed by rotary evaporation. The mixture was dissolved in ethanol and recrystallized with methyl tert-butyl ether, and then freeze-dried to obtain a hydrophobic monomer. (4) By weight, 10 parts of acrylamide, 2.04 parts of maleic acid, 1.6 parts of emulsifier, and 25 parts of pure water were mixed evenly, and the pH was adjusted to 8. Under a nitrogen atmosphere, 6.26 parts of amphoteric monomer, 3.08 parts of hydrophobic monomer, and 0.016 parts of initiator were added. The mixture was reacted at 80°C and 400 r / min for 10 h, and naturally cooled to room temperature. The mixture was chopped, washed with anhydrous ethanol 5 times, and vacuum-dried at 65°C for 8 h. The mixture was granulated and ground into powder using a high-speed crusher, and passed through a 120-mesh sieve to obtain modified polyacrylamide. (5) The formula of components by mass is as follows: slurry soil, 5%; polyacrylonitrile ammonium salt, 0.5%; organosilanol, 1.5%; emulsified paraffin, 2%; modified polyacrylamide, 0.4%; anti-boron agent, 2%; the balance is water; the slurry soil is prehydrated in 10 times the mass of water for 24 hours, and then polyacrylonitrile ammonium salt, organosilanol, emulsified paraffin, modified polyacrylamide, anti-boron agent and the remaining water are added, and stirred at 1000 rpm for 2 hours at room temperature to prepare a boron-proof and salt-resistant polymer suspension emulsion.

[0026] Comparative Example 1: The difference between the preparation method of the boron-resistant and salt-resistant polymer suspension emulsion of Comparative Example 1 and Example 2 lies in the difference in step (1). Step (1) is modified as follows: 3.5 parts of 1,3-bis(dimethylamino)-2-propanol and 18 parts of chloroform are mixed uniformly by mass, 2.66 parts of triethylamine are added dropwise at 7.5 ml / min at 250 r / min at room temperature, and 0.017 parts of hydroquinone are added. At room temperature, the mixture is stirred at 250 r / min for 25 minutes. n, then transferred to an ice-water bath, at 250 r / min, 12.44 parts of a 30 wt% acryloyl chloride solution in chloroform was added dropwise at 2.5 ml / min, and the reaction was continued at room temperature at 250 r / min for 11 hours. The mixture was heated to 38° C. and the reaction was continued for 11 hours. 1.1 parts of sodium acetate was added and the reaction was continued for 22 hours. The mixture was filtered with suction, and the filtrate was spin-dried to dryness, dissolved with dichloromethane, washed and extracted with a saturated sodium chloride aqueous solution, and the organic phase was concentrated and purified to obtain a double-bond modified tertiary amine. The remaining steps were the same as in Example 2.

[0027] Comparative Example 2: The method for preparing the boron-resistant and salt-resistant polymer suspension emulsion of Comparative Example 2 differs from that of Example 2 in that step (2) is omitted and step (4) is modified as follows: 9 parts of acrylamide, 1.84 parts of maleic acid, 1.55 parts of emulsifier, and 22 parts of pure water are mixed uniformly by mass, the pH is adjusted to 7.5, 2.77 parts of hydrophobic monomer and 0.0155 parts of initiator are added under a nitrogen atmosphere, the mixture is reacted at 78°C and 350 rpm for 11 hours, the mixture is naturally cooled to room temperature, the mixture is chopped, washed with anhydrous ethanol four times, vacuum-dried at 60°C for 9 hours, granulated and ground with a high-speed grinder, and passed through a 120-mesh sieve to obtain modified polyacrylamide. The remaining steps are the same as those of Example 2.

[0028] Comparative Example 3: The method for preparing the boron-resistant and salt-resistant polymer suspension emulsion of Comparative Example 3 differs from that of Example 2 in that step (3) is omitted and step (4) is modified as follows: 9 parts of acrylamide, 1.84 parts of maleic acid, 1.55 parts of emulsifier, and 22 parts of pure water are mixed uniformly by mass, the pH is adjusted to 7.5, 5.63 parts of amphoteric monomer and 0.0155 parts of initiator are added under a nitrogen atmosphere, the mixture is reacted at 78°C and 350 rpm for 11 hours, the mixture is naturally cooled to room temperature, the mixture is chopped, washed with anhydrous ethanol four times, vacuum-dried at 60°C for 9 hours, granulated and ground with a high-speed grinder, and passed through a 120-mesh sieve to obtain modified polyacrylamide. The remaining steps are the same as those of Example 2.

