CN118638528A - A -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling and its preparation method and application - Google Patents

Abstract

The present invention relates to a temperature-resistant 35°C small molecule drilling fluid wetting agent for polar drilling and its preparation method and application. The preparation method is as follows: carboxylic acid and polyamine are added to toluene to construct a reaction system; then the reaction system is passed nitrogen for 20-30min at room temperature, and then isothermal reaction is carried out for 4-5h under the conditions of reaction temperature of 150-180°C and stirring speed of 280-330r/min, and the reaction is cooled to 70-80°C after completion of the reaction, and the reaction product is filtered and decompression distilled to remove the solvent to obtain a temperature-resistant 35°C small molecule drilling fluid wetting agent for polar drilling. The small molecule drilling fluid wetting agent in the present invention is synthesized from three monomers of carboxylic acid, polyamine and toluene. The small molecule drilling fluid wetting agent mainly includes a plurality of polar groups such as amide groups and carbonyl groups, which can be strongly adsorbed on the surface and edge of the organic soil sheet, so that the dispersibility of the organic soil is improved under ultra-low temperature conditions.

Description

A -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling and its preparation method and application

Technical Field

The invention relates to a -35°C temperature-resistant small-molecule drilling fluid wetting agent for polar drilling and a preparation method and application thereof, belonging to the technical field of polar drilling.

Background Art

The Antarctic continent is rich in resources, with as many as 220 proven mineral species. During the drilling process, drilling fluid is the blood of drilling, playing the role of suspending and carrying cuttings. However, the low surface temperature and complex subglacial geological environment in Antarctica pose great challenges to drilling fluid technology. Organic soil has broad application prospects in the field of polar drilling. However, organic soil has poor dispersibility in aviation kerosene and white oil, and is easy to settle, resulting in deterioration of drilling fluid performance. Wetting agent is one of the important treatment agents for drilling fluid. It can be adsorbed on the surface of organic soil particles through the action between polar groups, thereby making organic soil easier to disperse in aviation kerosene and white oil.

At present, there have been many reports on the research and development of high temperature resistant drilling fluid wetting agents, and the developed wetting agents are mainly non-ionic or cationic wetting agents. For example, Chinese patent document CN116496767A discloses a wetting agent and its preparation method and application. The invention uses alkyl dimethyl carboxylic acid betaine, 3-sulfopropyl alkyl dimethyl betaine, dioctyl sulfosuccinate and water as raw materials to prepare an oil-based drilling fluid wetting agent that can resist high temperatures of 220°C. It can effectively wet weighting materials and drill cuttings in different base oils, and at the same time, it increases the demulsification voltage of synthetic drilling fluid from 429V to 537V, ensuring the stability of the emulsion. In view of the problem that barite in drilling fluid is easy to settle under high-density conditions, resulting in poor rheological properties of drilling fluid, Chinese patent document CN103194187A discloses a wetting agent for high-density oil-based drilling fluid and its application. In this invention, Span-80 and Tween-80 are compounded in a certain proportion to develop a wetting agent, which effectively improves the problem that barite is easy to aggregate and settle under high-density conditions; and 1% wetting agent increases the demulsification voltage of the drilling fluid from 514V to 650V, and the emulsion stability is improved. Chinese patent document CN114605974A discloses an oil-based drilling fluid and its preparation method. In this invention, SRRH-O-WET is selected as a wetting agent, which not only effectively improves the dispersion and suspension properties of the weighting agent, but also reduces the aggregation of organic clay particles.

However, there is no report on low-temperature drilling fluid wetting agents suitable for the Antarctic region. Therefore, it is urgent to develop ultra-low temperature drilling fluid wetting agents suitable for the Antarctic region to improve the dispersion performance of organic soil used in drilling fluid in base oil during polar drilling, thereby improving drilling efficiency.

Summary of the invention

In view of the shortcomings of the prior art, the present invention provides a -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling and a preparation method and application thereof. The small molecule drilling fluid wetting agent can withstand low temperatures of -35°C, can solve the problem of poor dispersibility of organic soil in drilling fluid, and can also improve the rheological properties of drilling fluid.

To achieve the above object, the technical solution of the present invention is as follows:

A method for preparing a -35°C temperature-resistant small-molecule drilling fluid wetting agent for polar drilling, comprising the following steps:

Carboxylic acid and polyamine are added to toluene to construct a reaction system; then nitrogen is passed through the reaction system at room temperature for 20 to 30 minutes, and then the reaction is carried out at a constant temperature of 150 to 180°C and a stirring speed of 280 to 330 r/min for 4 to 5 hours. After the reaction is completed, the reaction is cooled to 70 to 80°C, and the reaction product is filtered and the solvent is removed by vacuum distillation to obtain a -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling.

