CA3056525A1

CA3056525A1 - Process and system for comprehensively treating and upgrading high viscous heavy oil

Info

Publication number: CA3056525A1
Application number: CA3056525A
Authority: CA
Inventors: Yindong Liu; Luhai Wang; Yanmei Zhang; An Ma; Qian Xu; Litao Wang; Yuheng E; Long LIU; Yinghua He; Jingman Lu; Zhimin Yu; Qinling Bi; Shuang HAN; Haoran Zhang; Bo Zhang; Hang YANG
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2018-09-25
Filing date: 2019-09-24
Publication date: 2020-03-25
Anticipated expiration: 2039-09-24
Also published as: CA3056525C; CN110938455A; CN110938455B

Abstract

The invention provide a process and a system for comprehensively treating and upgrading high viscous heavy oil, wherein the process comprises the following steps: the salty aqueous high viscous heavy oil enters a desalination-dehydration unit, and the desalting and dehydration is completed after adding a diluent; the desalted and dehydrated heavy oil containing the diluent obtained enters a fractionation unit for fractionation to separate a light fraction, a medium fraction and a heavy fraction; the heavy fraction enters the mixing section of a phase separation unit to be mixed with a composite phase separation agent, and then the separation of solid-liquid two phases is completed in the sedimentation-phase separation section of the phase separation unit to obtain a liquid oily component and a solid-like asphaltene component; the liquid oily component enters the separation unit to partially recover the composite phase separation agent and then enters the oil blending unit, and is blended to obtain an upgraded oil; the solid-like asphaltene component is heated to a molten state and passed through a stripping-evaporation unit to recover the composite phase separation agent contained in the solid-like asphaltene component, and then enters a curing-molding unit, in which it is extruded and molded, and is discharged from the system, followed by temperature and pressure decrease, thereby obtaining a solid product.

Description

Process and system for comprehensively treating and upgrading high viscous heavy oil Technical field The invention provides a process and a system for comprehensively treating and upgrading high viscous heavy oil, specially, a process and a system for grading and separately delivering inferior heavy oil to produce upgraded oil and solid additive products.
Background Art With the reduction of recoverable reserves for light oil and the continuous improvement of oil, exploitation technology, the proportion of inferior heavy oil supply will gradually increase in the 21st century, and thus the development of high viscous heavy oils, such as Venezuelan high viscous heavy oil and Canadian oil sand bitumen, is of great significance.
Such crude oils have significant characteristics such as high specific gravity, high viscosity, no flow at normal temperature, difficulty in storage and delivery; high asphaltene, high metal content and high residual carbon value, which may cause a series of problems, for example, equipment coking, catalyst deactivation, and poor product quality during treatment and processing. They need to be treated to improve the flowability and oil quality thereof, and to improve energy efficiency and economic benefits during the development process.
The composition analysis indicates that this kind of high viscous heavy oil contains 5-20% or even higher of C7 insoluble asphaltenes, which acts as a carrier of viscosity and density. From the form of existence, it is dissolved in the system in a solid-like form.
Meanwhile, it forms a cementation aggregation center, and binds to colloid having strong polarity to form a micellae, which makes the deliverability of the whole system worse.
Therefore, the conversion or removal of asphaltenes is the preferred measure to reduce the viscosity of oil sand bitumen oil and improve API. Seen from the above, this kind of raw material can be regarded as two parts: one part is liquid oily component, and the other part is solid-like asphaltene component in which asphaltene is associated with colloid having strong polarity. The oil component is separated from solid-like asphaltene component by a physical separation technology. A diluent is incorporated into the liquid oily component to meet requirements for pipeline delivery, while the asphaltene component is delivered in the form of solid. Such a mode follows the inherent property of materials, and is called grading and separately delivering process, which is undoubtedly more economical and reasonable in terms of material and energy input. Another key is that although the asphaltene component is

2 enriched with elements that are unfavorable for storage, delivery, and refining processes such as metal and residual carbon, it has high molecular weight, good adhesion, and high temperature performance, and can be used as a resource to develop high-value products.
Solvent deasphalting technology is an effective means for separation pretreatment to heavy oil. At present, there are more than 100 sets of solvent deasphalting devices in the world (supercritical recovery solvent deasphalting device + deasphalting device with conventional evaporation and recovery solvent), and the total processing capacity is 5000x104 tons or more per year. The largest device is of 260x l04 t/a. Impurities such as asphaltenes and heavy metals in heavy oil raw materials can be removed by selecting solvents and process conditions, and obtain deasphalted oil (DAO) with improved quality and a certain proportion of deoiled asphalt (DOA). However, unlike the refinery with mature support, the special conditions of the field conditions of the oil field raise higher requirements for the adaptability and the smooth operation of the separation device. How to effectively separate the components and improve the stability of the operation of the device is a difficult problem to be solved in traditional separation technologies. Generally, in order to obtain a higher DAO
yield, it is necessary to increase the extraction depth, resulting in a DOA
having a high softening point in the process. This product not only has low value for utilization, but also lead to various problems such as high solvent loss, asphalt entrainment and posterior coking.
Meanwhile, it often requires a great cost to deliver these materials with high softening points and high viscosities out of the oil field.
A method for producing vehicle fuel and road asphalt by processing inferior heavy oil is disclosed in Chinese Patent CN108285801A, which comprises: mixing the heavy components, namely heavy deasphalted oil HDAO and deoiled asphalt DOA obtained from the bottom of the extraction device, with a catalytic slurry oil, to produce the road asphalt. Such method is .. suitable for devices supported by oil slurry production or areas with rich source of blending component. A method for upgrading heavy oil using SDA plus gasification is disclosed in U.S.
Patent No. 7,964,090, which comprises: delivering the DOA to a gasifier for gasification to form a synthesis gas by being carried with a solvent. The method converts DOA
in situ, but a large ,amount of solvent is consumed in the gasifier, leading to great loss for value.
CN101203586A and CN105189710A respectively provide a method for upgrading heavy oil such as asphalt by using mixed hydrocarbon as a solvent, which can realize the separation of components such as oil, water and asphaltene. However, it lacks technical measures capable of regulating product quality. Chinese Patent CN1891784A discloses a method and a treatment system for deep step separation of heavy oil by coupling raffinate granulation,

3 which adopts light hydrocarbon with higher carbon number as solvent to obtain higher yield DAO. By introducing a dispersing solvent into the DOA phase, the spray rapidly disperses into solid particles, thereby achieving DOA separation from the solvent in the gas-solid separator. This process needs to be carried out at a sufficiently high DOA
softening point and the resulting powdery particles have a tendency to absorb moisture. An apparatus and a method for recovering a solvent in granulation of de-oiled asphalt with a high softening point are disclosed in CN103102894A. Specifically, the de-oiled asphalt with a high softening point discharged from the bottom of a solvent deasphalting tower is granulated through a screw extrusion system, and obtained granular de-oiled asphalt is directly introduced into a de-oiled asphalt solvent enrichment chamber. The top of the solvent enrichment chamber is provided with a solvent gas recovery pipeline communicated with a solvent recovery system, and facilities like a de-oiled asphalt solid particle water entering slideway are arranged in the chamber, and the granular de-oiled asphalt directly falls into cooling water after sufficient time for releasing of the solvent. The process overcomes the problem of recovering the de-oiled asphalt solvent with a high softening point, but produces a lot of waste water that needs additional treatment. A proprietary device is disclosed in CN104053750A
and CN105324462A by MEG Energy's, which is to improve separation efficiency and ultimately yield higher deasphalted oil yields. However, the substantially oil-free solid asphaltenes can only have applications with low value such as combustion or gasification.

