CN111100613B

CN111100613B - Lubricant for drilling fluid and application thereof

Info

Publication number: CN111100613B
Application number: CN201911316527.4A
Authority: CN
Inventors: 夏小春; 刁琪; 郭磊; 李松; 张东升; 刘刚; 耿铁; 罗健生
Original assignee: China Oilfield Services Ltd; China National Offshore Oil Corp CNOOC
Current assignee: China Oilfield Services Ltd; China National Offshore Oil Corp CNOOC
Priority date: 2019-12-19
Filing date: 2019-12-19
Publication date: 2022-09-06
Anticipated expiration: 2039-12-19
Also published as: CN111100613A

Abstract

The lubricant for the drilling fluid comprises the following raw materials in parts by weight: 5-60 parts of vegetable oil acid lower alcohol ester; 30-94 parts of vegetable higher alcohol oleate and 1-20 parts of nonionic surfactant. The lubricant for the drilling fluid is applied to a water-based drilling fluid, and the preferable dosage of the lubricant in the water-based drilling fluid is 1-5% (w/v); the lubricant provided by the invention is mutually inserted and adsorbed on the metal surface through the synergistic effect of the plant oleic acid lower alcohol ester, the plant oleic acid higher alcohol ester and the nonionic surfactant, so that the formed hydrophobic film is more compact, and the abrasion resistance of the hydrophobic film is stronger. The lubricating effect of the compounding effect is obviously better than that of a single component.

Description

Lubricant for drilling fluid and application thereof

Technical Field

The invention relates to a lubricant, in particular to a lubricant for drilling fluid and application thereof.

Background

The lubricating properties of the drilling fluid have a great influence on the drilling operation. Especially in drilling deep wells, directional wells, horizontal wells and cluster wells, the rotational resistance and the pull-up resistance of the drill string are greatly increased. The main adjustable factor due to the effects on drilling torque and drag and tool wear is the lubricating properties of the drilling fluid. Therefore, the lubricating property of the drilling fluid plays a crucial role in reducing downhole complex conditions such as drill sticking and the like and ensuring safe and rapid drilling.

The lubricant for the drilling fluid is selected to meet the following basic requirements: (1) the lubricant must be capable of lubricating the metal surface and forming a boundary film and secondary structures on the surface; (2) the drilling fluid has good compatibility with base slurry, and does not have adverse effect on the rheological property and the fluid loss property of the drilling fluid; (3) the efficiency of rock crushing is not reduced; (4) the heat stability and the cold stability are good; (5) the metal is not corroded, and the sealing material is not damaged; (6) no environmental pollution, easy biodegradation, reasonable price and sufficient sources. In addition to improving the life and performance of the drilling tool, the drilling fluid lubricant should not affect the analysis and evaluation of formation data, i.e., the lubricant should have low or no fluorescence. Therefore, the lubricant base material should be selected without using organic substances containing benzene rings, especially polyaromatic hydrocarbons, and crude oil, especially heavy fractions, still residues, asphalt, etc. are avoided because of the high content of fluorescent substances.

A number of literature reports methods for preparing lubricants for drilling fluids.

The natural vegetable oil is used as a raw material for Howestwary and the like, is chemically modified at a medium-high temperature (130-180 ℃), is emulsified at a medium-low temperature (70-90 ℃) after the temperature resistance and the salt resistance of the natural vegetable oil are improved, and the environment-friendly lubricant is prepared. (Oshiseki, Doudoshi, development and application of environment-friendly efficient lubricant (GLub) [ J ], prospecting engineering (rock drilling engineering), 2006,4:48,49 ].

Chinese patent 200710158398.1 discloses a method for preparing a high-temperature-resistant lubricant for drilling fluid by using animal and vegetable oil. Carrying out esterification reaction on 50-70 parts by weight of waste oil and fat, 3-10 parts by weight of ethanolamine and 5-20 parts by weight of diethylene glycol; then carrying out a vulcanization reaction by adopting 1-3 parts of sulfur; and adding 2-5 parts of oil-soluble resin and 10-30 parts of graphite powder into the reaction product, and mixing and uniformly stirring to obtain the high-temperature-resistant lubricant for the drilling fluid.

