阅读说明：本技术 一种钻井液用抗高温降滤失剂及其制备方法 (High-temperature-resistant fluid loss additive for drilling fluid and preparation method thereof ) 是由 葛炼 钱帆 胡宗建 肖沣峰 蒋弈黎 杨芮 欧猛 谢显涛 吴义 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种钻井液用抗高温降滤失剂及其制备方法,属于油田开采钻井处理剂技术领域。其包括：腐殖酸树脂30份-60份、丙烯酰胺10份-50份、丙烯酸10份-40份、2-丙烯酰胺基-2-甲基丙磺酸10份-30份、马来酸酐10份-20份、N-乙烯基吡咯烷酮5份-20份和纳米材料5份-10份。本发明的降滤失剂以腐蚀酸树脂与其他单体接枝共聚形成,并且添加了纳米材料,能有效提高降滤失剂的抗温性能和抗盐性能,保证其在高温220℃和高盐条件下仍具有良好的性能。(The invention discloses a high-temperature-resistant fluid loss additive for drilling fluid and a preparation method thereof, belonging to the technical field of oil field exploitation drilling treatment agents. It includes: 30-60 parts of humic acid resin, 10-50 parts of acrylamide, 10-40 parts of acrylic acid, 10-30 parts of 2-acrylamido-2-methylpropanesulfonic acid, 10-20 parts of maleic anhydride, 5-20 parts of N-vinyl pyrrolidone and 5-10 parts of nano material. The filtrate reducer is formed by graft copolymerization of corrosive acid resin and other monomers, and is added with a nano material, so that the temperature resistance and the salt resistance of the filtrate reducer can be effectively improved, and the filtrate reducer still has good performance at a high temperature of 220 ℃ and under a high-salt condition.)

1. A high-temperature resistant fluid loss additive for drilling fluid is characterized by comprising: 30-60 parts of humic acid resin, 10-50 parts of acrylamide, 10-40 parts of acrylic acid, 10-30 parts of 2-acrylamido-2-methylpropanesulfonic acid, 10-20 parts of maleic anhydride, 5-20 parts of N-vinyl pyrrolidone and 5-10 parts of nano material.

2. The high temperature resistant fluid loss additive for drilling fluids according to claim 1, comprising: 40-50 parts of humic acid resin, 15-35 parts of acrylamide, 20-30 parts of acrylic acid, 15-25 parts of 2-acrylamido-2-methylpropanesulfonic acid, 10-20 parts of maleic anhydride, 5-20 parts of N-vinyl pyrrolidone and 5-10 parts of nano material.

3. The high-temperature-resistant fluid loss additive for drilling fluid as claimed in claim 1 or 2, wherein the preparation step of the humic acid resin comprises the following steps: adding the methyl vinyl cyclosiloxane prepolymer, acrylic acid, acrylamide and humate into water, stirring and dissolving to obtain a mixed solution, adjusting the pH value to 7-11, heating the mixed solution to 50-70 ℃, introducing nitrogen for 25-35 min, adding a mixed initiator under the protection of nitrogen, and stirring and reacting for 2-4 h to obtain the corrosive acid resin.

4. The high-temperature-resistant fluid loss additive for drilling fluid as claimed in claim 3, wherein the content of humic acid in the humic acid resin is 5-10 wt% of that of the humic acid resin; wherein the weight ratio of the methyl vinyl cyclosiloxane prepolymer to the acrylic acid to the acrylamide substance is 1: (1-3): (1.5-4.5); the concentration of the humate solution is 8 wt% -10 wt%, and the humate comprises potassium humate or sodium humate.

5. The high-temperature-resistant fluid loss additive for the drilling fluid as claimed in claim 4, wherein the mixed initiator is a mixed aqueous solution of ammonium persulfate and sodium bisulfite, the concentration of the ammonium persulfate and the sodium bisulfite is 1 wt% -1.5 wt%, and the mass of the ammonium persulfate and the sodium bisulfite is 1: 1.

