CN107814738A - A kind of high density oil base drilling fluid flow pattern regulator, its preparation method and application - Google Patents

Abstract

The present invention provides a flow pattern regulator for high-density oil-based drilling fluid, its preparation method and application. The flow pattern regulator is shown in formula _I , and R1 is selected from C8-22 alkyl or C17-21 alkenyl. The flow pattern adjustment has the functions of wetting and dispersing and increasing the shear force of drilling fluid, which can change the surface property of the weighted material from hydrophilic to lipophilic, reduce the plastic viscosity of drilling fluid, and can synergize with organic soil to improve drilling performance. The dynamic shear force of the liquid at high temperature ensures good suspension stability. The wettability of the flow regulator to barite is greater than 80%. When its addition is 2%, in oil-based drilling fluid with an oil-water ratio of 9:1 and a density of 2.62g/cm ³ , after 180 After aging at ℃/16h, the plastic viscosity of the drilling fluid can be lower than 80mPa·s, and the overall performance is good. In addition, the present invention has the characteristics of simple synthesis steps and mild reaction conditions, which is beneficial to large-scale production and popularization and application.

Description

A flow regulator for high-density oil-based drilling fluid, its preparation method and application

technical field

The invention relates to the technical field of chemicals for oil-based drilling fluid, in particular to a flow pattern regulator for high-density oil-based drilling fluid, its preparation method and application.

Background technique

In recent years, with the large-scale development of shale gas, domestic oil-based drilling fluids have developed rapidly. A series of oil-based drilling fluid treatment agents have been researched and applied, which basically meet the requirements of oil-based drilling fluids with a density below 2.2g/ ^cm3 . fluid performance requirements. However, with the gradual development of oil exploration and development to deep and complex formations, the number of high-temperature and high-pressure wells has gradually increased, and there is more demand for ultra-high-density oil-based drilling fluids (density>2.2g/cm ³ ). The ultra-high-density oil-based drilling fluid has a high solid phase content, and when the density reaches 2.5g/cm ³ , the volume fraction of the weighting material is about 55%, and the surface is hydrophilic. Limited by the type and amount of existing treatment agents, ultra-high-density oil-based drilling fluids have poor low-temperature fluidity, low shear force and easy sedimentation at high temperatures, and inability to balance rheological properties with high-temperature and high-pressure filtration.

Usually one of the methods to solve this kind of problem is to add wetting agent to change the wettability of the surface of the weighted material from hydrophilic to lipophilic, so that they can be suspended and dispersed in oil-based drilling fluid , reduce the viscosity of drilling fluid and improve the rheology of oil-based drilling fluid. However, the problem of low shear force and low suspension stability under high temperature cannot be effectively solved by this method, and the effect is not good in ultra-high density oil-based drilling fluid. In addition, under normal circumstances, the synthesis steps of wetting agents are cumbersome, which is not conducive to large-scale production and popularization and application.

Another method is to add a flow regulator to the oil-based drilling fluid to improve the rheology of the drilling fluid. For example, the Chinese patent document with publication number CN103666414A discloses a polyamidoamine flow pattern regulator for mineral oil oil-based drilling fluids and a preparation method thereof. The flow pattern regulator is composed of dimer fatty acid and polyamine at 120- The amidation reaction is carried out at 160°C. After the reaction is completed, the product and the solvent are mixed uniformly at a mass ratio of 0.5-1.5:1. This type of flow regulator has a large molecular weight and many active functional groups, which can form multi-point adsorption and is difficult to desorb from the surface of organic soil. However, it is not suitable for high-density oil-based drilling fluids.

Contents of the invention

In view of this, the application provides a flow pattern regulator for high-density oil-based drilling fluid, its preparation method and application. The flow pattern regulator provided by the invention has the functions of wetting and dispersing and improving the shear force of drilling fluid, and can It is used to adjust the flow pattern of high-density oil-based drilling fluid.

The invention provides a flow pattern regulator for high-density oil-based drilling fluid, which has a structure of formula I:

In formula I, R ₁ is selected from C8-22 alkyl or C17-21 alkenyl;

_R2 is methylene or R ₃ is -(CH ₂ ) ₃ - or

Y- is -COO- or -SO ₃ -.

