阅读说明：本技术 一种油基钻井液用提粘剂及其制备方法 (Viscosity improver for oil-based drilling fluid and preparation method thereof ) 是由 钱帆 陈智 万伟 袁翊 罗宇峰 胡宗建 李万强 吴义 张斌 于 2019-09-28 设计创作，主要内容包括：本发明公开了一种油基钻井液用提粘剂及其制备方法,提粘剂包括以下质量份的组分：改性有机土2～5份,改性植物胶2～4份,热塑性弹性树脂1～3份,丙烯酸5～10份,羟甲基纤维素3～5份,季铵盐1～3份,乳化剂0.5～1.5份,基油3～6份,引发剂0.05～0.15份。其中,改性有机土优选经过活化改性的膨润土,改性植物胶优选羟丙基瓜尔胶,引发剂为硫酸铵与亚硫酸钠按1:2～4的质量比混合的混合物。本发明中的油基钻井液用提粘剂能够弥补水基钻井液增粘剂不适用于油基钻井液的不足,有利于降低油基钻井液体系的配制成本和提高油基钻井液整体的环保性能,对于油基钻井液性能提高和使用发挥重要作用。(The invention discloses a viscosity increasing agent for oil-based drilling fluid and a preparation method thereof, wherein the viscosity increasing agent comprises the following components in parts by mass: 2-5 parts of modified organic soil, 2-4 parts of modified vegetable gum, 1-3 parts of thermoplastic elastic resin, 5-10 parts of acrylic acid, 3-5 parts of hydroxymethyl cellulose, 1-3 parts of quaternary ammonium salt, 0.5-1.5 parts of emulsifier, 3-6 parts of base oil and 0.05-0.15 part of initiator. The modified organic soil is preferably activated and modified bentonite, the modified vegetable gum is preferably hydroxypropyl guar gum, and the initiator is a mixture of ammonium sulfate and sodium sulfite in a mass ratio of 1: 2-4. The tackifier for the oil-based drilling fluid can make up the defect that the tackifier for the water-based drilling fluid is not suitable for the oil-based drilling fluid, is beneficial to reducing the preparation cost of an oil-based drilling fluid system and improving the integral environmental protection performance of the oil-based drilling fluid, and plays an important role in improving the performance and using of the oil-based drilling fluid.)

1. the viscosity enhancer for the oil-based drilling fluid is characterized by comprising the following components in parts by weight: the paint comprises the following components in parts by mass: 2-5 parts of modified organic soil, 2-4 parts of modified vegetable gum, 1-3 parts of thermoplastic elastic resin, 5-10 parts of acrylic acid, 3-5 parts of hydroxymethyl cellulose, 1-3 parts of quaternary ammonium salt, 0.5-1.5 parts of emulsifier, 3-6 parts of base oil and 0.05-0.15 part of initiator.

2. the viscosity enhancer for oil-based drilling fluids according to claim 1, wherein the viscosity enhancer comprises the following components in parts by mass: 4 parts of modified organic soil, 3 parts of modified vegetable gum, 2 parts of thermoplastic elastic resin, 8 parts of acrylic acid, 4 parts of hydroxymethyl cellulose, 2 parts of quaternary ammonium salt, 1 part of emulsifier, 3 parts of base oil and 0.1 part of initiator.

3. the viscosity enhancing agent for an oil-based drilling fluid according to claim 1 or 2, characterized in that: the modified organic soil is activated and modified bentonite.

4. the viscosity enhancing agent for an oil-based drilling fluid according to claim 3, wherein: the activation modification of the bentonite comprises the following steps:

S1: mixing bentonite and deionized water according to a material-liquid ratio of 1: 3-5 g/mL, and ultrasonically dispersing for 0.5-1 h by using a frequency of 15-20 KHz to obtain a bentonite suspension;

s2: heating the bentonite suspension to 40-45 ℃, and then dropwise adding a sulfuric acid or hydrochloric acid solution with the concentration of 8-12% into the bentonite suspension at the speed of 2-4 mL/min under the stirring condition, wherein the volume ratio of the dropwise added sulfuric acid or hydrochloric acid solution to the bentonite suspension is 0.5-1: 1; after the acid solution is dripped, continuously stirring for 2-4 h under heat preservation to obtain bentonite activation solution;

s3: dropwise adding a silicone oil emulsion into the bentonite activation liquid at room temperature, wherein the addition of the silicone oil emulsion is 2-4% of the solid content of the bentonite; and (3) continuously stirring for 0.5-1 h after the silicone oil emulsion is dripped, and then drying and crushing to obtain the activated and modified bentonite.

