Compound for oil-based drilling fluid viscosity reducer and oil-based drilling fluid viscosity reducer

Abstract

The present invention provides a compound for an oil-based drilling fluid viscosity reducer and an oil-based drilling fluid viscosity reducer. A preparation method for the compound for the oil-based drilling fluid viscosity reducer comprises: mixing a polyene polyamine, an alcohol amine, and humic acid for a reaction to obtain a first reaction intermediate; and reacting the first reaction intermediate with a fluorine-containing silane coupling agent to obtain the compound for the oil-based drilling fluid viscosity reducer, wherein the molar ratio of the humic acid to the polyene polyamine to the alcohol amine to the fluorine-containing silane coupling agent is 1:(0.5-0.75):(0.01-0.5):(0.5-5). The oil-based drilling fluid viscosity reducer comprises the compound for the oil-based drilling fluid viscosity reducer, as provided by the present invention, a fluorine-containing surfactant, and an oil phase solvent at a mass ratio of 100:(10-50):(20-80). The oil-based drilling fluid viscosity reducer provided by the present invention has excellent high-temperature resistance.

Description

Compound for oil-based drilling fluid viscosity reducer and oil-based drilling fluid viscosity reducer

[0001] Cross-reference information

[0002] The present application claims priority to the Chinese patent application No. 202411364925.4, filed on September 27, 2024, and entitled "Compound for oil-based drilling fluid viscosity reducer and oil-based drilling fluid viscosity reducer", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application belongs to the technical field of oil-based drilling fluid for oil drilling, and particularly relates to a compound for oil-based drilling fluid viscosity reducer and an oil-based drilling fluid viscosity reducer. BACKGROUND

[0004] With the increasing consumption of energy resources and the continuous improvement of unconventional oil and gas exploration and development technology, the demand for deep well / super deep well drilling is increasingly prominent. The bottomhole geology of deep well / super deep well is complex, and the temperature and pressure are significantly higher than those of conventional wells, which puts higher requirements on drilling technology, especially drilling fluid technology.

[0005] During the drilling process of deep well / super deep well, the oil-based drilling fluid will have the following problems as the use time increases: (1) a large number of small-sized solid particles enter the oil-based drilling fluid, resulting in continuous increase of solid content, thereby causing continuous rise of viscosity and shear of the drilling fluid; (2) high temperature causes reaction between the treating agents in the oil-based drilling fluid to generate macromolecular products, thereby causing the oil-based drilling fluid to thicken. The commonly used oil-based drilling fluid viscosity reducer is a modified fatty acid, which has the problem of easy failure at high temperature. When the temperature is higher than 200℃, the molecular chain of the viscosity reducer is easy to break and the structure is easy to be damaged, so it is difficult to continue to play the role of viscosity reduction.

[0006] In summary, there is still a need to study oil-based drilling fluid viscosity reducers with high temperature resistance at present, which has profound significance for the development of oil-based drilling fluid technology for deep well / super deep well and the exploration and development of deep / super deep oil and gas. SUMMARY

[0007] The purpose of the present application is to provide an oil-based drilling fluid viscosity reducer technical solution with high temperature resistance.

[0008] In order to achieve the above purpose, the present application provides the following five technical solutions.

[0009] In a first aspect, the present application provides a preparation method of a compound for oil-based drilling fluid viscosity reducer, wherein the method comprises:

[0010] mixing and reacting polyene polyamine, alcohol amine and humic acid to obtain a first reaction intermediate;

[0011] reacting the first reaction intermediate with a fluorine-containing silane coupling agent to obtain the oil-based drilling fluid viscosity reducer compound;

[0012] The ratio of the amount of substance (mol) of humic acid, polyene polyamine, alcohol amine and the fluorine-containing silane coupling agent is 1:(0.5-0.75):(0.01-0.5):(0.5-5).

[0013] In the preparation method of the oil-based drilling fluid viscosity reducer compound, the polyene polyamine and the alcohol amine compound are acylated with the humic acid having carboxyl and hydroxyl functional groups on the surface to modify the humic acid, and then the fluorine-containing silane coupling agent is added for condensation reaction to obtain the oil-based drilling fluid viscosity reducer compound; the oil-based drilling fluid viscosity reducer obtained by mixing the oil-based drilling fluid viscosity reducer compound with a certain proportion of fluorine-containing surfactant and oil phase solvent has excellent high temperature resistance.

[0014] According to the preferred embodiment of the first aspect, the ratio of the amount of substance (mol) of humic acid, polyene polyamine, alcohol amine and the fluorine-containing silane coupling agent is 1:(0.55-0.70):(0.05-0.25):(1-2.5).