discloses a process for upgrading heavy crude oil production, which employs low-carbon alkanes, aromatic hydrocarbons and the like as diluents to completely dissolve the crude oils.
The method has remarkable effects in removing solids, water and salts in high-viscosity crude oils, but the resultant deasphalted products have low values and are difficult to transfer, and are only suitable for use in situ. CN101952395A discloses an integrated solvent deasphalting and dewatering technique, which reduces the feed density by adding one or more solvents for gravity settling of aqueous phase, meanwhile it can achieve separation of asphaltenes from crude oil. Although the invention proposes a broader solvent range and raw material distillation range, it lacks necessary measures for the separation result of the actual process and solvent recovery.
In summary, many beneficial advances in the separation, storage and delivery of high viscous heavy oil have been made in the prior art. However, the economics of the separation process and the quality improvement of the resulting products are limited, and even the value of some products is reduced, which is critical for the economy of the whole process.
In the absence of effective upgrading technology, most of the development projects for

4 high viscous heavy oil choose to purchase a large amount of dilution oil for blending, and enter the market after desalting and dehydration.
Summary of Invention In order to solve the above disadvantages and deficiencies, it is an object of the invention to provide a process of grading and separately delivering a high viscous heavy oil.
Another object of the invention to provide a system for grading and separately delivering a high viscous heavy oil.
In order to achieve the above objectives, in one aspect, the invention provides a process of grading and separately delivering a high viscous heavy oil, wherein the process comprises the following specific steps:
a) the salty aqueous high viscous heavy oil enters a desalination-dehydration unit, and the desalting and dehydration is completed after adding a diluent;
b) the desalted and dehydrated heavy oil containing the diluent obtained in step a) enters a fractionation unit for fractionation to separate a light fraction, a medium fraction and a heavy fraction;
c) the heavy fraction enters the mixing section of a phase separation unit to be mixed with a composite phase separation agent, and then the separation of solid-liquid two phases is completed in the sedimentation-phase separation section of the phase separation unit to obtain a liquid oily component and a solid-like asphaltene component;
d) the liquid oily component enters the separation unit to partially recover the composite phase separation agent and then enters the oil blending unit, and is blended to obtain an upgraded oil;
e) the solid-like asphaltene component is heated to a molten state and passed through a .. stripping-evaporation unit to recover the composite phase separation agent contained in the solid-like asphaltene component, and then enters a curing-molding unit, in which it is extruded and molded, and is discharged from the system, followed by temperature and pressure decrease, thereby obtaining a solid product.
The "solid-like asphaltene component" in the invention refers to an n-heptane insoluble matter contained in the high viscous heavy oil and a strongly polar macromolecule associated therewith, which shows solid properties at normal temperature and normal pressure. It is not a solid in the strict sense but a solid-like phase.
According to a particular embodiment of the invention, in the process of grading and separately delivering a high viscous heavy oil, preferably, the high viscous heavy oil has a

5 density of 0.97 g/cm3 to 1.03 g/cm3, an asphaltene (n-heptane) content of 5 wt%-20 wt%, and a kinematic viscosity at 50 C of more than 10000 min2/s.
According to a particular embodiment of the invention, in the process of grading and separately delivering a high viscous heavy oil, preferably, the adding ratio of the diluent is not more than 90% by mass of the salty aqueous high viscous heavy oil, more preferably, the adding ratio of the diluent is not more than 50% by mass of the salty aqueous high viscous heavy oil.
According to a particular embodiment of the invention, in the process of grading and separately delivering a high viscous heavy oil, preferably, the diluent includes one or a combination of more of an oil field condensate oil, a light crude oil, a synthetic crude oil or a partial fraction thereof, a light fraction (which may be the light fraction obtained in step b), a light hydrocarbon oil, and the composite phase separation agent recovered in step d) or step e).
Among them, the oil field condensate oil generally refers to a light oil having gasoline fraction content of 70 wt% or more obtained by oil field exploitation; the light crude oil refers to an oil having an API greater than 30; the synthetic crude oil refers to an oil having an API
greater than 30 produced by a upgrading plant; the partial fraction of the synthetic crude oil refers to the partial fraction that satisfies an API greater than 30.
According to a particular embodiment of the invention, in step a) of the process of grading and separately delivering a high viscous heavy oil, the salty aqueous high viscous heavy oil enters a desalination-dehydration unit, and the desalting and dehydration is completed after adding a diluent. As for the high viscous heavy oil, the densities of oil and water are close. Mixed emulsification is serious, and oil and water are difficult to be separated.
Therefore, it is necessary to add a diluent to decrease the density and viscosity of the oil phase in order to separate the oil and water. The dehydration process is a common practice in the art.
The present invention is not particularly limited as long as it is ensured that water can be removed. Typically, the moisture content of the high viscous heavy oil before dehydration is more than 5 wt%, and the moisture content of the high viscous heavy oil after dehydration is less than 0.5 wt%. The devices and parameters used in the dehydration process can be referred to the equipment and process parameters disclosed in Chinese patent CN209178325U.
According to a particular embodiment of the invention, in the process of grading and separately delivering a high viscous heavy oil, preferably, the light fraction having a boiling point below 200 C, the medium fraction having a boiling point below 500 C
and the heavy fraction being the balance, are obtained by fractionation in the fractionation unit.

6 More preferably, the light fraction having a boiling point below 79 C, the medium fraction having a boiling point below 400 C and the heavy fraction being the balance, are obtained by fractionation in the fractionation unit.
Still more preferably, the light fraction having a boiling point below 61 C, the medium fraction having a boiling point below 380 C and the heavy fraction being the balance, are obtained by fractionation in the fractionation unit.
According to a particular embodiment of the invention, in step b) of the process of grading and separately delivering a high viscous heavy oil, the desalted and dehydrated heavy oil containing the diluent obtained in step a) (here it can be additionally added with a diluent) enters a fractionation unit for fractionation to separate a light fraction, a medium fraction and a heavy fraction. The fractionation unit mainly has three functions: 1) to provide a recycling diluent for the desalination-dehydration unit; 2) to extract the phase separation blending agent for the subsequent unit; and 3) to reduce the processing load of the phase separation unit.
The fractionation unit can be configured to have 2-3 fractionation columns for stepwise separation; preferably, the light fraction can be separated by an atmospheric pressure fractionation column to recover the diluent used in the desalination-dehydration unit and the phase separation blending agent required for the phase separation unit. It is recommended in the invention that that the diluent be sent to the fractionation unit for pretreatment, to separate and extract the product used as the composite phase separation agent. In addition, an extraction column for the phase separation blending agent may be separately provided, and if necessary, to extract the light hydrocarbon from the diluent and the light fraction as the phase separation blending agent. The medium fraction is separated into the oil blending unit through a vacuum column, and the oil at the bottom of the vacuum column enters the phase separation unit as a heavy fraction.
It is specifically recommended in the invention that the light fraction obtained by fractionation unit has a boiling point below 200 C, the light hydrocarbon oil used as a phase separation blending agent has a boiling point below 79 C, the medium fraction has a boiling point below 500 C, and the balance is the heavy fraction; preferably, the boiling point of the light fraction may be controlled below 79 C, at which the light fraction and the light hydrocarbon oil can be in the same stream, with the medium fraction having a boiling point below 400 C.
According to a particular embodiment of the invention, in the process of grading and separately delivering a high viscous heavy oil, preferably, the composite phase separation agent comprises alkanes of higher than 70 v%, olefins of less than 30 v% and aromatics of

