WO2021097662A1 - Method for preparing high-temperature resistant oil-based drilling fluid wetting agent - Google Patents

Abstract

A method for preparing a high-temperature resistant oil-based drilling fluid wetting agent. A drilling fluid wetting agent is prepared according to the following steps: a first step: preparing fatty acid esters; and a second step: preparing a drilling fluid wetting agent finished product. A drilling fluid wetting agent prepared by the method for preparing a high-temperature resistant oil-based drilling fluid wetting agent can improve the high-temperature emulsification stability of an oil-based drilling fluid system and the oil wetting performance of hydrophilic components, thereby promoting the stability of the drilling fluid system.

Description

[Name of invention formulated by ISA according to Rule 37.2] 　Preparation method of anti-high temperature oil-based drilling fluid wetting agent Technical field

The invention relates to the technical field of drilling fluid additives, in particular to a preparation method of a high-temperature resistant oil-based drilling fluid wetting agent.

Background technique

Drilling fluid, also known as drilling flushing fluid, is a circulating flushing medium used in the hole during drilling. During the drilling process, the drilling fluid mainly completes the tasks of suspension, pressure control, formation stability, buoyancy, lubrication and cooling. Drilling fluid can clean the bottom of the well and carry cuttings; cool and lubricate the drill bit and drill string; balance the rock side pressure of the well wall, seal and stabilize the well wall; balance the formation pressure; reduce the sedimentation speed of cuttings; it can settle sand and rock on the ground Chips; effective transmission of hydraulic power; bearing part of the gravity of the drill pipe and casing; providing a large amount of data of the drilled formation; important functions such as breaking the rock by hydraulic power. Drilling fluid is mainly composed of liquid phase, solid phase and chemical treatment agent. Drilling fluids can be divided into oil-based drilling fluids, water-based drilling fluids, and gas-based drilling fluids according to the dispersion medium (continuous phase).

In order to ensure the stability of the system and the adjustment and control of various properties, the inert solid phase in the system must have strong lipophilicity. For heavier oil-based drilling fluids, heavier materials, cuttings and inert materials account for a large proportion. Most of the surfaces of these materials are hydrophilic, and their addition will destroy the stability of the oil-based drilling fluid. At the same time, the oil-based drilling fluid will be contaminated by the hydrophilic clay of the formation during the drilling process, which will change the performance of the drilling fluid. difference. The usual way to solve such problems is to add a wetting agent to change the wettability of the hydrophilic particle surface, improve the suspension of the weighting agent and reduce the aggregation of drill cuttings and other particles, and prevent coalescence in the oil-based drilling fluid. And sedimentation, and it also has the advantages of less dosage and remarkable effect. Studies have shown that in the process of drilling, completion, workover, and implementation of stimulation measures, the wettability changes that occur on the surface of the rock pores after drilling fluids and completion fluids and other external fluids invade the reservoir are considered to cause reservoir damage An important reason. At the same time, with the increase of the mud density and the temperature of the drilling fluid caused by the increase of the well depth, higher requirements are put forward on the performance of the wetting agent. At present, the better wetting agents include quaternary ammonium salts (such as dodecyl trimethyl ammonium bromide), lecithin and petroleum sulfonate, etc. Among them, lecithin is rich in sources and has better wetting properties, but it also has its own The shortcomings of natural lecithin, the high temperature resistance and electrical stability of natural lecithin are limited, which greatly limits its application. Therefore, there is a need to provide a method for preparing a high-temperature resistant oil-based drilling fluid wetting agent.

Summary of the invention

In order to overcome the defects in the prior art, a method for preparing a high-temperature resistant oil-based drilling fluid wetting agent is provided.

