阅读说明：本技术 钻井液用抗高温抗盐降滤失剂四元聚合物 (High-temperature-resistant salt-resistant filtrate reducer quadripolymer for drilling fluid ) 是由 柳云涛 于 2020-08-07 设计创作，主要内容包括：本发明公开一种钻井液用抗高温抗盐降滤失剂四元聚合物,由如下重量份原料制成：去离子水100-200份、2-甲基-2丙烯酰胺基丙磺酸钠20-30份、丙烯酸钠8-10份、N-乙烯基吡咯烷酮11-15份、过硫酸铵40-60份、亚硫酸氢钠40-60份、大分子单体10-14份和引发剂0.1-0.5份；大分子单体表面带正电荷,且引入了有机硅官能团,提高了降滤失剂的抗高温性能,且该钻井液用抗高温抗盐降滤失剂四元聚合物的侧链的C-C、C-S和C-N等结构,进一步提高了聚合物的抗温性能；侧链上还引入了磺酸基团和羧酸基团,增强了降滤失剂在高温和高矿化度下的水解能力和抗高温抗盐能力。(The invention discloses a high-temperature-resistant salt-resistant filtrate reducer quaternary polymer for drilling fluid, which is prepared from the following raw materials in parts by weight: 100 portions of deionized water, 20 to 30 portions of 2-methyl-2 acrylamide propyl sodium sulfonate, 8 to 10 portions of sodium acrylate, 11 to 15 portions of N-vinyl pyrrolidone, 40 to 60 portions of ammonium persulfate, 40 to 60 portions of sodium bisulfite, 10 to 14 portions of macromonomer and 0.1 to 0.5 portion of initiator; the surface of the macromonomer is positively charged, and an organic silicon functional group is introduced, so that the high temperature resistance of the filtrate reducer is improved, and the high temperature resistance of the polymer is further improved by adopting the structures of C-C, C-S, C-N and the like of the side chain of the high temperature resistant salt-resistant filtrate reducer tetrapolymer for the drilling fluid; the side chain is also introduced with sulfonic acid group and carboxylic acid group, thus enhancing the hydrolytic capability and high-temperature resistance and salt resistance of the fluid loss additive under high temperature and high mineralization.)

1. The high-temperature-resistant salt-resistant filtrate reducer quaternary polymer for the drilling fluid is characterized by being prepared from the following raw materials in parts by weight: 100 portions of deionized water, 20 to 30 portions of 2-methyl-2 acrylamide propyl sodium sulfonate, 8 to 10 portions of sodium acrylate, 11 to 15 portions of N-vinyl pyrrolidone, 40 to 60 portions of ammonium persulfate, 40 to 60 portions of sodium bisulfite, 10 to 14 portions of macromonomer and 0.1 to 0.5 portion of initiator;

the high-temperature-resistant salt-resistant filtrate reducer quadripolymer for the drilling fluid is prepared by the following steps:

step one, adding deionized water into a four-neck flask, then sequentially adding 2-methyl-2-acrylamido propanesulfonic acid sodium salt, sodium acrylate, N-vinyl pyrrolidone, ammonium persulfate and sodium bisulfite, and stirring for 30min under the conditions that the rotating speed is 300-400r/min and the temperature is 25-30 ℃ to obtain a first mixed solution;

secondly, adding sodium hydroxide with the mass fraction of 40% into the first mixed solution to adjust the pH value of the system to be 7-9, setting the temperature to be 50-70 ℃ and the rotating speed to be 400r/min, and reacting for 4-6h to obtain a second mixed solution;

and thirdly, adding a macromonomer and an initiator into the second mixed solution under the protection of nitrogen, setting the temperature to be 30-60 ℃ and the rotating speed to be 350-plus-450 r/min, reacting for 4-12h, washing for three times by using absolute ethyl alcohol, and drying at the temperature of 100-plus-120 ℃ to constant weight to prepare the high-temperature-resistant salt-resistant filtrate reducer quaternary polymer for the drilling fluid.

