Base oil for environment-friendly oil-based drilling fluid and preparation method of base oil

Abstract

The invention discloses base oil for environment-friendly oil-based drilling fluid and a preparation method thereof.The preparation method comprises the steps that after a mixture of vacuum wax oil and normal-pressure distillate oil is mixed with hydrogen, the mixture enters a first reaction zone to be reacted, and a product sequentially passes through a high-pressure separator, a low-pressure separator and a fractionating tower to obtain the base oil for the environment-friendly oil-based drilling fluid. First tower bottom oil, first side line extract oil and first tower top oil are obtained; tower bottom oil and hydrogen are preheated and enter a second reaction zone and a third reaction zone for reaction, effluent passes through a high-pressure separator, a low-pressure separator and a fractionating tower, and second side line extract oil, second tower top oil and second tower bottom oil are obtained; one of the first side draw oil and the first side draw oil or the mixed oil is the base oil for the environment-friendly oil-based drilling fluid. According to the preparation method disclosed by the invention, the property of the base oil for the white oil-based drilling fluid can be adjusted.

Description

Technical Field

[0001] The invention belongs to the field of petroleum refining and relates to a base oil for environmentally friendly oil-based drilling fluid and a preparation method thereof. Background Art

[0002] With the increasing number of unconventional oil and gas wells and increasingly complex geological conditions, the application scope of oil-based drilling fluids is becoming wider and wider. Oil-based drilling fluids are mainly composed of base fluids, emulsifiers, fluid loss reducers, organic soils, etc., and base fluids account for about 70% of the cost of oil-based drilling fluids. The average single-well consumption of base fluids in shale gas horizontal wells is nearly 300 cubic meters; the average single-well consumption of deep wells in the Tarim Kuche piedmont / Junggar Basin is 880 cubic meters; the annual consumption of base fluids by the group company is 200,000 cubic meters, with a cost of more than 1.6 billion yuan.

[0003] At present, the domestic oil-based drilling fluid base oil is mainly diesel-based drilling fluid base oil, white oil-based drilling fluid base oil and a small amount of synthetic-based drilling fluid base oil. The reference standards are mainly ("Automobile Diesel" (GB19147-2016), "Crude White Oil" (NB / SH / T 0914-2015), "Industrial White Oil" (NB / SH / T0006-2017) and "Light White Oil" (NB / SH / T 0913-2015)). At present, diesel-based drilling fluid base oil is still used in areas where it is not mandatory. According to the GB 19147-2016 automotive diesel standard, the polycyclic aromatic hydrocarbon content is required to be ≯7wt%, and there is no restriction on the content of monocyclic aromatic hydrocarbons. However, the total aromatic content of diesel is currently about 15-20wt%, among which the high aromatic content greatly reduces its biodegradability, and its biological toxicity is toxic / slightly toxic; the future development trend is environmentally friendly drilling fluid base oil, non-toxic and highly degradable.

[0004] At present, the mainstream abroad uses low-toxic or non-toxic biodegradable oil-based or synthetic-based base fluids, such as Total's EDC95-11 base oil, with an aromatic hydrocarbon content of less than 0.03%, a sulfur content of less than 1 mg / kg, a nitrogen content of less than 2 mg / kg, a flash point of 115°C, and a kinematic viscosity of 3.5 mm 2 / s, the biodegradation rate in seawater within 28 days is 74%. Shell Saraline 185V, aromatic hydrocarbon content is less than 0.05%, sulfur content is less than 3mg / kg, flash point is 85℃, kinematic viscosity is 2.6mm 2 / s, and the biodegradation rate in seawater within 28 days is 60%.

[0005] CN113372951A discloses a method for producing low aromatic white oil, comprising the following steps: (a) heating, removing impurities and desulfurizing the raw vacuum wax oil; (b) desulfurization: heating the pretreated raw vacuum wax oil and entering a high-pressure stripping tower for desulfurization to obtain a first reaction oil; (c) cracking and decondensation: the first reaction oil and circulating hydrogen enter a second reactor for cracking and decondensation to obtain a second reaction oil; (d) catalytic saturation: the second reaction oil enters a third reactor, and a metal catalyst is added to react with hydrogen to cause an addition reaction, so that polycyclic aromatic hydrocarbons are saturated to obtain a catalytic oil; and (e) vacuum distillation: vacuum distilling the catalytic oil and performing fractional distillation and cutting to obtain a food-grade white oil product.

[0006] CN115353906A discloses a preparation method and product of light white oil for drilling fluid and its application, including: processing paraffin-based crude oil into distillate oil; hydrogenating and refining the distillate oil to obtain hydrogenated refined oil; performing deep hydrogenation and saturation treatment on the hydrogenated refined oil after simple fractionation, and obtaining light white oil for drilling fluid by precise fractionation after stripping. The technical product has high saturated hydrocarbon content, is colorless, has good light stability and thermal stability, has extremely low sulfur and nitrogen content, does not contain aromatic hydrocarbons and harmful solvents, has a narrow distillation range, and has good effect, but the properties of white oil and its composition content are greatly dependent on the properties of the raw materials, and the control performance is poor.