Preferably, R ₁ is selected from octyl, decyl, undecyl, tridecyl, tetradecyl, hexadecyl, heptadecyl or CH ₃ (CH ₂ ) _m -CH═CH- (CH ₂ ) _n -CH ₂ -, wherein m is 7 and n is 6 or 10.

The invention provides a method for preparing a flow pattern regulator for high-density oil-based drilling fluid, comprising the following steps:

The long-chain hydrocarbyl amido tertiary amine is reacted with a quaternizing agent in a solvent to obtain a flow pattern regulator for high-density oil-based drilling fluid;

The long-chain hydrocarbyl amido tertiary amine has a formula II structure:

Described quaternization reagent has formula III structure:

XR ₂ -Y-Na Formula III;

The high-density oil-based drilling fluid flow regulator has a formula I structure:

Wherein, R ₁ is selected from C8～22 alkyl or C17～21 alkenyl;

_R2 is methylene or R ₃ is -(CH ₂ ) ₃ - or

X is selected from halogen; Y ^- is -COO ^- or SO ₃ ^- .

Preferably, the long-chain hydrocarbyl amidopropyl dimethylamine is octyl amidopropyl dimethylamine, decyl amidopropyl dimethylamine, lauryl amidopropyl dimethylamine, tetradecyl amidopropyl dimethylamine, tetradecyl amidopropyl dimethylamine, Cetyl dimethylamine, cetyl amidopropyl dimethylamine, oleamidopropyl dimethylamine, stearamidopropyl dimethylamine, cocamidopropyl dimethylamine or erucamide Propyldimethylamine.

Preferably, the solvent is water or a mixture of organic solvents and water.

Preferably, the organic solvent is an alcoholic organic solvent.

Preferably, the mass ratio of the alcoholic organic solvent to water is 0.1-5:10.

Preferably, the reaction temperature is 75-85°C.

The present invention provides a high-density oil-based drilling fluid, including base oil and a treatment agent, wherein the treatment agent includes the above-mentioned flow pattern regulator.

Preferably, the added amount of the flow pattern regulator is 1-5 (w/v)% of the base oil.

Compared with prior art, the present invention adopts long-chain alkyl or alkenyl amido tertiary amine and quaternization reagent, through one-step reaction, generates the betaine type zwitterionic surfactant shown in formula I, and it is as high density The flow regulator (regulator) agent for oil-based drilling fluid has the functions of wetting and dispersing and increasing the shear force of the drilling fluid. It can change the surface property of the weighted material from hydrophilic to lipophilic, and reduce the plastic viscosity of the drilling fluid. At the same time, it can work synergistically with organic soil to increase the dynamic shear force of drilling fluid at high temperature and ensure good suspension stability, thereby overcoming the low shear force of existing wetting agents at high temperature in high-density oil-based drilling fluid, which is difficult to ensure drilling Liquid suspension stability, as well as the shortcomings of existing flow pattern regulators in high-density oil-based drilling fluids, such as high viscosity shear and poor rheology. The experimental results show that the wetting rate of the obtained flow pattern modifier to barite is greater than 80%. When the added amount is 2%, the oil-based drilling fluid with an oil-water ratio of 9:1 and a density of 2.62g/ ^cm3 Among them, after aging at 180℃/16h, the plastic viscosity of the drilling fluid can be kept below 80mPa·s, and the comprehensive performance is good.

In addition, the present invention has the characteristics of simple synthesis steps, mild reaction conditions, outstanding product performance advantages, etc., which is beneficial to large-scale production and popularization and application.

Description of drawings

Fig. 1 is the infrared spectrogram of the product obtained in Example 1 of the present invention;

Fig. 2 is the differential thermal scanning calorimetry diagram of the product obtained in Example 1 of the present invention.

Detailed ways

The following clearly and completely describes the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The invention provides a flow pattern regulator for high-density oil-based drilling fluid, which has a structure of formula I:

In formula I, R ₁ is selected from C8-22 alkyl or C17-21 alkenyl;

_R2 is methylene or R ₃ is -(CH ₂ ) ₃ - or

Y ^- is -COO ^- or -SO ₃ ^- .

The flow pattern regulator provided by the invention not only has the function of wetting and dispersing, but also can increase the shear force of drilling fluid, and is suitable for high-density oil-based drilling fluid.

