Continuous blending method for fuel oil
Technical Field
The invention relates to a fuel oil continuous blending method, in particular to a residue type heavy fuel oil continuous blending method.
Background
Bunker fuel oils are typically made by blending a high viscosity component oil (typically a residual oil) with a low viscosity component oil. Because the high viscosity component oil has a high viscosity, the low viscosity component oil for blending generally adopts light component oil with a low viscosity such as catalytic diesel oil, slurry oil, shale oil and the like.
At present, the marine fuel oil blending mode mostly adopts a ground tank blending mode, and particularly adopts methods such as pump circulation, electric stirring and the like to uniformly mix high-viscosity component oil and low-viscosity component oil. Since the viscosity difference between the high-viscosity component oil and the low-viscosity component oil is large, it is necessary to heat and keep the component oil, particularly the high-viscosity component oil, during the blending process to reduce the viscosity of the high-viscosity component oil. Therefore, the blending mode is long in time consumption and high in energy consumption, is intermittent blending and cannot be used for continuous production.
The prior art discloses a marine fuel oil blending device, and the technical scheme is as follows: the light oil and the heavy oil enter the static mixer and the colloid mill through the valve, the pipeline and the flowmeter respectively, so that the preliminary mixing of the fuel oil and the refinement of the colloid are realized. However, in the case of the device, when the viscosity ratio and density of the heavy component oil and the light component oil are relatively high, the mixed oil is difficult to be uniformly mixed in the static mixer, the layering phenomenon is easily caused, the local heterogeneity is large, and after the mixed oil is refined by the colloid mill, the colloid particle size is reduced, but the uniform mixing is difficult. Meanwhile, the colloid mill has higher power and higher energy consumption.
In addition, the prior art also discloses a heavy bunker fuel oil blending device, and the technical scheme is as follows: the heavy oil is respectively mixed with the backflow blend oil and the at least two light oil components in the static mixer according to a certain proportion, the viscosity of the blend oil is gradually reduced, and then the blend oil is fully mixed in the shearing mixing unit, so that the local uneven mixing caused by the large difference between the viscosity and the density of the heavy oil and the light oil is avoided. However, in the method, the heavy component oil needs to be heated to reduce the viscosity, and then the heavy component oil and the light component oil are subjected to gradual viscosity reduction in a static mixer, so that the energy consumption is high in the heating and heat preservation processes. And the blended oil is subjected to shear mixing through the shear mixing unit, so that the energy consumption in the process is high. In conclusion, the method is continuous blending, but has high energy consumption and large equipment investment.
Disclosure of Invention
In order to overcome the problems of the prior art, the invention provides a novel fuel oil continuous blending method, which solves the problems of low production efficiency, long blending time and high energy consumption of the traditional intermittent tank type blending method by utilizing an oil reservoir and a high-viscosity and low-viscosity component oil heat exchange mode, and improves the safety production capacity when the production process is in an underground oil reservoir. The safe, continuous, homogeneous and efficient blending of the heavy fuel oil is realized.
The technical scheme of the invention is as follows:
a method for continuously blending fuel oil, comprising:
(1) Delivering the low viscosity component oil into a first reservoir formation, and preheating the low viscosity component oil with geothermal energy to increase its temperature;
(2) Mixing and shearing the preheated low-viscosity component oil and the high-viscosity component oil in a second oil reservoir layer to obtain mixed oil;
(3) And (3) carrying out heat exchange on the mixed oil and the high-viscosity component oil, increasing the temperature of the high-viscosity component oil, and reducing the temperature of the mixed oil to be below the flash point of the mixed oil to obtain the fuel oil.
In the invention, the oil reservoir is a sandstone oil reservoir, the permeability range of the reservoir is 10 millidarcy-1000 millidarcy, and the oil reservoir temperature is within the range of 50-300 ℃. The first reservoir and the second reservoir may be in one reservoir, or may be two or more reservoirs connected in parallel or in series. According to the invention, the low-viscosity component oil is preheated by utilizing the geothermal energy of the sandstone reservoir, and the high-viscosity component oil is sheared and mixed for many times by utilizing the porous medium structure of the sandstone reservoir, so that the high-viscosity component oil and the low-viscosity component oil are mixed more fully.
In order to obtain better mixing effect and improve the quality of the fuel oil, in the step (2), the low-viscosity component oil and the high-viscosity component oil are subjected to heat exchange for 1 time or more, so that the temperature of the high-viscosity component oil is improved, the viscosity of the high-viscosity component oil is reduced, the pipe conveying resistance is reduced, and the mixing effect is improved. The specific number of times can be determined according to the type of the raw oil.
