Preparation method of heavy oil hydrogen donor

Abstract

The invention relates to the technical field of crude oil catalysis, in particular to a preparation method of a heavy oil hydrogen donor, which comprises the following steps: A, crushing biomass by a crusher, screening, and preparing the obtained biomass particles into slurry biomass; and B, conveying the slurry biomass into a steam pipeline through a conveying pump, introducing steam generated in a steam boiler into the steam pipeline, and liquefying the slurry biomass under the action of the steam to obtain the heavy oil hydrogen donor. According to the method, after biomass is liquefied through heat of steam, the generated hydrogen donor can enter the stratum along with the steam, the hydrogen donor and the thickened oil are subjected to hydrothermal cracking, in-situ modification is conducted on the thickened oil, modification and viscosity reduction are conducted on the thickened oil, and the purpose of improving the recovery rate is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of crude oil catalysis, and in particular to a method for preparing a heavy oil hydrogen donor. Background Art

[0002] With the in-depth development of oil fields, shallow light crude oil is gradually decreasing. Therefore, the effective exploitation of heavy oil resources has become crucial. At present, there are many technologies for heavy oil extraction, mainly including thermal oil recovery (such as steam drive, steam huff and puff, burning oil layers, etc.), chemical oil recovery and mechanical oil recovery. In my country, miscible gas injection oil recovery technology has been widely used. In order to improve the efficiency of heavy oil steam injection extraction, common methods include injecting nitrogen, air, mixed gas and chemicals. Among them, steam injection is the most common method. However, this method also faces the problem of high cost, requiring a large amount of steam generation equipment and energy, and has a strong dependence on water resources. Therefore, its application is limited in areas with water shortage or expensive water prices. In addition, the complexity of the technology and the difficulty of operation also affect its effect, especially in heterogeneous reservoirs, where uneven steam coverage may lead to a decrease in recovery.

[0003] Chinese invention patent document CN 107664031 A (application number 201610620741.9) discloses a method for improving oil recovery by determining the well pattern of steam drive in horizontal wells. The method involves: selecting physical parameters of the horizontal well steam drive oil layer, optimizing the deployment of horizontal wells, steam injection before conversion to steam drive, determining the well pattern and timing of steam drive, and setting other steam drive parameters. It is suitable for shallow and medium-deep ultra-heavy oil reservoirs, and improves the oil recovery effect by converting steam injection to steam drive, significantly improving the oil recovery. However, this method still uses high-temperature steam to drive oil, and the effect will decrease as the depth of the oil layer increases.

[0004] Chinese invention patent document CN103670351A (application number 201210345782.3) discloses a steam flooding method for heavy oil reservoirs, comprising: injecting an aqueous solution of an oil displacement agent into the reservoir stratum while performing steam flooding; the oil displacement agent contains 0.001 to 20 parts of sodium salt and / or calcium salt of sulfonated phenolic resin, 0.001 to 20 parts of nonionic surfactant for oil displacement and / or nonionic-anionic surfactant for oil displacement by mass; the number average molecular weight of the sulfonated phenolic resin is 2000 to 200000, and the mass fraction of sulfur in the sulfonated phenolic resin is 5% to 20%. Although this method improves the recovery rate of steam flooding, the mixing of chemical reagents inevitably enters the stratum, which will cause environmental pollution and increase the difficulty of secondary treatment of heavy oil.

[0005] In summary, steam-assisted oil recovery by mixing certain other fluids into steam is a widely used method. However, how to balance the decrease in heat transfer efficiency of steam as the depth of the formation increases and the environmental pollution caused by the addition of chemical reagents is an urgent problem to be solved in the field of heavy oil extraction. Summary of the invention

[0006] In order to solve the above technical problems, an embodiment of the present invention provides a method for preparing a heavy oil hydrogen donor.

[0007] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0008] The present invention provides a method for preparing a heavy oil hydrogen donor, comprising the following steps:

[0009] A. crushing the biomass by a crusher and then screening the obtained biomass particles to prepare slurry biomass;

[0010] B. The slurry biomass is transported to the steam pipeline by a delivery pump. Steam generated by a steam boiler is introduced into the steam pipeline. Under the action of the steam, the slurry biomass is liquefied to obtain a heavy oil hydrogen supply agent.