[0015] According to the preferred embodiment of the first aspect, the polyene polyamine includes one or a combination of two or more of diethylene triamine, triethylene tetramine, tetraethylene pentamine and ethylene diamine.

[0016] According to the preferred embodiment of the first aspect, the alcohol amine includes one or a combination of two or more of 2-hydroxyethylamine, diethanolamine, mono-isopropanolamine and di-isopropanolamine.

[0017] According to the preferred embodiment of the first aspect, the fluorine-containing silane coupling agent includes one or a combination of two or more of trifluoropropyl triethoxysilane, trifluoropropyl trimethoxysilane, trifluoropropyl methyl dimethoxysilane, perfluorodecyl trimethoxysilane, perfluorodecyl triethoxysilane, perfluorooctyl trimethoxysilane and perfluorooctyl triethoxysilane.

[0018] According to the preferred embodiment of the first aspect, the reaction temperature for mixing and reacting the polyene polyamine, the alcohol amine and the humic acid is 150-175℃.

[0019] According to the preferred embodiment of the first aspect, the reaction time for mixing and reacting the polyene polyamine, the alcohol amine and the humic acid is 3-5h.

[0020] According to the preferred embodiment of the first aspect, the reaction temperature for reacting the first reaction intermediate with the fluorine-containing silane coupling agent is 60-80℃.

[0021] According to a preferred embodiment of the first aspect, the reaction time for reacting the first reaction intermediate with the fluorine-containing silane coupling agent is 1-3 hours.

[0022] In a second aspect, the present application provides an oil-based drilling fluid viscosity reducer compound, wherein the oil-based drilling fluid viscosity reducer compound can be prepared by using the method for preparing the oil-based drilling fluid viscosity reducer compound provided in the first aspect of the present application.

[0023] In a third aspect, the present application provides an oil-based drilling fluid viscosity reducer, wherein the oil-based drilling fluid viscosity reducer comprises the oil-based drilling fluid viscosity reducer compound provided in the second aspect of the present application, the fluorine-containing surfactant, and the oil phase solvent in a mass ratio of 100:(10-50):(20-80).

[0024] According to a preferred embodiment of the third aspect, the fluorine-containing surfactant comprises at least one of an anionic fluorocarbon surfactant and a non-ionic fluorocarbon surfactant.

[0025] Further, the anionic fluorocarbon surfactant is selected from fluorine surfactant FS-61.

[0026] Further, the non-ionic fluorocarbon surfactant is selected from DuPont fluorine surfactant FS-31.

[0027] According to a preferred embodiment of the third aspect, the oil phase solvent comprises one or a combination of two or more of methyl tert-butyl ether, triethylene glycol monobutyl ether, and ethylene glycol carbonate.

[0028] According to a preferred embodiment of the third aspect, the mass ratio of the oil-based drilling fluid viscosity reducer compound provided in the second aspect of the present application, the fluorine-containing surfactant, and the oil phase solvent is 100:(20-40):(40-60).

[0029] In a fourth aspect, the present application provides a method for preparing the oil-based drilling fluid viscosity reducer provided in the third aspect of the present application, wherein the method comprises:

[0030] The oil-based drilling fluid viscosity reducer provided in the third aspect of the present application is obtained by mixing the oil-based drilling fluid viscosity reducer compound provided in the second aspect of the present application, the fluorine-containing surfactant, and the oil phase solvent in a suitable mass ratio.

[0031] According to a preferred embodiment of the fourth aspect, the oil-based drilling fluid viscosity reducer compound provided in the second aspect of the present application, the fluorine-containing surfactant, and the oil phase solvent are mixed under stirring at 400-500 r / min.

[0032] Further, the oil-based drilling fluid viscosity reducer compound, the fluorine-containing surfactant and the oil phase solvent are mixed and stirred for 1-3 hours under the condition of 400-500 r / min stirring to be uniformly mixed.

[0033] In the fifth aspect, the application provides application of the oil-based drilling fluid viscosity reducer provided in the third aspect of the application in the oil-based drilling fluid.

[0034] According to the preferred embodiment of the fifth aspect, the mass content of the oil-based drilling fluid viscosity reducer provided in the third aspect of the application in the oil-based drilling fluid is 0.5-2% based on 100% of the total mass of the oil-based drilling fluid.

[0035] According to the preferred embodiment of the fifth aspect, the oil phase in the oil-based drilling fluid can but is not limited to include at least one of diesel oil and white oil; and the white oil is preferably at least one of 3# white oil (flash point 220℃, 40℃ kinematic viscosity 3mm 2 / s, specific gravity 0.85) and 5# white oil (flash point 220℃, 40℃ kinematic viscosity 3.5mm 2 / s, specific gravity 0.85).