The structure of the flow regulator provided by the present invention is shown in formula I, including structures such as long-chain alkyl or alkenyl, amido and quaternization, and its essence is a betaine type amphoteric surfactant, which can make the weight of the material The surface properties are changed from hydrophilic to lipophilic, reducing the plastic viscosity of drilling fluid, and at the same time, it can cooperate with organic soil to increase the dynamic shear force of drilling fluid at high temperature and ensure good suspension stability.

In formula I, R ₁ is selected from C8-22 alkyl or C17-21 alkenyl, preferably from C8-22 alkyl. Wherein, the C8-22 alkyl group is an alkyl group with 8-22 carbon atoms, preferably a straight-chain alkyl group, such as octyl, decyl, undecyl, tridecyl, tetradecyl , hexadecyl, heptadecyl (straight chain alkyl with 17 carbon atoms). The C17-21 alkenyl group is an alkenyl group with 17-21 carbon atoms, preferably a monounsaturated alkenyl group. In some embodiments of the present invention, R ₁ is CH ₃ (CH ₂ ) _m -CH═CH-(CH ₂ ) _n -CH ₂ -, wherein m is 7 and n is 6 or 10.

In Formula I, Y ^- is -COO ^- or -SO ₃ ^- , preferably -COO ^- ; that is, Y is a carboxyl group (-COO-) or a sulfonic acid group (-SO ₃ -).

In formula I, R ₂ is methylene or Methylene (-CH ₂ -) is preferred.

In some embodiments of the present invention, R ₁ is heptadecyl; Y ^- is -COO ^- ; R ₂ is methylene; R ₃ is In some embodiments of the present invention, R ₁ is octyl; Y ^- is -SO ₃ ; R ₂ is R ₃ is -(CH ₂ ) ₃ -. In other embodiments of the present invention, R ₁ is CH ₃ (CH ₂ ) _m -CH═CH-(CH ₂ ) _n -CH ₂ -, wherein, m is 7, n is 6; Y ^- is -SO ₃ ; R ₂ is R ₃ is -(CH ₂ ) ₃ -.

In the embodiment of the present invention, the flow pattern regulator for high-density oil-based drilling fluid may be a light yellow to white liquid product. The flow regulator begins to decompose at 185.3°C; the weight loss rate is 5.42% within 250°C, and the thermal stability is good. In terms of mass fraction, the solid content of the flow pattern regulator can be 20-50%.

The invention provides a method for preparing a flow pattern regulator for high-density oil-based drilling fluid, comprising:

The long-chain hydrocarbyl amido tertiary amine is reacted with a quaternizing agent in a solvent to obtain a flow pattern regulator for high-density oil-based drilling fluid;

The long-chain hydrocarbyl amido tertiary amine has a formula II structure:

Described quaternization reagent has formula III structure:

XR ² -Y-Na Formula III;

The high-density oil-based drilling fluid flow regulator has a formula I structure:

Wherein, R ₁ is selected from C8～22 alkyl or C17～21 alkenyl;

_R2 is methylene or R ₃ is -(CH ₂ ) ₃ - or

X is selected from halogen; Y ^- is -COO ^- or SO ₃ ^- .

The preparation method of the flow pattern regulator provided by the invention has the characteristics of simple synthesis steps, mild reaction conditions, outstanding product performance advantages, etc., and is beneficial to large-scale production and popularization and application.

In the embodiment of the present invention, it is preferred to mix the long-chain hydrocarbyl amido tertiary amine solution with the quaternization reagent solution and react to obtain the flow pattern regulator product for high-density oil-based drilling fluid.

The present invention uses long-chain hydrocarbyl amido tertiary amines as raw materials, and its structure is shown in formula II. In formula II, the contents of R ₁ and R ₃ are as described above. The full name of the long-chain hydrocarbyl amidopropyl dimethylamine is long-chain hydrocarbyl amidopropyl dimethylamine, referred to as long-chain hydrocarbyl amidopropyl dimethylamine; it can be a long-chain alkyl amidopropyl amine, or a long-chain Alkenyl amido tertiary amine. In a preferred embodiment of the present invention, the long-chain hydrocarbyl amidopropyl dimethylamine is octyl amidopropyl dimethylamine, decyl amidopropyl dimethylamine, lauryl amidopropyl dimethylamine, decanoyl amidopropyl dimethylamine, Tetraalkylamidopropyldimethylamine, Hexadecylamidopropyldimethylamine, Oleamidopropyldimethylamine, Stearamidopropyldimethylamine, Cocamidopropyl Dimethylamine Methylamine or erucamidopropyldimethylamine, preferably octylamidopropyldimethylamine, tetradecylamidopropyldimethylamine, hexadecylamidopropyldimethylamine or hard Fatty amidopropyl dimethylamine.