[0011] In some embodiments, in step A, the biomass includes at least one of sawdust, microcrystalline cellulose, lignin, chlorella, liquidambar leaves, wheat straw, corn stalks, paper scraps, cherry blossoms, rape blossoms, bamboo, crabapple blossoms, morning glory, mugwort, clover, bagasse, qingming vegetable, melon seed shells, orange peels, banana peels, grapefruit peels, poultry hair, pig manure and cow manure.

[0012] In some embodiments, in step A, the biomass particles have a mesh size of 200-500 mesh.

[0013] In some embodiments, in step B, the temperature of the steam is 260°C to 380°C.

[0014] In some embodiments, in step B, the volume ratio of the slurry biomass to steam is 1:(5-15).

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] This method uses the heat of steam to liquefy biomass, and the generated hydrogen donor can enter the formation with the steam. The hydrogen donor will undergo aquathermal cracking with the heavy oil, and the heavy oil will be modified in situ to reduce the viscosity of the heavy oil, thereby achieving the purpose of improving the recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the production and injection of the heavy oil hydrogen donor of the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.

[0019] The embodiment of the present application provides a method for preparing a heavy oil hydrogen donor. In the process of steam drive production, biomass is mixed into the steam injection process, wherein the volume ratio of biomass to steam is 1 / 5 to 1 / 20. Under the action of steam, the biomass is liquefied and converted into a mixture of bio-crude oil and steam. The bio-crude oil contains methoxy compounds, small molecule alcohols, etc., and can enter the formation with the steam to perform in-situ modification of the heavy oil.

[0020] Specifically, the steps include:

[0021] First, the biomass is pretreated, the biomass is crushed by a pulverizer and then sieved, and the biomass particles of 200-500 mesh are mixed with liquid at a mass ratio of 1:10 to prepare slurry biomass, and the liquid can be waste water solution, backflow liquid, domestic sewage or mineral water from the oil field, wherein the petroleum content of the waste water solution of the oil field is greater than 0.05ppm, the residual peroxide concentration of the backflow liquid is 60-120mg / L, the chemical demand COD concentration of domestic sewage is 300-500mg / L, the biochemical oxygen demand BOD concentration is 180-250mg / L, and the mineral water concentration is greater than 1000mg / L.

[0022] The slurry biomass is transported by a transport pump 1 .

[0023] like Figure 1 As shown, the slurry biomass is transported into the steam pipeline 2 by using the delivery pump 1. The injection position of the slurry biomass can be located at the outlet of the steam boiler 3, the wellhead, the wellbore and the formation. During the well soaking process, the steam pipeline 2 continuously injects steam, and the steam temperature is between 260 and 380°C. During the injection process, it will be mixed with the continuously injected slurry biomass. The temperature of biomass liquefaction is between 280 and 350°C. During the mixing process, the steam will liquefy the biomass to produce bio-crude oil, and form bio-crude oil vapor droplets at high temperature, which follow the steam into the formation.

[0024] The mixture of steam and bio-crude oil will reach the formation through the injection well 4 and contact the heavy oil. After 3-7 days of well soaking, the hydrogen donor in the bio-crude oil will undergo aquathermal cracking with the heavy oil to perform in-situ modification of the heavy oil. Then the production well 5 will be opened for oil production.

[0025] The biomass mentioned above includes at least one of sawdust, microcrystalline cellulose, lignin, chlorella, liquidambar leaves, wheat straw, corn stalks, paper scraps, cherry blossoms, rape blossoms, bamboo, crabapple blossoms, morning glory, mugwort, clover, bagasse, qingming vegetables, melon seed shells, orange peels, banana peels, grapefruit peels, poultry hair, pig manure and cow manure.

[0026] Table 1 below shows the physical properties of existing heavy oil:

[0027] Table 1 Physical properties of two heavy oils

[0028]

[0029] In order to illustrate the viscosity reduction effect of heavy oil, the viscosity reduction rate is used in the following, and the calculation formula is as follows:

[0030] Viscosity reduction rate = (viscosity of heavy oil before modification - viscosity of heavy oil after modification) / viscosity of heavy oil before modification * 100%

[0031] The following will be analyzed and explained through specific examples.