5. The viscosity enhancing agent for an oil-based drilling fluid according to claim 1 or 2, characterized in that: the modified vegetable gum is hydroxypropyl guar gum.

6. The viscosity enhancing agent for an oil-based drilling fluid according to claim 1, wherein: the quaternary ammonium salt is methacryloyloxyethyl trimethyl ammonium chloride.

7. the viscosity enhancing agent for an oil-based drilling fluid according to claim 1, wherein: the initiator is a mixture of ammonium persulfate and sodium sulfite mixed according to the mass ratio of 1: 2-4.

8. The method for producing a viscosity enhancer for an oil-based drilling fluid according to any one of claims 1 to 7, comprising the steps of:

(1) dissolving acrylic acid and an emulsifier in deionized water, and stirring at the rotating speed of 4000-5000 rmp for 20-30 min to obtain an emulsion;

(2) Adding modified organic soil, modified vegetable gum, thermoplastic elastic resin, hydroxymethyl cellulose and quaternary ammonium salt into an emulsion, dispersing for 1-2 h at the power of 2000-3000W, then heating the mixed solution to 75-78 ℃, adding an initiator, reacting for 4-6 h, adding base oil, and uniformly stirring to obtain the adhesion promoter for the oil-based drilling fluid.

Technical Field

The invention belongs to the technical field of drilling aids, and particularly relates to a viscosity enhancer for oil-based drilling fluid and a preparation method thereof.

background

The oil-based drilling fluid is a drilling fluid taking oil as a continuous phase and is divided into two types of water-in-oil type oil-based drilling fluid and full-oil type oil-based drilling fluid, and the oil-based drilling fluid mainly comprises base oil, organic soil, an emulsifier, a wetting agent, a tackifier, a weighting agent and the like. The oil-based drilling fluid has good inhibitive performance, temperature resistance and stability, can better meet the requirements of special conditions such as complex stratum drilling, coring operation, underbalanced drilling, large-length horizontal well and the like, and can provide reliable technical support for the safe and efficient development of oil and gas fields.

The oil-based drilling fluid viscosity enhancer is an important component of the oil-based drilling fluid, and mainly has the functions of improving the viscosity and the shear force of the oil-based drilling fluid and ensuring that the oil-based drilling fluid has good suspension, rock carrying and water loss reduction properties.

At present, the research on the drilling fluid viscosity increasing agent at home and abroad mainly focuses on the field of the water-based drilling fluid viscosity increasing agent, and water-based drilling fluid viscosity increasing agents such as HV-CMC, PAC, HEC, GEL-30, biopolymer XC and the like are developed, so that the requirements of the water-based drilling fluid on the viscosity increasing agent are well met. However, in the technical field of oil-based drilling fluid viscosity enhancers, the following technical problems mainly exist in the current research: first, water-based drilling fluid viscosifiers are not suitable for oil-based drilling fluids. The water-based drilling fluid tackifiers such as HV-CMC, PAC, biopolymer XC and the like can effectively extend and fully dissolve in water, so that the viscosity and the shear force of the drilling fluid are improved, but in the oil-based drilling fluid, particularly in the full-oil-based drilling fluid, because the full-oil-based drilling fluid does not contain water, polymer molecules of the water-based drilling fluid tackifiers cannot extend, and thus the water-based drilling fluid tackifiers cannot play roles in increasing the viscosity and the shear force. Secondly, there is a lack of effective oil-based drilling fluid viscosifiers. The tackifying of the oil-based drilling fluid is realized mainly by the additional tackifying effect of materials such as organic soil and oil-based drilling fluid filtrate reducer polymers, and the like, so that the addition of the materials such as the organic soil and the oil-based drilling fluid filtrate reducer polymers is increased sometimes to meet the required viscosity and shear force of the drilling fluid, and the preparation cost of the oil-based drilling fluid is increased. And thirdly, the environmental protection of the oil-based drilling fluid needs to be improved. The environment-friendly performance is also one of important aspects concerned about in the using process of the oil-based drilling fluid, the environment-friendly performance of the existing oil-based drilling fluid has a larger improvement space, and the development and the use of environment-friendly oil-based drilling fluid materials, such as environment-friendly tackifier of the oil-based drilling fluid, are beneficial to improving the environment-friendly performance of the oil-based drilling fluid.