The present invention is realized through the following schemes:

A method for preparing a high-temperature resistant oil-based drilling fluid wetting agent. The drilling fluid wetting agent is prepared by the following steps:

The first step is to weigh the polyhydroxy organic amine compound and the fatty acid with carbon chain length of C8-C22 according to the molar mass ratio of 1:1-2 and mix them uniformly, then add p-toluenesulfonic acid to it, and then pass in nitrogen to remove oxygen. Condensate and reflux in an oil bath at 160-170°C for 24 hours, cool the reaction product to 70-90°C, add oxalic acid, keep the temperature at 70-90°C, react for 6 hours, and cool to room temperature to obtain fatty acid esters;

In the second step, the fatty acid ester obtained in the first step is added to the white oil and mixed uniformly, then the high temperature stabilizer and nonylphenol polyoxyethylene ether diester sodium salt are added, and the finished drilling fluid wetting agent is obtained after mixing uniformly. .

In the first step, the polyhydroxy organic amine compound is one or more of dimethanolamine, trimethanolamine, diethanolamine, triethanolamine, dipropanolamine, and tripropanolamine.

In the first step, the fatty acid is one or more of lauric acid, stearic acid, oleic acid, and linoleic acid.

In the first step, the molar mass ratio of the polyhydroxy organic amine compound to p-toluenesulfonic acid is 1:0.01-0.05, and the molar mass ratio of the polyhydroxy organic amine compound to oxalic acid is 1:0.3-07 .

In the second step, the molar mass ratio of the fatty acid ester: white oil: high temperature stabilizer: nonylphenol polyoxyethylene ether diester sodium salt is 1:2-10:0.1-0.3:0.3-0.5.

In the second step, the temperature stabilizer includes VC sodium salt, trioxane and citric acid.

The molar mass ratio of the sodium salt of VC, trioxane and citric acid is 1:0.3-0.5:0.1-0.3.

In the second step, the preparation method of the nonylphenol polyoxyethylene ether diester sodium salt includes the following steps:

A. Mix maleic anhydride and nonylphenol polyoxyethylene ether according to the molar mass ratio of 1:2-3, then add p-toluenesulfonic acid, and move to an oil bath at a temperature of 150-170°C to react under normal pressure 1 hour, then reduce pressure to 2-80kPa to perform a vacuum esterification reaction to obtain an esterification reaction mixture, and the reaction time of the vacuum esterification reaction is 3-5 hours;

B. Cool the esterification reaction mixture obtained in step A to 65-75°C, add sodium bisulfite, heat to 75-85°C, stir and react for 3 hours to obtain the finished product of sodium nonylphenol polyoxyethylene ether diester .

In step A, the molar mass ratio of the maleic anhydride to p-toluenesulfonic acid is 1:0.02-0.08.

In step B, the molar mass ratio of the maleic anhydride to sodium bisulfite is 1:1 to 1.1.

The beneficial effects of the present invention are:

The invention provides a method for preparing a high-temperature resistant oil-based drilling fluid wetting agent. The prepared drilling fluid wetting agent can improve the high-temperature emulsification stability of the oil-based drilling fluid system and the oil wetting performance of the hydrophilic component, and promote the drilling fluid The stability of the system.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments:

A method for preparing a high-temperature resistant oil-based drilling fluid wetting agent. The drilling fluid wetting agent is prepared by the following steps:

The first step is to weigh the polyhydroxy organic amine compound and the fatty acid with carbon chain length of C8-C22 according to the molar mass ratio of 1:1-2 and mix them uniformly, then add p-toluenesulfonic acid to it, and then pass in nitrogen to remove oxygen. Condensate and reflux in an oil bath at 160-170°C for 24 hours, cool the reaction product to 70-90°C, add oxalic acid, keep the temperature at 70-90°C, react for 6 hours, and cool to room temperature to obtain fatty acid esters;

In the second step, the fatty acid ester obtained in the first step is added to the white oil and mixed uniformly, then the high temperature stabilizer and nonylphenol polyoxyethylene ether diester sodium salt are added, and the finished drilling fluid wetting agent is obtained after mixing uniformly. .

