阅读说明：本技术 一种助剂协同重油热改质方法 (Thermal modification method for heavy oil by aid of aid ) 是由 王丽涛 刘贺 刘银东 王宗贤 韩爽 郭爱军 许倩 陈坤 卢竟蔓 沐宝泉 鄂宇恒 于 2019-03-28 设计创作，主要内容包括：本发明涉及一种重油热改质方法,特别是涉及一种助剂协同重油热改质方法,能够实现劣质重油的高效降黏、改善产物稳定性。具体方法是将劣质重油与助剂充分混合,而后进行热改质并对改质油性质进行评价。该助剂由具有供氢特性的工业供氢馏分、具有两亲性的表面活性物质(有机酯类、有机酸类、有机醇类化合物)混合而成,能够协同抑制重油热改质生焦、改善稳定性、提高降黏效率。(The invention relates to a thermal modification method of heavy oil, in particular to a thermal modification method of heavy oil by using an auxiliary agent in cooperation, which can realize high-efficiency viscosity reduction of inferior heavy oil and improve product stability. The specific method comprises the steps of fully mixing inferior heavy oil and an auxiliary agent, then carrying out thermal upgrading and evaluating the property of the upgraded oil. The auxiliary agent is formed by mixing industrial hydrogen-donating fractions with hydrogen-donating characteristics and amphiphilic surface active substances (organic esters, organic acids and organic alcohol compounds), and can synergistically inhibit heavy oil thermal modification coking, improve stability and improve viscosity reduction efficiency.)

1. An auxiliary agent-cooperated heavy oil thermal modification method comprises the following steps:

(1) fully stirring a hydrogen donor and an amphiphilic surface active substance at the temperature of 60-130 ℃ for 0.5-3 h to obtain a mixed assistant;

wherein, based on the raw heavy oil, the dosage of the hydrogen donor accounts for 5-40 wt% of the raw heavy oil, and the ratio of the amphiphilic surface active substance to the raw heavy oil is 10-500 mug/g;

(2) heating the raw material heavy oil until the raw material heavy oil is in a flowing state, adding the mixed auxiliary agent, fully stirring and mixing for 0.5-3 h at the temperature of 80-200 ℃, and then adding the mixture into a high-pressure reactor;

(3) and heating the high-pressure reactor to 380-460 ℃ and maintaining the reaction for 5-80 min, wherein the reaction pressure is 2-15 MPa, and obtaining the modified produced oil after the reaction is finished.

2. The process for thermally upgrading thermally enhanced heavy oil with assistant according to claim 1, wherein the hydrogen donor is industrial distillate oil rich in aromatic naphthenic structure.

3. The method for thermally upgrading auxiliary-synergistic heavy oil according to claim 1, wherein the hydrogen donor is straight-run industrial distillate oil with a distillation range of 200-450 ℃.

4. The thermal upgrading method of adjuvant-heavy oil according to claim 1, wherein the hydrogen donor is used in an amount of 5-40 wt% based on the raw heavy oil.

5. The assistant-heavy oil thermal upgrading method according to claim 1, wherein the amphiphilic surface active substance is one or more of organic esters, organic acids and organic alcohol compounds.

6. The method for thermally upgrading heavy oil by using the additive in cooperation with the heavy oil of claim 5, wherein the organic esters are one or more of diethyl oxalate, diethyl oxalate and methyl propionate;

the organic acid is one or more of acetic acid, oleic acid, benzoic acid, dodecyl benzene sulfonic acid and oxalic acid;

the organic alcohol refers to one or more of isopropanol, cyclohexanol and ethylene glycol.

7. The assistant-synergistic heavy oil thermal upgrading method as claimed in claim 1, wherein the ratio of the amphiphilic surface active substance to the raw heavy oil is 100-300 μ g/g.