2. The high temperature and salt resistant fluid loss additive tetrapolymer for drilling fluid according to claim 1, wherein the macromonomer is prepared by the steps of:

s11, adding phenylhydroxylamine and potassium iodide into a three-neck flask, stirring in an ice-water bath, setting the rotation speed to be 100-200r/min, dropwise adding epoxy chloropropane while stirring, keeping the rotation speed unchanged after the epoxy chloropropane is dropwise added, continuing to react for 2-3h in the ice-water bath, standing for 6-7 days at the temperature of 20-30 ℃ under the condition of keeping out of the sun after the reaction is finished, separating lower-layer viscous liquid by using a separating funnel, and washing the viscous liquid for three times by using ether to obtain a mixture A;

s12, adding sodium carboxymethyl starch and absolute ethyl alcohol into a three-mouth bottle, setting the rotation speed at 250-300r/min, stirring for 20min at the temperature of 25 ℃, adding deionized water and a sodium hydroxide solution with the mass fraction of 20% into the three-mouth bottle, raising the temperature to 60-70 ℃, adding dodecyl dimethyl benzyl ammonium chloride and the mixture A, keeping the rotation speed unchanged, stirring for 4-6h, cooling to 20-30 ℃, washing for three times by using the absolute ethyl alcohol, and drying at the temperature of 100-120 ℃ to constant weight to obtain a mixture B;

s13, adding the mixture B into a three-neck flask, firstly adding absolute ethyl alcohol, uniformly stirring, then adding dimethyl sulfoxide and toluene, uniformly stirring, adjusting the pH value to 3-5 by using 1mol/L hydrochloric acid solution, setting the temperature to be 60-70 ℃, introducing nitrogen, dropwise adding hexamethyldisilazane under the protection of nitrogen, reacting for 7-9h, cooling to 25 ℃, standing and filtering to obtain a precipitate, washing the precipitate for three times by using absolute ethyl alcohol, and drying at the temperature of 100 ℃ and 120 ℃ to constant weight to obtain the macromonomer.

3. The high temperature and salt resistant fluid loss additive tetrapolymer for drilling fluid according to claim 2, wherein the amount ratio of the substances of phenylhydroxylamine, potassium iodide and epichlorohydrin in step S11 is 1: 50-60: 10-13, and the epoxy chloropropane is dripped in 40 min; in the step S12, the mass ratio of the sodium carboxymethyl starch, the absolute ethyl alcohol, the deionized water, the sodium hydroxide solution with the mass fraction of 20%, the dodecyl dimethyl benzyl ammonium chloride and the mixture A is 4: 0.03: 26-30: 2-4: 1: 4; in the step S13, the mass ratio of the mixture B to the absolute ethyl alcohol to the dimethyl sulfoxide to the toluene to the hexamethyldisilazane is 4: 3: 26-30: 16-20: 2.

4. the high temperature and salt resistant filtrate reducer tetrapolymer for drilling fluid according to claim 1, wherein the average molecular weight of the prepared high temperature and salt resistant filtrate reducer tetrapolymer for drilling fluid is 800 ten thousand.

Technical Field

The invention belongs to the technical field of preparation of filtrate reducer, and particularly relates to a high-temperature-resistant salt-resistant filtrate reducer quaternary polymer for drilling fluid.

Background

As the depth of the formation increases, the formation temperature increases and during drilling, saline formations are often encountered. The polymer filtrate reducer molecule mainly ensures the stability and the multi-stage dispersibility of the drilling fluid through the action of functional groups on the side chain and clay particles, thereby leading the drilling fluid to form compact and low-permeability mud cakes in the drilling process and reducing the filtrate loss of the drilling fluid. The presence of inorganic salts in the drilling fluid can also severely affect the effect of the functional groups and the clay particles, thereby resulting in a reduction in the fluid loss performance of the polymer. The fluid loss additive is used as a drilling fluid treating agent, and can still keep a good fluid loss reducing effect under the severe environment of high temperature, high pressure and high salinity. Although the types of the current filtrate reducers are various, the filtrate reducers with high temperature resistance and composite salt water resistance are not common.