In the first step, the polyhydroxy organic amine compound is one or more of dimethanolamine, trimethanolamine, diethanolamine, triethanolamine, dipropanolamine, and tripropanolamine.

In the first step, the fatty acid is one or more of lauric acid, stearic acid, oleic acid, and linoleic acid.

In the first step, the molar mass ratio of the polyhydroxy organic amine compound to p-toluenesulfonic acid is 1:0.01-0.05, and the molar mass ratio of the polyhydroxy organic amine compound to oxalic acid is 1:0.3-07 .

In the second step, the molar mass ratio of the fatty acid ester: white oil: high temperature stabilizer: nonylphenol polyoxyethylene ether diester sodium salt is 1:2-10:0.1-0.3:0.3-0.5.

In the second step, the temperature stabilizer includes VC sodium salt, trioxane and citric acid.

The molar mass ratio of the sodium salt of VC, trioxane and citric acid is 1:0.3-0.5:0.1-0.3.

In the second step, the preparation method of the nonylphenol polyoxyethylene ether diester sodium salt includes the following steps:

A. Mix maleic anhydride and nonylphenol polyoxyethylene ether according to the molar mass ratio of 1:2-3, then add p-toluenesulfonic acid, and move to an oil bath at a temperature of 150-170°C to react under normal pressure 1 hour, then reduce pressure to 2-80kPa to perform a vacuum esterification reaction to obtain an esterification reaction mixture, and the reaction time of the vacuum esterification reaction is 3-5 hours;

B. Cool the esterification reaction mixture obtained in step A to 65-75°C, add sodium bisulfite, heat to 75-85°C, stir and react for 3 hours to obtain the finished product of sodium nonylphenol polyoxyethylene ether diester .

In step A, the molar mass ratio of the maleic anhydride to p-toluenesulfonic acid is 1:0.02-0.08.

In step B, the molar mass ratio of the maleic anhydride to sodium bisulfite is 1:1 to 1.1.

Example 1

A method for preparing a high-temperature resistant oil-based drilling fluid wetting agent. The drilling fluid wetting agent is prepared by the following steps:

The first step is to weigh the polyhydroxy organic amine compound and the fatty acid with the carbon chain length of C8-C22 according to the molar mass ratio of 1:2 and mix them uniformly, then add p-toluenesulfonic acid to it, bubbling in nitrogen and deoxygenating at 165℃ Condensate and reflux in the oil bath for 24 hours, cool the reaction product to 70°C, add oxalic acid, keep the temperature at 90°C, react for 6 hours, and cool to room temperature to obtain fatty acid ester; The molar mass ratio of p-toluenesulfonic acid is 1:0.03, and the molar mass ratio of the polyhydroxy organic amine compound to oxalic acid is 1:0.3.

In the second step, the fatty acid ester obtained in the first step is added to the white oil and mixed uniformly, then the high temperature stabilizer and nonylphenol polyoxyethylene ether diester sodium salt are added, and the finished drilling fluid wetting agent is obtained after mixing uniformly. . The molar mass ratio of the fatty acid ester: white oil: high temperature stabilizer: nonylphenol polyoxyethylene ether diester sodium salt is 1:10:0.2:0.3.

In the first step, the polyhydroxy organic amine compound is one or more of dimethanolamine, trimethanolamine, diethanolamine, triethanolamine, dipropanolamine, and tripropanolamine.

In the first step, the fatty acid is one or more of lauric acid, stearic acid, oleic acid, and linoleic acid.

In the second step, the temperature stabilizer includes VC sodium salt, trioxane and citric acid. The molar mass ratio of the sodium salt of VC, trioxane and citric acid is 1:0.4:0.2.

