Lubricant composition for drilling fluid and drilling fluid system
By compounding dialkyl phthalate and dodecyl alcohol ester, a lubricant composition is formed, which solves the problem of excessive friction and torque of drilling fluid in high-temperature formations, improves lubrication performance under high temperature and high salinity conditions, and reduces drilling costs.
Patent Information
- Application Number
- CN202410777444.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-17
- Publication Date
- 2025-12-19
AI Technical Summary
Existing drilling fluid lubricants cause excessive friction and torque when used in high-temperature formations, leading to frequent engineering accidents and increased costs during drilling.
A compound lubricant composition of dialkyl phthalate and dodecyl alcohol ester is used in fresh water, salt water and high temperature and high density drilling fluids to reduce flow resistance and friction coefficient.
It effectively reduces the lubrication coefficient of drilling fluid under complex conditions such as high temperature and high salinity, solves the problem of excessive friction and torque during drilling, improves drilling efficiency, and reduces costs.
Smart Images
Figure BDA0004896126550000031 
Figure BDA0004896126550000041 
Figure BDA0004896126550000101
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of oil and gas exploration and development, in particular to a lubricant composition for drilling fluid and a drilling fluid system. BACKGROUND
[0002] In the field of oil and gas exploration and development, unconventional wells such as ultra-long horizontal wells, cluster wells and extended reach wells are often used to exploit oil and gas, which have the advantages of higher production, recovery rate and wider applicability compared with conventional horizontal wells, resulting in an increasing number of such wells in oil and gas drilling year by year, and the proportion of such wells in the market is also gradually increasing. However, these wells are prone to problems such as collapse, pipe sticking and bit balling during drilling, which not only increases the drilling friction and torque, but also reduces the mechanical drilling speed of the drilling tool and affects the project progress, thereby increasing the drilling cost. At present, the most effective method is to add a lubricant to the drilling fluid to improve the lubricating performance of the drilling fluid, thereby preventing or even reducing or avoiding the occurrence of pressure sticking, differential pressure sticking, bit balling and other engineering accidents, compressing the drilling engineering cycle and reducing the drilling cost.
[0003] CN114686189B discloses a lubricant for water-based drilling fluid, a preparation method thereof and a water-based drilling fluid. The lubricant for water-based drilling fluid comprises 70-80 parts by weight of base oil, 2-5 parts by weight of non-ionic surfactant, 1-3 parts by weight of extreme pressure anti-wear agent, 2-3 parts by weight of pour point depressant and 10-20 parts by weight of water. The lubricant for water-based drilling fluid has good lubricating performance and high temperature resistance, and the preparation process is simple. However, the non-ionic surfactant used in the lubricant includes at least one of SP-80, OP-10 or TW-80, which has a cloud point and is not suitable for high temperature formations. SUMMARY
[0004] The present application aims to overcome the problem of high drilling fluid lubrication coefficient and excessive friction and torque during drilling in the prior art, and provides a lubricant composition for drilling fluid and a drilling fluid system. The lubricant composition can be used in fresh water drilling fluid, salt water drilling fluid and high temperature and high density drilling fluid, and can effectively reduce the drilling fluid lubrication coefficient and solve the problem of excessive friction and torque during drilling.
[0005] To achieve the above-mentioned purpose, the first aspect of the present application provides a lubricant composition for drilling fluid, wherein the composition comprises: dialkyl phthalate and dodecanol ester.
[0006] The second aspect of the present application provides a drilling fluid system, wherein the drilling fluid system comprises drilling fluid base paste and a lubricant, and the lubricant is the lubricant composition for drilling fluid provided by the present application.
[0007] The third aspect of the present application provides application of a combination of dialkyl phthalate and dodecanol ester in reducing flow resistance and friction coefficient of drilling fluid.