[0032] Example 1

[0033] First, the sawdust is pretreated, the sawdust is crushed by a pulverizer and then screened, the 200-mesh sawdust particles are mixed with the return liquid at a mass ratio of 1:10 to prepare slurry biomass, and the slurry biomass is transported by the delivery pump 1. Steam is continuously injected into the steam pipe 2, the steam temperature is 360°C, and it will be mixed with the continuously injected slurry sawdust during the injection process. The volume ratio of slurry sawdust to steam is 1 / 8, and the temperature of slurry sawdust liquefaction is 320°C. During the mixing process, the steam will liquefy the sawdust (the hydrothermal reaction of biomass below 400°C is called liquefaction), produce bio-crude oil, and form bio-crude oil vapor droplets at high temperature, which follow the steam into the formation through the injection well 4. The mixture of steam and bio-crude oil is injected into the 1# well and contacts the heavy oil. After 5 days of well stewing, the hydrogen donor in the bio-crude oil will undergo hydrothermal cracking with the heavy oil, and the heavy oil will be modified in situ, and then the production well 5 will be opened for oil production. The viscosity of the dehydrated heavy oil in Well 1# was 4630 mPa·s, and the viscosity reduction rate was 63.0%.

[0034] Example 2

[0035] First, the chlorella is pretreated, the chlorella is crushed by a pulverizer and then sieved, the 300-mesh chlorella particles are mixed with domestic sewage at a mass ratio of 1:10 to prepare slurry chlorella, and the slurry chlorella is transported by a delivery pump 1. Steam is continuously injected into the steam pipe 2, and the steam temperature is 350°C. During the injection process, it will be mixed with the continuously injected slurry chlorella. The volume ratio of slurry chlorella to steam is 1 / 10. The temperature of liquefaction of chlorella is 300°C. During the mixing process, the steam will liquefy the chlorella to produce bio-crude oil, and form bio-crude oil steam droplets at high temperature, which follow the steam into the formation through the injection well 4. The mixture of steam and bio-crude oil is injected into the 1# well and contacts the heavy oil. After 6 days of well stewing, the hydrogen donor in the bio-crude oil will undergo aquathermal cracking with the heavy oil, and the heavy oil will be modified in situ, and then the production well 5 will be opened for oil production. The viscosity of the dehydrated heavy oil in Well 1# was 2350 mPa·s, and the viscosity reduction rate was 81.2%.

[0036] Example 3

[0037] First, the liquidambar leaves are pretreated, the liquidambar leaves are crushed by a pulverizer and then sieved, the liquidambar leaf particles of 500 mesh are mixed with the return liquid at a mass ratio of 1:10 to prepare slurry liquidambar leaves, and the slurry liquidambar leaves are transported by a delivery pump 1. Steam is continuously injected into the steam pipe 2, and the steam temperature is 360°C. During the injection process, it will be mixed with the continuously injected slurry liquidambar leaves. The volume ratio of slurry liquidambar leaves to steam is 1 / 15. The temperature of liquidambar leaves liquefaction is 290°C. During the mixing process, the steam will liquefy the liquidambar leaves to produce bio-crude oil, and form bio-crude oil vapor droplets at high temperature, which follow the steam into the formation through the injection well 4. The mixture of steam and bio-crude oil is injected into the 1# well and contacts the heavy oil. After 7 days of well stewing, the hydrogen donor in the bio-crude oil will undergo aquathermal cracking with the heavy oil, and the heavy oil will be modified in situ, and then the production well 5 will be opened for oil production. The viscosity of the dehydrated heavy oil in Well 1# was 4310 mPa·s, and the viscosity reduction rate was 65.5%.

[0038] Example 4

[0039] First, the wheat straw is pretreated, the wheat straw is crushed by a pulverizer and then screened, the 400-mesh wheat straw particles are mixed with domestic sewage at a mass ratio of 1:10 to prepare slurry wheat straw, and the slurry wheat straw is transported by a delivery pump 1. Steam is continuously injected into the steam pipe 2, the steam temperature is 360°C, and it will be mixed with the continuously injected slurry wheat straw during the injection process. The volume ratio of slurry wheat straw to steam is 1 / 10. The temperature of wheat straw liquefaction is 330°C. During the mixing process, steam will liquefy the wheat straw to produce bio-crude oil, and form bio-crude oil vapor droplets at high temperature, which follow the steam into the formation through the injection well 4. The mixture of steam and bio-crude oil is injected into the 1# well and contacts the heavy oil. After 5 days of well stewing, the hydrogen donor in the bio-crude oil will undergo aquathermal cracking with the heavy oil, and the heavy oil will be in situ modified. Then the production well 5 is opened for oil production. The viscosity of the dehydrated heavy oil in the 1# well is 3320mPa·s, and the viscosity reduction rate is 73.4%.