[0007] CN111471488A relates to an isoparaffin solvent oil produced by using Fischer-Tropsch crude liquid wax or Fischer-Tropsch crude liquid wax and naphtha as raw materials using the Fischer-Tropsch synthesis process. The carbon chain length of the alkanes in the product is concentrated between C12 and C14, the distillation range is 210-245°C, the isoparaffins are of high purity, few impurities, no cycloalkanes, the aromatic content is less than 50ppm, and the flash point is greater than 80°C. However, this technology is limited by the raw materials and the low aromatic drilling fluid base oil developed based on this technology is relatively expensive.

[0008] CN107937024A discloses a method for producing high-quality light white oil from base oil, which comprises the following steps: the raw base oil is heated to the reaction temperature and fully mixed with hydrogen, and then enters into a hydrogenation reactor carrying catalyst I, and under the action of hydrogenation refining catalyst I, a hydrogenation refining reaction is carried out to remove most of the S, N, and aromatic impurities in the raw base oil; the product after the reaction enters into two reactors in series carrying catalyst II and catalyst III, respectively, and contacts with catalyst II and catalyst III to carry out S removal and dearomatization reaction; the obtained reactants are separated by gas and liquid in high and low pressure separators and then enter into a fractionation system for fine cutting to obtain a variety of high-quality light white oil products of different grades. This technology can produce high-quality light white oil with good quality, high yield, short distillation range, high purity, low sulfur, and low aromatics.

[0009] In summary, the base oil for environmentally friendly mineral-based drilling fluid is mainly light white oil. Through patent comparison and analysis, the production route of light white oil mainly uses light white oil fraction segment to achieve light white oil production through hydrogenation treatment and secondary deep hydrogenation saturation. However, this production process is relatively simple and the controllability of white oil properties is poor. It cannot meet the requirements for oil viscosity and composition during drilling. Summary of the invention

[0010] The technical problem to be solved by the present invention is to realize the production of drilling fluid base oils with different aromatic hydrocarbon contents / paraffin hydrocarbon contents, and to realize the property control of environmentally friendly drilling fluid base oils.

[0011] In order to solve the problems of single product structure or single composition of the same fraction segment in the existing production process of light white oil, and poor compatibility in specific application scenarios of drilling fluid, the present invention has developed an environmentally friendly aromatic base oil and process that can achieve hydrocarbon composition regulation based on the existing process flow units and hydrocarbon reaction characteristics, which can meet the needs of regulating both viscosity and hydrocarbon composition.

[0012] To achieve the above object, the present invention provides a method for preparing an environmentally friendly oil-based drilling fluid base oil, the preparation method comprising the following steps:

[0013] a) the mixture of vacuum wax oil and atmospheric distillate oil is mixed with hydrogen and then enters the first reaction zone for reaction;

[0014] b) the product flowing out of the first reaction zone passes through a high pressure separator, a low pressure separator and a fractionation tower in sequence to obtain a first bottom oil, a first side line oil and a first top oil;

[0015] c) the first tower bottom oil and hydrogen are preheated and enter the second reaction zone and the third reaction zone for reaction;

[0016] d) the effluent from the third reaction zone passes through a high-pressure separator, a low-fraction separator and a fractionation tower to obtain a second sideline oil, a second tower top oil and a second tower bottom oil;

[0017] e) Either one of the first sideline oil and the second sideline oil or a mixture of the two oils is an environmentally friendly base oil for oil-based drilling fluid.

[0018] The method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention comprises the following steps: the distillation range of the atmospheric distillate oil is 180-360° C., and the paraffin content thereof is 10-60wt%.

[0019] The method for preparing the base oil for the environment-friendly oil-based drilling fluid of the present invention comprises the following steps: the initial distillation point of the vacuum wax oil is ≮360°C, the final distillation point is ≯550°C, and the distillation range is 360-550°C.

[0020] In the method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention, the distillation range of the vacuum wax oil can be 400-470°C, or 470-550°C.

[0021] The method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention comprises the following steps: in step a), the mass ratio of the vacuum wax oil to the atmospheric distillate oil is 1:(0-1).

[0022] The method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention comprises the following steps: the catalyst in the first reaction zone is a graded combination of a non-precious metal hydrorefining catalyst and a non-precious metal hydrocracking catalyst, and the graded ratio of the hydrorefining catalyst to the hydrocracking catalyst is 1:(0-1).