[0008] By the technical solution, the present application has at least the following beneficial effects:
[0009] In the present application, dialkyl phthalate and dodecanol ester are compounded to form a lubricant composition, which has good lubricating performance and good compatibility with drilling fluid. The lubricant composition can be used in fresh water drilling fluid, salt water drilling fluid and high temperature and high density drilling fluid, and can be used under complex conditions such as high temperature and high salt. The lubricant composition effectively reduces the flow resistance and lubricating coefficient of drilling fluid, and solves the problem of excessive friction and torque in the drilling process. In the preferred embodiment of the present application, by selecting the types and proportions of dialkyl phthalate and dodecanol ester, the synergistic effect of dialkyl phthalate and dodecanol ester is further improved, thereby further reducing the flow resistance and lubricating coefficient of drilling fluid. DETAILED DESCRIPTION
[0010] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are understood to be approximate values. The endpoints of the ranges and the individual values are not to be construed as being meant to be precise values only. There is no implication that the endpoint values and / or the individual values are the same as one another in the context of the ranges. It is understood that the individual values and the endpoints of the ranges are not to be construed as being meant to be the same.
[0011] The first aspect of the present application provides a lubricant composition for drilling fluid, wherein the composition comprises dialkyl phthalate and dodecanol ester.
[0012] In the present application, dialkyl phthalate and dodecanol ester are compounded to form a lubricant composition, which has good lubricating performance and good compatibility with drilling fluid. The lubricant composition can be used under complex conditions such as high temperature and high salt, effectively reduces the lubricating coefficient of drilling fluid, and solves the problem of excessive friction and torque in the drilling process.
[0013] According to the present application, preferably, the dialkyl phthalate is selected from at least one of the compounds represented by formula (1),
[0014]
[0015] wherein R1 and R2 are each independently selected from a linear C1-C14 alkyl group, a branched C1-C14 alkyl group, a linear C1-C14 unsaturated hydrocarbon group or a branched C1-C14 unsaturated hydrocarbon group.
[0016] According to the present application, preferably, R1 and R2 are each independently selected from linear C1-C8 alkyl.
[0017] According to the present application, preferably, R1 and R2 are each independently selected from linear C1-C8 alkyl.
[0018] In the present application, the dialkyl phthalate can be commercially available or prepared by using the existing method.
[0019] When the dialkyl phthalate is prepared by using the existing method, in a preferred embodiment, the preparation steps of the dialkyl phthalate comprise: contacting phthalic anhydride, a fatty alcohol, a water carrying agent and a catalyst to perform esterification.
[0020] The fatty alcohol is selected from one of linear or branched saturated fatty alcohol with carbon number of 1-14 and linear or branched unsaturated fatty alcohol with carbon number of 1-14, preferably selected from one of linear saturated fatty alcohol with carbon number of 1-8; specifically, the fatty alcohol can be methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isopentanol, n-hexanol, isohexanol, n-heptanol, isoheptanol, n-octanol, isooctanol, etc. The water carrying agent can be toluene and / or xylene, preferably toluene. The catalyst can be at least one of sodium bisulfate, p-toluene sulfonic acid, concentrated sulfuric acid and hypophosphorous acid.
[0021] The molar ratio of the phthalic anhydride to the fatty alcohol is 1:(2.2-3), preferably 1:(2.5-2.8); the amount of the catalyst is 0.3-1 wt%, preferably 0.5-0.8 wt%, based on the total weight of the reaction mixture composed of phthalic anhydride, fatty alcohol, water carrying agent and catalyst; the amount of the water carrying agent is 10-40 wt%, preferably 20-30 wt%; the conditions of the esterification reaction include: temperature of 110-160℃, time of 3-8h, preferably 4-6h.
[0022] According to the present application, preferably, the dodecanol ester is selected from compounds represented by formula (2) and / or formula (3),
[0023]
[0024] Further, the dodecanol ester is selected from compounds represented by formula (2).
[0025] In order to further improve the synergistic effect of the dialkyl phthalate and the dodecanol ester, preferably, the content of the dialkyl phthalate and the dodecanol ester in the composition is 30-60wt% and 40-70wt%, respectively, based on the total weight of the composition.