[0029] Comparative Example 4: The method for preparing the boron-resistant and salt-resistant polymer suspension emulsion of Comparative Example 4 differs from that of Example 2 in that step (2) is omitted and step (4) is modified as follows: 9 parts by mass of acrylamide, 1.55 parts of emulsifier, and 22 parts of pure water are uniformly mixed, the pH is adjusted to 7.5, 2.46 parts of methacryloyloxyethyltrimethylammonium chloride, 2.77 parts of hydrophobic monomer, and 0.0155 parts of initiator are added under a nitrogen atmosphere, the mixture is reacted at 78°C and 350 rpm for 11 hours, the mixture is naturally cooled to room temperature, the mixture is chopped, washed with anhydrous ethanol four times, vacuum-dried at 60°C for 9 hours, granulated and ground with a high-speed grinder, and passed through a 120-mesh sieve to obtain modified polyacrylamide. The remaining steps are the same as those of Example 2.

[0030] Test Example 1: Salt resistance and temperature resistance test: The apparent viscosity, temperature resistance viscosity retention rate and salt resistance viscosity retention rate of the prepared boron-resistant and salt-resistant polymer suspension emulsion were tested to evaluate its temperature resistance and salt resistance. The specific test methods are as follows: Apparent viscosity: 500 ml of the prepared boron-resistant and salt-resistant polymer suspension emulsion was taken into a beaker and measured using a ZNND six-speed rotational viscometer at room temperature and a shear rate of 170 s -1 The apparent viscosity under the test conditions was tested 5 times in parallel for each group of samples, and the average value was recorded; Temperature resistance: The prepared boron-resistant and salt-resistant polymer suspension emulsion was heated at 90°C for 2h, and its shear rate was measured by a ZNND six-speed rotation viscometer at 170s -1 The viscosity under the temperature is measured and the viscosity retention rate is calculated and recorded as the temperature-resistant viscosity retention rate. Each group is tested 5 times in parallel and the average value is recorded. Salt resistance: The inorganic salt ratio is 5.5% sodium chloride + 2.0% potassium chloride + 0.45% magnesium chloride + 0.55% calcium chloride to prepare a standard brine with a mineralization degree of 85000 mg / L. The water in step (5) is replaced with the standard brine to prepare a sample. The ZNND six-speed rotation viscometer is used to measure the viscosity at room temperature and a shear rate of 170s. -1 The viscosity under the conditions of 100 μg / ml was measured and the viscosity retention rate was calculated and recorded as the salt-resistant viscosity retention rate. Each group was tested 5 times in parallel and the average value was recorded.

[0031] The results are shown in Table 1.

[0032] Table 1 Apparent viscosity / mPa·s Temperature resistant viscosity retention rate Salt-resistant viscosity retention rate Example 1 38.5 90.71% 126.39% Example 2 39.4 91.94% 127.29% Example 3 38.8 90.88% 125.44% Comparative Example 1 37.3 89.37% 121.57% Comparative Example 2 30.1 76.24% 73.24% Comparative Example 3 31.6 83.49% 114.68% Comparative Example 4 33.7 69.32% 44.89% From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 4 in Table 1, it can be found that the boron-proof and salt-resistant polymer suspension emulsion prepared in the present invention has good salt resistance and temperature resistance.

[0033] By comparing the data in the table, the data of Comparative Example 2 show that the addition of the amphoteric monomer increases the apparent viscosity, and at the same time, its anti-polyelectrolyte effect plays a role. Under high salt concentration conditions, the viscosity increases instead of decreases, showing good salt resistance, and the amphoteric monomers are self-associated together by electrostatic force, effectively improving the temperature resistance; the data of Comparative Example 3 show that after the long carbon chain in the hydrophobic monomer is added, it has a better emulsification effect due to the increase in lipophilicity, and the temperature resistance and salt resistance are improved; the data of Comparative Example 4 show that the sulfonic acid group and the carboxyl group provided by maleic acid have good synergistic ability with the quaternary ammonium cation. In the case of only cations, it does not have an anti-polyelectrolyte effect, and the temperature resistance and salt resistance are greatly reduced.

[0034] Test Example 2: Fluid loss reduction performance test: The room temperature medium pressure filtration loss of the prepared boron-resistant and salt-resistant polymer suspension emulsion was tested with reference to SY / T 5621-1993. Each group was tested 5 times in parallel and the average value was recorded.