In the present invention, there is no special limitation on the source of the long-chain hydrocarbyl amido tertiary amine, which can be prepared or commercially available. In the embodiment of the present invention, a certain amount of the long-chain hydrocarbyl amido tertiary amine can be weighed and dissolved in a solvent, preferably stirred and dissolved, to obtain a long-chain hydrocarbyl amido tertiary amine solution.

Wherein, the mass ratio of the long-chain hydrocarbyl amido tertiary amine to the solvent may be (10-35):(20-50), preferably (10.72-33.04):(25-40). The solvent is preferably water or a mixture of organic solvents and water. In the embodiment of the present invention, the mixture of organic solvent and water is a mixture of organic solvent and water, which is a mixed solvent; wherein the mass ratio of organic solvent and water is preferably 0.1-5:10. In a preferred embodiment of the present invention, the organic solvent is an alcoholic organic solvent, which can be one or more of ethanol, isopropanol and n-butanol, preferably any alcohol; the alcoholic organic solvent The mass ratio to water can be 0.1-5:10.

The present invention uses a quaternizing agent to react with the long-chain hydrocarbon amido tertiary amine, and the quaternizing agent is XR ₂ -Y-Na, which is shown in formula III. _Wherein , the contents of R and Y are as previously described. X is selected from halogen such as fluorine, chlorine, bromine, preferably chlorine or bromine. In an embodiment of the present invention, the quaternization agent may be sodium chloroacetate, sodium bromoacetate or sodium 3-chloro-2-hydroxypropanesulfonate.

In the present invention, there is no special limitation on the source of the quaternizing agent, and commercially available products can be used. In the embodiment of the present invention, a certain amount of the quaternization reagent can be weighed and dissolved in a solvent to obtain a quaternization reagent solution. Wherein, the mass ratio of the quaternizing agent to the solvent may be (6-25):(20-50), preferably (6.78-23.21):(25-40). The content of the solvent type is as described above, and will not be repeated here.

In the embodiment of the present invention, the long-chain hydrocarbyl amido tertiary amine solution can be placed in the reaction container first, and then the quaternization reagent solution is added, and the reaction is preferably carried out under stirring conditions to obtain a flow pattern regulator for high-density oil-based drilling fluid . Wherein, the temperature of the reaction is preferably 75-85°C; the time of the reaction is preferably 4h-10h. In the present invention, preferably, the quaternization reagent solution is dropped into the long-chain hydrocarbyl amido tertiary amine solution, such as using a dropping funnel, at a slow rate of 2-5 drops/second. After the dropwise addition, continue to stir for 4-8 hours to stop the reaction, and a light yellow to white liquid product can be obtained, which is the flow pattern regulator for high-density oil-based drilling fluid. In terms of mass fraction, the solid content of the flow pattern regulator can be 20-50%.

The embodiment of the present invention adopts long-chain alkyl or alkenyl amido tertiary amine and quaternizing agent, uses water or alcohol-water as solvent, and undergoes a one-step reaction to generate the betaine-type zwitterionic surfactant shown in formula I. The product prepared by the invention has the functions of wetting and dispersing and increasing the shear force of drilling fluid, and can be used as a flow pattern regulator (regulator) agent for high-density oil-based drilling fluid. In addition, the present invention has simple synthesis steps and mild reaction conditions, which is beneficial to large-scale production and popularization and application.

The present invention can apply the above-mentioned flow pattern regulator to oil-based drilling fluid, especially suitable for high-density oil-based drilling fluid. An embodiment of the present invention provides a high-density oil-based drilling fluid, including base oil and a treatment agent, wherein the treatment agent includes the above-mentioned flow pattern regulator.

In the embodiment of the present invention, the density of the high-density oil-based drilling fluid may be 2.2-2.62 g/m ³ . , the high-density oil-based drilling fluid includes base oil, commercially available 0 ^# white oil or 5 ^# diesel oil can be used.