7 less than 3 v%, based on a total volume of 100% of the composite phase separation agent.
More preferably, the content of aromatics is below 1 v%, based on a total volume of 100% of the composite phase separation agent. It is preferable to strictly control the content of aromatics to zero, because its existence has a negative effect on the phase separation process.
According to a particular embodiment of the invention, in step c) of the process of grading and separately delivering a high viscous heavy oil, the heavy fraction enters the mixing section of a phase separation unit to be mixed with a composite phase separation agent.
Such mixing process can be achieved by conventional means in the art, wherein the composite phase, separating agent is relative to a one-component phase separating agent, which is a .. multi-component phase separating agent. Preferably, the composite phase separation agent comprises a main phase separation agent and a phase separation blending agent, wherein the compounding mass ratio between the main phase separation agent and the phase separation blending agent is 0.1 to 99.9:1; the main phase separation agent is a C4-C6 alkane, and the phase separation blending agent is a light hydrocarbon oil having a boiling point below 79 C.
The light hydrocarbon oil having a boiling point below 79 C can be obtained by extraction during the fractionation of step b).
According to a particular embodiment of the invention, in step b) of the process of grading and separately delivering a high viscous heavy oil, the desalted and dehydrated heavy oil containing the diluent obtained in step a) enters a fractionation unit for fractionation to separate a light fraction with liquid phase properties, a medium fraction and a heavy fraction needed to be upgraded are separated. In addition, a part of the light fraction can be further extracted as a phase separation blending agent in the composite phase separation agent.
According to a particular embodiment of the invention, in step c) of the process of grading and separately delivering a high viscous heavy oil, preferably, the phase separation unit is operated at a temperature of 100 to 200 C, a pressure of 1 to 5 MPa and a mass ratio between the composite phase separation agent and the heavy fraction of 1-5:1.
According to a particular embodiment of the invention, in step c) of the process of grading and separately delivering a high viscous heavy oil, more preferably, the phase separation unit is operated at a temperature of 120 to 180 C, a pressure of 2 to 3.5 MPa and a mass ratio between the composite phase separation agent and the heavy fraction of 2-5:1.
According to a particular embodiment of the invention, in step c) of the process of grading and separately delivering a high viscous heavy oil, still more preferably, the phase separation unit is operated at a temperature of 140 to 180 C, a pressure of 2 to 3.5 MPa and a mass ratio between the composite phase separation agent and the heavy fraction of 2-3:1.

8 According to a particular embodiment of the invention, in step c) of the process of grading and separately delivering a high viscous heavy oil, the phase separation unit comprises a mixing section and a sedimentation phase separation section. The mixing section may be provided with a static mixer, a dynamic shear mixer, a fluctuation-enhanced mixer, etc.
For a high viscous heavy oil, premixing is necessary and intensive mixing measures are needed to improve mass transfer. Typically, agitating paddles, jet nozzles, and microwave/ultrasonic generators can be provided in mixer to improve mass transfer. The process occurred in the phase separation unit is the phase separation of the liquid oily component and the solid-like asphaltene component, and the stability of the original rubber colloidal volume system is changed by the action of the composite phase separation agent, so that the solid-like components is settled. This process fully utilizes the colloidal characteristics, and the phase separation equipment used may be an empty cylinder settling column, or a packed tower or a rotary tower, for example, the multilayer packed tower disclosed in CN105524649A.
According to a particular embodiment of the invention, in step c) of the process of grading and separately delivering a high viscous heavy oil, the thorough mixing is a process of enhancement mass, wherein the enhancement process is performed by one or more selected from heating, shearing, stirring and/or vibrating.
According to a particular embodiment of the invention, in step d) of the process of grading and separately delivering a high viscous heavy oil, preferably, the liquid oily component (comprising most of the composite phase separation agent) enters the separation unit to partially recover the composite phase separation agent by flash separation under reduced pressure or by increasing temperature and pressure, so that no more than 15 wt% of the composite phase separation agent is remained in the liquid oily component;
wherein, in step d), the partial recovery of composite phase separation agents, and even targeted control of the recovery rate of composite phase separation agents is also a technical measure to improve the gravity of graded oils.
According to a particular embodiment of the invention, in step d) of the process of grading and separately delivering a high viscous heavy oil, the liquid oily component enters the separation unit to partially recover the composite phase separation agent and then enters the oil blending unit, and is blended to obtain an upgraded oil. In a traditional solvent deasphalting process, in order to completely recover the solvent from the oil, especially when recovering the last 3 wt% of the solvent, an extra large energy consumption is often required.
In the invention, the fractionation unit may be provided with an extraction column for a phase

9 separation blending agent, while the blending unit requires a light component to increase the API degree of the oil. Therefore, it is preferred to partially recover the composite phase separation agent, that is, to allow the oil having composite phase separation agent of no more than 15 wt%.
According to a particular embodiment of the invention, the process of grading and separately delivering a high viscous heavy oil further comprises a step of adding the light fraction obtained in step b) to the oil blending unit and mixing it with the liquid phase oil component after partially recovering the composite phase separating agent to obtain a satisfactory graded oil.
According to a particular embodiment of the invention, preferably, the process further comprises delivering the medium fraction to oil blending unit, and blending it with the liquid oily component after partially recovering the composite phase separation agent to obtain the graded oil;
the process further comprises delivering the diluent to the fractionation unit for separation and extraction, to obtain a product used as the composite phase separation agent.
According to a particular embodiment of the invention, in step e) of the process of grading and separately delivering a high viscous heavy oil, preferably, the solid-like phase asphaltene component is heated in the stripping-evaporation unit to raise its temperature above its softening point by 80 C or more, to recover the composite phase separation agent contained in the solid-like phase asphaltene component.
According to a particular embodiment of the invention, in step e) of the process of grading and separately delivering a high viscous heavy oil, the solid-like asphaltene component has a high viscosity and dissolves part of the composite phase separation agent, and needs to be heated by a heating furnace or superheated steam to raise to a temperature by at least 80 C above its softening point to reduce the viscosity of the system. At this time, the solid-like asphaltene component has a certain fluidity and is convenient for extrusion molding;
then, it is discharged out of the system by the internal pressure of a stripper in the stripping-evaporation unit or a booster pump, then it is cured and molded by cooling under reduced pressure to obtain a solid product (solid asphaltene component). When the product is discharged by the invention, the product can be discharged by using the pressure of the system itself, and if necessary, a booster pump can be arranged to discharge the product. After that, it is cured and molded by cooling under reduced pressure. For example, it is discharged out of the system after being squeezed by a distributor. At this time, it is necessary to use low temperature air, water or a transmission steel belt to cool down quickly.