The invention CN106432632A provides an amino polymer fluid loss additive for a high-temperature-resistant and salt-resistant water-based drilling fluid, and a preparation method and application thereof, wherein the fluid loss additive is prepared from acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, allyl polyethylene glycol and trihydroxyethyl allyl ammonium bromide, the molar ratio of the four monomers is 8.1-20.2: 9-15.2: 2.1-4.3: 8 to 10. The filtrate reducer can be effectively adsorbed on clay particles, and simultaneously, hydration groups such as sulfonic groups and hydroxyl groups can bring adsorbed hydration layers to the clay particles, so that the space stability of a dispersion system is enhanced, the coalescence of fine particles is effectively inhibited, and compact mud cakes are formed, thereby achieving the effect of reducing the filtrate. Van der Waals force and electrostatic attraction exist between the cationic quaternary ammonium group and the clay particles with negative charges on the surface, the cationic quaternary ammonium group can be firmly adsorbed on the surface of the clay particles, and the rigidity of the main chain can be enhanced by the steric hindrance generated by the long side chain of the polyoxyethylene group, so that the temperature resistance of the polymer is improved.

Disclosure of Invention

In order to overcome the technical problems, the invention provides a high-temperature-resistant salt-resistant filtrate reducer quaternary polymer for drilling fluid.

The technical problems to be solved by the invention are as follows:

as the depth of the formation increases, the formation temperature also increases and during drilling, saline formations are often encountered; the presence of inorganic salts in the drilling fluid can also severely affect the effect of the functional groups and the clay particles, thereby resulting in a reduction in the fluid loss performance of the polymer. The fluid loss additive is used as a drilling fluid treating agent, and can still keep a good fluid loss reducing effect under the severe environment of high temperature, high pressure and high salinity.

The purpose of the invention can be realized by the following technical scheme:

the high-temperature-resistant salt-resistant filtrate reducer quaternary polymer for the drilling fluid is prepared from the following raw materials in parts by weight: 100 portions of deionized water, 20 to 30 portions of 2-methyl-2 acrylamide propyl sodium sulfonate, 8 to 10 portions of sodium acrylate, 11 to 15 portions of N-vinyl pyrrolidone, 40 to 60 portions of ammonium persulfate, 40 to 60 portions of sodium bisulfite, 10 to 14 portions of macromonomer and 0.1 to 0.5 portion of initiator;

the high-temperature-resistant salt-resistant filtrate reducer quadripolymer for the drilling fluid is prepared by the following steps:

step one, adding deionized water into a four-neck flask, then sequentially adding 2-methyl-2-acrylamido propanesulfonic acid sodium salt, sodium acrylate, N-vinyl pyrrolidone, ammonium persulfate and sodium bisulfite, and stirring for 30min under the conditions that the rotating speed is 300-400r/min and the temperature is 25-30 ℃ to obtain a first mixed solution;

secondly, adding sodium hydroxide with the mass fraction of 40% into the first mixed solution to adjust the pH value of the system to be 7-9, setting the temperature to be 50-70 ℃ and the rotating speed to be 400r/min, and reacting for 4-6h to obtain a second mixed solution;

and thirdly, adding a macromonomer and an initiator into the second mixed solution under the protection of nitrogen, setting the temperature to be 30-60 ℃ and the rotating speed to be 350-plus-450 r/min, reacting for 4-12h, washing for three times by using absolute ethyl alcohol, and drying at the temperature of 100-plus-120 ℃ to constant weight to prepare the high-temperature-resistant salt-resistant filtrate reducer quaternary polymer for the drilling fluid.

Further, the macromonomer is prepared by the following steps:

s11, adding phenylhydroxylamine and potassium iodide into a three-neck flask, stirring in an ice-water bath, setting the rotation speed to be 100-200r/min, dropwise adding epoxy chloropropane while stirring, keeping the rotation speed unchanged after the epoxy chloropropane is dropwise added, continuing to react for 2-3h in the ice-water bath, standing for 6-7 days at the temperature of 20-30 ℃ under the condition of keeping out of the sun after the reaction is finished, separating lower-layer viscous liquid by using a separating funnel, and washing the viscous liquid for three times by using ether to obtain a mixture A;