6. The high-temperature-resistant fluid loss additive for drilling fluid as claimed in claim 1 or 2, wherein the nano material is a mixture of silane coupling agent modified nano alumina and nano silica, and the mass ratio of the silane coupling agent to the nano alumina to the nano silica is 1: (5-15): (35-45).

7. The preparation method of the high-temperature-resistant fluid loss additive for the drilling fluid as claimed in any one of claims 1 to 6, which is characterized by comprising the following steps:

dissolving the acrylamide, the acrylic acid, the 2-acrylamide-2-methylpropanesulfonic acid, the maleic anhydride and the N-vinyl pyrrolidone in water, adding the nano material, uniformly stirring, adding the humic acid resin, mixing, adjusting the pH value to 6-8, adding the initiator at the temperature of 60-80 ℃, stirring for reaction for 4-6 h, drying and crushing to obtain the high-temperature resistant filtrate reducer for the drilling fluid.

8. The preparation method of the high-temperature resistant fluid loss additive for drilling fluid as claimed in claim 7, wherein the initiator is potassium persulfate or ammonium persulfate, and the addition amount of the initiator is 1-2 wt%.

Technical Field

The invention relates to the technical field of oil field exploitation drilling treatment agents, in particular to a high-temperature-resistant fluid loss additive for drilling fluid and a preparation method thereof.

Background

With the increase of oil exploitation amount, many oil fields enter high-temperature deep oil exploitation areas, the exploitation difficulty is increased, and a part of exploitation areas require that the filtrate reducer can resist the high temperature of more than 200 ℃. Although the types of the prior fluid loss additives used on site are various, most of the fluid loss additives are applied to the condition that the temperature of an oil well is below 180 ℃, when the oil well is in the environment of above 200 ℃, the fluid loss effect is obviously reduced, and in order to ensure the fluid loss effect of the drilling fluid, the dosage of chemicals in the oil well must be increased, but the addition amount is too much, so that the economic cost is increased, and the rheological property of the drilling fluid can be greatly changed, so that the drilling work can not be normally carried out.

Disclosure of Invention

The invention aims to provide a high-temperature resistant fluid loss additive for drilling fluid and a preparation method thereof, and aims to solve the problem that the conventional fluid loss additive is difficult to meet the high-temperature resistant requirement in deep well and ultra-deep well exploitation.

The technical scheme for solving the technical problems is as follows:

a high temperature resistant fluid loss additive for drilling fluids comprising: 30-60 parts of humic acid resin, 10-50 parts of acrylamide, 10-40 parts of acrylic acid, 10-30 parts of 2-acrylamido-2-methylpropanesulfonic acid, 10-20 parts of maleic anhydride, 5-20 parts of N-vinyl pyrrolidone and 5-10 parts of nano material.

Further, in a preferred embodiment of the present invention, the humic acid resin comprises 40 to 50 parts by weight of humic acid resin, 15 to 35 parts by weight of acrylamide, 20 to 30 parts by weight of acrylic acid, 15 to 25 parts by weight of 2-acrylamido-2-methylpropanesulfonic acid, 10 to 20 parts by weight of maleic anhydride, 5 to 20 parts by weight of N-vinylpyrrolidone, and 5 to 10 parts by weight of nanomaterial.

Further, in a preferred embodiment of the present invention, the preparation of the humic acid resin comprises: adding the methyl vinyl cyclosiloxane prepolymer, acrylic acid, acrylamide and humate into water, stirring and dissolving to obtain a mixed solution, adjusting the pH value to 7-11, heating the mixed solution to 50-70 ℃, introducing nitrogen for 25-35 min, adding a mixed initiator under the protection of nitrogen, and stirring and reacting for 2-4 h to obtain the corrosive acid resin.