8. The assistant-synergistic heavy oil thermal upgrading method as claimed in claim 1, wherein in the step (1), the mixing temperature of the hydrogen donor and the amphiphilic surface active substance is 80-120 ℃, and the mixing time is 0.5-2.5 h.

9. The assistant-cooperated heavy oil thermal upgrading method according to claim 1, wherein in the step (2), the mixing temperature of the inferior heavy oil and the mixed assistant is 100 to 150 ℃, and the mixing time is 0.5 to 2.5 hours.

10. The assistant-synergistic heavy oil thermal upgrading method as claimed in claim 1, wherein in the step (3), the reaction temperature of the raw material heavy oil thermal upgrading is 390-430 ℃, the reaction time is 5-60min, and the reaction pressure is 4.0-10 MPa.

Technical Field

The invention relates to a method for enhancing viscosity reduction and modification of inferior heavy oil by adopting an auxiliary agent, in particular to a modification method for enhancing the viscosity reduction rate of the inferior heavy oil and improving the stability of the produced oil by adopting a composite auxiliary agent with hydrogen supply capability and peptization stability.

Background

The recoverable reserves of light crude oil resources with better properties in the world are in a descending trend, while the reserves of heavy inferior heavy oil resources are huge, and although the oil source resources called as unconventional oil resources have larger recovery and processing potentials, the transportation and subsequent processing processes face huge challenges due to the characteristics of higher viscosity, lower API (American petroleum institute) degrees and high contents of impurities and non-hydrocarbons. At present, the main technologies for heavy oil modification at home and abroad include a dilution method, a solvent deasphalting method, a visbreaking process, a hydrogen supply thermal cracking process, an HTL modification technology and a hydrothermal catalytic cracking process. The hydrogen supplying visbreaking process is one method of lowering viscosity and improving quality of heavy oil and has hydrogen supplying component added based on conventional visbreaking process, and the active hydrogen released from the liquid hydrogen supplying agent is combined with the free radical produced in the thermal cracking of residual oil to produce stable molecule and inhibit the condensation of free radical. The most basic target of heavy oil transportation needs 50 ℃ kinematic viscosity to reach the relevant requirement of 380# fuel oil, meanwhile, the stability is kept above the second grade of the spot test grade, and on the basis, a higher target is pursued to obtain high-quality modified oil with high API (American Petroleum institute) degree. The hydrogen supply visbreaking process can meet the basic requirements of pipe transportation and shipping, but the upgrading visbreaking efficiency and the upgrading oil quality need to be improved. The literature reports about viscosity reduction and modification of inferior heavy oil and oil sand asphalt added with bifunctional auxiliary agents for hydrogen supply and stable dispersion are not found yet.

CN102504862A discloses a method for heavy oil hydrogen-donating thermal cracking, wherein a hydrogen-donating agent is added into a conventional visbreaking raw material to be used as a mixed feed for hydrogen-donating thermal cracking reaction, and hydrogen-donating thermal cracking generated oil is blended with gasoline and diesel oil fractions obtained in atmospheric and vacuum distillation to obtain hydrogen-donating thermal cracking modified oil; the hydrogen supply thermal cracking reaction temperature is 380-510 ℃, the reaction residence time is 0.1-180 min, and the reaction pressure is 0.1-4.0 MPa; the hydrogen donor is straight-run wax oil or a straight-run wax oil narrow fraction; the distillation range is between 350 and 500 ℃; the hydrogen distribution is: HA accounts for 18.0-50.0% of the total amount of hydrogen in the hydrogen donor, and H alpha accounts for 18.0-50.0% of the total amount of hydrogen in the hydrogen donor; the adding amount of the hydrogen donor is 0.1 to 50 percent of the weight of the visbreaking raw material; the method can obviously reduce the viscosity of the visbroken product and improve the stability of the product. However, the method only adds suitable hydrogen donor fractions for thermal modification, has certain improvement effect on conventional thermal viscosity-reducing modification, and needs to further improve the improvement degree, and the hydrogen donor related to the patent is shown as a formula (1).

