阅读说明：本技术 一种弱磁靶向润滑剂及含有该润滑剂的水基钻井液 (Weak magnetic targeting lubricant and water-based drilling fluid containing same ) 是由 卢福伟 王静 虞舟 王凯佩 王越支 罗霄 赵世贵 于 2019-11-21 设计创作，主要内容包括：本发明涉及一种弱磁靶向润滑剂及含有该润滑剂的水基钻井液,所述润滑剂包含基础油60～80份、聚酯10～20份、表面活性剂3～6份和磁性聚醚3～10份；所述磁性聚醚中含有非晶态羟基Fe<Sub>3</Sub>O<Sub>4</Sub>纳米颗粒作为起始剂,与传统油性润滑剂不同在于,该润滑剂能够有效降低在钻井液中固相颗粒表面吸附概率,大部分吸附在钻具表面,增强钻具表面油膜强度和疏水性,提高钻具在水平井长水平段的润滑效率,降低扭矩和摩阻,提高水功率传递效率。(The invention relates to a weak magnetic targeting lubricant and a water-based drilling fluid containing the same, wherein the lubricant comprises 60-80 parts of base oil, 10-20 parts of polyester, 3-6 parts of surfactant and 3-10 parts of magnetic polyether; the magnetic polyether contains amorphous hydroxyl Fe 3 O 4 The nano particles are used as an initiator, and the lubricant is different from the traditional oily lubricant in that the lubricant can effectively reduce the surface adsorption probability of solid-phase particles in drilling fluid, most of the solid-phase particles are adsorbed on the surface of a drilling tool, the oil film strength and the hydrophobicity of the surface of the drilling tool are enhanced, the lubricating efficiency of the drilling tool in the long horizontal section of a horizontal well is improved, the torque and the friction resistance are reduced, and the water power transfer efficiency is improved.)

1. The weak magnetic targeting lubricant is characterized by comprising the following raw material components in parts by weight:

base oil: 60 to 80 portions of,

Polyester: 10 to 20 parts of,

Surfactant (b): 3 to 6 parts of,

Magnetic polyether: 3-10 parts.

2. The weak magnetic targeting lubricant as claimed in claim 1, wherein the base oil is C₁₈～C₂₂Of vegetable oil or C₁₈～C₂₂Any one or a mixture of any two or more of the fatty acid methyl esters in any proportion;

the polyester is any one or a mixture of two of trimethylolpropane oleate or pentaerythritol oleate in any proportion;

the surfactant is span-80.

3. The weak magnetic targeting lubricant as claimed in claim 1, wherein the magnetic polyether is prepared from the following raw materials in parts by weight:

hydroxylated magnetic nanoparticle initiator: 180 portions of 300 portions,

Basic catalyst: 2-30 parts of,

Propylene oxide: 300 portions of 1800 portions,

Butylene oxide: 200-1500 parts.

4. The weakly magnetic targeting lubricant according to claim 3 wherein the hydroxylated magnetic nanoparticle initiator is amorphous hydroxyl Fe₃O₄A nanoparticle;

the alkaline catalyst is potassium hydroxide.

5. The weak magnetic targeting lubricant of claim 4 wherein said amorphous hydroxyl Fe₃O₄The average particle size of the nanoparticles is 20-40 nm, and the polymerization degree of a polyether chain segment single chain of the magnetic polyether is 3-12.

6. Amorphous state hydroxyl Fe₃O₄The preparation method of the nano-particles is characterized by comprising the following steps:

1) FeCl is added₂·4H₂O、FeCl₃·6H₂Reacting O and NaOH solution at a certain temperature to generate a reaction product;

2) solid-liquid separation of the reaction product, washing the solid with deionized water and absolute ethyl alcohol to neutrality, stoving to obtain amorphous Fe hydroxide₃O₄And (3) nanoparticles.

7. An amorphous hydroxyFe according to claim 6₃O₄A method for producing nanoparticles, characterized in that,

1) firstly, 100-160 parts of FeCl₂·4H₂O, 20-30 parts of FeCl₃·6H₂Adding O into a reaction kettle, heating the materials in the reaction kettle to 30-40 ℃ under a stirring state, adjusting the pH value to 10-12 by using a NaOH solution, reacting for 1-4 hours until the color is gray to black, and stopping stirring to generate a reaction product;

2) the reaction product is dried for solid-liquid separation, the solid is respectively washed by deionized water and absolute ethyl alcohol until the pH value is 7, and the amorphous hydroxyl Fe is obtained after drying at the temperature of 40 DEG C₃O₄And (3) nanoparticles.

8. The preparation method of the magnetic polyether is characterized by at least comprising the following steps: the magnetic polyether is prepared by reacting hydroxylated magnetic nano-particles serving as an initiator with propylene oxide and butylene oxide under the action of an alkaline catalyst.