The high-density oil-based drilling fluid includes a treatment agent, and the treatment agent includes the above-mentioned flow pattern regulator. In a preferred embodiment of the present invention, the amount of the flow regulator is 1-5 (w/v)% of the base oil, preferably 2-3 (w/v)%. In the embodiment of the present invention, the mass of each treatment agent is weighed based on the volume of the base oil. For example, adding 1 to 5% flow pattern regulator to 200mL base oil means adding 1 to 10g flow pattern regulator agent; the percentage of addition can be expressed as (w/v)%, and can also be abbreviated as %.

In the embodiment of the present invention, the treatment agent includes a weighting material, preferably barite, which is mainly used to adjust the density of the drilling fluid. Based on the base oil volume, the treatment agent may include 2-3% organic soil to ensure that the drilling fluid has a certain shear force. The treatment agent may include 2-4% alkalinity regulator, which is preferably at least one of calcium oxide and magnesium oxide, more preferably calcium oxide (commonly known as quicklime). The treatment agent may include 5-6% emulsifier, preferably 5-6% fatty acid amide emulsifier.

In the embodiment of the present invention, based on the base oil volume, the treatment agent may include 5-6% emulsifier and 3-5% fluid loss control agent such as oxidized bitumen. In addition to the flow pattern regulator, the present invention has no special limitation on the source of the treatment agent, commercially available products can be used, and oil-based drilling fluid chemicals commonly used in the field, such as brine solution, can also be included. The present invention has no special limitation on the preparation method of the high-density oil-based drilling fluid, which can be prepared according to conventional methods in the field.

To sum up, the application of the above-mentioned flow pattern regulator in the present invention makes the rheology of the high-density oil-based drilling fluid stable and the comprehensive performance better.

In order to further understand the present application, the flow pattern regulator for high-density oil-based drilling fluid provided by the present application, its preparation method and application are specifically described below in conjunction with examples.

In the following examples, the long-chain alkyl amido tertiary amine involved was purchased from Noco (Shanghai) Chemical Co., Ltd.; sodium chloroacetate was purchased from Shijiazhuang Bide Technology Co., Ltd.; bromoethanol, ethanol, isopropanol, n-butyl Alcohol and sodium 3-chloro-2-hydroxypropanesulfonate were purchased from Sinopharm Chemical Reagent Co., Ltd.; barite was provided by Hubei Yidu Hongxin Mining Development Co., Ltd., with a density of 4.2g/cm ³ .

Example 1

In a 500mL four-necked flask equipped with a thermometer, a condenser, and a stirrer, add 68.32g of stearamidopropyldimethylamine and 100g of water, and heat up to 80°C under stirring; weigh 21.68g of sodium chloroacetate and dissolve it in 110g Put it in the dropping funnel in water, drop it into the above-mentioned four-necked flask at a speed of 5 drops/second, continue to react for 6 hours after the dropwise addition, and obtain a white liquid product with a solid content of 30%, which is a high-density oil-based Flow pattern modifier for drilling fluid, can be used directly.

The resulting product was characterized and analyzed, and the results are shown in Figure 1 and Figure 2. Fig. 1 is the infrared spectrogram of the product obtained in Example 1 of the present invention, as can be seen, 3315.28cm- ¹ is the stretching vibration absorption peak of imide, and 2919.22cm- ¹ and 2850.55cm- ¹ are the hydrophobic length in the flow regulator The vibration absorption peak of -CH ₂ - in the chain, 1638.07cm _- ¹ is the characteristic absorption peak of -C=O, and the CN stretching vibration absorption peaks of multiple quaternary ammonium salts at 1065cm- ¹ ~ 1398cm- ¹ , so it can be determined that the raw material The reaction yielded the product with the expected structure.

The resulting product is a flow pattern regulator for high-density oil-based drilling fluid shown in formula _I , wherein R is selected from heptadecyl; Y ^- is -COO ^- ; R is methylene _{; R} is

Fig. 2 is the differential thermal scanning calorimetry diagram of the product obtained in Example 1 of the present invention. The test conditions include: the sample size is 4.540 mg, the air flow rate is 20-60 mL/min, the heating rate is 1-3 °C/min, and the temperature range From room temperature to 250°C. In Figure 2, two peaks (peak) appear on the DSC curve, corresponding to the temperatures of 61.5°C and 147.0°C; according to the temperature corresponding to the onset on the DTG curve is 185.3°C, the flow regulator is at 185.3 °C begins to decompose; according to the TG curve at 250 °C, the mass change (mass change) is reduced by 5.42%, and the weight loss rate of the flow pattern regulator is 5.42% within 250 °C, and the thermal stability is good.