In the second step, the preparation method of the nonylphenol polyoxyethylene ether diester sodium salt includes the following steps:

A. Mix maleic anhydride and nonylphenol polyoxyethylene ether according to the molar mass ratio of 1:2.6, then add p-toluenesulfonic acid, and move to an oil bath at a temperature of 160°C to react under normal pressure for 1 hour, then The pressure is reduced to 2 kPa to perform a vacuum esterification reaction to obtain an esterification reaction mixture, and the reaction time of the vacuum esterification reaction is 3-5 hours;

B. Cooling the esterification reaction mixture obtained in step A to 70°C, adding sodium bisulfite, heating to 80°C, and stirring and reacting for 3 hours to obtain the finished product of sodium nonylphenol polyoxyethylene ether diester.

In step A, the molar mass ratio of the maleic anhydride to p-toluenesulfonic acid is 1:0.05. In step B, the molar mass ratio of the maleic anhydride to sodium bisulfite is 1:1.06.

Example 2

In this embodiment, the similarities with embodiment 1 will not be repeated, and the differences are as follows:

A method for preparing a high-temperature resistant oil-based drilling fluid wetting agent. The drilling fluid wetting agent is prepared by the following steps:

The first step is to weigh the polyhydroxy organic amine compound and the fatty acid with carbon chain length of C8-C22 according to the molar mass ratio of 1:1 and mix them uniformly, then add p-toluene sulfonic acid to it, blow in nitrogen and deoxidize at 170℃ The reaction product was condensed and refluxed in the oil bath for 24 hours, the reaction product was cooled to 80°C, oxalic acid was added, and the temperature was kept at 70°C for 6 hours, and the fatty acid ester was obtained by cooling to room temperature; the polyhydroxy organic amine compound and The molar mass ratio of p-toluenesulfonic acid is 1:0.05, and the molar mass ratio of the polyhydroxy organic amine compound to oxalic acid is 1:0.5.

In the second step, the fatty acid ester obtained in the first step is added to the white oil and mixed uniformly, then the high temperature stabilizer and nonylphenol polyoxyethylene ether diester sodium salt are added, and the finished drilling fluid wetting agent is obtained after mixing uniformly. . The molar mass ratio of the fatty acid ester: white oil: high temperature stabilizer: nonylphenol polyoxyethylene ether diester sodium salt is 1:2:0.3:0.4.

Example 3

In this embodiment, the similarities with embodiment 1 will not be repeated, and the differences are as follows:

A method for preparing a high-temperature resistant oil-based drilling fluid wetting agent. The drilling fluid wetting agent is prepared by the following steps:

The first step is to weigh the polyhydroxy organic amine compound and the fatty acid with carbon chain length of C8-C22 according to the molar mass ratio of 1:1.5 and mix them uniformly, then add p-toluenesulfonic acid to it, blow in nitrogen and deoxidize at 160℃ Condensate and reflux in the oil bath for 24 hours, cool the reaction product to 90°C, add oxalic acid, keep the temperature at 80°C, react for 6 hours, and cool to room temperature to obtain fatty acid ester; The molar mass ratio of p-toluenesulfonic acid is 1:0.01, and the molar mass ratio of the polyhydroxy organic amine compound to oxalic acid is 1:-07.

In the second step, the fatty acid ester obtained in the first step is added to the white oil and mixed uniformly, then the high temperature stabilizer and nonylphenol polyoxyethylene ether diester sodium salt are added, and the finished drilling fluid wetting agent is obtained after mixing uniformly. . The molar mass ratio of the fatty acid ester: white oil: high temperature stabilizer: nonylphenol polyoxyethylene ether diester sodium salt is 1:5:0.1:0.5.

