CA2933277C - A centrally thermal recovery method for excavating oil from an oil reservoir by electrically heating edge-bottom water layer with horizontal wells - Google Patents
A centrally thermal recovery method for excavating oil from an oil reservoir by electrically heating edge-bottom water layer with horizontal wells Download PDFInfo
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- CA2933277C CA2933277C CA2933277A CA2933277A CA2933277C CA 2933277 C CA2933277 C CA 2933277C CA 2933277 A CA2933277 A CA 2933277A CA 2933277 A CA2933277 A CA 2933277A CA 2933277 C CA2933277 C CA 2933277C
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 76
- 238000000034 method Methods 0.000 title claims abstract description 38
- 238000011084 recovery Methods 0.000 title claims abstract description 26
- 238000010438 heat treatment Methods 0.000 title claims description 39
- 239000003921 oil Substances 0.000 claims abstract description 98
- 238000009413 insulation Methods 0.000 claims abstract description 23
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 12
- 239000010779 crude oil Substances 0.000 claims abstract description 5
- 238000004519 manufacturing process Methods 0.000 claims description 15
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- 238000005755 formation reaction Methods 0.000 claims description 14
- 230000000694 effects Effects 0.000 claims description 10
- 238000009835 boiling Methods 0.000 claims description 9
- 238000007789 sealing Methods 0.000 claims description 8
- 238000010795 Steam Flooding Methods 0.000 claims description 5
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- 230000005484 gravity Effects 0.000 claims description 4
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- 239000002826 coolant Substances 0.000 claims 1
- 238000012544 monitoring process Methods 0.000 claims 1
- 239000008398 formation water Substances 0.000 description 7
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- 238000011065 in-situ storage Methods 0.000 description 4
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- 230000007613 environmental effect Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000005086 pumping Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 239000012188 paraffin wax Substances 0.000 description 2
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- 230000003247 decreasing effect Effects 0.000 description 1
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- 238000005485 electric heating Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000008233 hard water Substances 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
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- 238000013508 migration Methods 0.000 description 1
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- 210000004080 milk Anatomy 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 239000004058 oil shale Substances 0.000 description 1
- 239000003129 oil well Substances 0.000 description 1
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection
- E21B43/2401—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection by means of electricity
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B36/00—Heating, cooling, insulating arrangements for boreholes or wells, e.g. for use in permafrost zones
- E21B36/04—Heating, cooling, insulating arrangements for boreholes or wells, e.g. for use in permafrost zones using electrical heaters
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/06—Measuring temperature or pressure
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/06—Measuring temperature or pressure
- E21B47/07—Temperature
Abstract
A centrally thermal recovery method for excavating oil from an oil reservoir, especially deep-ultra deep oil reservoir, is disclosed. Several horizontal wells, in which electric heaters are configured to be positioned, are drilled in upper edge-bottom water layer of the reservoir, to centrally electrically heat the edge-bottom water layer until temperatures in the whole oil reservoir rise up to a status of mobilized crude oil An electric heater is also disclosed. A slotted liner of the horizontal well is divided into upper and lower parts by a heat insulation board. The upper part is slotted, in which several ferrite permanent magnet bars are fixed on the internal surface, and a waterproof spring electric heater in series are provided on the heat insulation board, while the lower part is sealed in vacuum.
Description
A Centrally Thermal Recovery Method for Excavating Oil from an Oil Reservoir by Electrically Heating Edge-Bottom Water Layer with Horizontal Wells Technical Field [1] This centrally thermal recovery method is applicable to oil reservoirs with edge-bottom water layers, such as heavy oil reservoirs and high pour-point oil reservoirs, which can be thermally recovered in oil industry. This centrally thermal recovery method resolves the problems of in-place oil with high viscosity or high paraffin content, low thermal-recovery efficiency of huff and puff or steam flooding, short production plateau, high decline rate and low oil recovery.
