CN-122011352-A - 260 ℃ Resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent and preparation method and application thereof

CN122011352ACN 122011352 ACN122011352 ACN 122011352ACN-122011352-A

Abstract

The invention provides a 260 ℃ resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent and a preparation method and application thereof, belonging to the field of oilfield chemistry in petroleum industry. The preparation method of the wetting agent comprises the steps of mixing ricinoleic acid and base material fatty acid, adding a solid super acid catalyst I after dehydration treatment, adding polyol for reaction, filtering after the reaction is completed to obtain modified fatty acid, adding the solid super acid catalyst II after dehydration treatment, adding a grafting reagent containing epoxy groups for ring-opening grafting reaction, adding a polyhydroxy compound for esterification crosslinking reaction, adding a high-temperature stabilizing auxiliary agent into the obtained reaction liquid for curing treatment, then carrying out hot filtration, cooling the obtained filtrate, adding an oil phase dispersion medium, and stirring uniformly to obtain the wetting agent. The wetting agent can reduce the interfacial tension of oil and solid, and improve the wettability of oil-based drilling fluid to drill cuttings, well wall rock and weighting materials.

Inventors

HUANG XIANBIN
SHAO JUNHAO
SUN JINSHENG
LV KAIHE
WANG JINTANG
BAI YINGRUI
LI JIAN

Assignees

中国石油大学(华东)

Dates

Publication Date: 20260512
Application Date: 20260416

Claims (10)

1. The preparation method of the 260 ℃ resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent is characterized by comprising the following steps: (1) Mixing ricinoleic acid and substrate fatty acid, heating and dehydrating, adding a solid super acid catalyst I, continuously heating to a reaction temperature, adding polyol for reaction, cooling and filtering after the reaction is finished to obtain modified fatty acid, wherein the substrate fatty acid is one or more of oleic acid, linoleic acid, stearic acid and palmitic acid, the mass ratio of the ricinoleic acid to the substrate fatty acid is 1-3:1, the solid super acid catalyst I is one or more of SO 4 2- /ZrO 2 、SO 4 2- /TiO 2 、WO 3 /ZrO 2 、SO 4 2- /Fe 3 O 4 , the polyol is one of glycerol, pentaerythritol and trimethylolpropane, and the mass ratio of the polyol to the ricinoleic acid is 0.1-0.4:1; (2) The modified fatty acid obtained in the step (1) is dehydrated, then a solid super acidic catalyst II is added, after stirring uniformly, a grafting reagent containing epoxy groups is added for ring-opening grafting reaction, then a polyhydroxy compound is added for esterification crosslinking reaction, the solid super acidic catalyst II is the same as the solid super acidic catalyst I in the step (1), the grafting reagent containing epoxy groups is one or more of epoxidized soybean oil, phenyl glycidyl ether, glycidyl methacrylate and glycidyl trimethyl ammonium chloride, the mass ratio of the grafting reagent containing epoxy groups to the modified fatty acid is 0.15-0.25:1, the polyhydroxy compound is one or more of pentaerythritol, trimethylolpropane, xylitol and sorbitol, and the mass ratio of the polyhydroxy compound to the modified fatty acid is 0.05-0.15:1; (3) After the esterification crosslinking reaction is finished, adding a high-temperature stabilizing additive into the obtained reaction liquid for curing treatment, then carrying out hot filtration, cooling the obtained filtrate, adding an oil phase dispersion medium, and uniformly stirring to obtain the 260 ℃ ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent, wherein the high-temperature stabilizing additive is one or more of biphenyl, 1-phenyl naphthalene, 2-phenyl naphthalene, diphenyl ether, dibenzyl toluene and monobenzyl toluene, the mass ratio of the high-temperature stabilizing additive to the modified fatty acid is 0.05-0.15:1, the oil phase dispersion medium is one or more of mineral oil, synthetic oil and white oil, and the mass ratio of the oil phase dispersion medium to the modified fatty acid is 0.4-0.5:1.
2. The method for preparing the 260 ℃ resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent according to claim 1, wherein the temperature of the heating and dehydrating treatment in the step (1) is 110-130 ℃, the time of the heating and dehydrating treatment is 0.5-2h, and the heating and dehydrating treatment is carried out under nitrogen atmosphere.
3. The method for preparing the 260 ℃ resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent according to claim 1, wherein the mass of the solid super acid catalyst I in the step (1) is 1-5% of the total mass of ricinoleic acid and base material fatty acid; The reaction temperature is 160-180 ℃, the reaction time is 2-4h, the reaction is carried out under the nitrogen atmosphere, the temperature is reduced to 90-100 ℃, and the thermal filtration is carried out.
4. The method for preparing the 260 ℃ resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent according to claim 1, wherein the temperature of the dehydration treatment in the step (2) is 110-130 ℃, and the time of the dehydration treatment is 1-3 hours; The mass of the solid super acid catalyst II is 1-4% of the mass of the modified fatty acid, the temperature of stirring after adding the solid super acid catalyst II is 145-155 ℃, the stirring time is 20-40min, and the stirring rotating speed is 200-500r/min.
5. The method for preparing the 260 ℃ resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent according to claim 1, wherein the epoxy group-containing grafting reagent in the step (2) is dropwise added into the system at a dropwise adding rate of 1-2mL/min and at a dropwise adding temperature of 145-155 ℃; The temperature of the ring-opening grafting reaction is 160-175 ℃, and the time of the ring-opening grafting reaction is 2-4h.
6. The method for preparing the 260 ℃ resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent according to claim 1, wherein the temperature of the esterification and crosslinking reaction in the step (2) is 180-200 ℃, the time of the esterification and crosslinking reaction is 3-5h, and the operation process in the step (2) is carried out under nitrogen atmosphere.
7. The method for preparing the 260 ℃ resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent according to claim 1, wherein the curing treatment in the step (3) is carried out at 210-230 ℃, the curing treatment time is 1-3h, and the curing treatment is carried out under the protection of nitrogen.
8. The method for preparing the 260 ℃ resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent according to claim 1, wherein the hot filtration step in the step (3) is to cool the cured reaction solution to 110-120 ℃ and filter; In the step (3), the obtained filtrate is cooled to 70-80 ℃, the white oil is 5# white oil, 7# white oil or 10# white oil, the stirring rotating speed is 300-500r/min, and the stirring time is 50-70min; In the step (3), after the stirring is completed, a filtering step is further included, specifically, the mixed solution obtained by stirring is naturally cooled to room temperature, and filtering is carried out, wherein the pore diameter of a filter membrane used for filtering is less than or equal to 0.5 mu m.
9. An ultra-high temperature modified fatty acid oil-based drilling fluid wetting agent resistant to 260 ℃ is characterized in that the wetting agent is prepared by the preparation method of any one of claims 1-8.
10. Use of the 260 ℃ resistant ultra-high temperature modified fatty acid oil-based drilling fluid wetting agent of claim 9 in oil-based drilling fluids.