to According to a particular embodiment of the invention, in the process of grading and separately delivering a high viscous heavy oil, preferably, the pressure in the stripping-evaporation unit is maintained at 0.5 to 4 MPa.
According to a particular embodiment of the invention, in the process of grading and separately delivering a high viscous heavy oil, the heating is performed by a heating furnace or high temperature superheat steam.
According to a particular embodiment of the invention, preferably, the process of grading and separately delivering a high viscous heavy oil further comprises recycling the stripped steam containing the composite phase separation agent obtained in the stripping-evaporation unit into the desalination-dehydration unit to replenish the diluent. That is, the stripped steam contains water and a composite phase separation agent. While it is recycled to the desalination-dehydration unit, the composite phase separating agent carried therein can be used as a supplementary diluent.
According to a particular embodiment of the invention, the process of grading and separately delivering a high viscous heavy oil further comprises first condensing the stripped steam for oil-water separation treatment, and then delivering the treated product to the separation unit for oil-water separation treatment.
According to a particular embodiment of the invention, in step e) of the process of grading and separately delivering a high viscous heavy oil, preferably, the solid-like asphaltene component after recovering the composite phase separation agent enters the curing-molding unit and is discharged out of the system by the internal pressure of a stripper in the stripping-evaporation unit or a booster pump, and then it is cured and molded by cooling under reduced pressure to obtain a solid product.
According to a particular embodiment of the invention, in the process of grading and separately delivering a high viscous heavy oil, the discharge temperature of the product discharged out of the system after extrusion molding in the step e) is 150 to 300 C.
According to a particular embodiment of the invention, in the process of grading and separately delivering a high viscous heavy oil, the asphaltene component discharged from the curing-molding unit has a softening point of 100 to 180 C.
According to a particular embodiment of the invention, in the process of grading and separately delivering a high viscous heavy oil, the cooling is performed by natural cooling or forced cooling, and the cooling medium comprises one or a combination of more of low temperature air, nitrogen, water and metal strips.
According to a particular embodiment of the invention, in the process of grading and Ii separately delivering a high viscous heavy oil, the solid product is the one that can be transferred and utilized, and has a particle size of 3 to 15 mm and a bulk density of more than 600 kg/m3.
The high viscous heavy oil and diluent are pre-treated by the process of grading and separately delivering a high viscous heavy oil provided by the invention, and are compounded into a composite phase separation agent in line to selectively separate the high viscous heavy oil into liquid oily component and solid-like asphaltene component. The liquid phase oil component is partially diluted and then delivered through pipeline, and the solid-like asphaltene component is solidified to form a solid product with good deliverability and application performance. The process of grading and separately delivering a high viscous heavy oil is not only suitable for the upgrading process of heavy oil development, but also can be used for deep decarbonization pretreatment process of inferior heavy oil.
The process is simple, the investment and operation cost are low. The resultant solid has high softening point, and thus is easy to deliver and has high utilization value.
In another aspect, the invention further provide a system for grading and separately delivering a high viscous heavy oil, wherein the system for grading and separately delivering a high viscous heavy oil comprises a desalination-dehydration unit, a fractionation unit, a phase separation unit, a separation unit, a stripping-evaporation unit, an oil blending unit and a curing-molding unit;
wherein the phase separation unit comprises a mixing section and a sedimentation-phase separation section, and the sedimentation-phase separation section is provided with an outlet of liquid oily component and a solid-like asphaltene component outlet;
the desalination-dehydration unit is connected to the fractionation unit through a pipeline, and a light fraction outlet and a heavy fraction outlet of the fractionation unit are connected to the mixing section of the phase separation unit through a pipeline, and a liquid oily component outlet of the sedimentation phase separation section in the phase separation unit is connected to the separation unit through a pipeline, and the separation unit is connected to the oil blending unit through a pipeline; and a solid-like asphaltene component outlet of the sedimentation phase separation section in the phase separation unit is connected to the stripping-evaporation unit through a pipeline, and the stripping-evaporation unit is connected to the curing-molding unit.
According to a particular embodiment of the invention, in the system for grading and separately delivering a high viscous heavy oil, preferably, a stripped steam outlet of the stripping-evaporation unit is connected to the desalination-dehydration unit through a pipeline.
In the system, the stripped steam outlet of the stripping-evaporation unit is connected to the desalination-dehydration unit, and this can recycle the stripped steam obtained from the stripping-evaporation unit to the desalination-dehydration unit to supplement the diluent.
According to a particular embodiment of the invention, in the system for grading and separately delivering a high viscous heavy oil, preferably, the light fraction outlet of the fractionation unit is further connected to the oil blending unit and the desalination-dehydration unit through pipelines, respectively; and the outlet of medium fraction in the fractionation unit is connected to the blending unit through a pipeline.
In the system, the light fraction outlet of the fractionation unit is connected to the oil blending unit through a pipeline, and this can deliver the light fraction obtained from fractionation unit to the oil blending unit to compound with the liquid oily component; and the light fraction outlet of the fractionation unit is connected to the desalination-dehydration unit through a pipeline, and this can recycle the light fraction to the desalination-dehydration unit to supplement the diluent.
According to a particular embodiment of the invention, preferably, the system for grading and separately delivering a high viscous heavy oil further comprises a condensing device, and the stripped steam outlet of the stripping-evaporation unit is connected to the phase separation unit via the condensing device through a pipeline.
Ih the system, the stripped steam outlet of the stripping-evaporation unit is connected to the phase separation unit via the condensing device through a pipeline. This can allow the stripped steam containing composite phase separation agent in the stripping-evaporation unit to recycle to the mixing section in the phase separation unit for repeat use after removing water by condensation.
According to a particular embodiment of the invention, in the system for grading and separately delivering a high viscous heavy oil, preferably, the gas outlet of the separation unit is connected to the mixing section of the phase separation unit via the condensing device through a pipeline, and the liquid oily component outlet of the separation unit is connected to the desalination-dehydration unit through a pipeline.
In the system, the gas outlet of the separation unit is connected to the mixing section of the phase separation unit via the condensing device through a pipeline; this can recycle the stripped steam containing composite phase separation agent in the stripping-evaporation unit to the mixing section in the phase separation unit for repeat use after removing water by condensation. The separation unit is connected to the desalination-dehydration unit through a pipeline; this can recycle the composite phase separation agent to the desalination-dehydration unit to supplement the diluent.
In the system, a condensing device is provided and the stripped steam outlet of the stripping-evaporation unit is connected to the separating unit via the condensing device through a pipeline. This can firstly condense the stripped steam obtained from the stripping-evaporation unit for oil-water separation treatment, and the treated product is then transferred to the separation unit for oil-water separation treatment.
The process of grading and separately delivering a high viscous heavy oil provided by the invention utilizes the composition characteristics of the high viscous heavy oil to upgrade and separate the components based on theory of colloidal chemistry. It solves the problem of storage and delivery of high viscous heavy oil by a simple separation process, reduces the use amount of diluent, explores the value of each component, and finally develops high-value products. The high viscous heavy oil extracted from oil wells generally contains inorganic salts and water, which causes difficulties in storage, delivery and conversion processes.
Therefore, it is necessary to remove inorganic salts and water at first. In the case where the viscosity of the system is high and the oil density is close to the water, it is usually necessary to incorporate a diluent to promote desalination and dehydration, and then perform a subsequent treatment process. The invention is directed to a high viscous heavy oil which has been subjected to the demineralization and dehydration treatment, and provides a pretreatment to the high viscous heavy oil and diluent. By compounding a composite phase separation agent in line, it can selectively separate the high viscous heavy oil into liquid oily component and solid-like asphaltene component. The liquid phase oil component is partially diluted and then delivered through pipeline, and the solid-like asphaltene component is solidified to form a solid product with good deliverability and application performance. Based on the process, the viscosity of high viscous heavy oil can be effectively reduced, and the technical bottleneck of the DOA with high softening point in the solvent deasphalting device is overcome and the high value utilization is realized.
Description of Drawings Fig. I is a schematic structural view of the system for grading and separately delivering a high viscous heavy oil according to Example 1 of the invention.
The description for the main reference numerals:
I. desalination-dehydration unit;