The blending method is not only suitable for marine fuel oil, but also suitable for fuel oil of other purposes, such as fraction fuel oil, residual fuel oil and lubricating oil.
In the present invention, the low viscosity component oil is a low viscosity component oil having a relatively low viscosity such as catalytic diesel oil, slurry oil, shale oil, diesel oil, etc., and usually has a viscosity of 1 to 120mm 2 In the range of/s. Said low viscosityThe oil can be one or more of catalytic diesel oil, slurry oil, shale oil, diesel oil, etc.
In the present invention, the high viscosity component oil refers to residual oil, slurry oil, crude oil, etc., and generally has a viscosity of 200 to 10000mm 2 In the range of/s. The high-viscosity component oil can be one or more than two of residual oil, slurry oil, crude oil and the like.
Further, in the step (1), the preheating refers to heating the low-viscosity component oil to raise the temperature of the low-viscosity component oil to be more than 50 ℃, and a heat source in the preheating process is geothermal heat from the first reservoir stratum.
Further, in the step (2), the mixing ratio and flow rate of the high-viscosity component oil and the low-viscosity component oil can be determined by those skilled in the art according to the properties of the raw material oil and the target fuel oil in combination with the general knowledge.
Compared with the existing fuel oil blending method, the method has the advantages that:
according to the invention, the temperature rise and the viscosity reduction of the high-viscosity component oil are realized by utilizing the special geological structure and the geothermal resources of the sandstone oil reservoir and adopting a heat energy exchange mode, so that the viscosity and density difference of the high-viscosity component oil and the low-viscosity component oil is reduced; the problem of local uneven mixing caused by large viscosity and density difference of heavy oil and light oil in the prior art is avoided; compared with the traditional blending method, the energy consumption of heating and heat preservation of the high-viscosity component oil is reduced; meanwhile, by utilizing the geological characteristics of the sandstone reservoir stratum, the high-viscosity component oil and the low-viscosity component oil are fully sheared and mixed in the flowing process of the reservoir stratum, so that the stability of the oil product is improved. Realizes low-cost continuous blending.
Drawings
FIG. 1 is a schematic diagram of the continuous blending method of bunker fuel oil according to the present invention.
In the figure: 1. a low viscosity component oil; 2. a first reservoir; 3. a preheated low viscosity component oil; 4. high-viscosity component oil after first heat exchange; 5. high-viscosity component oil after the second heat exchange; 6. a low viscosity component oil after heat exchange; 7. a second reservoir; 8. mixing the oil; 9. a fuel oil; 10. a high viscosity component oil; 11. a heat exchanger; 12. a heat exchanger.
Detailed Description
The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
Example 1
As shown in fig. 1, the present embodiment provides a method for continuously blending bunker fuel, comprising the following steps:
step (1): mixing low viscosity component oil 1 (catalytic diesel oil and oil slurry mixture, viscosity of 80mm at 50 deg.C) 2 S) is transported from the surface into the first reservoir 2 for preheating in order to raise its temperature to 100 ℃;
step (2): conveying the low-viscosity component oil 3 preheated in the first reservoir stratum 2 to the ground, and carrying out heat exchange on the high-viscosity component oil 4 (hydrogenated residual oil, the viscosity of which is 300mm at the temperature of 50 ℃) after the first heat exchange 2 /s) second heat exchange is performed by the heat exchanger 11 to raise the temperature of the high-viscosity component oil 4;
and (3): conveying the high-viscosity component oil 5 subjected to the second heat exchange and temperature increase and the low-viscosity component oil 6 subjected to the heat exchange to a second oil reservoir 7 according to a certain proportion and flow rate, and mixing and shearing in the reservoir; the mixing proportion and the flow rate can be determined by the person skilled in the art according to the requirements of raw oil and fuel oil;
and (4): transporting the mixed oil 8 mixed in the second reservoir layer 7 to the ground, carrying out first heat exchange with the high-viscosity component oil 10 through a heat exchanger 12, and reducing the temperature of the mixed oil to be below the flash point of the fuel oil to obtain a marine fuel oil product 9 (the viscosity is 165mm under the condition of 50 ℃), wherein 2 /s)。
The first reservoir and the second reservoir refer to sandstone reservoir reservoirs, the permeability range is 500 millidarcy, and the reservoir temperature is 150 ℃.
Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.