[0023] The method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention, the active metal components in the non-precious metal hydrorefining catalyst are Group VIII metals and Group VIB metals; the Group VIII metals are Co and / or Ni; the Group VIB metals are W and / or Mo, and the carrier is alumina or phosphorus- and silicon-modified alumina. The present invention does not particularly limit the non-precious metal hydrorefining catalyst, which can adopt commercially available non-precious metal hydrorefining catalysts, such as commercially available or commercial PHD, PHF, FHUDS, RS series hydrorefining catalysts, and can also be prepared by conventional techniques in the art.

[0024] The method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention, the active metal components in the non-precious metal hydrocracking catalyst are Group VIII metals and Group VIB metals; the Group VIII metals are Co and / or Ni; the Group VIB metals are W and / or Mo, and the carrier is a carrier formed by a composite of alumina and Y-type molecular sieves and / or amorphous silicon aluminum. The present invention does not particularly limit the non-precious metal hydrocracking catalyst, which can be a commercially available hydrorefining catalyst, or can be prepared by conventional techniques in the art.

[0025] The method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention, the catalyst in the second reaction zone is a precious metal hydrogenation isomerization catalyst, the precious metal is mainly one or two of Pt and Pd, and the acidic component is at least one of ZSM-48, ZSM-23, ZSM-22, and SAPO-11.

[0026] The method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention, the catalyst in the third reaction zone is an aromatic hydrocarbon deep saturation catalyst, the metal component thereof can be one or a combination of Pt and Pd, and the carrier is one or two of Al2O3 and SiO2-Al2O3.

[0027] The method for preparing a base oil for an environmentally friendly oil-based drilling fluid of the present invention, wherein the base oil for the environmentally friendly drilling fluid can be the first sideline extracted oil, the second sideline extracted oil, or a mixture of the first sideline extracted oil and the second sideline extracted oil, with the ratio being (0-1):1.

[0028] The method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention comprises the following steps: the reaction pressure of the first reaction zone is 10-20 MPa, preferably 12-18 MPa, the temperature is 360-400°C, the air velocity is 0.5-2.0 h -1 .

[0029] The method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention, the reaction pressure of the second reaction zone is 10-20Mpa, preferably 12-18Mpa, the temperature is 350-390°C, the air velocity is 0.5-2.0h -1 .

[0030] The method for preparing the base oil for the environmentally friendly oil-based drilling fluid of the present invention comprises the following steps: the reaction pressure of the third reaction zone is 10-20 MPa, preferably 12-18 MPa, the temperature is 180-240° C., preferably 200-230° C., and the air velocity is 0.5-1.5 h -1 .

[0031] The present invention also provides an environmentally friendly drilling fluid base oil, wherein the environmentally friendly drilling fluid base oil has an aromatic content of 0.002-0.2 wt % and a kinematic viscosity of 1.8-3.0 mm at 40° C. 2 / s, the initial distillation point is not less than 190°C, the final distillation point is not higher than 360°C, and the paraffin content is adjustable from 30 to 70wt%.

[0032] The environmentally friendly base oil for drilling fluid of the present invention has an initial boiling point of not less than 190°C and a final boiling point of not more than 360°C, and may also be 200-240°C, 220-300°C, or 240-270°C.

[0033] Compared with the white oil-based drilling fluid base oil produced by conventional methods, the environmentally friendly drilling fluid base oil of the present invention has an ultra-low aromatic content, which can reach 0.003wt%, and can achieve a large proportion of increased production of drilling fluid base oil. The present invention combines the molecular composition of the drilling fluid base oil and the reaction process of the traditional high-pressure hydrogenation to produce lubricating oil base oil, and designs and invents the raw material ratio, process conditions and fractionation system. Through the proportion of the first sideline product and the second sideline product, different grades of drilling fluid base oil can be developed, which are suitable for applications in different scenarios. The present invention effectively regulates the proportion and properties of the target drilling fluid base oil, realizes the adjustable properties of the white oil-based drilling fluid base oil, solves the structural unadjustability or small adjustment range of the target product fraction in the traditional two-stage process production process, and cannot meet the on-site drilling fluid base oil demand, and can achieve an adjustable paraffin content of 30 to 70wt% and an adjustable aromatic content of 0.001 to 0.2wt%. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a production process diagram of the environmentally friendly base oil for drilling fluid of the present invention.

[0035] Wherein, the reference numerals are:

[0036] 1-hydrogen; 2-1: vacuum wax oil; 2-2: atmospheric distillate oil; 3: first reaction zone; 4-first reaction effluent; 5: high-pressure separator; 6-high-fraction liquid phase effluent; 7-low-pressure separator; 8: low-fraction liquid phase effluent; 9: fractionation tower; 9-1: first tower top effluent; 9-2: first side line effluent; 9-3: first tower bottom effluent; 11: second reaction zone: 12: second reaction zone effluent; 13: third reaction zone; 14: third reaction zone effluent; 15: high-pressure separator; 16: high-fraction effluent; 17: low-fraction separator; 18: low-fraction effluent; 19: fractionation tower; 19-1: second tower top effluent; 19-2: second side line effluent; 19-3: second tower bottom effluent. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with specific embodiments, but the present invention is not limited by the following embodiments. Any modification that does not exceed the concept and scope of the present invention is within the scope of the present invention.