9. The method for preparing magnetic polyether in claim 8, wherein 180-300 parts of amorphous Fe hydroxide₃O₄Adding 2-30 parts of potassium hydroxide as a catalyst into a nanoparticle initiator, and adding 1800 parts of propylene oxide (300-) -and 1500 parts of butylene oxide (200-) -at the temperature of 85-115 ℃ under the protection of high-purity nitrogen to react for 12-18 hours to obtain magnetic polyether;

wherein the amorphous hydroxyl group Fe₃O₄A nanoparticle initiator prepared according to the method of claim 6 or 7.

10. The water-based drilling fluid is characterized by comprising the following raw materials, by weight, 400 parts of clear water, 2-6 parts of bentonite, 0.4-0.8 part of NaOH, 0.3-0.8 part of tackifier, 0.5-4 parts of fluid loss additive, 0.5-1 part of coating agent, 1-4 parts of amine shale inhibitor, 1-3 parts of soda ash and 1-6 parts of lubricant;

wherein the lubricant is the weak magnetic targeting lubricant as claimed in any one of claims 1 to 5.

Technical Field

The invention relates to a weak magnetic targeting lubricant and a water-based drilling fluid containing the lubricant, belonging to the technical field of petroleum drilling.

Background

The water-based drilling fluid still has the technical problems of frequent supporting and pressing, drill sticking and the like and insufficient water power transmission and the like in the construction process of a long horizontal section complex structure well, and the main reason is that the lubricating continuity of a lubricant in the water-based drilling fluid is insufficient.

In the patent CN201711091999, a nonionic lubricant is synthesized by carrying out esterification reaction on C10-C18 mono-organic acid and alcohol, so that the interference of ionic components in the drilling fluid on the lubricating performance is effectively avoided.

In the patent CN201810754751, α -olefin is used as an oily lubricating component, composite nano-silica is used as a high-performance lubricant, and the lubricating agent added into drilling fluid can improve the lubricating property of the drilling fluid and reduce friction resistance and torque in the drilling process.

In patent CN201810367132, molybdenum dialkyl dithiocarbamate and molybdenum dialkyl dithiophosphate are used as important components of a liquid lubricant, both of which are oil-soluble organic molybdenum compounds, and a secondary structure film is formed on a friction surface under high pressure formed by contact between a drilling tool and a well wall, so that the secondary structure film is not easily damaged and has good lubricating and antifriction effects.

The newly developed lubricant has the problems that the surface of the solid phase particles of the drilling fluid is preferentially adsorbed, the consumption speed of effective lubricating components is too high and the like in the competitive adsorption and film forming process of the solid phase particles of the drilling tool and the drilling fluid, and the long-horizontal-section continuous lubrication cannot be effectively solved. The lubricant capable of having lasting lubricating performance under high-difficulty complex working conditions is still in a blank state.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention aims to provide a weak magnetic targeting lubricant which can be preferentially adsorbed on the surface of a drilling tool, has good lubricating effect and strong loss resistance and energy consumption resistance, and can greatly reduce the problems of low power transfer efficiency of long horizontal section drilling water and the like.

The weak magnetic targeting lubricant comprises the following components in parts by weight: 60-80 parts of base oil, 10-20 parts of polyester, 3-6 parts of surfactant and 3-10 parts of magnetic polyether;

wherein the base oil is C₁₈～C₂₂Of vegetable oil or C₁₈～C₂₂Any one or mixture of any two or more of the fatty acid methyl esters in any proportion;

wherein the polyester is any one of trimethylolpropane oleate or pentaerythritol oleate or a mixture of two of trimethylolpropane oleate and pentaerythritol oleate in any proportion;

wherein the surfactant is span-80;

the magnetic polyether is prepared from the following raw materials in parts by weight: 300 parts of hydroxylated magnetic nanoparticle initiator 180-.

Preferably, the hydroxylated magnetic nanoparticle initiator is amorphous hydroxyl Fe₃O₄A nanoparticle;

preferably, the basic catalyst is potassium hydroxide;

preferably, the degree of polymerization of the polyether chain segment single chain of the magnetic polyether is 3-12, the length is moderate, and the foaming of impurities in span-80 in a water phase can be effectively inhibited.

Span-80 as a surfactant can be mutually soluble with base oil in any proportion; the span-80 can enable the base oil to form uniform emulsion drops in the water phase of the drilling fluid, so that the oil phase is more effectively adsorbed to a friction surface, and the lubricating effect of the oil phase lubricant is improved; trimethylolpropane oleate or pentaerythritol oleate can be effectively coupled with base oil and span-80 surfactant in the lubricant, so that the oil phase lubricant forms a uniform whole; the magnetic polyether is gray oily liquid at normal temperature and can be mutually dissolved with the base oil in any proportion; after the oil-phase lubricant is carried to the surface of the drilling tool by the magnetic polyether, the amide group of the span-80 can form chemical adsorption on the surface of the metal drilling tool, so that a stable oil film is strengthened, and the lubricating effect is improved.