[0036] According to the preferred embodiment of the fifth aspect, the water phase in the oil-based drilling fluid can but is not limited to use CaCl2 aqueous solution; and the mass concentration of CaCl2 in the CaCl2 aqueous solution is preferably 20-40%.

[0037] According to the preferred embodiment of the fifth aspect, the volume ratio of the oil phase to the water phase in the oil-based drilling fluid is 80-90:20-10.

[0038] According to the preferred embodiment of the fifth aspect, the oil-based drilling fluid can further contain other treatment agents, such as one or a combination of two or more of the emulsifier, the flow pattern regulator, the alkalinity regulator and the weighting agent; the above treatment agents and their amounts can be selected according to the conventional types and amounts in the art, and the application does not have a particular limitation thereon.

[0039] The oil-based drilling fluid viscosity reducer provided in the application can effectively reduce the viscosity and shear of the oil-based drilling fluid under a high temperature environment of 220℃ or above by the cooperation of the special oil-based drilling fluid viscosity reducer compound, the surfactant and the oil solvent, so as to meet the actual drilling requirements of the deep well / super deep well at present and reduce the viscosity and shear of the oil-based drilling fluid under the high temperature environment of the deep well / super deep well. DETAILED DESCRIPTION

[0040] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0041] In the following examples, unless otherwise specified, the chemical reagents used are commercially available. Among them, humic acid is purchased from Shandong Changyao New Material Co., Ltd.; diethylenetriamine, ethylenediamine, triethylenetetramine, tetraethylenepentamine, diethanolamine, 2-hydroxyethylamine, perfluorooctyltriethoxysilane, trifluoropropyltriethoxysilane and triethylene glycol monobutyl ether are purchased from San Chemical Technology (Shanghai) Co., Ltd.; DuPont fluorine surfactant FS-31 and fluorine surfactant FS-61 are purchased from Guangzhou Huituo New Material Co., Ltd.

[0042] Example 1

[0043] The present embodiment provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0044] The oil-based drilling fluid viscosity reducer compound is prepared by the following method:

[0045] First, 22.7g of humic acid is added to a solution obtained by mixing 2.84g of diethylenetriamine, 5.21g of tetraethylenepentamine and 0.53g of diethanolamine in a reaction kettle, vacuum is drawn and the temperature is raised to 150℃ for 3h to obtain a first reaction intermediate; then the first reaction intermediate is lowered to room temperature; 51.04g of perfluorooctyltriethoxysilane is added to the first reaction intermediate, the temperature is raised to 60℃, and the reaction is continued for 1h to obtain the oil-based drilling fluid viscosity reducer compound.

[0046] The oil-based drilling fluid viscosity reducer is prepared by the following method:

[0047] The oil-based drilling fluid viscosity reducer compound prepared in the present embodiment, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether are stirred at a speed of 350r / min for 0.5h at a mass ratio of 100:20:40 to make them fully mixed, to obtain the oil-based drilling fluid viscosity reducer OD-1.

[0048] Example 2

[0049] The present embodiment provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0050] The oil-based drilling fluid viscosity reducer compound is prepared by the following method:

[0051] First, 22.7 g of humic acid was added to a solution obtained by mixing 3.03 g of diethylene triamine, 5.56 g of tetraethylene pentamine and 1.05 g of diethanol amine in a reaction kettle, vacuum was drawn and the temperature was raised to 155°C for 3.5 h to obtain a first reaction intermediate; then the first reaction intermediate was lowered to room temperature; 70.17 g of perfluorooctyl triethoxysilane was added to the first reaction intermediate, the temperature was raised to 65°C, and the reaction was continued for 1.5 h to obtain an oil-based drilling fluid viscosity reducer compound.

[0052] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0053] The oil-based drilling fluid viscosity reducer OD-2 was obtained by stirring the oil-based drilling fluid viscosity reducer compound prepared in this example, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether at a mass ratio of 100:20:50 at a rotation speed of 350 r / min for 1 h to fully mix them.

[0054] Example 3

[0055] This example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0056] The oil-based drilling fluid viscosity reducer compound was prepared by the following method:

[0057] First, 22.7 g of humic acid was added to a solution obtained by mixing 3.03 g of diethylene triamine, 5.56 g of tetraethylene pentamine and 1.05 g of diethanol amine in a reaction kettle, vacuum was drawn and the temperature was raised to 155°C for 3.5 h to obtain a first reaction intermediate; then the first reaction intermediate was lowered to room temperature; 70.17 g of perfluorooctyl triethoxysilane was added to the first reaction intermediate, the temperature was raised to 65°C, and the reaction was continued for 1.5 h to obtain an oil-based drilling fluid viscosity reducer compound.