2. fractionation unit;
3'. phase separation unit;
3-1. mixing section;
3-2. sedimentation-phase separation section;
4. separation unit;
5. stripping-evaporation unit;
6. oil blending unit;
7. curing-molding unit;
8. condensing device;
A. high viscous heavy oil;
B. diluents;
C. main phase separation agent.
Detailed Description of Invention In order to understand more clearly the technical features, objects, and advantages of the invention, the technical solutions of the invention are described in detail below with reference to the specific embodiments of the invention, but are not to be construed as limiting the scope of the invention.
The raw materials processed by the invention are high viscous heavy oils or extra heavy crude oils with a density of 0.97 g/cm3to 1.03 g/cm3, an asphaltene (n-heptane) content of 5 wt%-20 wt%, and a kinematic viscosity at 50 C of more than 10000 mm2/s.
Typical representatives of such crude oils include Venezuela's high viscous heavy oil and Canadian oil sand bitumen. After being degassed in the mining area, they are solid at normal temperature and at'e extremely poor in the low temperature storage and delivery performance. The reasons for this lie in that: in addition to low content of light components, the micellae centered on asphaltene components makes the density viscosity increase greatly. They exist in the form that the liquid oily component and solid-like asphaltene component bond together to form a metastable colloidal system. Based on the colloidal chemical properties, the stability of the system can be determined by the ratio of (A+R)/(S+As), where the numerator (A+R) is the content of aromatic and colloid in the system, and the denominator (S+As) is the content of saturated fraction and asphaltene in the system. When the saturated fraction of the system is increased to a sufficient amount, the stabilizing system is broken, and the asphaltene components are separated and precipitated to different degrees. A traditional solvent deasphalting process uses a single component such as propane, butane or pentane as the solvent, and has a narrow range of adjustment in the weight distribution and quality of the isolated product. In addition, only the temperature, pressure and solvent ratio can be adjusted with limitation, which is difficult to meet the requirements for the property change of the wellhead material and product requirements. The invention adopts C4-C6 saturated hydrocarbon as the main phase separation agent, and simultaneously extracts part of the light fraction as the phase separation agent. The phase separation blending agent has an at least comparative or broader boiling point and composition range than the main phase separation agent, however, it needs to be moderately treated and the aromatic compound contained therein will be cut off.
According to the requirement for desalting and dehydration, a diluent needs to be added to the system before the phase separation, and the source thereof can be oil field condensate, light crude oil, synthetic crude oil or some fractions thereof, with a blending ratio not exceeding 50% by mass of the inferior heavy oil (high viscous heavy oil containing salts and water). As an exceptional case, it can be in the same stream as the phase separation agent. In the frdctionation unit, the phase separation blending agent obtained by separation has a same composition as that in the diluent used for desalting and dehydration or is part of the diluent used for desalting and dehydration, and has an initial distillation point of the distillation range of 79 C. After compounding in line, the composite phase separation agent used in the phase separation unit occupies more than 70 v% of the saturated hydrocarbons, and the olefin is below 30 v%. In the fractionation unit, the separation process can obtain the light fraction which can be used as composite phase separation agent and the heavy fraction which needs to be reformed.
The phase separation unit can be divided into in two sections. First, the heavy fraction and the composite phase separation agent enter the mixing section and mixed therein. This section requires input of thermal energy and mechanical energy to promote the back-mixing mass transfer, and break the equilibrium stability of the system colloid.
Then, it enters the sedimentation and phase separation section for a certain period of sedimentation separation, and the section needs to be injected with an appropriate amount of phase separation agent.
After the two-phase (solid-liquid) separation is completed, a liquid oily component and a solid-like asphaltene component are obtained. The operating conditions of the section are:
temperature: 100-200 C, pressure: 1-4MPa, mass ratio of the composite phase separation agent to the heavy fraction: 1-5:1. The distribution ratio is adjusted as needed, wherein the yield for liquid oily component can be adjusted between 60 wt%-90 wt%. The liquid oily component containing most of the light phase separation agent enters the separation unit, and the composite phase separation agent is separated and recovered by raising the temperature or reducing the pressure. The phase separation blending agent has a protective effect on the main phase separation agent, so that the main phase separation agent is preferentially separated and completely recovered. The composite phase separation agent is partially recovered and then enters the oil blending unit. According to the product requirements, the light fraction and medium fraction obtained from the fractionation unit is added or a diluted oil is separately supplemented, so as to obtain an upgraded oil that meets the requirements. For the requirements at different regions, such as Canada, the API of upgraded oil should reach 19 or more.
In view of the problems that the phase separation agent escapes and is difficult to recover and the value of the product decrease due to the increasing in the hardness of the asphaltene component, in the present invention, the softening point is controlled below 180 C or even more by raw material processing, solvent compounding and optimization of process parameters, to solve the problem from the source. As a result, an efficient recovery of the phase separation agent in the solid-like asphaltene component containing a small amount of composite phase separation agent is achieved, and the quality of the asphaltene component is regulated to produce high-value products. By injecting superheated steam or external heating, the solid-like asphaltene component containing a small amount of composite phase separation agent 'whose quality is effectively controlled is heated to a temperature higher than the softening point by 80 C, stripping-evaporated to recover the oil and phase separation agent.
After that, it enters the curing-molding unit, discharges out of the system under its own temperature and pressure, and a solid asphaltene component product that can be delivered and utilized is then obtained by lowering the temperature and the pressure. In order to improve the performance of the product, some modified substances may be added to the unit to meet different application requirements, for example, silicon-containing components may be added to enhance its electrochemical performance. The asphaltene component is discharged out of the curing-molding unit by a pressure in a stripping tower or a booster pump, and molded with naturally cooling or reinforced refrigeration. Particles having a particle diameter of 3 to 15 mm and a bulk density of more than 600kg/m3 are preferably made. The stripping steam containing oil, water and composite phase separation agent recovered in this process can be directly recycled into the desalination-dehydration unit to be supplemented with diluents, and water treatment is completed concurrently.
The invention can greatly reduce the delivery cost of the high viscous heavy oils and obtain high-value products.

Example 1 This example provides a system for grading and separately delivering a high viscous heavy oil, of which the schematic structural view is shown in Fig. 1. As can be seen from Fig.
1, the system for grading and separately delivering a high viscous heavy oil comprises a desalination-dehydration unit 1, a fractionation unit 2, a phase separation unit 3, a separation unit 4, a stripping-evaporation unit 5, an oil blending unit 6 and a curing-molding unit 7;
wherein the phase separation unit 3 comprises a mixing section 3-1 and a sedimentation-phase separation section 3-2, the sedimentation-phase separation section 3-2 is provided with an outlet of liquid oily component and a solid-like asphaltene component outlet;
the desalination-dehydration unit is connected to the fractionation unit through a pipeline, and a light fraction outlet and a heavy fraction outlet of the fractionation unit are connected to the mixing section of the phase separation unit through a pipeline, and a liquid oily component outlet of the sedimentation phase separation section in the phase separation unit is connected to the separation unit through a pipeline, and the separation unit is connected to the oil blending unit through a pipeline;
a light fraction outlet of the fractionation unit is further connected to the oil blending unit and the desalination-dehydration unit through pipelines, respectively;
a solid-like asphaltene component outlet of the sedimentation phase separation section in the phase separation unit is connected to the stripping-evaporation unit through a pipeline, and the stripping-evaporation unit is connected to the curing-molding unit;
a stripped steam outlet of the stripping-evaporation unit is connected to the desalination-dehydration unit;
the system for grading and separately delivering a high viscous heavy oil further comprises a condensing device 8, and a stripped steam outlet of the stripping-evaporation unit is connected to the phase separation unit via the condensing device through a pipeline;
a gas outlet of the separation unit is connected to the mixing section of the phase separation unit via the condensing device through a pipeline, and the liquid oily component outlet is connected to the desalination-dehydration unit through a pipeline.
Example 2 This example provides a system for grading and separately delivering a high viscous heavy oil, wherein the system for grading and separately delivering a high viscous heavy oil comprises a desalination-dehydration unit, a fractionation unit, a phase separation unit, a separation unit, a stripping-evaporation unit, an oil blending unit and a curing-molding unit;

wherein the phase separation unit comprises a mixing section and a sedimentation-phase separation section, the sedimentation-phase separation section is provided with an outlet of liquid oily component and a solid-like asphaltene component outlet;
the desalination-dehydration unit is connected to the fractionation unit through a pipeline, and a light fraction outlet and a heavy fraction outlet of the fractionation unit are connected to the mixing section of the phase separation unit through a pipeline, and a liquid oily component outlet of the sedimentation phase separation section in the phase separation unit, is connected to the separation unit through a pipeline, and the separation unit is connected to the oil blending unit through a pipeline;
a, light fraction outlet of the fractionation unit is further connected to the oil blending unit and the desalination-dehydration unit through pipelines, respectively;
a solid-like asphaltene component outlet of the sedimentation phase separation section in the phase separation unit is connected to the stripping-evaporation unit through a pipeline, and the stripping-evaporation unit is connected to the curing-molding unit;
a stripped steam outlet of the stripping-evaporation unit is connected to the desalination-dehydration unit;
the system for grading and separately delivering a high viscous heavy oil further comprises a condensing device, and a stripped steam outlet of the stripping-evaporation unit is connected to the phase separation unit via the condensing device through a pipeline;
a gas outlet of the separation unit is connected to the mixing section of the phase separation unit via the condensing device through a pipeline, and the liquid oily component outlet is connected to the desalination-dehydration unit through a pipeline;
a medium fraction outlet of the fractionation unit is connected to the blending unit through a pipeline.
Example 3 This Example provides a process of grading and separately delivering a high viscous heavy oil, which is performed by using the system provided in Example 1.
Specifically, the process comprises the following steps:
The high viscous heavy oil A treated in this example is a Venezuelan high viscous heavy oil, and the properties are as follows: a density of 1.012g/cm3, a viscosity (50 C) of 18568 min2/s, a n-heptane asphaltene content of 12.05 wt%, a sulfur content of 4.3 wt%, residual carbon of 14.6 wt%, and a content of nickel and vanadium of 359 ppm.
wt% condensate oil is added to the Venezuela high viscous heavy oil, dehydrated at 125 C to a water content of less than 0.5 wt%, so as to complete desalting and dehydration.

