Wetting agent for oil-based drilling fluid with extremely low surface tension and preparation method thereof

Abstract

The invention relates to the technical field of corrosion inhibitors for crude oil, and is a wetting agent for oil-based drilling fluid with extremely low surface tension and a preparation method thereof. The raw materials of the wetting agent for oil-based drilling fluid with extremely low surface tension include 20 to 30 parts of tall oil fatty acid, 20 to 30 parts of oleic acid, 5 to 10 parts of turpentine, 10 to 20 parts of hydroxyethyltetraethylenepentamine, 10 to 20 parts of white oil, and 10 to 20 parts of dispersant by weight. The wetting agent for oil-based drilling fluid with extremely low surface tension provided by the invention has good application effect in well slurry, is easy to operate in the preparation method, can effectively reduce the surface activity of the drilling fluid system, has good rheological properties, improves the demulsification voltage, has low cost, and has strong wettability, which provides a strong guarantee for on-site drilling fluid construction.

Description

Technical Field

[0001] The invention relates to the technical field of wetting agents for oil-based drilling fluids, and is a wetting agent for oil-based drilling fluids with extremely low surface tension and a preparation method thereof. Background Art

[0002] At present, the commonly used wetting agents are quaternary ammonium salts (such as dodecyl trimethyl ammonium bromide), lecithin and petroleum sulfonate. These products are used under high temperature and high density conditions, that is, temperature resistance above 200°C and density 2.2g / cm 3 The above wetting effect is not ideal, resulting in a large amount of precipitation of the weighting material due to poor wetting, a significant increase in the viscosity of the system, and excessive viscosity of the drilling fluid, which seriously affects the rheological properties of the system and brings a series of problems to the subsequent drilling construction, such as poor drilling, drilling fluid sticking to the drill pipe, etc., and there are also problems such as large addition amount and insufficient temperature resistance. At present, there is an urgent need for a wetting agent for oil-based drilling fluid that can improve the wettability of the surface of barite and drill cuttings particles in the oil-based drilling fluid system under high temperature and high density conditions, thereby ensuring that the barite and drill cuttings particles can be better suspended in the oil phase. Summary of the invention

[0003] The present invention provides a wetting agent for oil-based drilling fluid with extremely low surface tension, which overcomes the above-mentioned deficiencies of the prior art and can effectively solve the problem that the prior wetting agent has poor wetting effect under high temperature and high density conditions.

[0004] One of the technical solutions of the present invention is achieved by the following measures: a wetting agent for oil-based drilling fluid with extremely low surface tension, wherein the raw materials include, by weight, 20 to 30 parts of tall oil fatty acid, 20 to 30 parts of oleic acid, 5 to 10 parts of turpentine, 10 to 20 parts of hydroxyethyltetraethylenepentamine, 10 to 20 parts of white oil, and 10 to 20 parts of dispersant.

[0005] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions:

[0006] The above-mentioned wetting agent for oil-based drilling fluid with extremely low surface tension is prepared by the following method:

[0007] The first step is to add the required amount of tall oil fatty acid, oleic acid and turpentine oil into a reactor and mix them evenly to obtain a first mixed solution;

[0008] The second step is to add hydroxyethyltetraethylenepentamine to the first mixed solution, and stir the mixture for 6 to 8 hours to obtain a second mixed solution;

[0009] The third step is to cool the second mixed liquid to 50° C. to 60° C., add dispersant and white oil thereto, and stir for 20 to 45 minutes to obtain a wetting agent for oil-based drilling fluid with extremely low surface tension.

[0010] The above dispersant is diethylene glycol butyl ether.

[0011] The above-mentioned white oil is No. 3 white oil.

[0012] The above oleic acid is soybean oleic acid.

[0013] In the above second step, the reaction is carried out at a temperature of 170°C to 180°C.

[0014] The stirring speed in the second and third steps is 100 rpm to 150 rpm.

[0015] The second technical solution of the present invention is achieved by the following measures: A method for preparing a wetting agent for oil-based drilling fluid with extremely low surface tension comprises the following steps:

[0016] The first step is to add the required amount of tall oil fatty acid, oleic acid and turpentine oil into a reactor and mix them evenly to obtain a first mixed solution;

[0017] The second step is to add hydroxyethyltetraethylenepentamine to the first mixed solution, and stir the mixture for 6 to 8 hours to obtain a second mixed solution;

[0018] The third step is to cool the second mixed liquid to 50° C. to 60° C., add dispersant and white oil thereto and stir for 20 to 45 minutes to obtain a wetting agent for oil-based drilling fluid with extremely low surface tension.