[0058] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0059] The oil-based drilling fluid viscosity reducer OD-3 was obtained by stirring the oil-based drilling fluid viscosity reducer compound prepared in this example, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether at a mass ratio of 100:30:50 at a rotation speed of 350 r / min for 1 h to fully mix them.

[0060] Example 4

[0061] This example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0062] The oil-based drilling fluid viscosity reducer compound was prepared by the following method:

[0063] First, 22.7 g of humic acid was added to a solution obtained by mixing 3.42 g of diethylene triamine, 6.27 g of tetraethylene pentamine and 2.10 g of diethanol amine in a reaction kettle, vacuum was drawn and the temperature was raised to 170°C for 4 h to obtain a first reaction intermediate; then the first reaction intermediate was lowered to room temperature; 108.45 g of perfluorooctyl triethoxysilane was added to the first reaction intermediate, the temperature was raised to 75°C, and the reaction was continued for 2.5 h to obtain an oil-based drilling fluid viscosity reducer compound.

[0064] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0065] The oil-based drilling fluid viscosity reducer compound prepared in this example, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether were mixed at a mass ratio of 100:40:50 under stirring at a speed of 350 r / min for 1 h to fully mix and obtain an oil-based drilling fluid viscosity reducer OD-4.

[0066] Example 5

[0067] This example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0068] The oil-based drilling fluid viscosity reducer compound was prepared by the following method:

[0069] First, 22.7 g of humic acid was added to a solution obtained by mixing 3.42 g of diethylene triamine, 6.27 g of tetraethylene pentamine and 2.10 g of diethanol amine in a reaction kettle, vacuum was drawn and the temperature was raised to 170°C for 4 h to obtain a first reaction intermediate; then the first reaction intermediate was lowered to room temperature; 108.45 g of perfluorooctyl triethoxysilane was added to the first reaction intermediate, the temperature was raised to 75°C, and the reaction was continued for 2.5 h to obtain an oil-based drilling fluid viscosity reducer compound.

[0070] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0071] The oil-based drilling fluid viscosity reducer compound prepared in this example, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether were mixed at a mass ratio of 100:40:50 under stirring at a speed of 350 r / min for 1 h to fully mix and obtain an oil-based drilling fluid viscosity reducer OD-4.

[0072] Example 6

[0073] This example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0074] The oil-based drilling fluid viscosity reducer compound was prepared by the following method:

[0075] First, 22.7 g of humic acid was added to a solution obtained by mixing 1.88 g of diethylene triamine, 4.57 g of tetraethylene pentamine and 1.58 g of diethanol amine in a reaction kettle, vacuum was drawn and the temperature was raised to 160℃ for 4 h to obtain a first reaction intermediate; then the first reaction intermediate was lowered to room temperature; 89.31 g of perfluorooctyl triethoxysilane was added to the first reaction intermediate, the temperature was raised to 70℃, and the reaction was continued for 2 h to obtain an oil-based drilling fluid viscosity reducer compound.

[0076] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0077] The oil-based drilling fluid viscosity reducer OD-6 was obtained by stirring the oil-based drilling fluid viscosity reducer compound prepared in this example, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether in a mass ratio of 100:30:50 at a stirring speed of 350 r / min for 1 h to fully mix them.

[0078] Example 7

[0079] This example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0080] The oil-based drilling fluid viscosity reducer compound was prepared by the following method:

[0081] First, 22.7 g of humic acid was added to a solution obtained by mixing 1.88 g of diethylene triamine, 4.57 g of tetraethylene pentamine and 1.58 g of diethanol amine in a reaction kettle, vacuum was drawn and the temperature was raised to 160℃ for 4 h to obtain a first reaction intermediate; then the first reaction intermediate was lowered to room temperature; 89.31 g of perfluorooctyl triethoxysilane was added to the first reaction intermediate, the temperature was raised to 70℃, and the reaction was continued for 2 h to obtain an oil-based drilling fluid viscosity reducer compound.

[0082] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0083] The oil-based drilling fluid viscosity reducer OD-7 was obtained by stirring the oil-based drilling fluid viscosity reducer compound prepared in this example, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether in a mass ratio of 100:30:50 at a stirring speed of 350 r / min for 1 h to fully mix them.