The resultant desalted and dehydrated heavy oil containing diluents B enters the fractionation device for fractionation to obtain three parts: a light fraction (dry point 79 C), which can be used as a phase separation blending agent; a medium fraction (the 90%
distillation temperature is 385 C), and a heavy fraction (the 10 %
distillation temperature is 398 C), at a mass ratio of 5:30:90;
A composite phase-separating agent is obtained by compounding an alkane having a C5 content of more than 85 v% as a main phase separation agent C and a phase separation blending agent for the light fraction at a mass ratio of 9:1, and the composition thereof is shown in Table 1 below. The phase separation unit is provided with a static mixer and an empty cylinder settling column. The conditions for controlling the phase separation process are: a temperature of 150 C, a pressure of 3.6MPa, and a mass ratio of composite phase separation agent to heavy fraction of 2.5:1. The phase separation is performed under such conditions, and the composite phase separation agent is recovered in a secondary flash separator. The resultant liquid oily component has a yield of 85 wt%. After blending with the medium fraction obtained by fractional distillation, the API reaches 13.8 (the density is 0.974 g/cm3).
The separated solid-like asphaltene fraction is heated to 260 C in a heating furnace and transferred to a stripping tower. The amount of stripping steam used is 5 wt%
of the asphaltene component, the stripping time is 20 minutes, and the composite phase separating agent is separated and recovered. Thereafter, it is extruded out of the system and cooled to a temperature of 36 C with low temperature air purge, to obtain a solid asphaltene component having a softening point of 145 C.
Table 1 Composition of the composite phase separation agent used in this example Composition, v%
Component name analysis 1 analysis 2 n-pentane 36.2 34.6 isopentane 39.4 41.5 cyclopentane 4.9 3.8 n-hexane 3.3 4.6 2-methyl pentane 3.2 2.9 3-methylpentane 2.7 2.3 2,2-dimethylbutane 5 4.7 2,3-d imethylbutane 4.6 4.9 methylcyclopentane 0.3 0.5 others 0.4 0.2 As can be seen from Table 1, in this example, the addition of the phase separation blending agent enriches the composition of the solvent, especially the increase of cyclopentane and methylcyclopentane, such that the yield of the liquid oily component reaches 85 wt%, which is a higher level.
Example 4 This example provides a process of grading and separately delivering a high viscous heavy oil, which is performed by the system provided in Example 1.
Specifically, the process comprises the following steps:
The high viscous heavy oil treated in this example is an oil sand bitumen obtained by SAGD process in Canada, and the properties are as follows: a density of 1.019 g/cm3, a viscos'ity (50 C) of 23928 mm2/s, a n-heptane asphaltene content of 10.86 wt%, a sulfur content of 3.3 wt%, residual carbon of 12.1 wt%, and a content of nickel and vanadium of 325 ppm.
wt% condensate oil is added to the aqueous asphalt emulsion, desalinated and 15 .. dehydrated to a water content of 0.3 wt% under a temperature of 120 C
and a pressure of 1MPa.
The resultant desalted and dehydrated product enters the fractionation device for fractionation to obtain three parts: a light fraction (from the initial boiling point to 65 C), which can be used as a phase separation blending agent; a medium fraction (the 90%
20 distillation temperature is 360 C), and a heavy fraction.
A composite phase-separating agent is obtained by compounding isopentane as a main phase. separation agent and a light fraction below 65 C at a mass ratio of 1:1, and the composition thereof is shown in Table 2 below. The conditions for controlling the phase separation process are: a temperature of 160 C, a pressure of 4.0 MPa, and a mass ratio of composite phase separation agent to heavy fraction of 3:1. The phase separation is performed under such conditions.
After 20 minutes, the phase separation is completed, and the yield for liquid oily component is 80 wt%. After blending with light fraction, its API reaches 14.3, and after blending with 50 wt% of a light crude oil ( API of 32), the API reaches 19.5.
The solid asphaltene fraction is heated to 260 C, and the composite phase separating agent is recovered by steam stripping-evaporation. Thereafter, it is dropped into a cooling belt at normal pressure through a porous pressure-variable distributor under the action of system pressure and heat, to collect solid particles having an average particle diameter of 8 mm.
Table 2 Composition of the composite phase separation agent used in this example Name composition, v%
butane 2.2 butene 3.7 n-pentane 11.2 isopentane 67.8 cyclopentane 7.0 2-methylpentane 1.7 3-methylpentane 2.6 2,2-d imethylbutane 3.3 2,3-dimethylbutane 0.5 As can be seen from Table 2, the composite phase separation agent used in this example has dominant component of isopentane, and the addition of the blending agents such as butane and butene reduces the difficulty of separation in the stripping-evaporation process.
Example 5 This example provides a process of grading and separately delivering a high viscous heavy oil, which is performed by the system provided in Example 1.
Specifically, the process comprises the following steps:
The high viscous heavy oil treated in this example is a Venezuelan high viscous heavy oil having the same properties as that in Example 2, and the properties are as follows: a density of 1.012g/cm3, a viscosity (50 C) of 18568 mm2/s, a n-heptane asphaltene content of 12.05 wt%, a sulfur content of 4.3 wt%, residual carbon of 14.6 wt%, and a content of nickel and vanadium of 359 ppm.
A light crude oil (in an amount of 50 wt% of the high viscous heavy oil) is charged into the first fractionation column for extraction to obtain a light fraction A
(dry point below 75 C) and a light fraction B (dry point below 160 C) which can be used as a phase separation blendi'ng agent. The light fraction B is added as a diluent to the desalination-dehydration unit and mixed with the high viscous heavy oil, to complete the desalination and dehydration at a temperature of 128 C and a pressure of 0.9 MPa. Thereafter, the diluent is recycled through the second fractionation column, and a medium fraction (the 90% distillation temperature is 305 C) for dilution and blending is obtained at the same time. The heavy oil at the bottom of the second fractionation column enters the phase separation unit. The phase separation unit is provided with a mixer having a stirring paddle and a settling tower, wherein the mixer is stirred at a rate of 30 rpm, the mixing temperature is 125 C, the temperature of the material in the settling tower is 120 C, and the settling time is 30 minutes. The object of two-phase separation is achieved.
The liquid oily component is subjected to a two-step recovery operation in the separation unit. First, 75 wt% of the composite phase separation agent (the composition can be found in Table 3) is recovered at a temperature of 125 C and a pressure of 5.2 MPa, and 20 wt% of the composite phase separation agent contained therein is recovered at a temperature of 220 C
and a pressure of 1.2 MPa. The remaining 5 wt% of the composite phase separation agent contained in the oil components enters the blending unit and is mixed with the medium fraction to form an upgraded oil having an API of 17.9. The solid phase asphaltene component is heated to 260 C, and the composite phase separation agent is recovered by steam stripping-evaporation. Thereafter, it is dropped into a cooling belt at normal pressure under the action of system pressure and heat, to collect solid particles having an average particle diameter of 8 mm.
Table 3 Composition of the composite phase separation agent used in this example Name composition, v%
butane 9.8 n-pentane 10.6 isopentane 61.2 cyclopentane 9.8 2-methylpentane 2.9 3-methylpentane 3 2,2-d imethylbutane 2.5 2,3-dimethylbutane 0.2 Example 6 The oil sand bitumen treated in this example has the following properties: a density of 1.012g/cm3, a viscosity (80 C) of 4916 mm2/s, and a n-heptane asphaltene content of 15.27 wt%.