[0040] Example 5

[0041] First, corn stalks are pretreated, the corn stalks are crushed by a pulverizer and then screened, 500-mesh corn stalk particles are mixed with mineralized water at a mass ratio of 1:10 to prepare slurry corn stalks, and the slurry corn stalks are transported by a delivery pump 1. Steam is continuously injected into the steam pipe 2, and the steam temperature is 320°C. During the injection process, it will be mixed with the continuously injected slurry corn stalks. The volume ratio of slurry corn stalks to steam is 1 / 15. The temperature of biomass liquefaction is 310°C. During the mixing process, the steam will liquefy the corn stalks to produce bio-crude oil, and form bio-crude oil vapor droplets at high temperature, which follow the steam into the formation through the injection well 4. The mixture of steam and bio-crude oil is injected into the 1# well and contacts the heavy oil. After 6 days of well stewing, the hydrogen donor in the bio-crude oil will undergo aquathermal cracking with the heavy oil, and the heavy oil will be in situ modified. Then the production well 5 is opened for oil production. The viscosity of the dehydrated heavy oil in the 1# well is 3890mPa·s, and the viscosity reduction rate is 68.9%.

[0042] Example 6

[0043] First, the paper scraps are pretreated, the paper scraps are crushed by a crusher and then screened, and the 300-mesh paper scrap particles are mixed with the return liquid at a mass ratio of 1:10 to prepare slurry paper scraps, and the slurry paper scraps are transported by a delivery pump 1. Steam is continuously injected into the steam pipe 2, and the steam temperature is 350°C. During the injection process, it will be mixed with the continuously injected slurry paper scraps. The volume ratio of slurry paper scraps to steam is 1 / 10. The temperature of paper scrap liquefaction is 330°C. During the mixing process, the steam will liquefy the waste paper to produce bio-crude oil, and form bio-crude oil vapor droplets at high temperature, which follow the steam into the formation through the injection well 4. The mixture of steam and bio-crude oil is injected into the 2# well and contacts the heavy oil. After 7 days of well stewing, the hydrogen donor in the bio-crude oil will undergo aquathermal cracking with the heavy oil, and the heavy oil will be in-situ modified. Then the production well 5 is opened for oil production. The viscosity of the dehydrated heavy oil in the 2# well is 8360mPa·s, and the viscosity reduction rate is 82.5%.

[0044] Example 7

[0045] First, the bagasse is pretreated, the bagasse is crushed by a crusher and then screened, the 500-mesh bagasse particles are mixed with domestic sewage at a mass ratio of 1:10 to prepare slurry bagasse, and the slurry bagasse is transported by a delivery pump 1. Steam is continuously injected into the steam pipe 2, the steam temperature is 360°C, and it will be mixed with the continuously injected slurry bagasse during the injection process. The volume ratio of slurry bagasse to steam is 1 / 5. The temperature of biomass liquefaction is 320°C. During the mixing process, the steam will liquefy the bagasse to produce bio-crude oil, and form bio-crude oil vapor droplets at high temperature, which follow the steam into the formation through the injection well 4. The mixture of high-temperature steam and bio-crude oil is injected into the 2# well to contact the heavy oil. After 5 days of well stewing, the hydrogen donor in the bio-crude oil will undergo aquathermal cracking with the heavy oil, and the heavy oil will be modified in situ, and then the production well 5 will be opened for oil production. The viscosity of the dehydrated heavy oil in Well 2# was 6040 mPa·s, and the viscosity reduction rate was 87.4%.

[0046] Example 8

[0047] First, the melon seed shells are pretreated, crushed by a crusher and then sieved, and the 400-mesh melon seed shell particles are mixed with mineral water at a mass ratio of 1:10 to prepare slurry melon seed shells, which are then transported by a delivery pump 1. Steam is continuously injected into the steam pipe 2, and the steam temperature is 330°C. During the injection process, the steam will mix with the continuously injected slurry melon seed shells. The volume ratio of the slurry melon seed shells to the steam is 1 / 15. The temperature of the melon seed shell liquefaction is 300°C. During the mixing process, the steam will liquefy the melon seed shells to produce bio-crude oil, and form bio-crude oil vapor droplets at high temperature, which follow the steam into the formation through the injection well 4. The mixture of steam and bio-crude oil is injected into the 2# well and contacts the heavy oil. After 4 days of well stewing, the hydrogen donor in the bio-crude oil will undergo aquathermal cracking with the heavy oil, and the heavy oil will be modified in situ, and then the production well 5 will be opened for oil production. The viscosity of the dehydrated heavy oil in Well 2# was 7820 mPa·s, and the viscosity reduction rate was 83.6%.