Chinese patent 200810055861.4 discloses a water-based lubricant for drilling fluid and a preparation method thereof, wherein the formula of the lubricant is as follows: 100-300 parts of water, 10-30 parts of emulsifier, 50-300 parts of castor oil, 50-400 parts of white oil, 50-600 parts of oleic soap and 50-200 parts of defoamer.

Chinese patent 01102104.7 discloses a lubricant for drilling fluid, which is characterized in that the components of the lubricant are 5-10% of polymer lubricating material, 0.1-0.5% of surfactant, and water is added to 100%; the high molecular lubricating material comprises polyoxyethylene nonyl phenol ether, polyoxyethylene decyl phenol ether, polyoxypropylene decyl phenol ether and polyoxypropylene nonyl phenol ether; the active agent is selected from NP-10, OP-10, NP-6 or Tween 80.

Chinese patent 201611054061.1 discloses a method for producing polyhydroxy vegetable oil from swill oil, which comprises using swill oil as raw material, first generating epoxy swill oil by epoxidation reaction, and then using epoxy swill oil as raw material to synthesize polyhydroxy vegetable oil by hydroxylation reaction. The method has the advantages that the polyhydroxy vegetable oil produced by the method is obtained by refining swill oil, so that waste resources are reasonably utilized, energy is maximally utilized, the environment is protected, and the production cost is reduced; the method is simple, convenient and effective, has low cost, no complicated post-treatment and no harmful substance emission, is a real green environment-friendly process, and the hydroxy base oil produced by the process has wide application prospect in environment-friendly lubricant base oil and additives.

In the prior art, some lubricants for drilling fluid use mineral oil (such as white oil, diesel oil, kerosene and the like), but the mineral oil has high toxicity, is not easy to biodegrade and has poor environmental protection performance; some of the swill and swill oil are prepared by chemical modification of swill and waste oil produced by chemical modification of waste oil or swill oil have harmful substances to environment and the environment-friendly performance of the product is not up to standard.

With the increasingly strict environmental protection regulations in China, higher requirements are put forward on the environmental protection performance of the lubricant for the drilling fluid. Especially offshore drilling, impose restrictions on the bio-toxicity limits of the drilling fluid materials. According to GB18420.1, the biotoxicity limit of the primary sea area is 30000mg/L and the biotoxicity limit of the secondary sea area is 20000mg/L for water-based drilling fluids. This requires that the added lubricant in the water-based drilling fluid not be more than the above-mentioned limits with respect to bio-toxicity.

Therefore, there is a need for an environmentally friendly lubricant for water-based drilling fluids that has acceptable biotoxicity.

Disclosure of Invention

The invention provides a lubricant for drilling fluid and application thereof, which can remarkably reduce the wear resistance and the torque of a drilling tool and improve the lubricity of the drilling fluid.

The invention provides a lubricant for drilling fluid, which comprises the following raw materials in parts by weight: 5-60 parts of vegetable oil acid lower alcohol ester; 30-94 parts of plant higher alcohol oleate and 1-20 parts of nonionic surfactant.

Optionally, 20-40 parts of vegetable lower alcohol oleate; 40-80 parts of vegetable higher alcohol oleate and 5-20 parts of nonionic surfactant;

preferably, 15-30 parts of vegetable lower alcohol oleate; 65-80 parts of vegetable higher alcohol oleate and 5-10 parts of nonionic surfactant.

In the lubricant for the drilling fluid, provided by the invention, the vegetable oil acid is selected from one or more of oleic acid, linoleic acid, ricinoleic acid, palmitic acid and stearic acid.

In the lubricant for drilling fluid provided by the present invention, preferably, the lubricant for drilling fluid consists of the above-mentioned vegetable oil acid lower alcohol ester, vegetable oil acid higher alcohol ester and nonionic surfactant.

In the lubricant for the drilling fluid, the vegetable oil acid lower alcohol ester is prepared by one or more of oleic acid, linoleic acid, ricinoleic acid, palmitic acid and stearic acid and one or two of methanol or ethanol through esterification.

In the lubricant for the drilling fluid, the vegetable higher alcohol ester is one or more of oleic acid, linoleic acid, ricinoleic acid, palmitic acid and stearic acid, and is prepared by esterification reaction of one or more of C4-C8 fatty alcohol.