Description

260 ℃ Resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent and preparation method and application thereof Technical Field The invention relates to a 260 ℃ resistant ultrahigh temperature modified fatty acid oil-based drilling fluid wetting agent and a preparation method and application thereof, belonging to the field of oilfield chemistry in petroleum industry. Background With the continuous development of oil and gas exploration to deep, ultra-deep and complex stratum, the downhole temperature is continuously increased, deep wells, ultra-deep wells and high-temperature high-pressure wells are increasingly increased, well sections with the bottom hole temperature exceeding 200 ℃ are quite common, and the bottom hole temperature of part of ultra-deep wells can reach more than 240 ℃ and approach or exceed 260 ℃ under extreme working conditions. In such high temperature environments, the thermal stability and overall performance of the drilling fluid system can directly impact the safety and economics of the drilling operation. The oil-based drilling fluid is widely applied to high-temperature high-pressure and complex stratum drilling by virtue of excellent inhibition, lubricity and borehole wall stabilizing capability. However, this system relies on the synergistic action of various functional treatments, the high temperature stability of which is particularly important as a key material for regulating the wetting state of the solid phase particle surface, maintaining emulsion stability and improving rheological properties. Under the ultra-high temperature condition of 260 ℃ or above, the conventional wetting agent is easy to thermally degrade and decline in interfacial activity, so that an oil-based drilling fluid emulsion system is damaged, solid phase wetting is uneven, performance is seriously deteriorated, and even underground accidents can occur. Therefore, development of an oil-based drilling fluid wetting agent capable of maintaining high-efficiency wetting and interfacial stability in an ultra-high temperature environment at 260 ℃ for a long time has become a key technical problem to be broken through in the field of oilfield chemistry. The wetting agent has the main effects of changing the surface wettability of solid phase particles to ensure that drill cuttings, weighting materials and other solid particles in the drilling fluid are wetted by an oil phase preferentially, so as to maintain a water-in-oil structure, reducing the interfacial tension of oil water and oil, improving the strength of an emulsion film, enhancing the stability of a system and improving the rheological property and the lubricating property of the drilling fluid. At present, research on improving the temperature resistance of a wetting agent at home and abroad mainly focuses on modification of a surface molecular structure, for example, a patent document CN117229766A carries out modification reaction on oxidized plant polyphenol by using organic amine to obtain the organic amine modified plant polyphenol drilling fluid wetting agent, and the additive can effectively improve the high-temperature high-pressure rheological stability and sedimentation stability of the drilling fluid. The patent document CN116496767A prepares a wetting agent from alkyl dimethyl carboxylic acid betaine, 3-sulfopropyl alkyl dimethyl betaine, dioctyl sulfosuccinate, water and the like, has good solid-phase wetting effect at high temperature, and has good compatibility with anionic, cationic or nonionic oil-based emulsifying agents. However, the wetting reversal efficiency of a part of wetting agents is not high, the suitability or pertinence of the wetting agents to different types or surface properties of solid phases is insufficient, the ideal and stable wetting effect is difficult to realize, and meanwhile, the above wetting agents are difficult to maintain the long-term effective suspension stability of the oil-based drilling fluid system at the ultra-high temperature of 260 ℃. Although commercial products (such as HYPERWET ℃ C.) have improved performance through a compounding process, the principle of action is still based on physical adsorption and interface coating, desorption risks exist in a long-term high-temperature dynamic environment, and the synergistic stability with a complex compatibility system is insufficient. The patent document WO2021097662A1 adopts fatty acid ester and polyhydroxy organic amine (such as triethanolamine) to carry out direct condensation, and the principle is that a plurality of hydroxyl groups, ether bonds and even aromatic ring structures are introduced to enhance the thermodynamic stability and interfacial adsorption strength of molecules. Such molecules attempt to maintain a more stable adsorbed conformation at elevated temperatures by increasing the hydrogen bonding sites and steric hindrance. However, the multifunctional structure is more complex synthetically, and par