Further, in a preferred embodiment of the present invention, the content of humic acid in the humic acid resin is 5 wt% to 10 wt% of the humic acid resin; wherein the weight ratio of the methyl vinyl cyclosiloxane prepolymer to the acrylic acid to the acrylamide substance is 1: (1-3): (1.5-4.5); the concentration of the humate solution is 8 wt% -10 wt%, and the humate comprises potassium humate or sodium humate.

Further, in a preferred embodiment of the present invention, the mixed initiator is a mixed aqueous solution of ammonium persulfate and sodium bisulfite, the concentration of the ammonium persulfate and the sodium bisulfite is 1 wt% to 1.5 wt%, and the mass of the ammonium persulfate and the sodium bisulfite is 1: 1.

Further, in a preferred embodiment of the present invention, the nanomaterial is a mixture of silane coupling agent modified nano alumina and nano silica, wherein the mass ratio of the silane coupling agent, the nano alumina and the nano silica is 1: 5-15: 35-45.

The preparation method of the high-temperature-resistant fluid loss additive for the drilling fluid comprises the following steps:

dissolving the acrylamide, the acrylic acid, the 2-acrylamide-2-methylpropanesulfonic acid, the maleic anhydride and the N-vinyl pyrrolidone in water, adding the nano material, uniformly stirring, adding the humic acid resin, mixing, adjusting the pH value to 6-8, adding the initiator at the temperature of 60-80 ℃, stirring for reaction for 4-6 h, drying and crushing to obtain the high-temperature resistant filtrate reducer for the drilling fluid.

Further, in a preferred embodiment of the present invention, the initiator is potassium persulfate or ammonium persulfate, and the addition amount is 1 wt% to 2 wt%.

The invention has the following beneficial effects:

1. the filtrate reducer is formed by graft copolymerization of corrosive acid resin and other monomers, and is added with a nano material, so that the temperature resistance and the salt resistance of the filtrate reducer can be effectively improved, and the filtrate reducer still has good performance at a high temperature of 220 ℃ and under a high-salt condition.

2. The humic acid resin is obtained by copolymerization and grafting of humic acid, methyl vinyl cyclosiloxane prepolymer, acrylamide and acrylic acid, wherein a corrosion acid structure contains a rigid group benzene ring, a phenolic hydroxyl group capable of being adsorbed by clay, an alcoholic hydroxyl group and a carboxyl functional group with strong hydration, and has the performances of resisting high temperature, reducing filtration loss and diluting. The methyl vinyl cyclosiloxane prepolymer is added in the corrosion acid modification, and a flexible and asymmetric polysiloxane chain link is introduced in the copolymerization structure of the methyl vinyl cyclosiloxane prepolymer, so that the high temperature resistance of the methyl vinyl cyclosiloxane prepolymer can be effectively improved. And siloxane groups (Si-OR) in the methyl vinyl cyclosiloxane prepolymer are easy to hydrolyze (Si-OH) and are easy to condense with rich silicon hydroxyl on the surface of hydrated clay particles to form firm silicon-oxygen bonds (Si-O-Si), so that the fluid loss additive can be firmly adsorbed on the clay particles through the silicon-oxygen bonds, and the formed silicon-oxygen bonds have extremely high energy and are not broken under the action of high temperature and calcium salt, thereby ensuring the good adsorption stability of the fluid loss additive.

3. The filtrate reducer is added with alumina and silicon dioxide modified by a silane coupling agent, the particle size of the filtrate reducer is small, the filtrate reducer is easy to fill micro cracks of a graft copolymer and mud cakes, pore throats of the graft copolymer and mud cakes are blocked to form bridges, free water is restrained from entering a stratum, and the permeability of a well wall is reduced. Meanwhile, the added nano material can be easily crosslinked with other copolymers in the fluid loss additive to form a net structure, so that the rigidity and the thermal stability of the whole fluid loss additive are improved, and the temperature resistance and the salt resistance of the fluid loss additive are further effectively improved.

Detailed Description

The principles and features of this invention are described below in conjunction with embodiments, which are included to explain the invention and not to limit the scope of the invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.