In the lubricant for the drilling fluid, provided by the invention, the C4-C8 fatty alcohol comprises one or more of trimethylolpropane, neopentyl glycol, 1,2, 5-pentanetriol, pentaerythritol and isooctanol.

In the lubricant for drilling fluid provided by the invention, when the C4-C8 fatty alcohol is polyhydroxy fatty alcohol, the higher alcohol ester of vegetable oleic acid can be either mono-vegetable oleate or poly-vegetable oleate.

In the lubricant for drilling fluid provided by the present invention, the nonionic surfactant is selected from one or more of sorbitan monooleate, sorbitan dioleate, sorbitan trioleate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monoleate, polyoxyethylene sorbitan trioleate, triglycerol monooleate, pentaglycerol monooleate, hexaglycerol monooleate, octaglycerol monooleate and decaglycerol monooleate.

In the lubricant for drilling fluid provided by the invention, the HLB value of the nonionic surfactant is 6-15.

In another aspect, the invention provides the use of a lubricant for drilling fluids as described above in water-based drilling fluids.

The environment-friendly lubricant for the water-based drilling fluid can be used in various water-based drilling fluid systems commonly used in oil fields, such as fresh water drilling fluid, salt water drilling fluid and seawater drilling fluid. When the lubricant is used in the oil field, 1-5% (w/v) (based on the total volume of the slurry) of the environment-friendly lubricant can be added into a slurry pool.

The technical scheme of the invention has the beneficial effects that:

the environment-friendly lubricant for the water-based drilling fluid contains the plant oleic acid lower alcohol ester and the plant oleic acid higher alcohol ester, and can be adsorbed on the surfaces of metal such as a drilling tool, a casing and the like to form a hydrophobic film, so that the rotating frictional resistance of the drilling tool is reduced, and the lubricity of the water-based drilling fluid is improved.

The plant oleic acid lower alcohol ester, the plant oleic acid higher alcohol ester and the nonionic surfactant have a synergistic effect, and are mutually inserted and adsorbed on the metal surface, so that the formed hydrophobic membrane is more compact, and the abrasion resistance of the hydrophobic membrane is stronger. The lubricating effect of the compounding effect is obviously better than that of a single component.

The environment-friendly lubricant for the water-based drilling fluid has excellent environment-friendly performance and is an environment-friendly product.

Therefore, when the environment-friendly lubricant for the water-based drilling fluid is applied to the water-based drilling fluid, the abrasion resistance and the torque of a drilling tool can be obviously reduced, and the lubricity of the drilling fluid is improved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. Other advantages of the invention may be realized and attained by the instrumentalities and combinations particularly pointed out in the specification.

Drawings

The accompanying drawings are included to provide an understanding of the present invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the examples serve to explain the principles of the invention and not to limit the invention.

FIG. 1 is a photograph of a lubricant for drilling fluid prepared according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in detail below. It should be noted that the embodiments and features of the embodiments of the present invention may be arbitrarily combined with each other without conflict.

The embodiment of the invention provides a lubricant for drilling fluid, which comprises the following raw materials in parts by weight: 5-60 parts of vegetable oil acid lower alcohol ester; 30-94 parts of vegetable higher alcohol oleate and 1-20 parts of nonionic surfactant.

In the embodiment of the invention, the lubricant comprises the following raw materials in parts by weight: 20-40 parts of vegetable lower alcohol oleate; 40-80 parts of vegetable higher alcohol oleate and 5-20 parts of nonionic surfactant; most preferably, 15-30 parts of vegetable lower alcohol oleate; 65-80 parts of plant higher alcohol oleate and 5-10 parts of nonionic surfactant.

In an embodiment of the invention, the vegetable oil acid is selected from one or more of oleic acid, linoleic acid, ricinoleic acid, palmitic acid and stearic acid.

In the embodiment of the present invention, preferably, the lubricant for drilling fluid is composed of the above-mentioned vegetable oil acid lower alcohol ester, vegetable oil acid higher alcohol ester and nonionic surfactant.