[0048] Example 9

[0049] First, banana peels are pretreated, crushed by a crusher and then sieved, and banana peel particles of 200 mesh are mixed with domestic sewage at a mass ratio of 1:10 to prepare slurry banana peels, which are transported by a delivery pump 1. Steam is continuously injected into steam pipe 2, and the steam temperature is 360°C. During the injection process, it will be mixed with the continuously injected slurry banana peels. The volume ratio of slurry banana peels to steam is 1 / 8. The temperature of banana peel liquefaction is 340°C. During the mixing process, steam will liquefy banana peels to produce bio-crude oil, and form bio-crude oil vapor droplets at high temperature, which follow the steam into the formation through injection well 4. The mixture of steam and bio-crude oil is injected into well 2# and contacts the heavy oil. After 7 days of well stewing, the hydrogen donor in the bio-crude oil will undergo aquathermal cracking with the heavy oil, and the heavy oil will be in situ modified. Then the production well 5 is opened for oil production. The viscosity of the dehydrated heavy oil in well 2# is 6170mPa·s, and the viscosity reduction rate is 87.1%.

[0050] Example 10

[0051] First, the poultry hair is pretreated, the poultry hair is crushed by a pulverizer and then sieved, the 400-mesh poultry hair particles are mixed with mineral water at a mass ratio of 1:10 to prepare slurry poultry hair, and the slurry poultry hair is transported by a delivery pump 1. Steam is continuously injected into the steam pipe 2, and the steam temperature is 320°C. During the injection process, it will be mixed with the continuously injected slurry poultry hair. The volume ratio of slurry biomass to steam is 1 / 10. The temperature of poultry hair liquefaction is 280°C. During the mixing process, the steam will liquefy the poultry hair to produce bio-crude oil, and form bio-crude oil vapor droplets at high temperature, which follow the steam into the formation through the injection well 4. The mixture of steam and bio-crude oil is injected into the 2# well and contacts the heavy oil. After 6 days of well stewing, the hydrogen donor in the bio-crude oil will undergo aquathermal cracking with the heavy oil, and the heavy oil will be modified in situ, and then the production well 5 will be opened for oil production. The viscosity of the dehydrated heavy oil in Well 2# was 6220 mPa·s, and the viscosity reduction rate was 87.0%.

[0052] The viscosity changes of 1# and 2# heavy oils after hydrothermal in-situ modification of different biomasses were obtained from Examples 1-10, and the results are shown in Table 2 below.

[0053] Table 2 Viscosity of heavy oil after hydrothermal modification of different biomass

[0054]

[0055]

[0056] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0057] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing a heavy oil hydrogen donor, characterized in that: The following steps are involved: A. crushing the biomass by a crusher and then screening the obtained biomass particles to prepare slurry biomass; B. The slurry biomass is transported to the steam pipeline by a delivery pump. Steam generated by a steam boiler is introduced into the steam pipeline. Under the action of the steam, the slurry biomass is liquefied to obtain a heavy oil hydrogen supply agent.

2. The preparation method according to claim 1, characterized in that: In step A, the biomass includes at least one of sawdust, microcrystalline cellulose, lignin, chlorella, liquidambar leaves, wheat straw, corn stalks, paper scraps, cherry blossoms, rape blossoms, bamboo, crabapple blossoms, morning glory, mugwort, clover, bagasse, qingming vegetable, melon seed shells, orange peels, banana peels, grapefruit peels, poultry hair, pig manure and cow manure.

3. The preparation method according to claim 1, characterized in that: In step A, the mesh size of the biomass particles is 200-500 meshes.

4. The preparation method according to claim 1, characterized in that: In step B, the temperature of the steam is 260°C to 380°C.

5. The preparation method according to claim 1, characterized in that: In step B, the volume ratio of the slurry biomass to steam is 1:(5-15).

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