On the one hand, the research on the catalytic modification viscosity reduction reaction under the action of a hydrogen donor is studied in the research on the underground modification viscosity reduction mechanism and application research of thickened oil (Zhao Fa Jun. Daqing Petroleum institute, 2008), wherein tetrahydronaphthalene, dihydroanthracene, formic acid and methyl formate are selected as the hydrogen donor, and formic acid is preferably selected as a hydrogen donor, and the addition amount of the formic acid is 7 wt%. It discloses the hydrogen donor in modifying and reducing viscosityThe medium action mechanism is mainly to provide hydrogen which is easy to be abstracted, kill partial free radicals, reduce the concentration of the free radicals in the system and inhibit the condensation coking reaction. On the other hand, the document also researches the modification and viscosity reduction reaction under the action of an auxiliary agent, the disclosed auxiliary agent is ammonium carbonate, ammonium bicarbonate, urea and the like, the urea is preferably selected as the modification and viscosity reduction reaction auxiliary agent, and the auxiliary agent is CO generated by decomposition₂Mixed phase displacement is formed so as to enhance the oil extraction effect, and the structure of the thick oil is not changed after the mixed phase displacement is added.

In the literature, "catalytic viscosity reducer with dual structure of hydrogen donor and catalytic center and viscosity reduction mechanism thereof" (li jian, china geological university, 2014), a method for improving recovery ratio by utilizing hydrogen donor and auxiliary agent to cooperate thick oil thermal viscosity reduction modification is reported, the modification temperature is below 300 ℃, and the modification time is more than 12 hours. Specifically, the document discloses a series of novel heavy oil hydrothermal cracking catalysis viscosity reducer (including single metal center type and double metal center type) with a hydrogen donor and catalysis center dual structure, so that the viscosity reducer has more excellent low-temperature cracking viscosity reduction effect, and simultaneously, the cost is reduced and the viscosity reducer is convenient to use on site. Research results show that the heavy components of the heavy oil are subjected to depolymerization, bridge bond breaking, hydrogenation impurity removal, ring opening, isomerization, decarboxylation and other effects in the hydrothermal cracking catalysis viscosity reduction process; the content of heavy components after cracking is reduced, the average molecular structure is reduced, the association structure is looser, the intermolecular cohesion is weakened, and finally the viscosity of the thickened oil is greatly reduced. The catalytic viscosity reducer has a small-molecular hydrogen donor structure, so that the catalytic viscosity reducer can enter an association structure of a heavy component more easily, and can attack C-R (R ═ S, N, O) bonds on special positions more easily. These bonds react with surrounding high temperature water molecules under the action of the catalytic metal center, resulting in the removal of heteroatoms.

An assistant disclosed in the research on a thickened oil steam injection chemical assisted in-layer catalytic cracking agent system (treviao, university of chinese petroleum, 2010) is a JA-1 type surfactant, but no synergetic oil extraction by using a hydrogen donor and the assistant is proposed.

CN201410681492 discloses an underground hydrogenation catalytic upgrading mining method for heavy oil and ultra heavy oil reservoirs, which comprises: deploying an injection-production well pattern; a high-energy molten salt heating pipe is arranged in the injection well, and a catalyst injection pipe and the high-energy molten salt heating pipe are arranged in the production well; continuously heating the injection well and the production well through high-energy molten salt heating pipes respectively; injecting a catalyst fluid into the catalyst injection pipe during injection of the medium into the injection well; the injection speed of the catalyst fluid is 1-100kg of catalyst fluid per 1 ton of crude oil produced; wherein the catalyst fluid comprises 1-50 wt% of catalyst, 0.01-10 wt% of hydrogen donor or deuterium donor, 0.01-5 wt% of coking inhibitor, 0-1 wt% of aqueous phase suspending agent or dispersing auxiliary agent, and the balance of supercritical fluid. The coking inhibitor related in the invention is one or a combination of more of a sulfur-containing compound, a phosphorus-containing compound, an organic sulfur-phosphorus compound, a boron-containing compound, an alkali metal salt and an alkaline earth metal salt, an organic polysiloxane compound, a rare earth metal and a rare earth metal compound.