[0038] The properties of the atmospheric distillate oil and vacuum gas oil used in the examples and comparative examples are shown in Table 1.

[0039] Table 1 Properties of atmospheric distillate oil and vacuum gas oil

[0040] nature Atmospheric distillate Vacuum wax oil <![CDATA[Density, kg / m 3 > 835.2 870.5 Sulfur content, μg / g 430 1200 Nitrogen content, μg / g 35 300 Paraffin, wt% 60 30 Distillation range, ℃ 200-320 390-470

[0041] Embodiment 1:

[0042] Vacuum wax oil and atmospheric distillate oil are mixed with hydrogen, wherein the ratio of vacuum wax oil to atmospheric distillate oil is 1:0.2 (mass ratio), and the mixture of hydrogen and oil enters the first reaction zone. The catalyst is a traditional non-precious metal hydrorefining catalyst and a hydrocracking catalyst, Ni-Mo-P / Al2O3 and Ni-W / USY-Al2O3, and the volume ratio of the refining catalyst to the cracking catalyst is 1:0.1; the reaction system pressure is 18Mpa, based on the total oil intake, the hydrogen-oil ratio (v / v) is 1500, and the total volume space velocity is 0.75h -1 The average reaction temperature of the first reaction zone is 380°C. The product of the first reaction zone passes through a high-pressure separator, a low-pressure separator and a fractionation tower in sequence to obtain the first tower bottom oil, the first side-line oil and the first tower top oil, wherein the initial boiling point of the first tower bottom oil is ≮180°C, and the hydrogen and the first tower bottom oil all enter the second reaction zone and the third reaction zone. The catalysts of the second reaction zone and the third reaction zone are Pt / ZSM-48 catalyst and Pt-Pd / SiO2-Al2O3 catalyst, respectively. The space velocity of the second reaction zone and the third reaction zone is 1.0h-1, respectively. -1 and 1.5h -1 , the hydrogen-to-oil ratio is 600:1, and the reaction temperatures are 375°C and 230°C respectively. The effluent from the third reaction zone passes through a high-pressure separator, a low-fraction separator and a fractionation tower to finally obtain the second sideline oil, wherein the second sideline oil is the obtained environmentally friendly drilling fluid base oil, with a kinematic viscosity of 2.7 mm at 40°C. 2 / s, distillation range is 240-280℃, aromatic content is 0.003wt%, yield is 23wt%, and paraffin content is 50wt%.

[0043] Comparative Example 1:

[0044] The vacuum wax oil is mixed with hydrogen, and the hydrogen and the vacuum wax oil enter the first reaction zone. The catalysts are traditional non-precious metal hydrorefining catalysts and hydrocracking catalysts, Ni-Mo-P / Al2O3 and Ni-W / USY-Al2O3, and the volume ratio of the refining catalyst to the cracking catalyst is 1:0.1; the reaction system pressure is 18Mpa, based on the total oil intake, the hydrogen-oil ratio (v / v) is 1500, and the total volume space velocity is 0.625h -1 The average reaction temperature of the first reaction zone is 380°C. The product of the first reaction zone passes through a high-pressure separator, a low-pressure separator and a fractionation tower in sequence to obtain a first tower bottom oil, a first side-line extracted oil and a first tower top oil. The initial boiling point of the first tower bottom oil is ≮180°C. The hydrogen and the first tower bottom oil all enter the second reaction zone and the third reaction zone. The catalysts of the second reaction zone and the third reaction zone are Pt / ZSM-48 catalyst and Pt-Pd / SiO2-Al2O3 catalyst, respectively. The space velocity of the second reaction zone and the third reaction zone is 1.0h-1, respectively. -1and 1.5h -1 , the hydrogen-to-oil ratio is 600:1, and the reaction temperatures are 375°C and 230°C respectively. The effluent from the third reaction zone passes through a high-pressure separator, a low-fraction separator and a fractionation tower to finally obtain the second sideline oil, wherein the second sideline oil is the obtained environmentally friendly drilling fluid base oil, and the kinematic viscosity at 40°C is 2.85mm 2 / s, distillation range is 240-280℃, aromatic content is 0.003wt%, yield is 10wt%, paraffin content is 35wt%.

[0045] The difference from Example 1 is that by adjusting the raw material composition, the base oil for drilling fluid can be increased by 13wt%, and the paraffin content is 50%. Compared with Comparative Example 1, the paraffin content is increased by 15%.