s12, adding sodium carboxymethyl starch and absolute ethyl alcohol into a three-mouth bottle, setting the rotation speed at 250-300r/min, stirring for 20min at the temperature of 25 ℃, adding deionized water and a sodium hydroxide solution with the mass fraction of 20% into the three-mouth bottle, raising the temperature to 60-70 ℃, adding dodecyl dimethyl benzyl ammonium chloride and the mixture A, keeping the rotation speed unchanged, stirring for 4-6h, cooling to 20-30 ℃, washing for three times by using the absolute ethyl alcohol, and drying at the temperature of 100-120 ℃ to constant weight to obtain a mixture B;

s13, adding the mixture B into a three-neck flask, firstly adding absolute ethyl alcohol, uniformly stirring, then adding dimethyl sulfoxide and toluene, uniformly stirring, adjusting the pH value to 3-5 by using 1mol/L hydrochloric acid solution, setting the temperature to be 60-70 ℃, introducing nitrogen, dropwise adding hexamethyldisilazane under the protection of nitrogen, reacting for 7-9h, cooling to 25 ℃, standing and filtering to obtain a precipitate, washing the precipitate for three times by using absolute ethyl alcohol, and drying at the temperature of 100 ℃ and 120 ℃ to constant weight to obtain the macromonomer.

Further, the ratio of the amounts of the substances of phenylhydroxylamine, potassium iodide and epichlorohydrin in step S11 is 1: 50-60: 10-13, and the epoxy chloropropane is dripped in 40 min; in the step S12, the mass ratio of the sodium carboxymethyl starch, the absolute ethyl alcohol, the deionized water, the sodium hydroxide solution with the mass fraction of 20%, the dodecyl dimethyl benzyl ammonium chloride and the mixture A is 4: 0.03: 26-30: 2-4: 1: 4; in the step S13, the mass ratio of the mixture B to the absolute ethyl alcohol to the dimethyl sulfoxide to the toluene to the hexamethyldisilazane is 4: 3: 26-30: 16-20: 2.

further, the average molecular weight of the prepared high-temperature-resistant salt-resistant filtrate reducer quadripolymer for the drilling fluid is 800 ten thousand.

The invention has the beneficial effects that:

the main chain of the high-temperature-resistant salt-resistant filtrate reducer quaternary polymer for the drilling fluid is of a C-C single bond structure, the average bond energy of the C-C single bonds is 347.3kJ/mol, and the quaternary polymer is not easy to degrade at high temperature; the side chain of the high-temperature-resistant salt-resistant filtrate reducer quaternary polymer for the drilling fluid has C-C, C-S and other structures provided by 2-methyl-2-acrylamido propanesulfonic acid sodium salt, has C-C, C-N and other structures provided by N-vinyl pyrrolidone, and has high structural bond energy of C-C, C-S, C-N and other structures, so that the temperature resistance of the polymer is further improved; the side chain is also introduced with a sulfonic acid group provided by 2-methyl-2 acrylamido propyl sodium sulfonate and a carboxylic acid group provided by sodium acrylate, and the sulfonic acid group and the carboxylic acid group can form a hydration film, so that the drilling fluid has stronger stability, and the hydrolysis capability of the fluid loss additive under high temperature and high mineralization is enhanced.

The surface of the macromonomer is positively charged, and an organic silicon functional group is introduced, so that the high temperature resistance of the fluid loss additive is improved, the average molecular weight of the high temperature resistant salt-resistant fluid loss additive quaternary polymer for the drilling fluid is 800 ten thousand, the quaternary polymer can be quickly adhered to the surfaces of drill cuttings and clay, and the effects of coating, flocculating and reducing fluid loss are achieved; the dodecyl dimethyl benzyl ammonium chloride is easy to dissolve in water, is a transparent solution, has no toxicity, does not corrode metal, is stable even in boiling water, can effectively prevent the filtrate reducer from further hydration expansion by introducing ammonium salt, ammonium salt and organic silicon functional groups, reduces the absorption of hydroxyl on the surface of the filtrate reducer, and reduces the apparent viscosity of the drilling fluid. The quaternary polymer of the high-temperature-resistant and salt-resistant filtrate reducer for the drilling fluid has strong salt and temperature resistance, the temperature resistance can reach 260 ℃, and the product performance is stable.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.