CN201510882793 discloses an injection method of heavy oil underground modified viscosity-reducing nano catalyst, which comprises injecting a precursor microemulsion of the heavy oil modified viscosity-reducing nano catalyst into a formation, wherein the precursor microemulsion is a water-in-oil microemulsion, and the outer phase is a hydrogen donor with oleophylic property, so that the precursor microemulsion can spontaneously enter an oil phase and uniformly disperse after being injected into the formation, and when the temperature of the inner phase is increased to 160-200 ℃, a nanocrystallization reaction can occur, and the decomposition temperature is lower than the heavy oil modification temperature, so that no additional energy needs to be injected. The related surfactant is one or more of dioctyl sodium sulfosuccinate (AOT), Span-20, Span-40, Span-60, Span-80, Span-85 and the like; it is noted that the hydrogen donors disclosed in patent CN201410681492 and patent CN201510882793 are all model compounds such as tetrahydronaphthalene and dihydroanthracene, the practical application of which is limited by the expensive price and cost, and these methods are only used in underground oil recovery processes.

U.S. Pat. No. 3,7392846 uses additives containing one or more silicates to treat heavy oils to reduce the viscosity of the heavy oil; U.S. patent No. USP7665523 uses a treatment fluid containing an additive styrene-acrylate polymer to react with heavy oil to partially reduce the viscosity of the heavy oil and thereby reduce its adhesion, both methods using additives in the treatment of heavy oil and having a positive effect on heavy oil adhesion reduction, but only partially reducing the adhesion.

Patent 103173240A discloses a visbreaking treatment improver containing an organic oxygen functional group, and a co-visbreaking process of coal tar or biomass oil and heavy oil containing the organic oxygen functional group. The organoxy functional group is, for example, carbonyl [ -C (O) -activated](ii) a Ether group [ R-O-R'](ii) a Aldehyde group [ -CHO](ii) a Keto [ R-C (O) -R'](ii) a Quinonyl [ C₆H₄O₂](ii) a Furyl [ C)₄H₄O]And/or any furan and quinone substituent, wherein R and R' are each independently alkyl or other organic group. Illustrative, but non-limiting examples of specifically contemplated modifiers are 3-hydroxy-4-methoxyphenol, furan, quinone, 4-hydroxy-3-methoxyphenol, 4-hydroxy-3-methoxyphenylacetic acid, dibenzofuran, 2-methoxy-4-methylphenol, 3, 4-dimethoxybenzoic acid, 2-methoxyphenol, acetaldehyde, 4-ethyl-2-methoxyphenol, 1, 4-dimethoxy-2-methylphenol, acetic acid, 2-methoxy-6- (1-propenyl) phenol, 3, 4-dimethoxyphenol, 2-methoxy-5- (1-propenyl) phenol, 2, 6-dimethoxyphenol, m, 2-methoxy-4- (1-propenyl) phenol, 4-hydroxy-3-methoxybenzoic acid, benzofuran, 2, 5-dimethoxybenzyl alcohol, (1, 1-dimethylethyl) -1, 2-benzenediol, C1-C2 substituted benzofuran, methanol, 1- (4-hydroxy-3-methoxyphenyl) ethanone, hydroxyacetone, 3, 4-dimethoxyphenol, 3, 4-dimethoxybenzoic acid, 2-methoxy-4-ethylphenol, polysubstituted benzofuran, ethylene glycol, 2, 6-dimethoxy-4- (2-propenyl) -phenol, 2-methoxy-dibenzofuran, 2, 3-butanedione, 1-hydroxy-acetaldehyde, 2-hydroxy-3-methoxybenzoic acid, 2-hydroxy-ethyl ketone, 2-hydroxy-3-methyl-ethyl ketone, 2-hydroxy-ethyl ketone, 2-methyl, Tartronic acid, and any substituents and/or mixtures thereof. From the viewpoint of the amount of the improver, even if the oxygen content is 50%, the minimum addition amount is as high as 2000. mu.g/g. Meanwhile, the coal tar or the biomass oil has high thermal instability, the mixing compatibility of the coal tar or the biomass oil with heavy oil, the self thermal reaction activity and the like can influence the viscosity reduction efficiency, particularly the stability of the modified oil, and the patent does not mention the modified oilIn the qualitative case. Obviously, the thermal cracking of heavy oil by hydrogen and the viscosity reduction of single additive have certain limitation problems.