[0019] The wetting agent for oil-based drilling fluid with extremely low surface tension provided by the present invention has good application effect in well slurry, is easy to operate in the preparation method, can effectively reduce the surface activity of the drilling fluid system, has good rheological properties, improves the demulsification voltage, has low cost, and has strong wettability, which provides a strong guarantee for on-site drilling fluid construction. DETAILED DESCRIPTION

[0020] The present invention is not limited by the following embodiments, and the specific implementation method can be determined according to the technical scheme of the present invention and the actual situation. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all chemical reagents and chemicals known and used in the prior art; unless otherwise specified, the percentages in the present invention are all mass percentages; unless otherwise specified, the solutions in the present invention are all aqueous solutions with water as the solvent, for example, hydrochloric acid solution is a hydrochloric acid aqueous solution; the normal temperature and room temperature in the present invention generally refer to a temperature of 15°C to 25°C, and are generally defined as 25°C.

[0021] The present invention will be further described below in conjunction with embodiments:

[0022] Embodiment 1: The wetting agent for oil-based drilling fluid with extremely low surface tension comprises, by weight, 20 to 30 parts of tall oil fatty acid, 20 to 30 parts of oleic acid, 5 to 10 parts of turpentine, 10 to 20 parts of hydroxyethyltetraethylenepentamine, 10 to 20 parts of white oil, and 10 to 20 parts of dispersant.

[0023] Embodiment 2:

[0024] As an optimization of the above embodiment, the wetting agent for oil-based drilling fluid with extremely low surface tension is prepared according to the following method:

[0025] The first step is to add the required amount of tall oil fatty acid, oleic acid and turpentine oil into a reactor, mix them evenly, and obtain a first mixed solution; the second step is to add hydroxyethyltetraethylenepentamine to the first mixed solution, stir and react for 6 to 8 hours, and obtain a second mixed solution; the third step is to cool the second mixed solution to 50° C. to 60° C., add a dispersant and white oil thereto, and stir for 20 to 45 minutes, so as to obtain a wetting agent for an oil-based drilling fluid with extremely low surface tension.

[0026] Example 3: As an optimization of the above example, the dispersant is diethylene glycol butyl ether.

[0027] Example 4: As an optimization of the above example, the white oil is No. 3 white oil.

[0028] Example 5: As an optimization of the above example, the oleic acid is soybean oleic acid.

[0029] Example 6: As an optimization of the above example, in the second step, the reaction is carried out at a temperature of 170°C to 180°C.

[0030] Embodiment 7: As an optimization of the above embodiment, the stirring speed in the second step and the third step is 100 rpm to 150 rpm.

[0031] Example 8: The wetting agent for oil-based drilling fluid with extremely low surface tension is prepared by the following method:

[0032] The first step is to add the required amount of tall oil fatty acid, oleic acid and turpentine into a reactor, mix them evenly, and obtain a first mixed solution; the second step is to add hydroxyethyltetraethylenepentamine to the first mixed solution, stir and react for 6 to 8 hours, and obtain a second mixed solution; the third step is to cool the second mixed solution to 50° C. to 60° C., add a dispersant and white oil thereto, and stir for 20 to 45 minutes, so as to obtain a wetting agent for an oil-based drilling fluid with extremely low surface tension.

[0033] Embodiment 9:

[0034] The oil-based drilling fluid wetting agent with extremely low surface tension comprises 20 parts of tall oil fatty acid, 20 parts of oleic acid, 5 parts of turpentine, 10 parts of hydroxyethyltetraethylenepentamine, 20 parts of No. 3 white oil and 20 parts of diethylene glycol butyl ether in parts by mass.

[0035] The preparation method is as follows: the first step is to add the required amount of tall oil fatty acid, oleic acid and turpentine oil into a reactor and mix them evenly to obtain a first mixed solution; the second step is to add hydroxyethyltetraethylenepentamine to the first mixed solution and stir the mixture at 170°C for 8 hours to obtain a second mixed solution; the third step is to cool the second mixed solution to 50°C, add diethylene glycol butyl ether and No. 3 white oil thereto and stir for 30 minutes to obtain an oil-based drilling fluid wetting agent with extremely low surface tension.