Technical Background
Technical Background
[2] Huff and puff, steam flooding, hot-water flooding and in-situ combustion are examples of efficient technical methods in thermal recovery. However, with increases in in-depth oil well development, more and more problems with these methods are being exposed during production. Especially for the middle-deep and super-deep reservoirs (depth 600-2300m), the contradiction during production is gradually becoming more severe: (1) Because of long distance transportation of the steam and hot water, huff and puff, steam flooding and hot-water flooding have severe thermal loss and low thermal efficiency. Other problems which impact final reservoir recovery include high water cut, low production rate, and high decline rate in production well; (2) Although in-situ combustion is effective to production test some common-heavy oil fault blocks and can satisfy the requirements of industry, it cannot be applied to most of the extra and super-heavy oil reservoirs. In addition, this development method is destructive and is akin to draining the pond to catch all the fish or killing the goose that lays the golden eggs. Once the reservoir is destroyed, any advanced thermal-recovery method invented in the future cannot be carried out. That is, only in-situ combustion can be followed; (3) at present, electrically heating method is confined to heating the pumping rod and borehole. Its purpose is to improve the oil and gas lifting ability of the production well, and to reduce oil viscosity and the phenomenon of paraffin precipitation near the wellbore; (4) as for the in-situ thermal-recovery method of hydraulic-fractured electrically heating oil-shale by horizontal wells, it would be difficult, costly, and severely contaminative to apply it into heavy oil reservoirs; 5) At present, all thermal-recovery methods belong to a method of locally heating oil layers. In these methods, oil layers are heated unevenly and there exists only a short thermal effective time, low efficiency and high residual oil saturation, which is mainly located in thermal un-swept regions and low heat efficiency areas.
Summary of the Invention According to an aspect of the invention, there is provided a method for thermal recovery of oil from an oil reservoir said oil reservoir comprising an upper edge-bottom water layer proximal to oil layers within the oil reservoir, said oil reservoir is at a first temperature and comprising a quantity of in-place oil, said method comprising:
providing several horizontal wells extending into the oil reservoir, each horizontal well comprising an electric heater positioned in the upper edge-bottom water layer of the oil reservoir;
electrically heating the edge-bottom water layer with the electric heaters until the temperature of the oil reservoir increases such that all of the in-place oil becomes mobile and flows; and recovering the mobilized oil.
According to another aspect of the invention, there is provided an electric heater thermal recovery system, comprising, an electric heater comprising an inner liner comprising an upper liner and a lower liner;
several ferrite permanent magnet bars fixed at a top of the upper liner, waterproof spring electrical heating bars in series connection in a middle part of the upper liner; and a heat insulation board set at a horizontal diameter of the inner liner;
wherein the lower liner, in cooperation with the heat insulation board insulates heat, and is vacuum-sealed to reduce downward transmission of thermal energy.
According to another aspect of the invention, there is provided a method for centrally thermal recovery of oil from an oil reservoir, said oil reservoir comprising an upper edge-bottom water layer proximal to oil layers within the oil reservoir, said oil reservoir is at a first temperature and comprises a quantity of in-place oil, said method comprising: providing several horizontal wells extending into the oil reservoir, each horizontal well comprising an electric heater thermal recovery system comprising: an electric heater comprising an inner liner comprising a slotted liner and a vacuum-sealed liner, said electric heater positioned in the upper edge-bottom water layer of the oil reservoir; several ferrite permanent magnet bars fixed at a top of the slotted liner to protect the electric heater from scaling; waterproof spring electrical heating bars in series connection in the slotted liner to generate heat; and a heat insulation board set in the inner liner; wherein the vacuum-sealed liner, in cooperation with the heat insulation board insulates heat, and is vacuum-sealed to reduce downward transmission of thermal energy; centrally electrically heating the edge-bottom water layer with the electric heaters until the temperature of the whole oil reservoir increases such that all of the in-place oil becomes mobile and flows; and centrally recovering the mobilized oil.
According to another aspect of the invention, there is provided an electric heater thermal recovery system, comprising, an electric heater comprising an inner liner comprising a slotted liner and a vacuum-sealed liner divided into two parts by a heat insulation board; the heat insulation board set in the inner liner;
waterproof spiral electrical heating bars in series connection provided on the heat insulation board in the slotted liner; several ferrite permanent magnet bars fixed at a top of the slotted liner, a sealing board provided on either side of the vacuum-sealed liner; wherein the vacuum-sealed liner, in cooperation with the heat insulation board insulates heat, and is vacuum-sealed by the sealing board and the heat insulation board to reduce downward transmission of thermal energy.