50 wt% of light crude oil is added to the aqueous asphalt emulsion, dehydrated under a temperature of 120 C and a pressure of 0.7MPa to a water content of 0.5 wt%.
The resultant desalted and dehydrated product enters the fractionation device for fractionation to obtain three parts: a light fraction (from the initial boiling point to 75 C), which can be used as a phase separation blending agent; a medium fraction (the 90%
distillation temperature is 480 C), and a heavy fraction.
A composite phase-separating agent is obtained by compounding n-butane as a main phase separation agent and a light fraction at a mass ratio of 2:1. The conditions for controlling the phase separation process are: a temperature of 110 C, a pressure of 5.0 MPa, and a mass ratio of composite phase separation agent to heavy fraction is 4:1.
After 25 minutes, the phase separation is completed. After entering the separation unit, 97 wt% of the composite phase separation agent contained therein is recovered at a temperature of 220 C
and a pressure of 1.0 MPa by two-stage evaporation. The resultant liquid oily component has a yield of 60 wt%. After blending with the medium fraction, an ungraded oil having an API
up to 19.2 is obtained.
The solid asphaltene fraction is heated to 270 C, and the composite phase separating agent is recovered by steam stripping-evaporation. Thereafter, it is dropped into a cooling belt having a surface temperature of 30 C, at normal pressure through a porous pressure-variable distributor under the action of system pressure and heat, to collect solid particles having an average particle diameter of 6 mm.
Example 7 The object treated in this example is also a Canada oil sand bitumen, which is the same as in Example 3. The properties are as follows: a density of 1.019 g/cm3, a viscosity (50 C) of 23928 mm2/s, a n-heptane asphaltene content of 10.86 wt%, a sulfur content of 3.3 wt%, residual carbon of 12.1 wt%, and a content of nickel and vanadium of 325 ppm;
The difference is that the diluent used in this example is a synthetic crude oil with an API of 35 produced by a upgrading plant, and a tower for producing phase separation blending agent is provided in the fractionation system for extracting 2% of the light fraction (boiling point below 65 C), which is compounding with a main phase separation agent (isopentane) at a mass ratio of 2.5:1 to obtain the composite phase separation agent. The advantage of providing the independent phase separation compounding and production tower lies in that the composition ratio of the composite phase separation agent can be flexibly adjusted to better adapt to changes in the properties of the raw materials and changes in the product market. The liquid oily component obtained by the treatment recovers 99 wt% of the composite phase separation agent through a separation unit for 20 minutes. The resultant liquid oily component is blended with the light fraction. As a result, its API reaches 14.9.
After blending with 50 wt% of a light crude oil ( API of 32), its API reaches 19.7;
The solid asphaltene fraction is heated to 260 C, and the composite phase separating agent is recovered by steam stripping-evaporation. Thereafter, it is dropped into a cooling belt at normal pressure through a porous pressure-variable distributor under the action of system pressure and heat, to collect solid particles having an average particle diameter of 8 mm.
txample 8 On the basis of Example 7, the tower for producing phase separation blending agent is retained, and the extraction ratio of the light fraction is increased to 3.5 wt% in this example.
In the separation unit, 3 wt% steam is introduced at a temperature of 215 C, and the composite phase separation agent is partially recovered. The liquid oily component contains 2.5 wt% of the composite phase separation agent. After blending with the light fraction, its API reaches 15.8; and after blending with 45 wt% of a light crude oil ( API of 32), its API
reaches 19.6. As compared with Example 3, the amount of light crude oil used is reduced by

10 wt%.
Comparative example 1 This example provides a process of grading and separately delivering a high viscous heavy' oil, which is performed by the system provided in Example 1.
Specifically, the process comprises the following steps:
The high viscous heavy oil treated in this example is an oil sand bitumen obtained by SAGD process in Canada, and the properties are as follows: a density of 1.019 g/cm3, a viscosity (50 C) of 23928 mm2/s, a n-heptane asphaltene content of 10.86 wt%, a sulfur content of 3.3 wt%, residual carbon of 12.1 wt%, and a content of nickel and vanadium of 325 ppm.
20 wt% condensate oil is added to the aqueous asphalt emulsion, and desalinated and dehydrated.
The resultant desalted and dehydrated product enters the fractionation device for fractionation to obtain three parts: a light fraction (from the initial boiling point to 65 C), which' can be used as a phase separation blending agent; a medium fraction (the 90%
distillation temperature is 360 C), and a heavy fraction.
Isopentane is used as a main phase separation agent. The conditions for controlling the phase separation process are: a temperature of 160 C, a pressure of 4.0 MPa, and a mass ratio of composite phase separation agent to heavy fraction of 3:1. The phase separation is performed under such conditions.
After 20 minutes, the phase separation is completed, and the yield for liquid oily component is 70 wt%. After blending with light fraction, its API reaches 14.3, and after blending with 50 wt% of a light crude oil ( API of 32), the API reaches 19.5.
The solid asphaltene fraction is heated to 260 C, and the composite phase separating agent is recovered by steam stripping-evaporation. Thereafter, it is dropped into a cooling belt at normal pressure through a porous pressure-variable distributor under the action of system pressure and heat, to collect solid particles having an average particle diameter of 8 mm.
From the above, it can be seen that the phase separation formulation is not added in this comparative example, and the yield of the liquid oily component is only 70 wt%.
Comparative example 2 This example provides a process of grading and separately delivering a high viscous heavy oil, which is performed by the system provided in Example 1.
Specifically, the process comprises the following steps:
The high viscous heavy oil treated in this example is an oil sand bitumen obtained by SAGD process in Canada, and the properties are as follows: a density of 1.019 g/cm3, a viscosity (50 C) of 23928 mm2/s, a n-heptane asphaltene content of 10.86 wt%, a sulfur content of 3.3 wt%, residual carbon of 12.1 wt%, and a content of nickel and vanadium of 325 ppm.
20 wt% condensate oil is added to the aqueous asphalt emulsion, and desalinated and dehydrated;
The resultant desalted and dehydrated product enters the fractionation device for fractionation to obtain three parts: a light fraction (from the initial boiling point to 65 C), which can be used as a phase separation blending agent; a medium fraction (the 90%
distillation temperature is 360 C), and a heavy fraction.
A composite phase-separating agent is obtained by compounding isopentane as a main phase separation agent and a light fraction below 65 C at a mass ratio of 1:1. The conditions for controlling the phase separation process are: a temperature of 160 C, a pressure of 4.0 MPa, and a mass ratio of composite phase separation agent to heavy fraction of 3:1. The phase separation is performed under such conditions.
After over 30 minutes, the phase separation is completed, and the yield for liquid oily component is 80 wt%.After blending with light fraction, its API reaches 14.3, and after blending with 50 wt% of a light crude oil ( API of 32), the API reaches 19.5.
The solid asphaltene fraction is heated to 260 C, and the composite phase separating agent is recovered by steam stripping-evaporation. Thereafter, it is dropped into a cooling belt at normal pressure through a porous pressure-variable distributor under the action of system pressure and heat, to collect solid particles having an average particle diameter of 8 mm.
From the above, it can be seen that in this comparative example, the phase separation blending agent became heavier, and it has increased difficulty for liquid-solid phase separation, and the time taken for completion is increased.
Comparative example 3 The oil sand bitumen treated in this comparative example has the following properties: a density of 1.012 g/cm3, a viscosity (80 C) of 4916 mm2/s, and a n-heptane asphaltene content of 15.27 wt%.
50 wt% condensate oil is added to the aqueous asphalt emulsion, and desalinated and dehydrated.
The resultant desalted and dehydrated product enters the fractionation device for fractionation to obtain three parts: a light fraction (from the initial boiling point to 75 C), which can be used as a phase separation blending agent; a medium fraction (the 90%
distillation temperature is 480 C), and a heavy fraction.
A composite phase-separating agent is obtained by compounding n-butane as a main phase separation agent and a light fraction at a mass ratio of 2:1. The conditions for controlling the phase separation process are: a temperature of 110 C, a pressure of 5.0 MPa, and a mass ratio of composite phase separation agent to heavy fraction is 4:1.
After 25 minutes, the phase separation is completed, and the yield for liquid oily component is 60 wt%.
After blending with the medium fraction, an ungraded oil having an API up to 19.2 is obtained.
The solid asphaltene fraction is heated to 270 C, and the composite phase separating agent is recovered by steam stripping-evaporation. Thereafter, an asphaltene component at a high-temperature molten state is obtained. Since there are no technical measures for curing molding, it requires high temperature conditions for all of storage, delivery and use. In addition to high energy consumption, it is also necessary to isolate the air to prevent spontaneous combustion.