[0036] Embodiment 10:

[0037] The oil-based drilling fluid wetting agent with extremely low surface tension comprises 30 parts of tall oil fatty acid, 30 parts of oleic acid, 10 parts of turpentine, 20 parts of hydroxyethyltetraethylenepentamine, 10 parts of No. 3 white oil and 10 parts of diethylene glycol butyl ether in parts by mass.

[0038] The preparation method is as follows: the first step is to add the required amount of tall oil fatty acid, oleic acid and turpentine oil into a reactor and mix them evenly to obtain a first mixed solution; the second step is to add hydroxyethyltetraethylenepentamine to the first mixed solution and stir the mixture at 180°C for 6 hours to obtain a second mixed solution; the third step is to cool the second mixed solution to 60°C, add diethylene glycol butyl ether and No. 3 white oil thereto and stir for 30 minutes to obtain an oil-based drilling fluid wetting agent with extremely low surface tension.

[0039] Embodiment 11:

[0040] The oil-based drilling fluid wetting agent with extremely low surface tension comprises 25 parts of tall oil fatty acid, 25 parts of oleic acid, 8 parts of turpentine, 12 parts of hydroxyethyltetraethylenepentamine, 15 parts of No. 3 white oil and 15 parts of diethylene glycol butyl ether in parts by mass.

[0041] The preparation method is as follows: the first step is to add the required amount of tall oil fatty acid, oleic acid and turpentine oil into a reactor and mix them evenly to obtain a first mixed solution; the second step is to add hydroxyethyltetraethylenepentamine to the first mixed solution and stir the mixture at 180°C for 6 hours to obtain a second mixed solution; the third step is to cool the second mixed solution to 60°C, add diethylene glycol butyl ether and No. 3 white oil thereto and stir for 30 minutes to obtain an oil-based drilling fluid wetting agent with extremely low surface tension.

[0042] Example 12: The wetting agent for oil-based drilling fluid with extremely low surface tension prepared in Example 11 of the present invention is used in a diesel system.

[0043] The system formula used in this embodiment is: diesel + 2% primary emulsifier + 6% secondary emulsifier + calcium chloride brine (obtained by adding 30g of anhydrous calcium chloride to 70mL of distilled water) + 5% oil-based drilling fluid fluid loss reducer + 4% calcium oxide + 1% wetting agent of the present invention + barite, and the system density is 2.5g / cm 3 ; Among them, the main emulsifier is a commercially available fatty acid amide emulsifier, the auxiliary emulsifier is a commercially available alkanolamide emulsifier, and the fluid loss reducer is a commercially available humic acid amide fluid loss reducer.

[0044] After the diesel system mixed liquid was rolled and aged at 250°C for 16h, 48h and 72h, its related parameters were tested. The rheological parameters (apparent viscosity, plastic viscosity, dynamic shear force, initial shear / final shear) were tested at 65°C, and the high temperature and high pressure water loss test conditions were 180°C 3.5MPa. The experimental results are shown in Table 1. As can be seen from Table 1, after adding the wetting agent of the present invention, the system has a good wetting effect under high temperature and high density conditions, has good rheological properties and thermal stability after rolling and aging at 250°C, has a small change range of rheological parameters, good rheological properties, stable demulsification voltage, and has obvious advantages in wettability under high temperature and high density, which fully meets the requirements of on-site drilling.

[0045] Example 13: Comparative experiment between the wetting agent of the present invention and commercially available wetting agents.

[0046] The wetting agent prepared in Example 11 of the present invention and three commercially available wetting agents were used for application comparison. Four portions of 300 ml of diesel oil of the same amount were taken, and 1% of the commercially available wetting agent and the wetting agent of the present invention were added respectively. The mixture was stirred at high speed for 5 minutes, and immediately poured into a graduated cylinder. The volume was read, and the surface tension and foaming rate were measured. The experimental results are shown in Table 2. As can be seen from Table 2, the surface tension of the wetting agent system of the present invention is low, and the foaming rate is low, indicating that the wetting agent of the present invention can make the surface tension of the oil-based drilling fluid system much lower than that of the existing commercially available wetting agents, and the foaming rate is low.