Disclosure of Invention

The invention aims to develop a method for modifying inferior heavy oil by using an auxiliary agent in cooperation with the inferior heavy oil aiming at the characteristics of easy coking and poor stability of the modified oil in the modification process of the inferior heavy oil, and has important significance for improving the modification viscosity reduction rate and ensuring the excellent stability of the modified oil.

In order to achieve the purpose, the invention provides the following technical scheme:

the assistant-heavy oil thermal upgrading method comprises the following steps:

(1) fully stirring a hydrogen donor and an amphiphilic surface active substance at the temperature of 60-130 ℃ for 0.5-3 h to obtain a mixed assistant;

wherein, based on the raw heavy oil, the dosage of the hydrogen donor accounts for 5-40 wt% of the raw heavy oil, and the ratio of the amphiphilic surface active substance to the raw heavy oil is 10-500 mug/g;

(2) heating the raw material heavy oil until the raw material heavy oil is in a flowing state, adding the mixed auxiliary agent, fully stirring and mixing for 0.5-3 h at the temperature of 80-200 ℃, and then adding the mixture into a high-pressure reactor;

(3) and heating the high-pressure reactor to 380-460 ℃ and maintaining the reaction for 5-80 min, wherein the reaction pressure is 2-15 MPa, and obtaining the modified produced oil after the reaction is finished.

The invention provides a method for thermally modifying heavy oil by using an assistant in cooperation, wherein a hydrogen donor is industrial distillate oil rich in aromatic naphthenic structure.

The assistant is cooperated with the heavy oil thermal modification method, wherein the hydrogen donor is straight-run industrial distillate oil with the distillation range of 200-450 ℃.

The assistant and heavy oil thermal upgrading method provided by the invention is characterized in that the hydrogen donor accounts for 5-40 wt% of the raw heavy oil on the basis of the raw heavy oil.

The assistant is cooperated with the heavy oil thermal modification method, wherein the amphiphilic surface active substance is one or more of organic esters, organic acids and organic alcohol compounds.

The invention provides a method for thermally modifying heavy oil by using an auxiliary agent in cooperation, wherein organic esters refer to one or more of diethyl oxalate, diethyl oxalate and methyl propionate;

the organic acid is one or more of acetic acid, oleic acid, benzoic acid, dodecyl benzene sulfonic acid and oxalic acid;

the organic alcohol refers to one or more of isopropanol, cyclohexanol and ethylene glycol.

The assistant and heavy oil thermal modification method provided by the invention is characterized in that the ratio of the amphiphilic surface active substance to the raw material heavy oil is 100-300 mu g/g.

The assistant and heavy oil thermal modification method provided by the invention is characterized in that in the step (1), the mixing temperature of the hydrogen supply agent and the amphiphilic surface active substance is 80-120 ℃, and the mixing time is 0.5-2.5 h.

The assistant and heavy oil thermal modification method provided by the invention is characterized in that in the step (2), the mixing temperature of the inferior heavy oil and the mixed assistant is 100-150 ℃, and the mixing time is 0.5-2.5 h.