[0046] Embodiment 2:

[0047] Vacuum wax oil and atmospheric distillate oil are mixed with hydrogen, wherein the ratio of vacuum wax oil to atmospheric distillate oil is 1:0.3 (mass ratio), and the mixture of hydrogen and oil enters the first reaction zone. The catalyst is a traditional non-precious metal hydrorefining catalyst and a hydrocracking catalyst, Ni-Mo-P / Al2O3 and Ni-W / USY-Al2O3, and the volume ratio of the refining catalyst to the cracking catalyst is 1:0.2; the reaction system pressure is 18Mpa, based on the total oil intake, the hydrogen-oil ratio (v / v) is 1500, and the total volume space velocity is 0.75h -1 The average reaction temperature of the first reaction zone is 390°C. The product of the first reaction zone passes through a high-pressure separator, a low-pressure separator and a fractionation tower in sequence to obtain the first tower bottom oil, the first side-line oil and the first tower top oil. The initial boiling point of the first tower bottom oil is ≮180°C. The hydrogen and the first tower bottom oil all enter the second reaction zone and the third reaction zone. The catalysts of the second reaction zone and the third reaction zone are Pt / ZSM-48 catalyst and Pt-Pd / SiO2-Al2O3 catalyst respectively. The space velocity of the second reaction zone and the third reaction zone is 1.0h-1 respectively. -1 and 1.5h -1 , the hydrogen-to-oil ratio is 400:1, and the reaction temperatures are 375°C and 200°C respectively. The effluent from the third reaction zone passes through a high-pressure separator, a low-fraction separator and a fractionation tower to finally obtain the second sideline oil, wherein the second sideline oil is the obtained environmentally friendly drilling fluid base oil, and the kinematic viscosity at 40°C is 2.57 mm 2 / s, distillation range is 240-280℃, aromatic content is 0.003wt%, yield is 28.5wt%, and paraffin content is 53wt%.

[0048] Embodiment 3:

[0049] Vacuum wax oil and atmospheric distillate oil are mixed with hydrogen, wherein the ratio of vacuum wax oil to atmospheric distillate oil is 1:0.3 (mass ratio), and the mixture of hydrogen and oil enters the first reaction zone. The catalyst is a traditional non-precious metal hydrorefining catalyst and a hydrocracking catalyst, Ni-Mo-P / Al2O3 and Ni-W / USY-Al2O3, and the volume ratio of the refining catalyst to the cracking catalyst is 1:0.2; the reaction system pressure is 18Mpa, based on the total oil intake, the hydrogen-oil ratio (v / v) is 1500, and the total volume space velocity is 0.75h -1 The average reaction temperature of the first reaction zone is 390°C. The product of the first reaction zone passes through the high-pressure separator, the low-pressure separator and the fractionation tower in turn to obtain the first bottom oil, the first side-line oil and the first top oil. The hydrogen and the first bottom oil all enter the second reaction zone and the third reaction zone. The catalysts of the second reaction zone and the third reaction zone are Pt / ZSM-48 catalyst and Pt-Pd / SiO2-Al2O3 catalyst respectively. The space velocity of the second reaction zone and the third reaction zone is 0.75h-1 respectively. -1 and 1.0h -1 , the hydrogen-to-oil ratio is 600:1, and the reaction temperatures are 365°C and 220°C respectively. The effluent from the third reaction zone passes through a high-pressure separator, a low-fraction separator and a fractionation tower to finally obtain the second sideline oil, wherein the second sideline oil can be divided into two fractions, wherein the kinematic viscosity of fraction 1 at 40°C is 1.9 mm 2 / s, distillation range 200-235℃, aromatic content 0.001wt%, yield 13wt%, kinematic viscosity of fraction 2 at 40℃ 2.57mm 2 / s, distillation range is 240-280℃, aromatic content is 0.003wt%, yield is 15wt%, and paraffin content is 53wt%.

[0050] Embodiment 4:

[0051] Vacuum wax oil and atmospheric distillate oil are mixed with hydrogen, wherein the ratio of vacuum wax oil to atmospheric distillate oil is 1:0.2 (mass ratio). The mixture of hydrogen and oil enters the first reaction zone. The catalyst is a traditional non-precious metal hydrorefining catalyst Ni-Mo-P / Al2O3 and Ni-W / USY-Al2O3 hydrocracking catalyst. The volume ratio of the refining catalyst to the cracking catalyst is 10:1. The pressure of the reaction system is 18Mpa. Based on the total oil intake, the hydrogen-oil ratio (v / v) is 1500, and the total volume space velocity is 0.75h -1 The average reaction temperature of the first reaction zone is 380°C. The product of the first reaction zone passes through the high-pressure separator, the low-pressure separator and the fractionation tower in turn to obtain the first bottom oil, the first side line oil and the first top oil. The distillation range of the first side line oil is 240-280°C, 2.65mm 2 / s, aromatic content 0.2wt%, yield 19wt%, paraffin content 65wt%. Hydrogen and the first bottom oil>280℃ fraction all enter the second reaction zone and the third reaction zone. The catalysts in the second reaction zone and the third reaction zone are Pt / SAPO-11 catalyst and Pt-Pd / SiO2-Al2O3 catalyst respectively. The space velocity in the second reaction zone and the third reaction zone is 0.8h -1 and 1.2h -1 , the hydrogen-to-oil ratio is 600:1, and the reaction temperatures are 370°C and 230°C respectively. The effluent from the third reaction zone passes through a high-pressure separator, a low-fraction separator and a fractionation tower to finally obtain the second sideline oil, wherein the second sideline oil is the obtained environmentally friendly drilling fluid base oil, and the kinematic viscosity at 40°C is 2.75mm 2 / s, distillation range is 240-280℃, aromatic content is 0.003wt%, yield is 8wt%, and paraffin content is 35wt%.

[0052] Comparative Example 2:

[0053] Vacuum wax oil and atmospheric distillate oil are mixed with hydrogen, wherein the ratio of vacuum wax oil to atmospheric distillate oil is 1:0.2 (mass ratio), and the mixture of hydrogen and oil enters the first reaction zone. The catalyst is a traditional non-precious metal hydrorefining catalyst and a hydrocracking catalyst, Ni-Mo-P / Al2O3 and Ni-W / USY-Al2O3, and the volume ratio of the refining catalyst to the cracking catalyst is 1:0.1; the reaction system pressure is 8Mpa, based on the total oil intake, the hydrogen-to-oil ratio (v / v) is 1500, and the total volume space velocity is 0.75h -1 The average reaction temperature of the first reaction zone is 380°C. The product of the first reaction zone passes through a high-pressure separator, a low-pressure separator and a fractionation tower in sequence to obtain the first bottom oil, the first sideline oil and the first top oil. The distillation range of the first sideline oil is 240-280°C. The kinematic viscosity at 40°C is 2.85mm 2 / s, distillation range is 240-280℃, aromatic content is 4.3wt%, yield is 19wt%, paraffin content is 45wt%.

[0054] Comparative Example 3:

[0055] Vacuum wax oil and atmospheric distillate oil are mixed with hydrogen, wherein the ratio of vacuum wax oil to atmospheric distillate oil is 1:0.2 (mass ratio), the catalyst is a traditional non-precious metal hydrorefining catalyst and a hydrocracking catalyst, Ni-Mo-P / Al2O3 and Ni-W / USY-Al2O3, and the volume ratio of the refining catalyst to the cracking catalyst is 1:0.1; the reaction system pressure is 15Mpa, based on the total oil intake, the hydrogen-oil ratio (v / v) is 1500, and the total volume space velocity is 0.75h -1The average reaction temperature of the first reaction zone is 380°C. The product of the first reaction zone passes through a high-pressure separator, a low-pressure separator and a fractionation tower in sequence to obtain the first bottom oil, the first sideline oil and the first top oil. The distillation range of the first sideline oil is 240-280°C. The kinematic viscosity at 40°C is 2.80mm 2 / s, distillation range is 240-280℃, aromatic content is 1.0wt%, yield is 19wt%, paraffin content is 42wt%.

[0056] Embodiment 5:

[0057] Vacuum wax oil and atmospheric distillate oil are mixed with hydrogen, wherein the ratio of vacuum wax oil to atmospheric distillate oil is 1:0.2 (mass ratio). The mixture of hydrogen and oil enters the first reaction zone. The catalyst is a traditional non-precious metal hydrorefining catalyst Ni-Mo-P / Al2O3 and Ni-W / USY-Al2O3 hydrocracking catalyst. The volume ratio of the refining catalyst and the cracking catalyst is 1:1. The pressure of the reaction system is 18Mpa. Based on the total oil intake, the hydrogen-oil ratio (v / v) is 1500, and the total volume space velocity is 0.75h -1 The average reaction temperature of the first reaction zone is 380°C. The product of the first reaction zone passes through the high-pressure separator, the low-pressure separator and the fractionation tower in turn to obtain the first bottom oil, the first side line oil and the first top oil. The distillation range of the first side line oil is 240-280°C, 2.60mm 2 / s, aromatic content 0.3wt%, yield 25wt%, paraffin content 60wt%. Hydrogen and the first bottom oil>280℃ fraction all enter the second reaction zone and the third reaction zone. The catalysts in the second reaction zone and the third reaction zone are Pt / ZSM-22 catalyst and Pt-Pd / Al2O3 catalyst respectively. The space velocity in the second reaction zone and the third reaction zone is 0.8h -1 and 1.2h -1 , the hydrogen-to-oil ratio is 600:1, and the reaction temperatures are 370°C and 230°C respectively. The effluent from the third reaction zone passes through a high-pressure separator, a low-fraction separator and a fractionation tower to finally obtain the second sideline oil, wherein the second sideline oil is the obtained environmentally friendly drilling fluid base oil, and the kinematic viscosity at 40°C is 2.75mm 2 / s, distillation range is 240-280℃, aromatic content is 0.003wt%, yield is 7wt%, and paraffin content is 35wt%.