[0047] Example 14: Comparison of the application of the oil-based drilling fluid wetting agent with extremely low surface tension prepared in Example 11 of the present invention and a commercially available wetting agent in the slurry system of Jinlong 2 Well.

[0048] The wetting agent of the present invention and the commercially available alcohol ether wetting agent were respectively used for application comparison, and the system formula used was:

[0049] Formula 1: Jinlong 2 well slurry density: 1.4g / cm 3

[0050] Formula 2: Jinlong 2 well slurry + 1% wetting agent (the present invention)

[0051] Formula 3: Jinlong 2 well slurry + 1% wetting agent (commercially available alcohol ether wetting agent)

[0052] The above three formulation systems were respectively subjected to rolling aging at 240°C for 16 hours, and their related parameters were tested. The rheological parameters (apparent viscosity, plastic viscosity, dynamic shear force, initial cutting / final cutting test) were tested at a temperature of 65°C, and the high temperature and high pressure water loss test conditions were 180°C 3.5MPa. The experimental results are shown in Table 3. As can be seen from Table 3, after the wetting agent product of the present invention was added to the on-site well slurry of the Jinlong 2 well, the rheological properties of the system were reduced, and it was very stable after aging, and the demulsification voltage of the system was increased, indicating that the wetting agent of the present invention has good thermal stability and wettability in the Jinlong 2 well slurry system.

[0053] Example 15: Comparison of the application of the oil-based drilling fluid wetting agent with extremely low surface tension prepared by Example 11 of the present invention and a commercially available wetting agent in the well slurry system of Well Ke044.

[0054] The wetting agent of the present invention and the commercially available wetting agent were respectively used for application comparison, and the system formula used was:

[0055] Formula 1: 044 well slurry (density 1.46g / cm 3 )

[0056] Formula 2: 044 well slurry + 1% wetting agent (the present invention)

[0057] Formula 3: 044 well slurry + 1% wetting agent (commercially available anionic wetting agent)

[0058] The above three formulation systems were respectively subjected to rolling aging at 120°C for 16 hours and rolling aging of the well slurry and wetting agent system for 72 hours, and then their relevant parameters were tested. The test temperature of rheological parameters (apparent viscosity, plastic viscosity, dynamic shear force, initial shear / final shear) was 65°C, and the test conditions of high temperature and high pressure water loss were 120°C 4.2MPa. The experimental results are shown in Table 4. As can be seen from Table 4, compared with the commercially available wetting agent, after the wetting agent of the present invention was added to the well slurry of Ke 044 well, the rheological properties of the system, such as apparent viscosity, plastic viscosity, dynamic shear force, and final shear force, were significantly reduced, and the demulsification voltage was significantly increased, indicating that the wetting agent of the present invention can effectively reduce the surface tension of the system emulsion.

[0059] Example 16: Comparison of the application of the oil-based drilling fluid wetting agent with extremely low surface tension prepared in Example 11 of the present invention and a commercially available wetting agent in the slurry system of Gaoquan 5 Well.

[0060] The wetting agent of the present invention and the commercially available wetting agent were respectively used for application comparison, and the system formula used was:

[0061] Formula 1: Gaoquan 5 well slurry density 1.43g / cm 3

[0062] Formula 2: Gaoquan 5 well slurry + 1% wetting agent (the present invention)

[0063] Formula 3: Gaoquan 5 well slurry + 1% wetting agent (commercially available non-ionic wetting agent)

[0064] The above three formulation systems were respectively subjected to rolling aging at 120°C for 16 hours, and their relevant parameters were tested. The temperature of the rheological test (i.e., apparent viscosity, plastic viscosity, dynamic shear force, initial shear force / final shear force test) was 65°C, and the experimental results are shown in Table 5. As can be seen from Table 5, compared with the commercially available wetting agent, after the wetting agent of the present invention was added to the slurry of Gaoquan 5 well, the rheological properties of the system, such as apparent viscosity, plastic viscosity, dynamic shear force, and final shear force, decreased significantly, and the demulsification voltage increased significantly, indicating that the wetting agent of the present invention can effectively reduce the surface tension of the emulsion and has a good application effect.