In the embodiment of the invention, the vegetable oil acid lower alcohol ester is prepared by one or more of oleic acid, linoleic acid, ricinoleic acid, palmitic acid and stearic acid and one or two of methanol or ethanol through esterification reaction.

In the embodiment of the invention, the higher alcohol ester of vegetable oleic acid is prepared by one or more of oleic acid, linoleic acid, ricinoleic acid, palmitic acid and stearic acid and one or more of C4-C8 fatty alcohol through esterification reaction.

In embodiments of the invention, the C4-C8 fatty alcohol includes one or more of trimethylolpropane, neopentyl glycol, 1,2, 5-pentanetriol, pentaerythritol and isooctanol.

In the embodiment of the present invention, when the C4-C8 fatty alcohol is a polyhydroxy fatty alcohol, the higher alcohol ester of vegetable oleic acid may be a mono-vegetable oleate or a poly-vegetable oleate.

In an embodiment of the invention, the non-ionic surfactant is selected from one or more of sorbitan monooleate, sorbitan dioleate, sorbitan trioleate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monoleate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, triglycerol monooleate, pentaglycerol monooleate, hexaglycerol monooleate, octaglycerol monooleate and decaglycerol monooleate.

In the present examples, the nonionic surfactant has an HLB value of 6 to 15.

In another aspect, the present invention provides the use of the above lubricant for drilling fluids in water-based drilling fluids.

The starting materials used in the following examples are all commercially available.

Example 1

35 portions of methyl oleate

Neopentyl glycol dioleate 60 parts

Tween 805 parts (HLB value 15)

And (3) putting the raw materials into a reaction kettle, stirring at room temperature for 0.5-2 hours, and discharging.

Examples 2 to 5, comparative examples 1 to 4

The preparation method is the same as example 1, and the material amounts are shown in Table 1. Decaglycerol monooleate has an HLB value of 12.5.

Table 1: compositions and amounts of examples 2-5 and comparative examples 1-4

Performance evaluation:

test example 1: evaluation of lubricating Properties

Preparing 2 parts of polymer slurry: weighing 308mL of seawater, adding 0.7g of caustic soda, 0.7g of soda, 7g of starch, 1g of xanthan gum, 1.4g of coating agent PF-BIOCAP (Tianjin Zhonghai oil-coating chemical Co., Ltd.), 10.5g of inhibitor PF-BIOTROL (Tianjin Zhonghai oil-coating chemical Co., Ltd.), 34g of sodium chloride and 55g of barite, and stirring at a high speed of 11000r/min for 20min to obtain base slurry; adding 7g of the sample prepared in the embodiment or the comparative example into one part of slurry, and stirring at a high speed of 11000r/min for 20min to obtain test slurry; on an extreme pressure lubrication instrument, torque readings of distilled water, base slurry and test slurry at 20-30 ℃ are respectively measured, the measuring time of the extreme pressure lubrication instrument is not less than 5min, and a stable value is read. The test results are shown in table 2.

The friction coefficient was calculated as follows.

In the formula: k is the coefficient of friction of the sample; t is the torque value reading of the sample; f-correction factor, which is the ratio of 34 to the distilled water test torque value reading.

Table 2: statistical table of friction coefficients of base slurry, distilled water, examples and comparative examples

	Coefficient of friction
		Base pulp	0.20
Distilled water	0.34
		Example 1	0.12
Example 2	0.14
		Example 3	0.10
Example 4	0.10
		Example 5	0.13
Comparative example 1	0.16
		Comparative example 2	0.18
Comparative example 3	0.16
		Comparative example 4	0.17

As can be seen from Table 2, after 7g of the samples in examples are added into the base slurry, the friction coefficient of the base slurry can be reduced from 0.20 to 0.10-0.14, and the samples in examples 3 and 4 have certain capability of reducing the friction coefficient of the drilling fluid, wherein the capability of reducing the friction coefficient of the drilling fluid is strongest. Comparing the friction coefficients of the test slurries added in comparative example 1, example 2, example 3, example 4, example 5 and comparative example 2, the friction coefficient of the test slurry decreased and then increased with the increase of the ethyl oleate content in the sample, and the lowest friction coefficient was 0.10 when the test slurry added in example 3 and example 4 was added. Comparing the coefficient of friction of the experimental slurries added to example 3 and comparative example 3, the coefficient of friction of the experimental slurry increased from 0.10 to 0.16 when the decaglycerol monooleate content decreased to zero. The ethyl oleate, the pentaerythritol tetraoleate and the decaglycerol monooleate have a synergistic effect, and the proper proportion of the ethyl oleate, the pentaerythritol tetraoleate and the decaglycerol monooleate ensures that the product has the best lubricating effect.