[0026] Further, the content of the dialkyl phthalate and the dodecanol ester in the composition is 40-50 wt% and 50-60 wt%, respectively, based on the total weight of the composition.
[0027] The second aspect of the present application provides a drilling fluid system, wherein the drilling fluid system comprises a drilling fluid base paste and a lubricant, and the lubricant is the drilling fluid lubricant composition provided by the present application.
[0028] The preparation method of the lubricant is not particularly limited in the present application, and a conventional mixing method in the art can be used, as long as the dialkyl phthalate and the dodecanol ester can be uniformly mixed. In a preferred case, the dialkyl phthalate and the dodecanol ester are mixed under stirring, and the stirring time is 10-60 min and the temperature is 10-50℃.
[0029] The way and timing of adding the lubricant to the drilling fluid base paste are not particularly limited in the present application. The dialkyl phthalate and the dodecanol ester can be mixed in proportion in a drilling fluid mixing tank and stirred uniformly, and then added to the circulating drilling fluid in the form of a glue solution at one time, or directly added to the circulating drilling fluid in the circulating tank in the form of "water in a long stream", so as to effectively reduce the lubrication coefficient of the drilling fluid and solve the problem of excessive friction and torque in the drilling process.
[0030] The proportion of the drilling fluid base paste and the drilling fluid lubricant composition in the drilling fluid system is not particularly limited in the present application, and can be adjusted as needed.
[0031] The lubricant composition of the present application can be used in fresh water drilling fluid, salt water drilling fluid and high temperature and high density drilling fluid, effectively reducing the lubrication coefficient of the drilling fluid and solving the problem of excessive friction and torque in the drilling process.
[0032] The third aspect of the present application provides the application of the combination of dialkyl phthalate and dodecanol ester in reducing the flow resistance and friction coefficient of the drilling fluid. The drilling fluid lubricant composition provided by the present application has good lubricating performance, good compatibility with the drilling fluid, and can be used under complex conditions such as high temperature and high salt, effectively reducing the lubrication coefficient of the drilling fluid and solving the problem of excessive friction and torque in the drilling process.
[0033] The present application will be described in detail below through examples and comparative examples. In the following examples, unless otherwise specified, the methods are conventional methods; and the reagents and materials used, unless otherwise specified, can be obtained from commercial channels.
[0034] In the following examples and comparative examples, unless otherwise specified, diethyl phthalate was purchased from Beijing Inokai Technology Co., Ltd., with purity > 96%; dioctyl phthalate was purchased from Beijing Inokai Technology Co., Ltd., with purity of 95%; didecyl phthalate was purchased from Beijing Inokai Technology Co., Ltd., with purity of 95%; dodecanol ester (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, ) was purchased from Beijing Inokai Technology Co., Ltd., with purity > 95%.
[0035] Dibutyl phthalate (No. LSD-1) was prepared as follows: In a four-necked flask equipped with a mechanical stirrer, a constant pressure dropping funnel, a water separator, and a thermometer, 14.8 g (0.1 mol) of phthalic anhydride was added, 18.5 g (0.25 mol) of n-butanol was added, 0.35 g of sodium bisulfate was added, 12 g of toluene was added, and N2 was introduced to prevent oxidation. After stirring uniformly, heating was started to reflux at 140°C and water was separated, and the reaction was carried out for 5 h. After the reaction was completed, the reaction solution was neutralized with 5% sodium carbonate until the pH value test paper showed neutral. The upper ester layer was retained, washed with deionized water for 2-3 times, and then distilled under reduced pressure to obtain oily dibutyl phthalate product (nuclear magnetic resonance test results confirmed that dibutyl phthalate was indeed obtained).
[0036] In the following examples, “per weight part” means 0.1 g.
[0037] Example 1
[0038] At 30°C, 45 parts by weight of diethyl phthalate, 55 parts by weight of dodecanol ester (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, ) were added to a reaction kettle, stirred for 30 min, and a lubricant was prepared, No. RHJ-1.