The assistant-heavy oil thermal upgrading method provided by the invention is characterized in that in the step (3), the reaction temperature of the raw material heavy oil thermal upgrading is 390-430 ℃, the reaction time is 5-60min, and the reaction pressure is 4.0-10 MPa.

The present invention can be described in detail as follows:

an auxiliary agent-cooperated heavy oil thermal modification method comprises the following specific steps:

(1) fully stirring a hydrogen donor and an amphiphilic surface active substance at the temperature of 60-130 ℃ for 0.5-3 h to obtain a mixed assistant; wherein the hydrogen donor is 5-40 wt% of the raw heavy oil, and the amphiphilic surface active substance is 10-500 μ g/g of the raw heavy oil;

(2) heating inferior heavy oil until the inferior heavy oil is in a flowing state, adding a mixed auxiliary agent, and fully stirring and mixing for 0.5-3 h at the temperature of 80-200 ℃; adding it to a high pressure reactor;

(3) heating to 380-460 ℃ and maintaining the reaction for 5-80 min, wherein the reaction pressure is 2-15 MPa; after the reaction, the modified product oil is obtained.

The hydrogen donor of the invention can be a commonly used hydrogen donor in the technical field, mainly plays a role in releasing active hydrogen in a heating process, inhibiting macromolecular free radical mutual condensation of heavy oil cracking, and delaying coking, can be hydrogenated aromatic hydrocarbon model compounds such as tetrahydronaphthalene, dihydroanthracene and the like, and can also be a complex hydrocarbon mixture rich in aromatic and naphthenic ring structures, and the invention is not particularly limited.

In the invention, the preferable hydrogen donor is industrial distillate oil rich in aromatic naphthenic ring structure, and the distillation range is preferably 200-450 ℃. The hydrogen donor available in the invention has the characteristics of wide source, easy acquisition and low cost.

The ratio of the hydrogen donor to the raw heavy oil is not particularly required in the present invention, and may be adjusted according to the type of the raw heavy oil and the type of the hydrogen donor, and the preferable ratio is 5 to 25 wt%.

The amphiphilic surface active substance in the invention is of a type including but not limited to organic acids, organic esters and organic alcohol compounds, and has the efficiency of peptizing and stabilizing a heavy oil thermal reaction system, for example, the organic acids include but not limited to acetic acid, oleic acid, benzoic acid, dodecylbenzene sulfonic acid, oxalic acid and the like, and can be one or more; organic esters include, but are not limited to, diethyl oxalate, methyl propionate, and the like, and may be one or more; the organic alcohols include, but are not limited to, isopropanol, cyclohexanol, ethylene glycol, and the like, and may be one or more.

In the present invention, the ratio of the amphiphilic surface active substance to the amount of the raw heavy oil is not particularly limited, and the preferable ratio is 100 to 300 μ g/g.

Preferably, the mixing temperature of the hydrogen donor and the surface active substance is 80-120 ℃, and the mixing time is 0.5-2.5 h.

Preferably, the mixing temperature of the inferior heavy oil and the mixing auxiliary agent is 100-150 ℃, and the mixing time is 0.5-2.5 h.

Preferably, before the reaction, the air in the reactor is purged by inert gas, and the inert gas is filled for protection.

Preferably, the reaction temperature of the inferior heavy oil thermal upgrading is 390-430 ℃, the reaction time is 5-60min, and the reaction pressure is 4.0-10 MPa.

According to the invention, the auxiliary agent with hydrogen supply capability and peptization stabilization effect is added in the visbreaking and upgrading process of inferior heavy oil and oil sand asphalt, so that the problem of easy coking of a reaction system caused by reduced colloid stability in the reaction process can be relieved to a certain extent, the visbreaking degree of the generated oil can be obviously reduced, the stability of the generated oil is improved, and the requirements of pipe transportation or ship transportation are better met.

The invention has the advantages that the industrial hydrogen donor with the hydrogen supply function and the surface active substance with the peptization and stabilization function are cooperatively utilized to modify the heavy oil, thus delaying the coke formation of the system, improving the viscosity reduction efficiency and the stability of the modified oil, and having important guiding significance for realizing the high-efficiency modification of the heavy oil.

