Environment-friendly temperature-resistant salt-resistant liquid lubrication plugging agent for drilling fluid

Abstract

The invention discloses an environment-friendly temperature-resistant salt-resistant liquid lubrication plugging agent for drilling fluid, and relates to the technical field of oil field chemicals. The lubricant comprises the following components in parts by mass: 60-90 parts of base oil and 10-40 parts of an emulsifier, and the lubricant can be obtained by reacting for 2-6 hours under the condition of 80-95 DEG C. The lubricant disclosed by the invention has a good effect of reducing friction resistance; the extreme pressure lubrication washing reduction rate can reach more than 80%, and the mud cake adhesion washing reduction rate can reach more than 60%; salt resistance reaches saturation; the temperature resistance can reach 180 DEG C; the EC50 value is larger than 1 * 10 < 5 > mg / L, the water-based drilling fluid additive is evenly dispersed in water-based drilling fluid, bubbles are not prone to occurring, and the adsorbability and wettability of mud cakes and drilling tool metal surfaces can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield chemicals, in particular to an environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid. Background Art

[0002] With the increasing expansion of the exploration and development field, the drilling strata are constantly deepening, the drilling methods are constantly being refurbished, and the difficulty of drilling is also increasing year by year. The number of special wells such as deep wells, ultra-deep wells, directional wells, horizontal wells, large displacement wells, small borehole wells, high-density long open hole wells, etc. is increasing. At the same time, the requirements for drilling speed have been greatly improved, and complex situations underground have occurred more frequently. During the drilling process, power equipment such as diesel engines and gas turbines have their own fixed power. The torque that the drill string bears during the rotation process is limited, and the stability of the well wall (especially the shale formation) is poor. If the drilling fluid used does not have good lubrication properties, the rotation resistance will increase during the process of drilling and normal drilling, resulting in a stuck drill. In addition, when the rotation resistance of the drill tool exceeds the load, it may cause the drill tool to break, increasing unnecessary drilling costs. If the drilling fluid has good lubricity, it can not only extend the service life of drilling accessories such as drill bits and drilling tools, but also effectively prevent the occurrence of complex underground accidents such as stuck drill and well wall instability. In addition to the working conditions, the main factors affecting the lubricity of drilling fluids are the use of lubricants. If no human and treatment agents and weighting agents, i.e., clean water, are added to the water-based drilling fluid, it will show a large friction resistance. However, after adding a small amount of lubricants (mainly anionic surfactants) relative to other treatment agents, the lubrication performance of the drilling fluid (clean water) will be greatly improved, which is specifically manifested in the reduction of the rotary torque value of the drill tool. Therefore, in order to make the drilling fluid have good lubricity that meets the use requirements, the use of lubricants is the most effective way.

[0003] Since the 1990s, drilling fluid systems with environmental protection performance have been developed successively at home and abroad. However, these drilling fluid systems have not been promoted and applied due to high costs or unsatisfactory application effects. Some newly developed environmentally friendly drilling fluids are difficult to achieve industrial production due to the complex synthesis process of additives. Therefore, according to the needs of on-site production, it is urgent to develop a new high-temperature resistant and environmentally friendly drilling fluid system that integrates environmental protection and oil and gas layer protection functions, has an acceptable cost, a relatively simple synthesis process, and can meet the requirements of drilling projects. Summary of the invention

[0004] In order to solve the above problems, that is, to solve the problems raised by the above background technology, the present invention proposes an environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid, and the specific technical scheme is as follows:

[0005] An environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid. The lubricant comprises the following components in the following mass fractions: 60-90 parts of base oil and 10-40 parts of emulsifier.

[0006] Preferably, the mass ratio of base oil:emulsifier in the lubricant is any one of 60:10, 60:20, 60:30, 60:40, 70:10, 70:20, 70:30, 70:40, 80:10, 80:20, 80:30, 80:40, 90:10, 90:20, 90:30, and 90:40.

[0007] Preferably, the emulsifier is one or a mixture of monoglyceride, diglyceride and polyol ester.

[0008] Preferably, the base oil is 20-50% cycloparaffin oil.

[0009] Preferably, the base oil is a mixture of one or more of a diesel fraction at atmospheric distillation temperature between 200 and 350° C., atmospheric gas oil, a lubricating oil fraction at 350 to 500° C., vacuum gas oil and industrial products thereof.

[0010] Preferably, the vacuum gas oil and its industrial products are specifically a mixture of one or more of national standard white oil, national standard diesel, non-national standard white oil, and non-national standard diesel.

[0011] Preferably, the national standard white oil is a mixture of one or more of No. 3 national standard white oil, No. 5 national standard white oil, No. 7 national standard white oil, No. 11 national standard white oil, No. 15 national standard white oil, No. 18 national standard white oil, No. 24 national standard white oil, and No. 48 national standard white oil.

[0012] Preferably, the lubricant is prepared as follows: the base oil and the emulsifier are uniformly mixed in proportion, and reacted at 80-95° C. for 2-6 hours to obtain the lubricant.

[0013] The beneficial technical effects of the present invention are as follows: the lubricant of the present invention has a good effect of reducing friction; the extreme pressure lubrication washing reduction rate can reach more than 80%, and the mud cake adhesion washing reduction rate can reach more than 60%; the salt resistance reaches saturation; the temperature resistance can reach 180°C; the EC50 value is greater than 1×105mg / L, it is evenly dispersed in water-based drilling fluid, is not easy to form bubbles, and can improve the adsorption and wettability of the mud cake and the metal surface of the drilling tool. DETAILED DESCRIPTION

[0014] The preferred embodiments of the present invention are described below with reference to the examples. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0015] An environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid, the raw material mass ratio is base oil: emulsifier = (60-90): (10-40), the two are mixed evenly in proportion, and reacted at 80-95°C for 2-6h to obtain the lubricant.