Summary of the Invention According to an aspect of the invention, there is provided a method for thermal recovery of oil from an oil reservoir said oil reservoir comprising an upper edge-bottom water layer proximal to oil layers within the oil reservoir, said oil reservoir is at a first temperature and comprising a quantity of in-place oil, said method comprising:
providing several horizontal wells extending into the oil reservoir, each horizontal well comprising an electric heater positioned in the upper edge-bottom water layer of the oil reservoir;
electrically heating the edge-bottom water layer with the electric heaters until the temperature of the oil reservoir increases such that all of the in-place oil becomes mobile and flows; and recovering the mobilized oil.
According to another aspect of the invention, there is provided an electric heater thermal recovery system, comprising, an electric heater comprising an inner liner comprising an upper liner and a lower liner;
several ferrite permanent magnet bars fixed at a top of the upper liner, waterproof spring electrical heating bars in series connection in a middle part of the upper liner; and a heat insulation board set at a horizontal diameter of the inner liner;
wherein the lower liner, in cooperation with the heat insulation board insulates heat, and is vacuum-sealed to reduce downward transmission of thermal energy.
According to another aspect of the invention, there is provided a method for centrally thermal recovery of oil from an oil reservoir, said oil reservoir comprising an upper edge-bottom water layer proximal to oil layers within the oil reservoir, said oil reservoir is at a first temperature and comprises a quantity of in-place oil, said method comprising: providing several horizontal wells extending into the oil reservoir, each horizontal well comprising an electric heater thermal recovery system comprising: an electric heater comprising an inner liner comprising a slotted liner and a vacuum-sealed liner, said electric heater positioned in the upper edge-bottom water layer of the oil reservoir; several ferrite permanent magnet bars fixed at a top of the slotted liner to protect the electric heater from scaling; waterproof spring electrical heating bars in series connection in the slotted liner to generate heat; and a heat insulation board set in the inner liner; wherein the vacuum-sealed liner, in cooperation with the heat insulation board insulates heat, and is vacuum-sealed to reduce downward transmission of thermal energy; centrally electrically heating the edge-bottom water layer with the electric heaters until the temperature of the whole oil reservoir increases such that all of the in-place oil becomes mobile and flows; and centrally recovering the mobilized oil.
According to another aspect of the invention, there is provided an electric heater thermal recovery system, comprising, an electric heater comprising an inner liner comprising a slotted liner and a vacuum-sealed liner divided into two parts by a heat insulation board; the heat insulation board set in the inner liner;
waterproof spiral electrical heating bars in series connection provided on the heat insulation board in the slotted liner; several ferrite permanent magnet bars fixed at a top of the slotted liner, a sealing board provided on either side of the vacuum-sealed liner; wherein the vacuum-sealed liner, in cooperation with the heat insulation board insulates heat, and is vacuum-sealed by the sealing board and the heat insulation board to reduce downward transmission of thermal energy.
3 Date Recue/Date Received 2020-04-17 Open Technical Problems about Invention [3] Principle Foundation
[4] 1. Centrally heating In cold, one gets heat by wearing a coat, and a family gets heat by having a fire in the house. For a large building, the best way of heating is central heating. The most economic, most effective, most convenient method among the three is central heating. During the process of thermal recovery, huff and puff in a single well is similar to one person getting heat and the composite huff and puff is similar to heating a house. If the whole reservoir can be regarded as a unit and heated with central heating, the formation temperature can be raised as a whole so that the thermal-recovery problems within a single well can be solved as well.
[5] 2. "Immersion heater" is a common electric heater and can be used to boil water, heat milk, boil coffee, and so on, characterized in that a container is heated from the outside. Once the container is waterproofed, the benefits of saving time, saving water, saving electric power and saving effort can all be realized, and at the same time it is cheap, convenient and effective. For edge-bottom water reservoirs, water is natural resource which makes it possible to electrically heat the water layer. The method is economical, environmental, simple and highly efficient so that it can meet the needs of oil production.