[0084] Example 8

[0085] This example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0086] The oil-based drilling fluid viscosity reducer compound was prepared by the following method:

[0087] First, 22.7 g of humic acid was added to a solution obtained by mixing 3.22 g of diethylene triamine, 5.92 g of tetraethylene pentamine and 1.58 g of diethanol amine in a reaction kettle, vacuum was drawn and the temperature was raised to 160°C for 4 h to obtain a first reaction intermediate; then the first reaction intermediate was lowered to room temperature; 45.56 g of perfluorooctyl triethoxysilane was added to the first reaction intermediate, the temperature was raised to 70°C, and the reaction was continued for 2 h to obtain an oil-based drilling fluid viscosity reducer compound.

[0088] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0089] The oil-based drilling fluid viscosity reducer OD-8 was obtained by stirring the oil-based drilling fluid viscosity reducer compound prepared in this example, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether at a mass ratio of 100:30:50 at a rotation speed of 350 r / min for 1 h to fully mix them.

[0090] Example 9

[0091] This example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0092] The oil-based drilling fluid viscosity reducer compound was prepared by the following method:

[0093] First, 22.7 g of humic acid was added to a solution obtained by mixing 3.22 g of diethylene triamine, 5.92 g of tetraethylene pentamine and 1.58 g of diethanol amine in a reaction kettle, vacuum was drawn and the temperature was raised to 160°C for 4 h to obtain a first reaction intermediate; then the first reaction intermediate was lowered to room temperature; 45.56 g of perfluorooctyl triethoxysilane was added to the first reaction intermediate, the temperature was raised to 70°C, and the reaction was continued for 2 h to obtain an oil-based drilling fluid viscosity reducer compound.

[0094] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0095] The oil-based drilling fluid viscosity reducer OD-9 was obtained by stirring the oil-based drilling fluid viscosity reducer compound prepared in this example, fluorine surfactant FS-61 and triethylene glycol monobutyl ether at a mass ratio of 100:30:50 at a rotation speed of 350 r / min for 1 h to fully mix them.

[0096] Comparative Example 1

[0097] This comparative example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0098] The oil-based drilling fluid viscosity reducer compound was prepared by the following method:

[0099] In a reaction kettle, 5.10 g of perfluorooctyltriethoxysilane was added to 22.7 g of humic acid, the temperature was raised to 60°C, and the reaction was continued for 1 h to obtain an oil-based drilling fluid viscosity reducer compound.

[0100] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0101] The oil-based drilling fluid viscosity reducer DOD-1 was obtained by stirring the oil-based drilling fluid viscosity reducer compound prepared in this example, DuPont fluorine surfactant FS-31, and triethylene glycol monobutyl ether in a mass ratio of 100:20:40 at a rotation speed of 350 r / min for 0.5 h to fully mix them.

[0102] Example 2

[0103] This example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0104] The oil-based drilling fluid viscosity reducer compound was prepared by the following method:

[0105] First, in a reaction kettle, 22.7 g of humic acid was added to a solution obtained by mixing 2.58 g of diethylenetriamine, 4.73 g of tetraethylenepentamine, and 5.26 g of diethanolamine, vacuum was applied, the temperature was raised to 150°C, and the reaction was continued for 3 h to obtain an oil-based drilling fluid viscosity reducer compound.

[0106] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0107] The oil-based drilling fluid viscosity reducer DOD-2 was obtained by stirring the oil-based drilling fluid viscosity reducer compound prepared in this example, DuPont fluorine surfactant FS-31, and triethylene glycol monobutyl ether in a mass ratio of 100:20:40 at a rotation speed of 350 r / min for 0.5 h to fully mix them.

[0108] Example 3

[0109] This example provides an oil-based drilling fluid viscosity reducer.

[0110] This example uses the oil-based drilling fluid viscosity reducer compound provided in Example 1 as an oil-based drilling fluid viscosity reducer, which is denoted as DOD-3.

[0111] Example 4

[0112] This example provides an oil-based drilling fluid viscosity reducer.

[0113] The oil-based drilling fluid viscosity reducer was prepared by the following method:

[0114] Humic acid, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether are stirred at a speed of 350 r / min for 0.5 h at a mass ratio of 100:20:40 to fully mix them, to obtain the oil-based drilling fluid viscosity reducer DOD-4.

[0115] Comparative Example 5

[0116] The present comparative example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0117] The oil-based drilling fluid viscosity reducer compound is prepared by the following method:

[0118] First, 22.7 g of humic acid is added to a solution obtained by mixing 0.52 g of diethylene triamine, 0.95 g of tetraethylene pentamine and 1.05 g of diethanol amine in a reaction kettle, vacuum is applied and the temperature is raised to 150°C for 3 h to obtain a first reaction intermediate; then the first reaction intermediate is lowered to room temperature; 2.55 g of perfluorooctyl triethoxysilane is added to the first reaction intermediate, the temperature is raised to 60°C, and the reaction is continued for 1 h to obtain the oil-based drilling fluid viscosity reducer compound.