Example 4

In this embodiment, the similarities with embodiment 1 will not be repeated, and the differences are as follows:

A method for preparing a high-temperature resistant oil-based drilling fluid wetting agent. The drilling fluid wetting agent is prepared by the following steps:

The first step is to weigh the polyhydroxy organic amine compound and the fatty acid with carbon chain length of C8-C22 according to the molar mass ratio of 1:1.5 and mix them uniformly, then add p-toluenesulfonic acid to it, blow in nitrogen and deoxidize at 165℃ Condensate and reflux in the oil bath for 24 hours, cool the reaction product to 80°C, add oxalic acid, keep the temperature at 85°C, and react for 6 hours, then cool to room temperature to obtain fatty acid ester; The molar mass ratio of p-toluenesulfonic acid is 1:0.04, and the molar mass ratio of the polyhydroxy organic amine compound to oxalic acid is 1:0.6.

In the second step, the fatty acid ester obtained in the first step is added to the white oil and mixed uniformly, then the high temperature stabilizer and nonylphenol polyoxyethylene ether diester sodium salt are added, and the finished drilling fluid wetting agent is obtained after mixing uniformly. . The molar mass ratio of the fatty acid ester: white oil: high temperature stabilizer: nonylphenol polyoxyethylene ether diester sodium salt is 1:6:0.2:0.4.

Add 1mL of one of the anti-high temperature oil-based drilling fluid wetting agents prepared in Example 1-4 to 100ml of 3# white oil, stir at 10000rpm for 20min, and then add 7g of barite (barite particle size is 20μm ), then stir at 10000rpm for 20min, pour it into a 200ml graduated cylinder and let it stand for 1 hour, and calculate its wetting rate based on the volume V (ml) of the clear oil separated from the upper layer. The calculation formula of the wetting rate is as follows: Wetting rate (%)=[(100-V)/100]×100%, the wetting rate of the high temperature resistant oil-based drilling fluid wetting agent prepared in Examples 1-4 of this application As shown in Table 1, it can be seen from Table 1 that the high temperature resistant oil-based drilling fluid wetting agent prepared in this application has a maximum wetting rate of 95.1% and a minimum of 91.6%, which is much higher than the existing market similar products .

Table 1 The wetting rate of the high temperature resistant oil-based drilling fluid wetting agent prepared in different examples

Experimental conditions Wetting rate (%) Example 1 92.3 Example 2 91.6 Example 3 93.4 Example 4 95.1

The preparation method of a high-temperature resistant oil-based drilling fluid wetting agent applied by the present invention has simple conditions and is easy to implement. It can not only meet the requirements for oil-based drilling fluids in the process of drilling in high-pressure formations, but also provide for the development of unconventional gas reservoirs. Technical support can significantly reduce the cost of oil-based drilling fluids, obtain good economic and social benefits, and is worthy of popularization and application. The prepared drilling fluid wetting agent is conducive to the suspension of the weighted material in the oil-based drilling fluid, and there is no need to increase the viscosity of the drilling fluid system in the high-density oil-based drilling fluid, and has little effect on the rheology of the high-density oil-based drilling fluid. , The formulated high-density oil-based drilling fluid has good rheology, manifested in low plastic viscosity and low static shear force. The method for preparing a high-temperature resistant oil-based drilling fluid wetting agent proposed by the invention has a simple formula, a wide source of wetting agent components, low price, strong temperature resistance, and simple on-site operation and maintenance.

This application adds nonylphenol polyoxyethylene ether diester sodium salt to the preparation method, so that the prepared drilling fluid wetting agent has the dual properties of non-ionic and anionic surfactants, and can promote the formation of O/W emulsions. Effectively reduce the viscosity of heavy oil, improve fluidity, and significantly reduce the oil-water interfacial tension. The addition of a high-temperature stabilizer composed of VC sodium salt, trioxane and citric acid enables the high-temperature resistant oil-based drilling fluid wetting agent prepared in the present application to maintain its original performance under elevated temperature conditions, which can reduce the effects of thermal oxidative degradation The destructive effect of drilling fluid components improves the high temperature stability of the wetting agent and other components, expands the application range of the wetting agent, and significantly reduces drilling costs.

Although the technical solutions of the present invention have been described and enumerated in more detail, it should be understood that for those skilled in the art, it is important for those skilled in the art to modify the above-mentioned embodiments or adopt equivalent alternatives. Obviously, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of the present invention.