Preferably according to the present invention, the mass proportion of toluene in the reaction system is 65-70wt%.

Preferably according to the present invention, the carboxylic acid is sebacic acid or myristic acid.

More preferably, the carboxylic acid is sebacic acid.

Preferably according to the present invention, the polyamine is N-ethylethylenediamine or tetraethylenepentamine.

More preferably, the polyamine is tetraethylenepentamine.

Preferably according to the present invention, the molar ratio of the carboxylic acid to the polyamine is (2.5-3):1.

Preferably according to the present invention, the reaction temperature is 160-170° C. and the stirring speed is 300-320 r/min.

The present invention also provides a -35°C temperature-resistant small-molecule drilling fluid wetting agent for polar drilling, which is prepared by the above-mentioned preparation method.

Preferably according to the present invention, the -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling has a colloid rate of 76.4%~87.2% at -35°C, a contact angle of 10.4°~16.2°, a dynamic shear force of 0.75~1.25Pa, and a shear lift rate of 50%~150%.

According to the present invention, the above-mentioned -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling is used in polar formations; preferably, the polar region is Antarctica.

The technical features and beneficial effects of the present invention are as follows:

1. The preparation method of the present invention is simple, and the obtained small molecule drilling fluid wetting agent is safe, environmentally friendly, and has no irritating odor.

2. The monomers used in the preparation of the small molecule drilling fluid wetting agent of the present invention are optimally combined in specific types and specific proportions, and their combined effect achieves the excellent effect of the present invention.

3. The small molecule drilling fluid wetting agent in the present invention is synthesized from three monomers: carboxylic acid, polyamine and toluene. The small molecule drilling fluid wetting agent mainly includes multiple polar groups such as amide groups and carbonyl groups, which can be strongly adsorbed on the surface and edge of the organic soil layer, so that the dispersibility of the organic soil is improved under ultra-low temperature conditions.

4. The molar ratio of carboxylic acid to polyamine in the present invention needs to be appropriate. If the ratio is too low, the unreacted polyamine will affect the adsorption of the small molecule drilling fluid wetting agent on the organic soil layer, thereby affecting the improvement of the lipophilicity of the organic soil by the small molecule drilling fluid wetting agent. At the same time, the amount of solvent added is also directly related to the conversion rate of the reaction product. If the amount of solvent added is too low, the conversion rate of the reaction product will be low.

5. The -35°C temperature-resistant small molecule drilling fluid wetting agent of the present invention can be used at ultra-low temperatures below -35°C in polar regions, providing technical support for the research and development of polar drilling fluid treatment agents and having broad application prospects.

DETAILED DESCRIPTION

The present invention will be further described below by means of specific examples, but is not limited thereto.

The experimental methods described in the examples are conventional methods unless otherwise specified; the reagents and materials used are commercially available unless otherwise specified.

Example 1

A method for preparing a -35°C temperature-resistant small-molecule drilling fluid wetting agent for polar drilling, comprising the following steps:

First, toluene is added into a three-necked flask, and then sebacic acid and tetraethylenepentamine are added into the toluene to construct a reaction system; then, nitrogen is passed through the reaction system at room temperature for 25 minutes; then, the temperature is raised to 165°C, a condenser is added above the flask, and the reaction is carried out at a constant temperature for 5 hours at a stirring speed of 310 r/min, and the reaction is cooled to 80°C after the reaction is completed; the reaction product is filtered and the solvent is removed by reduced pressure distillation to obtain a -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling;

The mass proportion of toluene in the reaction system is 65wt%, and the molar ratio of sebacic acid to tetraethylenepentamine is 2.5:1.

Example 2

A method for preparing a -35°C temperature-resistant small-molecule drilling fluid wetting agent for polar drilling, comprising the following steps:

First, toluene is added into a three-necked flask, and then sebacic acid and tetraethylenepentamine are added into the toluene to construct a reaction system; then, nitrogen is passed through the reaction system at room temperature for 25 minutes; then, the temperature is raised to 165°C, a condenser is added above the flask, and the reaction is carried out at a constant temperature for 5 hours at a stirring speed of 310 r/min, and after the reaction is completed, the temperature is cooled to 80°C; the reaction product is filtered and the solvent is removed by reduced pressure distillation to obtain a -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling;

The mass proportion of toluene in the reaction system is 65wt%, and the molar ratio of sebacic acid to tetraethylenepentamine is 2.7:1.