[0119] The oil-based drilling fluid viscosity reducer is prepared by the following method:

[0120] The oil-based drilling fluid viscosity reducer compound prepared in the present comparative example, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether are stirred at a speed of 350 r / min for 0.5 h at a mass ratio of 100:20:40 to fully mix them, to obtain the oil-based drilling fluid viscosity reducer DOD-5.

[0121] Comparative Example 6

[0122] The present comparative example provides an oil-based drilling fluid viscosity reducer compound and an oil-based drilling fluid viscosity reducer.

[0123] The oil-based drilling fluid viscosity reducer compound is prepared by the following method:

[0124] First, 22.7 g of humic acid is added to a solution obtained by mixing 0.52 g of diethylene triamine, 0.95 g of tetraethylene pentamine and 1.05 g of diethanol amine in a reaction kettle, vacuum is applied and the temperature is raised to 150°C for 3 h to obtain a first reaction intermediate; then the first reaction intermediate is lowered to room temperature; 2.55 g of perfluorooctyl triethoxysilane is added to the first reaction intermediate, the temperature is raised to 60°C, and the reaction is continued for 1 h to obtain the oil-based drilling fluid viscosity reducer compound.

[0125] The oil-based drilling fluid viscosity reducer is prepared by the following method:

[0126] The oil-based drilling fluid viscosity reducer compound prepared in the present comparative example, DuPont fluorine surfactant FS-31 and triethylene glycol monobutyl ether were mixed at a mass ratio of 100:20:40 at a stirring speed of 350 r / min for 0.5 h to make them fully mixed, to obtain an oil-based drilling fluid viscosity reducer DOD-6.

[0127] Test Example 1

[0128] The present test example was used to test the effect of the oil-based drilling fluid viscosity reducers provided in Examples 1-9 and Comparative Examples 1-6 on the rheological properties of the oil-based drilling fluid.

[0129] The rheological properties, emulsion stability and fluid loss reduction effect of the base oil-based drilling fluid before and after high-temperature aging at 220℃ were tested respectively. The results are shown in Table 1.

[0130] Field drill cuttings and organic soil (the organic soil was TYODF-601 purchased from Kuerlesameyi Trade Co., Ltd.) were added to the base oil-based drilling fluid respectively, and the rheological properties, emulsion stability and fluid loss reduction effect of the drilling fluid before and after high-temperature aging at 220℃ were tested respectively; wherein the addition amount of the field drill cuttings was 20% and the addition amount of the organic soil was 8% based on 100% of the mass of the base oil-based drilling fluid. The results are shown in Table 1. Among them, the field drill cuttings were added to the drilling fluid for performance testing to simulate and evaluate the rheological deterioration of the drilling fluid caused by drill cuttings in the drilling site; the organic soil was added to the drilling fluid for performance testing to simulate and evaluate the rheological deterioration of the drilling fluid caused by clay in the drilling site.

[0131] The oil-based drilling fluid viscosity reducers provided in Examples 1-9 and Comparative Examples 1-6 were added to the mixture of the base oil-based drilling fluid and field drill cuttings (the addition amount of the field drill cuttings was 20% based on 100% of the mass of the base oil-based drilling fluid) and the mixture of the base oil-based drilling fluid and organic soil (the addition amount of the organic soil was 8% based on 100% of the mass of the base oil-based drilling fluid) respectively, and the rheological properties, emulsion stability and fluid loss reduction effect of the drilling fluid before and after high-temperature aging at 220℃ were tested respectively; wherein the addition amount of the oil-based drilling fluid viscosity reducers provided in Examples 1-9 and Comparative Examples 1-6 was 1% based on 100% of the mass of the base oil-based drilling fluid. The results are shown in Tables 2 and 3, Table 2 is the performance evaluation of the oil-based drilling fluid viscosity reducers provided in Examples 1-9 and Comparative Examples 1-6 for improving the rheological deterioration of the drilling fluid caused by the addition of drill cuttings, and Table 3 is the performance evaluation of the oil-based drilling fluid viscosity reducers provided in Examples 1-9 and Comparative Examples 1-6 for improving the rheological deterioration (mainly represented by the dramatic increase in viscosity and shear) of the drilling fluid caused by the addition of organic soil.