As a specific embodiment, the invention provides that the amorphous hydroxyl Fe₃O₄A method for preparing nanoparticles, comprising the steps of:

1) FeCl is added₂·4H₂O、FeCl₃·6H₂Reacting O with a certain amount of NaOH solution at a certain temperature to generate a reaction product;

2) solid-liquid separation of the reaction product, washing the solid with deionized water and absolute ethyl alcohol to neutrality, stoving to obtain amorphous Fe hydroxide₃O₄And (3) nanoparticles.

Optionally, the reaction temperature is 30-40 ℃, and the reaction time is 1-4 hours;

controlling the reaction temperature not to exceed 50 ℃, and sacrificing the magnetism of part to ensure Fe₃O₄The hydroxyl content on the surface of the nano-particles enables the surface of the nano-particles to be grafted with propylene oxide or butylene oxide;

optionally, the reaction environment is an alkaline environment, and a certain amount of NaOH solution is added to adjust the pH value of the reaction kettle to 10-12; control of product amorphous hydroxyl Fe₃O₄The average particle size of the nano particles is between 20 and 40 nm.

In a preferred embodiment of the present invention, the amorphous Fe hydroxide₃O₄The preparation method of the nano-particles comprises the following steps:

1) firstly, 100-160 parts of FeCl₂·4H₂O, 20-30 parts of FeCl₃·6H₂Adding O into a reaction kettle, heating the materials in the reaction kettle to 30-40 ℃ under a stirring state, adjusting the pH value to 10-12 by using a NaOH solution, reacting until the color is gray to black, and stopping stirring to generate a reaction product;

2) the reaction product is dried for solid-liquid separation, the solid is respectively washed by deionized water and absolute ethyl alcohol until the pH value is 7, and the amorphous hydroxyl Fe is obtained after drying at the temperature of 40 DEG C₃O₄And (3) nanoparticles.

In another aspect of the present invention, a preparation method of the magnetic polyether is provided, which at least comprises the following steps: the magnetic polyether is prepared by reacting hydroxylated magnetic nano-particles serving as an initiator with propylene oxide and butylene oxide under the action of an alkaline catalyst.

Optionally, the reaction conditions are: the reaction temperature is 85-115 ℃, and the reaction time is 12-18 hours;

as a preferred embodiment of the present invention, the preparation method of the magnetic polyether comprises the following steps: 180-300 parts of amorphous hydroxyl Fe₃O₄Adding 2-30 parts of potassium hydroxide as a catalyst into a nanoparticle initiator, and adding 1800 parts of propylene oxide (300-) -and 1500 parts of butylene oxide (200-) -at the temperature of 85-115 ℃ under the protection of high-purity nitrogen to react for 12-18 hours to obtain the magnetic polyether.

The invention also aims to provide the water-based drilling fluid which can reduce the drilling resistance of a drilling tool in a long horizontal complex well section and effectively transfer water power;

the water-based drilling fluid comprises the following raw materials, by weight, 400 parts of clear water, 2-6 parts of bentonite, 0.4-0.8 part of NaOH, 0.3-0.8 part of tackifier, 0.5-4 parts of fluid loss additive, 0.5-1 part of coating agent, 1-4 parts of amine shale inhibitor, 1-3 parts of soda and 1-6 parts of weak magnetic targeting lubricant;

the weak magnetic targeting lubricant comprises the following components in parts by weight: 60-80 parts of base oil, 10-20 parts of polyester, 3-6 parts of surfactant and 3-10 parts of magnetic polyether; the raw materials are stirred in a stirring tank for 1-3 hours at normal temperature and normal pressure to form the weak magnetic targeting lubricant.

Compared with the prior art, the invention has the advantages that ① a mixture of base oil and polyester forms an oil film main body adsorbed on the surfaces of a drilling tool and a well wall, magnetic polyether enables the whole oily lubricant to have magnetism in an oil phase, the lubricant is carried to the surface of the drilling tool, and forms a firm oil film on the surface of the drilling tool by means of magnetic adsorption, ② the weak magnetic targeting lubricant can provide enough lubrication at high temperature to reduce friction resistance and effectively inhibit foaming of drilling fluid caused by impurities in synthetic oil and polyester, ③ the weak magnetic targeting lubricant has strong adsorption capacity, has a continuous lubrication effect which is 3-5 times that of the traditional oily lubricant under the condition of small dosage due to the magnetic adsorption, can effectively reduce torque and resistance encountered by the drilling tool during drilling in a long horizontal section, has a lubrication reduction rate which is obviously superior to that of the traditional lubricant, has a remarkable lubrication effect on the rheological property of the drilling fluid which is obviously smaller than that of the traditional lubricant, especially has a deep well and a long horizontal section gas well, ④ the lubricant forms a high-strength protective oil film on the surface of the drilling tool, can help to resist extreme temperature, pressure and weight of the drilling tool, can also prevent foreign matter from being corroded by shale and water, and can only have a harmless magnetic adsorption effect on the magnetic detection of ⑤.

Detailed Description

The present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.