Test example 2: evaluation of Dispersion Properties

5% of the sample of example 1 was added to water, sheared for 5min at 5000rpm by a SILVERSON shear emulsifier to simulate the shear of the on-site drilling fluid circulating to the eye, and placed in a stoppered graduated cylinder for 30 days. The dispersion state of the sample of example 1 in water after 30 days is shown in FIG. 1.

As is clear from FIG. 1, the sample of example 1 was uniformly dispersed in water, and the dispersion stability time was long.

Test example 3: evaluation of biotoxicity

Compare the sample of example 1 in the Chinese patent 201210119376.5 with the sample of example 4 in this patent.

The biological toxicity test of the test sample is carried out according to GB/T18420.2-2009 part 2 of biological toxicity of marine petroleum exploration and development pollutants: test methods 72h hydrostatic biotoxicity test was performed. The test organism was artemia. The hatching method of the artemia comprises the following steps: adding 1L artificial seawater into a sterilized beaker (1L), adding 1g artemia egg, and appropriate amount of Chlorella solution (concentration 1X 10) ⁵ One/ml) beaker mouth is sealed by preservative film, and a vent pipe is added. The incubation was carried out for 24h at 25 ℃ in an incubator with an illumination intensity of 2000 lx. After 24 hours, the hatchability of the artemia cysts can reach more than 85 percent. The results are shown in Table 3.

Table 3: biotoxicity evaluation results statistics

	72h half-lethal concentration LC50/(mg/L)
		Example 1 of Chinese patent 201210119376.5	36000
Example 3 of this patent	1500000

As can be known from the table above, this patent example 3 appearance is 1500000mg/L to the half lethal concentration LC50 of artemia 72h, is greater than the comparison appearance far away, also is higher than national standard GB4914-2008 to the marine oil exploration development pollutant emission concentration limit value (first grade sea area is 30000mg/L), does not have the biological toxicity to the artemia, embodies excellent environmental protection.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The above-described embodiments of the invention are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. The lubricant for the drilling fluid is prepared from the following raw materials in parts by weight: 20-36 parts of vegetable lower alcohol oleate; 40-80 parts of vegetable higher alcohol oleate and 5-20 parts of nonionic surfactant;

the nonionic surfactant is selected from one or more of sorbitan monooleate, sorbitan dioleate, sorbitan trioleate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, triglycerol monooleate, pentaglycerol monooleate, hexaglycerol monooleate, octaglycerol monooleate and decaglycerol monooleate;

the vegetable oleic acid lower alcohol ester is prepared by carrying out esterification reaction on one or more of oleic acid, linoleic acid, ricinoleic acid, palmitic acid and stearic acid and one or two of methanol or ethanol;

the vegetable oleic acid higher alcohol ester is prepared by carrying out esterification reaction on one or more of oleic acid, linoleic acid, ricinoleic acid, palmitic acid and stearic acid and one or more of C4-C8 fatty alcohol.

2. The lubricant for drilling fluids of claim 1, wherein the C4-C8 fatty alcohol comprises one or more of trimethylolpropane, neopentyl glycol, 1,2, 5-pentanetriol, pentaerythritol and isooctanol.

3. The drilling fluid lubricant of claim 2, wherein when the C4-C8 fatty alcohol is a polyhydric fatty alcohol, the higher ester of vegetable oleic acid is a mono-or poly-vegetable oleate.

4. The lubricant for drilling fluids according to claim 1, wherein the nonionic surfactant has an HLB value of 6 to 15.

5. Use of a lubricant for drilling fluids according to any one of claims 1 to 4 in water-based drilling fluids.

6. The use of the lubricant for drilling fluids in water-based drilling fluids according to claim 5, wherein the amount of the lubricant for drilling fluids in the water-based drilling fluids is 1% to 5% w/v.