Claims

What is claimed is:

1. A process of grading and separately delivering a high viscous heavy oil, wherein the process comprises the following specific steps:
a) the salty aqueous high viscous heavy oil enters a desalination-dehydration unit, and the desalting and dehydration is completed after adding a diluent;
b) the desalted and dehydrated heavy oil containing the diluent obtained in step a) enters a fractionation unit for fractionation to separate a light fraction, a medium fraction and a heavy fraction;
c) the heavy fraction enters the mixing section of a phase separation unit to be mixed with a composite phase separation agent, and then the separation of solid-liquid two phases is completed in the sedimentation-phase separation section of the phase separation unit to obtain a liquid oily component and a solid-like asphaltene component;
d) the liquid oily component enters the separation unit to partially recover the composite phase separation agent and then enters the oil blending unit, and is blended to obtain an upgraded oil;
e) the solid-like asphaltene component is heated to a molten state and passed through a stripping-evaporation unit to recover the composite phase separation agent contained in the solid-like asphaltene component, and then enters a curing-molding unit, in which it is extruded and molded, and is discharged from the system, followed by temperature and pressure decrease, thereby obtaining a solid product.

2. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein the high viscous heavy oil has a density of 0.97 g/cm3 to 1.03 g/cm3, an asphaltene content of 5 wt%-20 wt%, and a kinematic viscosity at 50 °C
of more than 10000 m m2/s .

3. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein the adding ratio of the diluent is not more than 90% by mass of the salty aqueous high viscous heavy oil.

4. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein the diluent includes one or a combination of more of an oil field condensate oil, a light crude oil, a synthetic crude oil or a partial fraction thereof, a light fraction, a light hydrocarbon oil, and the composite phase separation agent recovered in step d) or step e).

5. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein the light fraction having a boiling point below 200 °C, the medium fraction having a boiling point below 500°C and the heavy fraction being the balance, are obtained by fractionation in the fractionation unit.

6. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein the composite phase separation agent comprises alkanes of higher than 70 v%, olefins of less than 30 v% and aromatics of less than 3 v%, based on a total volume of 100% of the composite phase separation agent.

7. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein the composite phase separation agent comprises a main phase separation agent and a phase separation blending agent, wherein the compounding ratio between the main phase separation agent and the phase separation blending agent is 0.1 to 99.9:1, the main phase separation agent is a C4-C6alkane, and the phase separation blending agent is a light hydrocarbon oil having a boiling point below 79 °C.

8. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein in the step c), the phase separation unit is operated at a temperature of 100 to 200 °C, a pressure of 1 to 5 MPa and a mass ratio between the composite phase separation agent and the heavy fraction of 1-5:1.

9. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein in the step d), the liquid oily component enters the separation unit to partially recover the composite phase separation agent by flash separation under reduced pressure or by increasing temperature and pressure, so that no more than 15 wt% of the composite phase separation agent is remained in the liquid oily component.

10. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein the process further comprises delivering the medium fraction to oil blending unit, and blending it with the liquid oily component after partially recovering the composite phase separation agent to obtain the graded oil;

the process further comprises delivering the diluent to the fractionation unit for separation and extraction, to obtain a product used as the composite phase separation agent.

11. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein in the step e), the solid-like phase asphaltene component is heated in the stripping-evaporation unit to raise its temperature above its softening point by 80 °C or more, to recover the composite phase separation agent contained in the solid-like phase asphaltene component.

12. The process of grading and separately delivering a high viscous heavy oil according to claim 11, wherein the pressure in the stripping-evaporation unit is maintained at 0.5 to 4 MPa.

13. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein the process further comprises recycling the stripped steam containing the composite phase separation agent obtained in the stripping-evaporation unit into the desalination-dehydration unit to replenish the diluent.

14. The process of grading and separately delivering a high viscous heavy oil according to claim 11, wherein in the step e), the solid-like asphaltene component after recovering the composite phase separation agent enters the curing-molding unit and is discharged out of the system by the internal pressure of a stripper in the stripping-evaporation unit or a booster pump, and then it is cured and molded by cooling under reduced pressure to obtain a solid product.

15. The process of grading and separately delivering a high viscous heavy oil according to claim 1, wherein the discharge temperature of the product discharged out of the system after extrusion molding in the step e) is 150 to 300 °C.

16. A system for grading and separately delivering a high viscous heavy oil, wherein the system for grading and separately delivering a high viscous heavy oil comprises a desalination-dehydration unit, a fractionation unit, a phase separation unit, a separation unit, a stripping-evaporation unit, an oil blending unit and a curing-molding unit;
wherein the phase separation unit comprises a mixing section and a sedimentation-phase separation section, and the sedimentation-phase separation section is provided with an outlet of liquid oily component and a solid-like asphaltene component outlet;
the desalination-dehydration unit is connected to the fractionation unit through a pipeline, and a light fraction outlet and a heavy fraction outlet of the fractionation unit are connected to the mixing section of the phase separation unit through a pipeline, and a liquid oily component outlet of the sedimentation phase separation section in the phase separation unit, is connected to the separation unit through a pipeline, and the separation unit is connected to the oil blending unit through a pipeline; and a solid-like asphaltene component outlet of the sedimentation phase separation section in the phase separation unit is connected to the stripping-evaporation unit through a pipeline, and the stripping-evaporation unit is connected to the curing-molding unit.

17. The system for grading and separately delivering a high viscous heavy oil according to claim 16, wherein a stripped steam outlet of the stripping-evaporation unit is connected to the desalination-dehydration unit through a pipeline.

18. The system for grading and separately delivering a high viscous heavy oil according to claim 16, wherein the light fraction outlet of the fractionation unit is further connected to the oil blending unit and the desalination-dehydration unit through pipelines, respectively, the outlet of medium fraction in the fractionation unit is connected to the blending unit through a pipeline.

19. The system for grading and separately delivering a high viscous heavy oil according to claim 16, wherein the system further comprises a condensing device, and a stripped steam outlet of the stripping-evaporation unit is connected to the phase separation unit via the condensing device through a pipeline.

20. The system for grading and separately delivering a high viscous heavy oil according to claim 19, wherein a gas outlet of the separation unit is connected to the mixing section of the phase separation unit via the condensing device through a pipeline, and an liquid oily component outlet of the separation unit is connected to the desalination-dehydration unit through a pipeline.