[0132] The base oil-based drilling fluid is prepared by mixing base oil and CaCl2 aqueous solution (the concentration of CaCl2 in the CaCl2 aqueous solution is 25wt%) in a volume ratio of 80:20 to obtain base oil-based drilling fluid base fluid, adding 6% of high-temperature-resistant main emulsifier, 6% of high-temperature-resistant emulsifier, 5-8% of organic clay, 5% of CaO powder, 5% of filtrate reducer OFL, and then adding barite to a density of 1.5g / cm 3 The base oil-based drilling fluid is obtained. The base oil is 3# white oil purchased from Guangdong Maoming Petrochemical Company; the high-temperature-resistant main emulsifier is main emulsifier fatty acid amide DR-EM, and the high-temperature-resistant auxiliary emulsifier is auxiliary emulsifier alkanolamide DR-CO; the organic clay is TYODF-601 purchased from Korle Tongyi Trade Co., Ltd.

[0133] The aging is achieved by the following method: the drilling fluid to be aged is loaded into an aging tank, and after aging at 220℃ for 16h, the tank is opened after cooling to room temperature.

[0134] The rheological property of the drilling fluid is tested by the following method: the drilling fluid to be tested is stirred at high speed at 11000rpm for 20min, and then the scale readings at 600r / min, 300r / min, 6r / min and 3r / min are tested at 65℃ using a ZNN-D6 type six-speed rotary viscometer, and the rheological parameters of the drilling fluid are calculated according to the following formula:

[0135] Apparent viscosity (mPa·s): AV=1 / 2×600r / min scale reading;

[0136] Plastic viscosity (mPa·s): PV=600r / min scale reading-300r / min scale reading;

[0137] Yield point (Pa): YP=1 / 2×(300r / min scale reading-PV);

[0138] The emulsion stability (demulsification voltage ES) is determined according to the electrical stability determination method provided in GB / T 16783.2-2012 "Oil-based drilling fluid for oil and gas industry on-site test Part 2: oil-based drilling fluid"; the filtrate reduction effect (high-temperature high-pressure filtration loss FLHTHP) is determined according to the filtration loss determination method provided in GB / T 16783.2-2012 "Oil-based drilling fluid for oil and gas industry on-site test Part 2: oil-based drilling fluid" at 220℃ and 3.5MPa pressure difference.

[0139] Table 1

[0140] As shown in Table 1, the base oil-based drilling fluid keeps stable in various performances before and after aging at 220 DEG C. After the drilling fluid is polluted by 20% field drilling cuttings, the apparent viscosity, plastic viscosity, dynamic shear force and initial and final shear of the drilling fluid greatly increase, which will result in significant reduction of the flowability of the drilling fluid, and the demulsification voltage of the drilling fluid is reduced after high-temperature aging, which is caused by adsorption of part of emulsifiers on the surface of the field drilling cuttings. After the drilling fluid is polluted by 8% organic soil, the rheological property of the drilling fluid is deteriorated sharply, which cannot meet the actual construction requirements.

[0141] Table 2

[0142] Table 3

[0143] As shown in the performance comparison of the oil-based drilling fluid polluted by field cuttings and organic soil treated by the viscosity reducer synthesized in Examples 1-9 and Comparative Examples 1-6 in Table 2 and Table 3, the viscosity reducer provided by the present application has specific raw materials and structural design, and can easily control the performance of the drilling fluid including the deteriorated rheological property and has good high-temperature resistance. The result analysis shows that the viscosity reducer synthesized in Examples has good control function for the drilling fluid with deteriorated rheological property, and can effectively reduce the viscosity and shear of the drilling fluid, so that the drilling fluid can meet the requirements of field construction. The viscosity reducers synthesized in Comparative Examples 1-6 cannot effectively reduce the viscosity and shear of the drilling fluid, which is not conducive to the field construction of the drilling fluid, and the downhole is complicated due to excessive pump pressure. At the same time, after the drilling fluid in all Examples and Comparative Examples is subjected to high-temperature rolling at 220 DEG C, the high-temperature and high-pressure filtration loss is less than 3.0 mL, and the demulsification voltage is greater than 800 V, which shows that the viscosity reducer has no obvious influence on the emulsion stability and filtration loss of the drilling fluid.

[0144] As shown in the comparison of Examples and Comparative Examples, when the amidation reaction on the surface of humic acid, the condensation reaction of fluorine-containing silane coupling agent, the mixing of the fluorine-containing surfactant are not performed in the preparation of raw materials, or the viscosity reducer obtained by simply mixing humic acid, surfactant and oil phase solvent has less influence on the drilling fluid with deteriorated rheological property, and cannot effectively reduce the viscosity and shear of the drilling fluid.