disclosure of Invention

Aiming at the prior art, the invention provides the tackifier for the oil-based drilling fluid and the preparation method thereof, and the tackifier for the oil-based drilling fluid can make up the defect that the tackifier for the water-based drilling fluid is not suitable for the oil-based drilling fluid, is beneficial to reducing the preparation cost of an oil-based drilling fluid system and improving the overall environmental protection performance of the oil-based drilling fluid, and plays an important role in improving the performance and using the oil-based drilling fluid.

In order to achieve the purpose, the invention adopts the technical scheme that: the invention provides a viscosity enhancer for oil-based drilling fluid, which comprises the following components in parts by mass: 2-5 parts of modified organic soil, 2-4 parts of modified vegetable gum, 1-3 parts of thermoplastic elastic resin, 5-10 parts of acrylic acid, 3-5 parts of hydroxymethyl cellulose, 1-3 parts of quaternary ammonium salt, 0.5-1.5 parts of emulsifier, 3-6 parts of base oil and 0.05-0.15 part of initiator.

when the components in the adhesion promoter for the oil-based drilling fluid are matched according to the following mixture ratio, the effect is best: 4 parts of modified organic soil, 3 parts of modified vegetable gum, 2 parts of thermoplastic elastic resin, 8 parts of acrylic acid, 4 parts of hydroxymethyl cellulose, 2 parts of quaternary ammonium salt, 1 part of emulsifier, 3 parts of base oil and 0.1 part of initiator.

the adhesion promoter for the oil-based drilling fluid comprises modified organic soil, wherein the modified organic soil layer is a porous active substance with a microporous network structure and a large specific surface area, is favorable for diffusion of adsorbate molecules, and shows strong chemical activity and physical adsorption performance. Acrylic acid in the adhesion promoter is used as an intercalation agent to perform in-situ intercalation in modified organic soil, the acrylic acid inserted into the modified organic soil performs polymerization reaction under the action of an initiator to generate a water-soluble high polymer, and the modified organic soil is subjected to in-situ intercalation copolymerization to form an acrylic acid/modified organic soil composite thickening agent; meanwhile, when the acrylic acid is subjected to polymerization reaction, the modified vegetable gum, the thermoplastic elastic resin, the hydroxymethyl cellulose and the like are encapsulated in the modified organic soil, and in the drilling process, the components are mutually synergistic, so that the viscosity and the shear force of the oil-based drilling fluid can be remarkably improved, and the oil-based drilling fluid is ensured to have good suspension, rock-carrying and water loss reduction performances.

On the basis of the technical scheme, the invention can be further improved as follows.

further, the modified organic soil is activated and modified bentonite.