Example 3

A method for preparing a -35°C temperature-resistant small-molecule drilling fluid wetting agent for polar drilling, comprising the following steps:

First, toluene is added into a three-necked flask, and then sebacic acid and tetraethylenepentamine are added into the toluene to construct a reaction system; then, nitrogen is passed through the reaction system at room temperature for 25 minutes; then, the temperature is raised to 165°C, a condenser is added above the flask, and the reaction is carried out at a constant temperature for 4 hours at a stirring speed of 310 r/min, and the reaction is cooled to 80°C after the reaction is completed; the reaction product is filtered and the solvent is removed by reduced pressure distillation to obtain a -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling;

The mass proportion of toluene in the reaction system is 65wt%, and the molar ratio of sebacic acid to tetraethylenepentamine is 2.7:1.

Example 4

A method for preparing a -35°C temperature-resistant small-molecule drilling fluid wetting agent for polar drilling, comprising the following steps:

First, toluene is added into a three-necked flask, and then sebacic acid and tetraethylenepentamine are added into the toluene to construct a reaction system; then, nitrogen is passed through the reaction system at room temperature for 25 minutes; then, the temperature is raised to 170°C, a condenser is added above the flask, and the reaction is carried out at a constant temperature for 4 hours at a stirring speed of 310 r/min, and the reaction is cooled to 80°C after the reaction is completed; the reaction product is filtered and the solvent is removed by reduced pressure distillation to obtain a -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling;

The mass proportion of toluene in the reaction system is 65wt%, and the molar ratio of sebacic acid to tetraethylenepentamine is 2.7:1.

Example 5

A method for preparing a -35°C temperature-resistant small-molecule drilling fluid wetting agent for polar drilling, comprising the following steps:

First, toluene is added into a three-necked flask, and then myristic acid and tetraethylenepentamine are added into the toluene to construct a reaction system; then nitrogen is passed through the reaction system at room temperature for 30 minutes; then the temperature is raised to 170°C, a condenser is added above the flask, and the reaction is carried out at a constant temperature for 5 hours at a stirring speed of 320 r/min, and the reaction is cooled to 80°C after the reaction is completed; the reaction product is filtered and the solvent is removed by reduced pressure distillation to obtain a -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling;

The mass ratio of toluene in the reaction system is 70wt%, and the molar ratio of myristic acid to tetraethylenepentamine is 3:1.

Example 6

A method for preparing a -35°C temperature-resistant small-molecule drilling fluid wetting agent for polar drilling, comprising the following steps:

First, toluene is added into a three-necked flask, and then sebacic acid and N-ethylethylenediamine are added into the toluene to construct a reaction system; then, nitrogen is passed through the reaction system at room temperature for 20 minutes; then, the temperature is raised to 160°C, a condenser is added above the flask, and the reaction is carried out at a constant temperature for 4 hours at a stirring speed of 300 r/min, and the reaction is cooled to 70°C after the reaction is completed; the reaction product is filtered and the solvent is removed by reduced pressure distillation to obtain a -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling;

The mass proportion of toluene in the reaction system is 65wt%, and the molar ratio of sebacic acid to N-ethylethylenediamine is 2.5:1.

Comparative Example 1

A wetting agent, the preparation method of which is as described in Example 3, except that sebacic acid is replaced by camphoric acid, and other conditions are the same as in Example 3.

Comparative Example 2

A wetting agent, the preparation method of which is as described in Example 3, except that the molar ratio of sebacic acid to tetraethylenepentamine is 3.2:1, and other conditions are the same as those in Example 3.

Comparative Example 3

A wetting agent, the preparation method of which is as described in Example 3, except that the reaction time is 6 hours.

Comparative Example 4

An amide wetting agent CHS-1 is prepared by mixing plant fatty acids, polyene polyamines and acid anhydrides in a molar mass ratio of 7.5:2.5:1, and reacting the mixture at a constant temperature of 170°C for 5 hours to obtain the amide wetting agent CHS-1.

Test Example 1

The wetting agents prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were tested for colloid rate, contact angle and rheological properties.