Claims (10)

A method for preparing a high-temperature resistant oil-based drilling fluid wetting agent, characterized in that the drilling fluid wetting agent is prepared by the following steps: The first step is to weigh the polyhydroxy organic amine compound and the fatty acid with carbon chain length of C8-C22 according to the molar mass ratio of 1:1-2 and mix them uniformly, then add p-toluenesulfonic acid to it, and then pass in nitrogen to remove oxygen. Condensate and reflux in an oil bath at 160-170°C for 24 hours, cool the reaction product to 70-90°C, add oxalic acid, keep the temperature at 70-90°C, react for 6 hours, and cool to room temperature to obtain fatty acid esters; In the second step, the fatty acid ester obtained in the first step is added to the white oil and mixed uniformly, then the high temperature stabilizer and nonylphenol polyoxyethylene ether diester sodium salt are added, and the finished drilling fluid wetting agent is obtained after mixing uniformly. . The method for preparing a high-temperature resistant oil-based drilling fluid wetting agent according to claim 1, characterized in that: in the first step, the polyhydroxy organic amine compound is dimethanolamine, trimethanolamine, and diethanolamine , One or several of triethanolamine, dipropanolamine, and tripropanolamine. The method for preparing a high temperature resistant oil-based drilling fluid wetting agent according to claim 1, characterized in that: in the first step, the fatty acid lauric acid, stearic acid, oleic acid, linoleic acid One or several kinds. The method for preparing a high-temperature resistant oil-based drilling fluid wetting agent according to claim 1, characterized in that: in the first step, the molar mass ratio of the polyhydroxy organic amine compound to p-toluenesulfonic acid is 1 : 0.01-0.05, the molar mass ratio of the polyhydroxy organic amine compound to oxalic acid is 1:0.3-07. The method for preparing a high temperature resistant oil-based drilling fluid wetting agent according to claim 1, characterized in that: in the second step, the fatty acid ester: white oil: high temperature stabilizer: nonylphenol polyoxygen The molar mass ratio of vinyl ether diester sodium salt is 1:2-10:0.1-0.3:0.3-0.5. The method for preparing a high-temperature resistant oil-based drilling fluid wetting agent according to claim 1, characterized in that: in the second step, the temperature stabilizer includes VC sodium salt, trioxane and citric acid. The method for preparing a high-temperature resistant oil-based drilling fluid wetting agent according to claim 6, wherein the molar mass ratio of the sodium salt of VC, trioxane and citric acid is 1:0.3-0.5:0.1 -0.3. The method for preparing a high-temperature resistant oil-based drilling fluid wetting agent according to claim 1, characterized in that, in the second step, the preparation method of the nonylphenol polyoxyethylene ether diester sodium salt comprises the following step: A. Mix maleic anhydride and nonylphenol polyoxyethylene ether according to the molar mass ratio of 1:2-3, then add p-toluenesulfonic acid, and move to an oil bath at a temperature of 150-170°C to react under normal pressure 1 hour, then reduce pressure to 2-80kPa to perform a vacuum esterification reaction to obtain an esterification reaction mixture, and the reaction time of the vacuum esterification reaction is 3-5 hours; B. Cool the esterification reaction mixture obtained in step A to 65-75°C, add sodium bisulfite, heat to 75-85°C, stir and react for 3 hours to obtain the finished product of sodium nonylphenol polyoxyethylene ether diester . The method for preparing a high temperature resistant oil-based drilling fluid wetting agent according to claim 8, characterized in that: in step A, the molar mass ratio of maleic anhydride to p-toluenesulfonic acid is 1: 0.02-0.08. The method for preparing a high-temperature resistant oil-based drilling fluid wetting agent according to claim 8, characterized in that: in step B, the molar mass ratio of the maleic anhydride to sodium bisulfite is 1: 1-1.1.