[6] 3. Cooking buns with a steamer is one typical example of getting a thermal effect by heating bottom water in daily life. There's no problem of continuously steaming as long as there is enough bottom-water. The pressure and temperature in the steamer will be released when the steamed buns are taken out of the steamer.
Similarly, when the edge-bottom water layer of a reservoir 3a Date Recue/Date Received 2020-04-17 is heated, the heat will conduct upwards to the whole reservoir gradually. The gradually accumulated reservoir pressure, which results from thermal expansion of the formations and fluids, and the temperature will be released with the oil production. Meanwhile, it is convenient to manage the extent of the temperature and the pressure rising up in the reservoir by controlling heating time and heating temperature. When the temperature in the edge-bottom water reservoir increases to the range of 80 C and 100 C, the in-place oil becomes "movable" and can be thermally recovered.
[714. Gravity differentiation phenomenon of cold and hot water When the ocean is heated by the Sun, the temperature of the top or surface water is warmer than that of the water closer to the bottom. The cold and hot water present a phenomenon of gravity differentiation if there's no effect of the ocean current. That is, the phenomenon of cold and hot water scrolling up-and-down will not occur. Heat loss only behaves as the heat conduction between cold and hot water. Therefore, the temperature of the whole reservoir can be effectively improved by continuously electrically heating the top of the water layer near the oil layer.
[8] Feasibility Demonstration:
[9] 1. As a petroleum system, the premise of oil and gas migration and accumulation is that the formations have characteristics, such as fine connection, well sealed overlying layers, high initial temperature and movable in-place oil. It can be inferred from crude oil having unmovable status that the temperature of the formation has decreased to a temperature that is much lower than the initial temperature. So, it can be realized that the oil in an effective channel can return to the movable state when the temperature is increased to a certain degree. The pores where the oil and gas could reach are all effective flow channel and the heat conduction in the formation is faster than that in the surrounding mudstones. Heat can conduct gradually from the bottom to the top and be kept effectively by the surrounding mudstone so that the "centrally heating" can be realized in the whole reservoir.
[10] 2.Reservoirs can be categorized into 10 types according to the distribution of oil, gas and water, such as block bottom-water oil reservoirs, layer-structure block bottom-water oil reservoirs, block edge-bottom and top-water oil reservoirs, layer-structure edge-water oil reservoir, block gas-cap (bottom-water) oil and gas reservoirs, block gas-cap and bottom-water oil and gas reservoirs, layer-structure gas-cap and bottom-water oil and gas reservoirs, layer-structure gas-cap oil and gas reservoirs, pure oil reservoirs, and pure gas reservoirs. Except for the pure oil reservoir, pure gas reservoir and layer-structure gas-cap oil and gas reservoir, most of the reservoirs develop edge and bottom water and contain adequate formation water resources, which provides sufficient material for electrically heating edge-bottom water layers with horizontal wells drilled in water layer.
[11] 3. Under the condition of a geothermal gradient between 2.5 C and 4.5 C/100m, the temperature of middle-deep layers and super-deep layers is between 35 C and 103.5 C although it can also be higher. The temperature difference is about 23.5-47.5 C for electrically heating the formation water from the initial formation temperature to the temperature of the reservoir at a range of 80-150 C under which in-place oil would be in a movable state. The deeper the formation water layer is, the less electric energy is needed. The higher the power of the electric heater is, the faster the water temperature rises. On the other hand, several electric heaters could be used simultaneously so that the formation temperature can be increased quickly;
[12] 4. Fora sealed reservoir heated as a whole, the characteristics of formation temperature and formation pressure rising is similar to that of a pressure cooker being heated. Under high pressure conditions, the boiling temperature of formation water is higher than 100 C. The relationship between water melting and boiling point and pressure demonstrates that when the formation pressure is between 3MPa and 20MPa, the water boiling temperature ranges from 132.9 C
to 211.4 C. The higher the pressure is, the higher the boiling point is. When the temperature is below the boiling point, the temperature in the reservoir could be raised up to the point at which the crude oil transitions to a movable state.