[0035] The results are shown in Table 2.

[0036] Table 2 Medium pressure filtration loss at room temperature / ml Medium pressure filtration loss at room temperature / ml Example 1 4.1 Comparative Example 1 8.4 Example 2 3.9 Comparative Example 2 14.5 Example 3 4.2 Comparative Example 3 6.9 Comparative Example 4 7.8 From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 4 in Table 2, it can be found that the boron-proof and salt-resistant polymer suspension emulsion prepared in the present invention has good fluid loss reduction performance.

[0037] By comparing the data in the table, the data of Comparative Example 1 shows that the addition of monoallyl oxalyl chloride has better hydrogen bonding and complexing ability, and has a better effect than acryloyl chloride, effectively improving the fluid loss control performance; the data of Comparative Example 2 shows that the amphoteric monomer not only binds to the clay through hydrogen bonds, but also adsorbs on the clay surface through electrostatic adsorption, and anions such as carboxyl and sulfonic acid groups prevent free water molecules from contacting clay particles through hydration, effectively improving the fluid loss control performance; the data of Comparative Example 3 shows that the introduction of hydrophobic monomers also improves the fluid loss control performance. The hydrophobic effect of the long carbon chain enables it to prevent free water from penetrating into clay particles through hydrophobic association in a small range, thereby reducing the fluid loss amount; the data of Comparative Example 4 shows that when only cations are present, its fluid loss control performance is insufficient, and it is necessary to synergize with anions such as sulfonic acid groups and carboxyl groups to exert the effect of its amphoteric polymer to better improve the fluid loss control effect.

[0038] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A boron-proof and salt-resistant polymer suspension emulsion, characterized in that: The boron-proof and salt-resistant polymer suspension emulsion is prepared by mixing modified polyacrylamide, slurry preparation soil, polyacrylonitrile ammonium salt, organic silicon alcohol, emulsified paraffin, and a boron-proof agent with water; The modified polyacrylamide is prepared by copolymerizing acrylamide, maleic acid, amphoteric monomers, and hydrophobic monomers; The amphoteric monomer is prepared by reacting a double-bond modified tertiary amine with propane sultone; The hydrophobic monomer is prepared by reacting a double-bond modified tertiary amine with 1-bromodecane; The double-bond modified tertiary amine is prepared by reacting 1,3-bis(dimethylamino)-2-propanol with monoallyl oxalyl chloride.

2. A boron-proof and salt-resistant polymer suspension emulsion according to claim 1, characterized in that, The slurry preparation soil is bentonite.

3. A boron-proof and salt-resistant polymer suspension emulsion according to claim 1, characterized in that: The anti-boron agent is one or a mixture of gypsum, potassium carbonate, sodium sulfate, potassium chloride, oxidized asphalt, sulfonated asphalt, cationic modified asphalt, emulsified asphalt, trichloromethylsilane, silicon fluoride and its modified preparations, ethylene oxide-propylene oxide copolymer, propylene oxide-polystyrene copolymer, polyvinyl alcohol, polypropylene alcohol, humic acid amide, potassium humate, and humic acid silicon.

4. A method for preparing a boron-proof and salt-resistant polymer suspension emulsion, characterized in that: The method comprises the following preparation steps: (1) 1,3-bis(dimethylamino)-2-propanol and chloroform were mixed, triethylamine was added dropwise, hydroquinone was added, and the mixture was stirred. A 30 wt% chloroform solution of monoallyl oxalyl chloride was added dropwise in an ice-water bath, and the mixture was reacted for 10-12 hours. The mixture was heated and the reaction was continued for 10-12 hours. Sodium acetate was added and the reaction was continued for 20-24 hours. The mixture was filtered and purified to obtain a double-bond modified tertiary amine. (2) Mixing the double-bond modified tertiary amine, hydroquinone, and acetone, adding dropwise 40 wt% propane sultone acetone solution, heating for reaction, filtering, washing, and drying to obtain an amphoteric monomer; (3) mixing a double-bond modified tertiary amine, 1-bromodecane, hydroquinone, potassium iodide, and acetonitrile, heating for reaction, rotary evaporation, recrystallization, and freeze drying to obtain a hydrophobic monomer; (4) acrylamide, maleic acid, emulsifier, and pure water are mixed, the pH is adjusted, and under a nitrogen atmosphere, an amphoteric monomer, a hydrophobic monomer, and an initiator are added, heated for reaction, naturally cooled, chopped, washed, dried, granulated, ground, and sieved to obtain modified polyacrylamide; (5) The formula of components by mass is: slurry soil, 3%~5%; polyacrylonitrile ammonium salt, 0.5%~0.8%; Organosilanol, 1%~1.5%; emulsified paraffin, 2%~3%; modified polyacrylamide, 0.3%~0.4%; anti-boron agent, 0.5%~2%; the balance is water; the slurry soil is prehydrated in 10 times the mass of water for 24 hours, and then polyacrylonitrile ammonium salt, organosilanol, emulsified paraffin, modified polyacrylamide, anti-boron agent and the remaining water are added, and stirred at 800~1000 rpm at room temperature for 2~3 hours to prepare a boron-proof and salt-resistant polymer suspension emulsion.