[0039] Example 2
[0040] At 40°C, 45 parts by weight of dibutyl phthalate LSD-1, 55 parts by weight of dodecanol ester (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, ) were added to a reaction kettle, stirred for 30 min, and a lubricant was prepared, No. RHJ-2.
[0041] Example 3
[0042] At 30°C, 50 parts by weight of diethyl phthalate, 50 parts by weight of dodecanol ester (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, ) were added to a reaction kettle, stirred for 30 min, and a lubricant was prepared, No. RHJ-3.
[0043] Example 4
[0044] A lubricant was prepared according to the method of Example 1, except that the type of dialkyl phthalate was different. Specifically, "dialkyl phthalate" was replaced with "dioctyl phthalate". A lubricant was prepared, designated RHJ-4.
[0045] Example 5
[0046] A lubricant was prepared according to the method of Example 2, except that the amounts of dibutyl phthalate LSD-1 and dodecanol ester were different. Specifically, "45 parts by weight of dibutyl phthalate LSD-1, 55 parts by weight of dodecanol ester" was replaced with "30 parts by weight of dibutyl phthalate LSD-1, 70 parts by weight of dodecanol ester". A lubricant was prepared, designated RHJ-5.
[0047] Example 6
[0048] A lubricant was prepared according to the method of Example 2, except that the amounts of dibutyl phthalate LSD-1 and dodecanol ester were different. Specifically, "45 parts by weight of dibutyl phthalate LSD-1, 55 parts by weight of dodecanol ester" was replaced with "60 parts by weight of dibutyl phthalate LSD-1, 40 parts by weight of dodecanol ester". A lubricant was prepared, designated RHJ-6.
[0049] Example 7
[0050] A lubricant was prepared according to the method of Example 1, except that the type of dialkyl phthalate was different. Specifically, "dialkyl phthalate" was replaced with "didecyl phthalate". A lubricant was prepared, designated RHJ-7.
[0051] Example 8
[0052] A lubricant was prepared according to the method of Example 1, except that the type of dodecanol ester was different. Specifically, the dodecanol ester was the compound shown below. A lubricant was prepared, designated RHJ-8.
[0053] Example 9
[0054] A lubricant was prepared according to the method of Example 1, except that the type of dodecanol ester was different. Specifically, the dodecanol ester (55 parts by weight) was a mixture of the compounds shown below in a weight ratio of 1:1. A lubricant was prepared, designated RHJ-9.
[0055] Example 10
[0056] A lubricant was prepared according to the method of Example 1, except that the type of dialkyl phthalate was changed. Specifically, di(2-ethylhexyl) phthalate was used in place of an equal weight portion of diethyl phthalate. The lubricant was prepared, and was designated RHJ-10.
[0057] Comparative Example 1
[0058] A lubricant was prepared according to the method of Example 2, except that dibutyl phthalate LSD-1 was used in place of an equal weight portion of dodecanol ester. The lubricant was prepared, and was designated DB-1.
[0059] Comparative Example 2
[0060] A lubricant was prepared according to the method of Example 2, except that dodecanol ester was used in place of an equal weight portion of dibutyl phthalate LSD-1. The lubricant was prepared, and was designated DB-2.
[0061] Comparative Example 3
[0062] An oilfield lubricant was used directly as a lubricant sample, and was designated DB-3.
[0063] Comparative Example 4
[0064] A lubricant was prepared according to the method of Example 2, except that diethyl terephthalate was used in place of an equal weight portion of dibutyl phthalate LSD-1. The lubricant was prepared, and was designated DB-4.
[0065] Comparative Example 5
[0066] A lubricant was prepared according to the method of Example 2, except that diethyl terephthalate was used in place of an equal weight portion of dibutyl phthalate LSD-1, and dodecanol was used in place of an equal weight portion of dodecanol ester. The lubricant was prepared, and was designated DB-5.