Example 2

In a 500mL four-neck flask equipped with a thermometer, condenser, and stirrer, add 80.38g of octylamidopropyldimethylamine and a mixed solvent composed of 20g of ethanol and 60g of water, and heat up to 80°C under stirring; Take 69.62g of sodium 3-chloro-2-hydroxypropanesulfonate, dissolve it in 70g of water and place it in the dropping funnel, add it dropwise to the above four-necked flask at a speed of 2-3 drops/second, and continue the reaction after the addition is complete After 8 hours, a light yellow liquid product with a solid content of 50% was obtained, which was the flow pattern regulator for high-density oil-based drilling fluid.

The resulting product is a flow pattern modifier for high-density oil-based drilling fluid shown in formula I, wherein R ₁ is octyl; Y ^- is -SO ₃ ; R ₂ is R ₃ is -(CH ₂ ) ₃ -.

Embodiment 3-11

According to the same steps as in Example 1, flow pattern regulators for high-density oil-based drilling fluids were prepared respectively, which had the structure of formula I. Specific reaction substances and reaction conditions are shown in Table 1, and Table 1 shows the amount of reaction substances and reaction conditions for preparing the flow regulator in Examples 3-11.

Table 1 Reaction substance consumption and reaction conditions

Examples 12-22

The wettability of the products of the present invention prepared in Examples 1 to 11 is evaluated respectively. The wettability evaluation method is: in 300mL 0 ^# white oil, add 6g of the products described in Examples 1 to 11 of the present invention respectively, Stir at a high speed of 11000r/min for 5min, then add 10g of barite respectively to obtain oil-based drilling fluids; then stir at a high speed of 11000r/min for 20min, pour into a 500mL graduated cylinder, and let stand for 1h. The wetting rate was calculated according to the volume V (mL) of the clear oil separated from the upper layer, and the results are shown in Table 2. Table 2 shows the wetting properties of the oil-based drilling fluids prepared in Examples 12-22. The formula for calculating the wetting rate is as follows:

Wetting rate = (300-V)/300×100%;

In the above formula, V is the volume (mL) of the oil layer separated in 1 h. It can be seen from Table 2 that the wettability of the flow regulator of the present invention to barite is >80%.

The wettability of the oil-based drilling fluid prepared in Table 2 Examples 12-22

Examples 23-33

Preparation of drilling fluid: first add 2 to 3% organic soil to the base oil (0 ^#diesel oil), stir for 5 minutes at a rotating speed of 10000rpm, then add 5% emulsifier and 2% of the organic soil obtained in Examples 1 to 11 of the present invention Described flow regulator, continue to stir for 5min, add 3% alkalinity regulator respectively, stir for 5min, add aqueous solution (20% mass concentration calcium chloride solution) respectively, continue to stir for 5min, then add 4% fluid loss reducer respectively (Oxidized asphalt), and then stirred for 5 minutes, respectively added barite, and finally stirred for 20 minutes to obtain drilling fluid respectively.

Among them, the organic soil used was purchased from Zhejiang Fenghong New Material Co., Ltd., and the model was HFGEL-120; the emulsifier was purchased from the China Petroleum Group Drilling Engineering Technology Research Institute, which is a fatty acid amide, and the residual acid value is between 10 and 35. , the residual amine value was between 10 and 15; calcium oxide was purchased from Wenxing Building Materials Chemical Factory, Tangyin County, Henan Province; oxidized asphalt was purchased from Xinxiang Seventh Chemical Co., Ltd., Henan Province, and the softening point was between 120 and 160 °C.

Comparative example 1

In Comparative Example 1, except that no flow conditioner was added, other components were the same as those in Examples 23 and 24, and the density of the prepared oil-based drilling fluid was 2.5 g/cm ³ .

Comparative example 2

Comparative Example 2 was the same as Example 25 except that no fluid conditioner was added, and the prepared oil-based drilling fluid had a density of 2.62 g/cm ³ .