(1) Sample preparation:

The composition of the drilling fluid base fluid is as follows: first, 4# aviation kerosene and 5# white oil are prepared into a base oil in a volume ratio of 7:3, with a total of 350 mL; secondly, 3% of the mass of the base oil, organic soil (produced by Baker Oil Company) is added to prepare a drilling fluid base fluid; the wetting agents prepared in Examples 1 to 6 and Comparative Examples 1 to 4 are respectively added to the drilling fluid base fluid in an amount of 2% of the mass of the drilling fluid base fluid, and the samples are fully stirred on a high-speed stirrer for 25 minutes to obtain samples; and then the performance thereof at -35°C is tested.

(2) Test method:

Colloid rate test: Pour 100mL of prepared drilling fluid into a colorimetric tube, then place the colorimetric tube in a low-temperature constant temperature box (-35℃) and let it stand for 16 hours. Then calculate the colloid rate, colloid rate = (lower volume/total volume) * 100%.

Rheological test: Pour 100 mL of prepared drilling fluid into the test slurry cup, use a low-temperature rheometer to test the 600r and 300r readings at -35°C, and then calculate the relevant rheological parameters.

Contact angle test: add the wetting agent to the drilling fluid base fluid according to 2% of the mass of the drilling fluid base fluid, stir it thoroughly for 20 minutes, then soak the mica sheet in the above drilling fluid and freeze it in a DW-40 ultra-low temperature constant temperature box for 24 hours; then use a contact angle meter to test the contact angle size, using a 5.0 μL oil droplet as a probe, measure each sample three times, and record the average value.

The test results of colloid rate, rheological properties and contact angle are shown in Table 1.

Table 1. Performance test of drilling fluid wetting agent at -35℃

It can be seen from the data in Table 1 that the -35°C temperature-resistant small molecule drilling fluid wetting agent for polar drilling prepared in Examples 1 to 6 of the present invention has good lipophilicity, and the contact angle can reach below 16.2°; at -35°C, it can effectively improve the dispersion performance of organic soil in base oil, and the colloid rate after standing for 16 hours can still reach more than 76.4%; it also has a good shearing effect, and the shearing rate at -35°C can reach more than 50%, and the plastic viscosity is below 16.5 mPa.s, indicating that the wetting agent also has good rheological properties.

In summary, the -35°C temperature-resistant small molecule drilling fluid wetting agent provided by the present invention can be used at ultra-low temperatures below -35°C in the polar regions, can meet the needs of polar drilling, provides technical support for the research and development of polar drilling fluid treatment agents, and has broad application prospects.

The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further explain various possible combinations. In addition, the various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims (10)

1. The preparation method of the small molecular drilling fluid wetting agent with the temperature resistance of minus 35 ℃ for polar region drilling is characterized by comprising the following steps:

Adding carboxylic acid and polyamine into toluene to construct a reaction system; and then introducing nitrogen into the reaction system at room temperature for 20-30 min, then performing constant-temperature reaction for 4-5 h at the reaction temperature of 150-180 ℃ and the stirring speed of 280-330 r/min, cooling to 70-80 ℃ after the reaction is finished, and filtering and distilling the reaction product under reduced pressure to remove the solvent to obtain the temperature-resistant-35 ℃ micromolecule drilling fluid wetting agent for polar region drilling.

2. The preparation method according to claim 1, wherein the mass ratio of toluene in the reaction system is 65-70wt%.

3. The method of claim 1, wherein the carboxylic acid is sebacic acid or myristic acid;

further preferably, the carboxylic acid is sebacic acid.

4. The method of claim 1, wherein the polyamine is N-ethylethylenediamine or tetraethylenepentamine;

Further preferably, the polyamine is tetraethylenepentamine.

5. The method of claim 1, wherein the molar ratio of carboxylic acid to polyamine is (2.5-3): 1.

6. The preparation method of claim 1, wherein the reaction temperature is 160-170 ℃ and the stirring speed is 300-320 r/min.

7. A temperature-resistant 35 ℃ small molecule drilling fluid wetting agent for polar region drilling, which is characterized by being prepared by the preparation method of any one of claims 1-7.

8. The small molecular drilling fluid wetting agent with the temperature resistance of minus 35 ℃ for polar drilling according to claim 7, wherein the gel rate of the small molecular drilling fluid wetting agent with the temperature resistance of minus 35 ℃ for polar drilling at minus 35 ℃ is 76.4% -87.2%, the contact angle is 10.4-16.2 degrees, the dynamic shear force is 0.75-1.25 Pa, and the extraction shear rate is 50% -150%.

9. The use of the small molecule drilling fluid wetting agent with the temperature resistance of minus 35 ℃ for polar region drilling in polar region stratum.

10. The use of claim 9, wherein the pole is a south pole.