[0067] Test Example
[0068] Lubricating property evaluation: A bentonite slurry having a mass fraction of 5% was prepared using tap water, and the lubricating coefficient of the bentonite slurry having a mass fraction of 5% was measured after rolling and aging at 130°C for 16 hours. The lubricant prepared in each of the examples and comparative examples was added to the bentonite slurry having a mass fraction of 5% described above, and the lubricating coefficient was measured after rolling and aging at 130°C for 16 hours. The reduction rate of the lubricating coefficient of the bentonite slurry having a mass fraction of 5% after the addition of the different lubricants was calculated by comparison. The test results are shown in Table 1.
[0069] Table 1
[0070]
[0071]
[0072] As can be seen from the data in Table 1, the lubrication coefficient of the 5% bentonite slurry is significantly reduced after the lubricant provided by the present application is added, and the reduction rate is all above 80%. In Comparative Example 1, dialkyl phthalate is used to replace the same weight of dodecanol ester, in Comparative Example 2, dodecanol ester is used to replace the same weight of dialkyl phthalate, in Comparative Example 3, it is a lubricant industrial product, in Comparative Example 4, diethyl terephthalate is used to replace the same weight of dibutyl phthalate, in Comparative Example 5, diethyl terephthalate is used to replace the same weight of dibutyl phthalate LSD-1, and dodecanol is used to replace the same weight of dodecanol ester. Compared with the lubricant prepared in Examples 1-10, the reduction rate of the lubrication coefficient of the 5% bentonite slurry after the lubricant of Comparative Examples 1-5 is added is significantly reduced.
[0073] In addition, the carbon chain length of R1 and R2 of dialkyl phthalate is changed in Example 4 and Example 7, the amount of dialkyl phthalate and dodecanol ester is changed in Example 5 and Example 6, the type of dodecanol ester is changed in Example 8 and Example 9, and R1 and R2 of dialkyl phthalate in Example 10 contain branches. Compared with the lubricant prepared in Examples 1-3, the reduction rate of the lubrication coefficient of the 5% bentonite slurry after the lubricant prepared in Examples 4-10 is added is reduced. Therefore, when the structure and composition of dialkyl phthalate and dodecanol ester, and the amount of dialkyl phthalate and dodecanol ester meet the preferred conditions, the lubrication performance of the lubricant can be further improved.
[0074] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.
Claims
1. A lubricant composition for drilling fluids, characterized by, The composition comprises: a dialkyl phthalate and a dodecanol ester.
2. The composition of claim 1, wherein, The dialkyl phthalate is selected from at least one of compounds shown in formula (1), wherein R1 and R2 are each independently selected from a linear C1-C14 alkyl group, a branched C1-C14 alkyl group, a linear C1-C14 unsaturated hydrocarbon group or a branched C1-C14 unsaturated hydrocarbon group.
3. The composition of claim 2, wherein, R1 and R2 are each independently selected from a linear C1-C8 alkyl group.
4. The composition of claim 3, wherein, R1 and R2 are each selected from a linear C2-C6 alkyl group.
5. The composition according to any one of claims 1 to 4, characterized in that, The dodecanol ester is selected from compounds shown in formula (2) and / or formula (3), 6. The composition of claim 5, wherein, The dodecanol ester is selected from compounds shown in formula (2).
7. The composition according to any one of claims 1 to 6, wherein The content of the dialkyl phthalate and the dodecanol ester in the composition is 30-60wt% and 40-70wt%, respectively, based on the total weight of the composition.
8. The composition of claim 7, wherein, The content of the dialkyl phthalate and the dodecanol ester in the composition is 40-50wt% and 50-60wt%, respectively, based on the total weight of the composition.
9. A drilling fluid system characterized by, The drilling fluid system comprises a drilling fluid base slurry and a lubricant, and the lubricant is the drilling fluid lubricant composition according to any one of claims 1-8.
10. Use of a combination of a dialkyl phthalate and a dodecanol ester in reducing flow resistance and friction coefficient of a drilling fluid.