[0058] Embodiment 6:

[0059] The first sideline oil and the second sideline oil obtained in Example 4 can be blended at a mass ratio of 1:1 to obtain a kinematic viscosity of 2.7 mm at 40°C. 2 / s, a distillation range of 240-280°C, an aromatic content of 0.115wt%, and an alkane content of 50wt% are environmentally friendly drilling fluid base oil.

[0060] Embodiment 7:

[0061] Vacuum wax oil and atmospheric distillate oil are mixed with hydrogen, wherein the ratio of vacuum wax oil to atmospheric distillate oil is 1:0.6 (mass ratio). The mixture of hydrogen and oil enters the first reaction zone. The catalyst is a traditional non-precious metal hydrorefining catalyst Ni-Mo-P / Al2O3. The reaction system pressure is 12Mpa. Based on the total oil intake, the hydrogen-oil ratio (v / v) is 1500, and the total volume space velocity is 2.0h -1 The average reaction temperature of the first reaction zone is 365°C. The product of the first reaction zone passes through a high-pressure separator, a low-pressure separator and a fractionation tower in sequence to obtain the first tower bottom oil, the first side-line oil and the first tower top oil, wherein the initial boiling point of the first tower bottom oil is ≮180°C. The hydrogen and the first tower bottom oil all enter the second reaction zone and the third reaction zone. The catalysts of the second reaction zone and the third reaction zone are Pt / ZSM-23 hydroisomerization catalyst and Pt-Pd / SiO2-Al2O3 catalyst, respectively. The space velocity of the second reaction zone and the third reaction zone is 2.0h-1, respectively. -1 and 1.5h -1 , the hydrogen-to-oil ratio is 600:1, and the reaction temperatures are 385°C and 200°C respectively. The effluent from the third reaction zone passes through a high-pressure separator, a low-fraction separator and a fractionation tower to finally obtain the second sideline oil, wherein the second sideline oil is the obtained environmentally friendly drilling fluid base oil, with a kinematic viscosity of 2.7 mm at 40°C. 2 / s, distillation range is 240-280℃, aromatic content is 0.002wt%, yield is 45wt%, and paraffin content is 55wt%.

[0062] Embodiment 8:

[0063] Vacuum wax oil and atmospheric distillate oil are mixed with hydrogen, wherein the ratio of vacuum wax oil to atmospheric distillate oil is 1:0.6 (mass ratio). The mixture of hydrogen and oil enters the first reaction zone. The catalyst is a traditional non-precious metal hydrorefining catalyst Ni-Mo-P / Al2O3. The reaction system pressure is 12Mpa. Based on the total oil intake, the hydrogen-oil ratio (v / v) is 1500, and the total volume space velocity is 2.0h -1The average reaction temperature of the first reaction zone is 365°C. The product of the first reaction zone passes through a high-pressure separator, a low-pressure separator and a fractionation tower in sequence to obtain the first tower bottom oil, the first side-line oil and the first tower top oil, wherein the initial boiling point of the first tower bottom oil is ≮180°C. The hydrogen and the first tower bottom oil all enter the second reaction zone and the third reaction zone. The catalysts of the second reaction zone and the third reaction zone are Pt / ZSM-23 hydroisomerization catalyst and Pt-Pd / SiO2-Al2O3 catalyst, respectively. The space velocity of the second reaction zone and the third reaction zone is 2.0h-1, respectively. -1 and 1.5h -1 , the hydrogen-oil ratio is 600:1, and the reaction temperatures are 385°C and 200°C respectively. The effluent from the third reaction zone passes through a high-pressure separator, a low-fraction separator and a fractionation tower to finally obtain the second sideline oil, wherein the second sideline oil is the obtained environmentally friendly drilling fluid base oil, the initial boiling point of the second sideline oil is ≮200°C, and the kinematic viscosity at 40°C is 2.45mm 2 / s, distillation range is 200-280℃, aromatic content is 0.002wt%, yield is 49wt%, and paraffin content is 55wt%.

[0064] Embodiment 9:

[0065] The environmentally friendly mineral-based oil-based drilling fluid base oil obtained in Example 1 was used as the base oil for drilling fluid compatibility research. The drilling fluid formula was: 240mL base oil + 8wt% shear-enhancing emulsifier + 2.5wt% organic soil + 60mL 20wt% CaCl2 aqueous solution + 2wt% CaO + 4wt% filtrate reducer (12g) + 650g barite. The apparent viscosity measured at 65°C was 45mPa·s, the plastic viscosity was 37mPa·s, and the dynamic shear force was 8Pa. The apparent viscosity after hot rolling at 180°C was 41mPa·s, the plastic viscosity was 34mPa·s, and the dynamic shear force was 7.2Pa.