[0145] When the proportion of the compounds in the reaction is not in the preferred range, the small amount will result in poor effect of the viscosity reducer, and the large amount will increase the viscosity and shear of the drilling fluid, and further deteriorate the rheological property of the drilling fluid. The viscosity reducer provided by the present application can keep good emulsion stability and low filtration loss of the drilling fluid after high-temperature rolling, and has good high-temperature resistance.

[0146] In conclusion, the viscosity reducer provided by the application can be applied to an oil-based drilling fluid system, can effectively reduce the rheological property of the oil-based drilling fluid with high viscosity and shear due to excessive use of drilling cuttings or organic soil, and has no obvious influence on the emulsion stability and filtration loss of the drilling fluid, and the temperature resistance can reach above 220 DEG C.

[0147] Of course, the present application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications shall belong to the protection scope of the claims of the present application.

Claims

1. A process for the preparation of a compound for use as an oil-based drilling fluid viscosity reducer, wherein, The method comprises: mixing polyene polyamine, alcohol amine and humic acid to react to obtain a first reaction intermediate; reacting the first reaction intermediate with a fluorine-containing silane coupling agent to obtain the oil-based drilling fluid viscosity reducer compound; The mass ratio of humic acid, polyene polyamine, alcohol amine and fluorine-containing silane coupling agent is 1:(0.5-0.75):(0.01-0.5):(0.5-5).

2. The production method according to claim 1, wherein The mass ratio of humic acid, polyene polyamine, alcohol amine and fluorine-containing silane coupling agent is 1:(0.55-0.70):(0.05-0.25):(1-2.5).

3. The production method according to claim 1, wherein, The polyene polyamine includes one or a combination of two or more of diethylene triamine, triethylene tetramine, tetraethylene pentamine and ethylenediamine.

4. The production method according to claim 1, wherein The alcohol amine includes one or a combination of two or more of 2-hydroxyethylamine, diethanolamine, monoisopropanolamine and diisopropanolamine.

5. The production method according to claim 1, wherein The fluorine-containing silane coupling agent includes one or a combination of two or more of trifluoropropyl triethoxysilane, trifluoropropyl trimethoxysilane, trifluoropropyl methyl dimethoxysilane, perfluorodecyl trimethoxysilane, perfluorodecyl triethoxysilane, perfluorooctyl trimethoxysilane and perfluorooctyl triethoxysilane.

6. The production method according to claim 1, wherein The reaction temperature for mixing polyene polyamine, alcohol amine and humic acid to react is 150-175℃.

7. The production method according to claim 1, wherein The reaction temperature for reacting the first reaction intermediate with the fluorine-containing silane coupling agent is 60-80℃.

8. A compound for use in oil-based drilling fluid viscosity reduction, wherein, The oil-based drilling fluid viscosity reducer compound can be prepared by using the preparation method of the oil-based drilling fluid viscosity reducer compound in any one of claims 1-7.

9. An oil-based drilling fluid viscosity reducer, wherein, The oil-based drilling fluid viscosity reducer comprises the oil-based drilling fluid viscosity reducer compound in claim 8, a fluorine-containing surfactant and an oil phase solvent in a mass ratio of 100:(10-50):(20-80).

10. The oil-based drilling fluid viscosity reducer of claim 9, wherein, The fluorine-containing surfactant includes at least one of an anionic fluorocarbon surfactant and a non-ionic fluorocarbon surfactant.

11. The oil-based drilling fluid viscosity reducer of claim 9, wherein, The oil phase solvent includes one or a combination of two or more of methyl tert-butyl ether, triethylene glycol monobutyl ether and ethylene glycol carbonate.

12. The oil-based drilling fluid viscosity reducer of claim 9, wherein, The mass ratio of the oil-based drilling fluid viscosity reducer compound, the fluorine-containing surfactant and the oil phase solvent is 100:(20-40):(40-60).

13. A method of preparing the oil-based drilling fluid viscosity reducer of any of claims 9-12, wherein, The method comprises: mixing the oil-based drilling fluid viscosity reducer compound, the fluorine-containing surfactant and the oil phase solvent in a proper mass ratio to obtain the oil-based drilling fluid viscosity reducer.

14. The oil-based drilling fluid viscosity reducer in any one of claims 9-12 is applied in an oil-based drilling fluid.

15. Use according to claim 14, wherein, In the oil-based drilling fluid, the mass content of the oil-based drilling fluid viscosity reducer is 0.5-2% based on 100% of the total mass of the oil-based drilling fluid.

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