[0016] Specifically, the mass ratio of base oil:emulsifier in the lubricant is any one of 60:10, 60:20, 60:30, 60:40, 70:10, 70:20, 70:30, 70:40, 80:10, 80:20, 80:30, 80:40, 90:10, 90:20, 90:30, and 90:40.

[0017] The emulsifier is one or a mixture of monoglyceride, diglyceride and polyol ester.

[0018] The base oil is 20-50% cycloparaffin oil. The base oil is specifically a mixture of one or more of the diesel fraction between 200-350°C at atmospheric distillation, atmospheric gas oil, 350-500°C lubricating oil fraction, vacuum gas oil and industrial products thereof. The vacuum gas oil and industrial products thereof are specifically a mixture of one or more of national standard white oil, national standard diesel, non-national standard white oil and non-national standard diesel. The national standard white oil is specifically a mixture of one or more of national standard white oil No. 3, national standard white oil No. 5, national standard white oil No. 7, national standard white oil No. 11, national standard white oil No. 15, national standard white oil No. 18, national standard white oil No. 24 and national standard white oil No. 48.

[0019] According to the standard, technical index evaluation, freshwater slurry and salt water slurry high temperature performance evaluation were carried out respectively, the liquid lubricant of the present invention was selected as an example, and a certain liquid lubricant on the market was purchased as a comparative example, and the comparison results are shown in Table 1. The raw material ratio of the lubricant in the example is base oil: emulsifier = 80:20, the base oil is No. 3 national standard white oil, and the emulsifier is diglyceride.

[0020] Table 1 Technical index evaluation, freshwater slurry and saltwater slurry high temperature performance evaluation table

[0021]

[0022] It can be seen from Table 1 that the lubricant of the embodiment is better than the lubricant of the comparative example in reducing the lubrication coefficient of fresh water slurry and the mud cake adhesion coefficient.

[0023] The lubricant described in the embodiment was evaluated for technical indicators according to the Q / GWDC0186-2021 standard (in compliance with Q / SY17088-2016).

[0024] Table 2 Technical index evaluation table

[0025]

[0026] According to Table 2, after inspection by a third-party quality inspection agency with CMA and CNAS dual quality management systems, the lubrication coefficient reduction rate is above 85%, and it has excellent extreme pressure lubrication effect.

[0027] The effects of the examples and comparative examples of the same price on the rheological properties of the base slurry and the improvement of lubricity were compared and evaluated in the KCl system and silicone system well slurries.

[0028] 1, with KCl system well slurry (KCl content of 5%) as the base, adding 2.33% of the embodiment lubricant as the experimental group 1, adding 3% of the comparative example lubricant as the control group 1, and pure well slurry as the blank group 1, the performance before and after rolling aging at 120°C for 16h was tested respectively, and the specific test results are shown in Table 3.

[0029] Table 3 KC1 system well slurry test results

[0030]

[0031] 2. With the organic silicon system well slurry as the base, 2.33% of the embodiment lubricant was added as the experimental group 2, 3% of the comparative example lubricant was added as the control group 2, and the pure well slurry was the blank group 2. The performance was tested before and after rolling aging for 16 hours at 20°C. The specific test results are shown in Table 4.

[0032] Table 4 Test results of organic silicon system in well slurry

[0033]

[0034] In the KCl system and the organosilicon system well slurry, there is no significant difference in rheological properties between the example lubricant and the comparative example lubricant of the same price. In terms of lubrication performance, the example lubricant has better lubricity than the comparative example lubricant.

[0035] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0036] In the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on directions or positional relationships, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0037] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The term "comprise" or any other similar term is intended to cover a non-exclusive inclusion, such that a process, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, article, or apparatus / device.

[0039] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments, but it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. An environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid, characterized in that: The lubricant comprises the following components in the following mass fractions: 60-90 parts of base oil and 10-40 parts of emulsifier.

2. The environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid according to claim 1, characterized in that: The mass ratio of base oil to emulsifier in the lubricant is any one of 60:10, 60:20, 60:30, 60:40, 70:10, 70:20, 70:30, 70:40, 80:10, 80:20, 80:30, 80:40, 90:10, 90:20, 90:30, and 90:

40.

3. The environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid according to claim 1 or 2, characterized in that: The emulsifier is one or a mixture of monoglyceride, diglyceride and polyol ester.

4. The environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid according to claim 1 or 2, characterized in that: The base oil is 20-50% cycloparaffin oil.

5. The environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid according to claim 4, characterized in that: The base oil is specifically a mixture of one or more of a diesel fraction distilled at 200-350°C under atmospheric pressure, atmospheric gas oil, a lubricating oil fraction distilled at 350-500°C, a vacuum gas oil and industrial products thereof.

6. The environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid according to claim 5, characterized in that: The vacuum gas oil and its industrial products are specifically a mixture of one or more of national standard white oil, national standard diesel, non-national standard white oil, and non-national standard diesel.

7. The environmentally friendly temperature-resistant and salt-resistant liquid lubricating plugging agent for drilling fluid according to claim 6, characterized in that: The national standard white oil is specifically a mixture of one or more of No. 3 national standard white oil, No. 5 national standard white oil, No. 7 national standard white oil, No. 11 national standard white oil, No. 15 national standard white oil, No. 18 national standard white oil, No. 24 national standard white oil, and No. 48 national standard white oil.

8. The drilling fluid according to any one of claims 1 to 7 comprises an environmentally friendly temperature-resistant and salt-resistant liquid lubricant, characterized in that: The preparation method of the lubricant is as follows: the base oil and the emulsifier are uniformly mixed in proportion, and then reacted at 80-95° C. for 2-6 hours to obtain the lubricant.

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