Detailed Description

The following examples illustrate the invention in detail: the present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and process are given, but the scope of the present invention is not limited to the following examples, and the experimental methods without specific conditions noted in the following examples are generally performed according to conventional conditions.

The detection method comprises the following steps:

viscosity at 50 ℃: reference is made to "measurement of kinematic viscosity of dark petroleum products (countercurrent method, GB/T11137)", which is suitable for measuring kinematic viscosity of dark petroleum products, used lubricating oils, crude oils, etc. at 0 ℃ or higher and calculating kinematic viscosity by the measured kinematic viscosity. The kinematic viscosity at 50 ℃ is measured for general crude oil, the kinematic viscosity at 80 ℃ is measured for heavy crude oil, the kinematic viscosity at 20 ℃ is measured for light crude oil, and the kinematic viscosity at 100 ℃ is measured for residual oil, but the kinematic viscosity of asphalt is not suitable for measurement. The main steps are as follows:

1. before measurement, a proper viscometer needs to be selected according to the estimated viscosity and temperature of the test oil, and the flowing time is longer than 200 s. And after the viscometer is selected, substituting the viscometer constant C and the viscosity estimated by the test oil into a formula, and checking whether the time t is more than 200 s.

2. The measurement is carried out by (1) vertically inverting the clean and dry viscometer, immersing the end E (the end of the capillary tube rubber tube) in the test oil, blocking the end G with the thumb, pumping the test oil from the end of the rubber tube fitted over the branch tube F with a rubber ball or a water flow pump until the test oil fills the ball D and flows to the marked line a, and there should be no air bubbles in the test oil and in the tube. And taking out the viscometer, wiping off the test oil stained on the outer wall of the capillary, slightly inclining the viscometer so that the test oil slowly flows into the ball A from the ball D through the capillary by virtue of gravity, and immediately sleeving a pipe orifice E at the upper end of the ball D by using a short rubber pipe with one clamped end after a small amount of sample enters the ball A. Then, the viscometer is placed vertically, a cork is sleeved on the upper end of the tube G so as to clamp the cork by a clamp, and the viscometer is fixed in a constant temperature bath; the viscometer is immersed in a constant temperature bath so that the liquid submerges the entire D-ball. The position of the viscometer capillary was adjusted from two intersecting directions with a vertical line to a vertical state. (2) The mercury position of the thermometer in the thermostatic bath must be at the same level as the capillary midpoint. In order to obtain an accurate indication of the thermometer, it is preferable to use a full immersion type thermometer, and the mercury line is exposed to the liquid surface of the constant temperature bath by only 10 mm. (3) After the specified constant temperature time is reached, the clamp on the short rubber tube is released, so that the test oil automatically flows into the ball A, then flows into the ball C and the ball J from the ball A, the stopwatch is started when the test oil surface just reaches the marking b, and the stopwatch is stopped when the test oil marking C. (4) When the viscosity of a sample of oil is measured by the above method, each test temperature should be tested in parallel. (5) The density of the sample was measured at the same temperature as the viscosity in GB/T1884 and GB/T2540 to 0.001g cm^-3。

3. Computing

(1) The kinematic viscosity of the sample was calculated as follows:

nt＝C·t

in the formula: C-C ball viscometer constant (mm)²·s^-2)；

Flow time of t-test oil in ball C, s.

(2) The dynamic viscosity η t (mPa · s) of the sample is calculated as follows:

ht＝r t·n t

in the formula: ht-kinematic viscosity of test oil at t ℃ in mm²·s^-1；

rt-test oil density at t deg.C, g cm^-3。

Coke rate: determination of toluene insolubles

Spot experiment rating: reference to the "Spot method for determining the stability and compatibility method of heavy Fuel oils (ASTM-D4740)"