[0066] It is not difficult to find from the above examples and comparative examples that the environmentally friendly oil-based drilling fluid base oil developed by the present invention has a lower aromatic content and a controllable composition, and is more suitable for the formulation of the oil-based drilling fluid base oil formula.

[0067] Of course, the present invention may have many other embodiments and variations thereof. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and variations based on the present invention, but these corresponding changes and variations should all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a base oil for an environmentally friendly oil-based drilling fluid, characterized in that: The steps include: a) the mixture of vacuum wax oil and atmospheric distillate oil is mixed with hydrogen and then enters the first reaction zone for reaction; b) the product flowing out of the first reaction zone passes through a high pressure separator, a low pressure separator and a fractionation tower in sequence to obtain a first bottom oil, a first side line oil and a first top oil; c) the first tower bottom oil and hydrogen are preheated and enter the second reaction zone and the third reaction zone for reaction; d) the effluent from the third reaction zone passes through a high-pressure separator, a low-fraction separator and a fractionation tower to obtain a second sideline oil, a second tower top oil and a second tower bottom oil; e) Either one of the first sideline oil and the second sideline oil or a mixture of the two oils is an environmentally friendly base oil for oil-based drilling fluid.

2. The preparation method according to claim 1, characterized in that: The atmospheric distillate oil has a distillation range of 180-360° C. and a paraffin content of 10-60 wt %.

3. The preparation method according to claim 1, characterized in that: The initial distillation point of the vacuum wax oil is ≮360°C, the final distillation point is ≯550°C, and the distillation range is 360-550°C.

4. The preparation method according to claim 1, characterized in that: The distillation range of the vacuum wax oil is 400-470°C or 470-550°C.

5. The preparation method according to claim 1, characterized in that: The catalyst in the first reaction zone is a graded combination of a non-precious metal hydrofining catalyst and a non-precious metal hydrocracking catalyst, and the graded ratio of the hydrofining catalyst to the hydrocracking catalyst is 1:(0-1).

6. The preparation method according to claim 5, characterized in that: The active metal components in the non-precious metal hydrorefining catalyst are Group VIII metals and Group VIB metals; the Group VIII metals are Co and / or Ni; the Group VIB metals are W and / or Mo, and the carrier is alumina or alumina modified by phosphorus and silicon.

7. The preparation method according to claim 5, characterized in that: The active metal components in the non-precious metal hydrocracking catalyst are Group VIII metals and Group VIB metals; the Group VIII metals are Co and / or Ni; the Group VIB metals are W and / or Mo, and the carrier is a carrier formed by a composite of alumina and Y-type molecular sieve and / or amorphous silicon aluminum.

8. The preparation method according to claim 1, characterized in that: The catalyst in the second reaction zone is a precious metal hydroisomerization catalyst, wherein the precious metal is mainly one or two of Pt and Pd, and the acidic component is at least one of ZSM-48, ZSM-23, ZSM-22 and SAPO-11.

9. The preparation method according to claim 1, characterized in that: The catalyst in the third reaction zone is an aromatic hydrocarbon deep saturation catalyst, wherein the metal component is one or a combination of Pt and Pd, and the carrier is one or two of Al2O3 and SiO2-Al2O3.

10. The preparation method according to claim 1, characterized in that: The base oil for the environmentally friendly drilling fluid is the first sideline oil, or the second sideline oil, or a mixture of the first sideline oil and the second sideline oil, and the ratio of the two is (0-1):

1.

11. The preparation method according to claim 1, characterized in that: The reaction pressure of the first reaction zone is 10-20 MPa, the temperature is 360-400°C, and the space velocity is 0.5-2.0 h -1 .

12. The preparation method according to claim 1, characterized in that: The reaction pressure of the second reaction zone is 10-20 MPa, the temperature is 350-390°C, and the space velocity is 0.5-2.0 h -1 .

13. The preparation method according to claim 1, characterized in that: The reaction pressure of the third reaction zone is 10-20 MPa, the temperature is 180-240°C, and the space velocity is 0.5-1.5 h -1 .

14. The preparation method according to claim 1, characterized in that: In step a), the mass ratio of vacuum wax oil to atmospheric distillate oil is 1:(0-1).

15. An environmentally friendly base oil for drilling fluid, characterized in that: Aromatic content 0.002~0.2wt%, kinematic viscosity 1.8-3.0mm at 40℃ 2 / s, the initial distillation point is not less than 190°C, the final distillation point is not higher than 360°C, and the paraffin content is adjustable from 30 to 70wt%.

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