Further, the activation modification of the bentonite comprises the following steps:

S1: mixing bentonite and deionized water according to a material-liquid ratio of 1: 3-5 g/mL, and ultrasonically dispersing for 0.5-1 h by using a frequency of 15-20 KHz to obtain a bentonite suspension;

S2: heating the bentonite suspension to 40-45 ℃, and then dropwise adding a sulfuric acid or hydrochloric acid solution with the concentration of 8-12% into the bentonite suspension at the speed of 2-4 mL/min under the stirring condition, wherein the volume ratio of the dropwise added sulfuric acid or hydrochloric acid solution to the bentonite suspension is 0.5-1: 1; after the acid solution is dripped, continuously stirring for 2-4 h under heat preservation to obtain bentonite activation solution;

S3: dropwise adding a silicone oil emulsion into the bentonite activation liquid at room temperature, wherein the addition of the silicone oil emulsion is 2-4% of the solid content of the bentonite; and (3) continuously stirring for 0.5-1 h after the silicone oil emulsion is dripped, and then drying and crushing to obtain the activated and modified bentonite.

the bentonite in the invention is firstly modified by acidification, so that Na between bentonite layers can be formed⁺、Mg²⁺、K⁺、Ca²⁺when the cation is converted into soluble salt to be dissolved out, the bond energy between layers is weakened, the interlayer spacing is increased, a porous active substance with a micropore network structure and a large specific surface area is formed, impurities distributed in a channel behind a bentonite joint can be removed, the pore volume of the bentonite joint is increased, the diffusion of adsorbate is facilitated, and the modified bentonite has strong chemical activity and physical adsorbability.

The modified bentonite is improved in dispersibility, the dispersion degree of organic soil in a solvent and the colloidal stability of a dispersion system can be effectively improved, the modified bentonite is suitable for improving the dispersibility of the organic soil in a common solvent, the time required for dispersing the organic soil in the solvent can be obviously shortened, the energy consumption is reduced, the cost is reduced, meanwhile, the additive is safe and environment-friendly, has obvious effect, is better in compatibility with other treatment agents in systems such as oil-based drilling fluid and the like, and is wider in application objects.

Further, the modified vegetable gum is hydroxypropyl guar gum.

the hydroxypropyl group in the hydroxypropyl guar gum is linked to the C6 hydroxyl group on galactose under the influence of the reactivity, steric hindrance and the like of the hydroxypropyl guar gum. The hydroxypropyl group belongs to a hydrophilic group, and the existence of the hydroxypropyl branched chain improves the branching degree of the guar gum, so that the guar gum powder is easier to dissolve and has better tackifying capability.

further, the quaternary ammonium salt is methacryloyloxyethyl trimethyl ammonium chloride.

Further, the initiator is a mixture of ammonium persulfate and sodium sulfite mixed according to the mass ratio of 1: 2-4.

Ammonium persulfate and sodium sulfite form an oxidation-reduction initiation system, free radicals can be generated at a lower temperature, the vinyl monomer aqueous solution is initiated to generate free radical addition copolymerization, water-soluble high polymers are generated, and the polymerization degree of acrylic acid can be improved.

The adhesion promoter for the oil-based drilling fluid is prepared by the following steps:

(1) dissolving acrylic acid and an emulsifier in deionized water, and stirring at the rotating speed of 4000-5000 rmp for 20-30 min to obtain an emulsion;

(2) adding modified organic soil, modified vegetable gum, thermoplastic elastic resin, hydroxymethyl cellulose and quaternary ammonium salt into an emulsion, dispersing for 1-2 h at the power of 2000-3000W, then heating the mixed solution to 75-78 ℃, adding an initiator, reacting for 4-6 h, adding base oil, and uniformly stirring to obtain the adhesion promoter for the oil-based drilling fluid.

the invention has the beneficial effects that: the viscosity enhancer for the oil-based drilling fluid disclosed by the invention has good viscosity enhancing and shear enhancing effects in the oil-based drilling fluid. In the oil phase, the polymer molecules in the viscosity enhancer can be effectively stretched and fully dissolved, so that the viscosity enhancer plays a role in enhancing viscosity and shear. In addition, the viscosity enhancer for the oil-based drilling fluid reduces the preparation cost of the oil-based drilling fluid. The viscosity improver overcomes the defect that the oil-based drilling fluid improves the viscosity and the shearing force of the oil-based drilling fluid by increasing the feeding amount of materials such as organic soil, fluid loss additive polymer of the oil-based drilling fluid and the like.

Detailed Description

The following examples are provided to illustrate specific embodiments of the present invention.