5. The method for preparing a boron-proof and salt-resistant polymer suspension emulsion according to claim 4, wherein The double bond modified tertiary amine in step (1) is prepared by mixing 3 to 4 parts of 1,3-bis(dimethylamino)-2-propanol and 15 to 20 parts of chloroform uniformly, adding 2.28 to 3.04 parts of triethylamine at 7 to 8 ml / min at 200 to 300 r / min at room temperature, and then adding 0.016 to 0.018 parts of hydroquinone, stirring at 200 to 300 r / min for 20 to 30 minutes at room temperature. in, then transferred to an ice water bath, 200-300 r / min, 10.67-14.22 parts of a 30wt% chloroform solution of monoallyl oxalyl chloride was added dropwise at 2-3 ml / min, and the mixture was reacted at 200-300 r / min for 10-12 h at room temperature, heated to 35-40°C, and continued to react for 10-12 h. 1-1.2 parts of sodium acetate was added, and the reaction was continued for 20-24 h. The mixture was filtered and purified to obtain the product.

6. The method for preparing a boron-proof and salt-resistant polymer suspension emulsion according to claim 4, wherein: The amphoteric monomer in step (2) is obtained by uniformly mixing 3 to 4 parts of double-bond modified tertiary amine, 0.01 to 0.012 parts of hydroquinone and 25 to 30 parts of acetone by weight, adding 7.8 to 10.4 parts of 40 wt% propane sultone acetone solution dropwise at 3 to 5 ml / min at 200 to 300 r / min at room temperature, reacting at 50 to 55° C. and 300 to 400 r / min for 18 to 20 hours, filtering, washing 3 to 4 times with a mixed solution of acetone and ether in a volume ratio of 1:1, and vacuum drying at 50 to 60° C. for 8 to 10 hours.

7. The method for preparing a boron-proof and salt-resistant polymer suspension emulsion according to claim 4, wherein: The hydrophobic monomer in step (3) is prepared by uniformly mixing 5 to 6 parts of double-bond modified tertiary amine, 10.27 to 12.33 parts of 1-bromodecane, 0.015 to 0.017 parts of hydroquinone, 0.3 to 0.4 parts of potassium iodide, and 25 to 30 parts of acetonitrile, in parts by mass, reacting at 40 to 45° C. and 300 to 400 r / min for 20 to 24 hours, rotary evaporation to remove the solvent, dissolving with ethanol, recrystallizing with methyl tert-butyl ether, and freeze-drying.

8. The method for preparing a boron-proof and salt-resistant polymer suspension emulsion according to claim 4, wherein: The modified polyacrylamide in step (4) is prepared by uniformly mixing 8 to 10 parts of acrylamide, 1.63 to 2.04 parts of maleic acid, 1.5 to 1.6 parts of emulsifier, and 20 to 25 parts of pure water, adjusting the pH to 7 to 8, adding 5 to 6.26 parts of amphoteric monomer, 2.46 to 3.08 parts of hydrophobic monomer, and 0.015 to 0.016 parts of initiator under a nitrogen atmosphere, reacting at 75 to 80° C. and 300 to 400 r / min for 10 to 12 hours, naturally cooling to room temperature, chopping, washing with anhydrous ethanol for 4 to 5 times, vacuum drying at 60 to 65° C. for 8 to 10 hours, granulating and grinding with a high-speed crusher, and passing through a 120-mesh sieve.

9. The method for preparing a boron-proof and salt-resistant polymer suspension emulsion according to claim 4, wherein: The model of the emulsifier in step (4) is OP-10.

10. The method for preparing a boron-proof and salt-resistant polymer suspension emulsion according to claim 4, characterized in that: The initiator in step (4) is one of azobisisobutyramidine hydrochloride and azobisisobutyronitrile.