Example 34

The flow pattern adjustment performance of the products of the present invention prepared in Examples 1 to 11 in high-density oil-based drilling fluids is evaluated, that is, the drilling fluids prepared in Examples 23 to 33 are respectively put into aging tanks and placed in 150 Roll in a roller furnace at ~180°C for 16 hours, and then measure the comprehensive performance of each drilling fluid at 60°C. The measurement method is carried out in accordance with GB/T 16783.2-2012 "On-site Testing of Drilling Fluids in the Petroleum and Natural Gas Industry Part 2: Oil-based Drilling Fluids" . At the same time, the comprehensive performance of the drilling fluid prepared in the comparative example was measured in the same way.

The performance evaluation results are shown in Table 3. Table 3 shows the comprehensive performance of the oil-based drilling fluids prepared in Examples 23-33 and Comparative Examples.

Table 3 Comprehensive properties of the prepared oil-based drilling fluids in Examples 23 to 33 and Comparative Examples

It can be seen from Table 3 that, compared with the condition without flow conditioner, the high-density (2.2-2.62g/cm ³ ) oil-based drilling fluid has better overall performance, lower plastic viscosity (<80mPa·s), After high temperature (180°C) aging, the dynamic shear force is high, which is more conducive to carrying cuttings and preventing the settlement of cuttings and heavy materials, and maintaining the rheological stability of drilling fluid. In addition, the high-temperature and high-pressure fluid loss of the drilling fluid decreased after the flow pattern adjustment was added, indicating that it can also play a role in reducing fluid loss to a certain extent.

The above is only a preferred embodiment of the present invention, and it should be pointed out that for those skilled in the art, without departing from the technical principle of the present invention, it is possible to realize various modifications to these embodiments, and These modifications should also be regarded as the protection scope of the present invention.

Claims (10)

1. A high-density oil-based drilling fluid flow regulator is characterized in that it has a formula I structure: In formula I, R ₁ is selected from C8-22 alkyl or C17-21 alkenyl; _R2 is methylene or R ₃ is -(CH ₂ ) ₃ - or Y ^- is -COO ^- or -SO ₃ ^- . 2. flow regulator according to claim ₁ , is characterized in that, R is selected from octyl, decyl, undecyl, tridecyl, tetradecyl, hexadecyl, heptadecyl Alkyl or CH ₃ (CH ₂ ) _m -CH═CH-(CH ₂ ) _n -CH ₂ -, wherein m is 7 and n is 6 or 10. 3. A preparation method for a high-density oil-based drilling fluid flow regulator, comprising the following steps: The long-chain hydrocarbyl amido tertiary amine is reacted with a quaternizing agent in a solvent to obtain a flow pattern regulator for high-density oil-based drilling fluid; The long-chain hydrocarbyl amido tertiary amine has a formula II structure: Described quaternization reagent has formula III structure: XR ₂ -Y-Na Formula III; The high-density oil-based drilling fluid flow regulator has a formula I structure: Wherein, R ₁ is selected from C8～22 alkyl or C17～21 alkenyl; _R2 is methylene or R ₃ is -(CH ₂ ) ₃ - or X is selected from halogen; Y ^- is -COO ^- or SO ₃ ^- . 4. preparation method according to claim 3, is characterized in that, described long-chain hydrocarbyl amido tertiary amine is octyl amidopropyl dimethylamine, decyl amido propyl dimethylamine, lauryl amido propyl dimethylamine, lauryl amido propyl dimethylamine, Propyldimethylamine, Myristylamidopropyldimethylamine, Hexadecylamidopropyldimethylamine, Oleamidopropyldimethylamine, Stearamidopropyldimethylamine, Cocamidopropyldimethylamine or Erucamidopropyldimethylamine. 5. The preparation method according to claim 3, characterized in that, the solvent is water or a mixture formed by an organic solvent and water. 6. The preparation method according to claim 5, characterized in that, the organic solvent is an alcoholic organic solvent. 7. The preparation method according to claim 6, characterized in that the mass ratio of the alcoholic organic solvent to water is 0.1-5:10. 8. The preparation method according to claim 3, characterized in that the reaction temperature is 75-85°C. 9. A high-density oil-based drilling fluid, comprising base oil and a treatment agent, characterized in that the treatment agent comprises the flow regulator according to any one of claims 1 to 2 or any one of claims 3 to 8 The flow regulator prepared by any one of the preparation methods. 10. The high-density oil-based drilling fluid according to claim 9, characterized in that, the added amount of the flow pattern modifier is 1-5 (w/v)% of the base oil.