[0065] The present invention provides a wetting agent for oil-based drilling fluid with extremely low surface tension and a preparation method thereof, which has the following advantages:

[0066] (1) The wetting agent of the present invention has a simple preparation process, and its raw materials come from natural plants (tall oil fatty acid comes from tall oil, and oleic acid comes from soybeans). It is highly degradable and will not cause damage to the formation.

[0067] (2) The system formed by the wetting agent of the present invention has good thermal stability and can be used at a density of up to 2.5 g / cm 3 Under the conditions of 250℃ rolling aging, it has good rheological and thermal stability, the rheological parameters change little, and the wettability has obvious advantages under high temperature and high density, which fully meets the requirements of on-site drilling.

[0068] (3) The wetting agent of the present invention is non-ionic and has good compatibility in the oil-based drilling fluid system. It has little effect on the rheological parameters of the high-density and high-temperature system. The product can be effectively used in the field of oil-based drilling fluid to reduce the low-density solid phase content of the drilling fluid. It has a stable demulsification voltage, strong compatibility, temperature and salt resistance, and reduces the amount of base oil used for dilution of the drilling fluid.

[0069] (4) The wetting agent of the present invention has a low foaming rate and has defoaming properties.

[0070] (5) The wetting agent of the present invention has good compatibility with other oil-based drilling fluid systems, which makes the oil-based drilling fluid highly reusable, reduces the application cost of the oil-based drilling fluid, and effectively alleviates the environmental pressure caused by the treatment of existing waste oil-based drilling fluid as hazardous waste.

[0071] In summary, the wetting agent for oil-based drilling fluid with extremely low surface tension provided by the present invention has good application effect in well slurry, the preparation method is easy to operate, can effectively reduce the surface activity of the drilling fluid system, has good rheological properties, improves the demulsification voltage, has low cost, and has strong wettability, which provides a strong guarantee for on-site drilling fluid construction.

[0072] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

[0073]

Claims

1. A wetting agent for oil-based drilling fluid with extremely low surface tension, characterized in that The raw materials include 20 to 30 parts of tall oil fatty acid, 20 to 30 parts of oleic acid, 5 to 10 parts of turpentine, 10 to 20 parts of hydroxyethyltetraethylenepentamine, 10 to 20 parts of white oil and 10 to 20 parts of dispersant by weight. The raw materials are prepared by the following method: the first step is to add required amounts of tall oil fatty acid, oleic acid and turpentine into a reactor, and mix them evenly to obtain a first mixed liquid; the second step is to add hydroxyethyltetraethylenepentamine into the first mixed liquid, and stir the mixture for 6 to 8 hours to obtain a second mixed liquid; the third step is to cool the second mixed liquid to 50 to 60° C., add the dispersant and white oil into the second mixed liquid, and stir the mixture for 20 to 45 minutes to obtain an oil-based drilling fluid wetting agent with extremely low surface tension.

2. The wetting agent for oil-based drilling fluid with extremely low surface tension according to claim 1, characterized in that The dispersant is diethylene glycol butyl ether.

3. The wetting agent for oil-based drilling fluid with extremely low surface tension according to claim 1 or 2, characterized in that The white oil is No. 3 white oil.

4. The wetting agent for oil-based drilling fluid with extremely low surface tension according to claim 3, characterized in that Oleic acid is soybean oleic acid.

5. The wetting agent for oil-based drilling fluid with extremely low surface tension according to claim 1, characterized in that In the second step, the reaction is carried out at a temperature of 170°C to 180°C.

6. The wetting agent for oil-based drilling fluid with extremely low surface tension according to claim 1, characterized in that The stirring speed in the second and third steps is 100 rpm to 150 rpm.

7. The method for preparing a wetting agent for oil-based drilling fluid with extremely low surface tension according to any one of claims 1 to 6, characterized in that The following steps are involved: The first step is to add the required amount of tall oil fatty acid, oleic acid and turpentine into a reactor, mix them evenly, and obtain a first mixed solution; the second step is to add hydroxyethyltetraethylenepentamine to the first mixed solution, stir and react for 6 to 8 hours, and obtain a second mixed solution; the third step is to cool the second mixed solution to 50° C. to 60° C., add a dispersant and white oil thereto, and stir for 20 to 45 minutes, so as to obtain a wetting agent for an oil-based drilling fluid with extremely low surface tension.

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