Therefore, it is feasible to control the lifting range of formation water temperature and pressure by keeping heating the formation water under high temperature and high pressure, as long as the temperature and pressure test is monitored reasonably in combination with of the blowdown of production well and pressure release.
[13] 5. At present, all these techniques are relatively mature in pipeline skin effect current tracing system, borehole or pumping rod electrically heated system, in which the temperature can be controlled and the material has high temperature resistance, that can satisfy the long-distance transportation of electrical energy, so that problems, such as heating the production oil, heat dissipation of conductor, can be addressed and overcome.
[14] 6. When "immersion heater" is immersed in the liquid, heat energy can conduct outside quickly through the liquid and the liquid can be heated quickly, and simultaneously the electric wire will not be burned, which is safe, environmental, economical and effective.
[15] 7. The technique of electrically heating magnet descaling can effectively solve the scaling problem arising during electrically heating. The scale originates from hard water. Magnets can soften the water, which is environmental, economical, convenient and safe. Ferrite permanent magnets are widely used, and their components mainly include BaFe12019 and SrFe12019. They are made by ceramic technology, and have the characteristics of temperature resistance, moderate price and are suitable for wide application.
Solutions for the Problems Schemes of Technical Solutions [16] 1) According to the size of the reservoir, horizontal wells are drilled in the upper water layer of the edge-bottom water reservoir, 20-30m away from the oil layer. An electric heater is installed in the sieve pipe of the horizontal well to conduct electric heat to the water layer.
[17] 2) the structure of the electric heater of the horizontal well is shown in Fig.1. The liner of the horizontal-well is divided into upper and lower parts by a heat insulation board. The upper part is slotted, in which several spiral electric heaters with series connection are set on the board which is set at the horizontal diameter of the liner. In the lower part, the liner is sealed in vacuum by a liner sealing board to insulate heat transferred downward in combination with the insulation board.
[18] 3) Several ferrite permanent magnet bars are fixed at the top of the inner upper limit to prevent scaling.
Beneficial Effect of the Invention Beneficial Effect [19] Middle deep¨super-deep heavy oil reservoirs and high pour-point oil reservoirs can be recovered safely, environmentally, economically and efficiently so that the development effect can be improved and the final recovery can be promoted.
This method can be widely applied in thermal recovery of other similar types of mineral resources.
Brief description to the Figure Figure Description Figure 1 shows:
[20] 0 Upper slotted and lower vacuum-sealed liner;
[21] Ferrite permanent magnet bar;
[22] Waterproof spiral electric heating bar;
[23] Heat insulation board;
[24] Liner sealing board.
Best Example about Applying the Invention Best Application Method about the Invention [25] 1) According to the size of the reservoir, horizontal wells are drilled in the
Similarly, when the edge-bottom water layer of a reservoir 3a Date Recue/Date Received 2020-04-17 is heated, the heat will conduct upwards to the whole reservoir gradually. The gradually accumulated reservoir pressure, which results from thermal expansion of the formations and fluids, and the temperature will be released with the oil production. Meanwhile, it is convenient to manage the extent of the temperature and the pressure rising up in the reservoir by controlling heating time and heating temperature. When the temperature in the edge-bottom water reservoir increases to the range of 80 C and 100 C, the in-place oil becomes "movable" and can be thermally recovered.
[714. Gravity differentiation phenomenon of cold and hot water When the ocean is heated by the Sun, the temperature of the top or surface water is warmer than that of the water closer to the bottom. The cold and hot water present a phenomenon of gravity differentiation if there's no effect of the ocean current. That is, the phenomenon of cold and hot water scrolling up-and-down will not occur. Heat loss only behaves as the heat conduction between cold and hot water. Therefore, the temperature of the whole reservoir can be effectively improved by continuously electrically heating the top of the water layer near the oil layer.
[8] Feasibility Demonstration:
[9] 1. As a petroleum system, the premise of oil and gas migration and accumulation is that the formations have characteristics, such as fine connection, well sealed overlying layers, high initial temperature and movable in-place oil. It can be inferred from crude oil having unmovable status that the temperature of the formation has decreased to a temperature that is much lower than the initial temperature. So, it can be realized that the oil in an effective channel can return to the movable state when the temperature is increased to a certain degree. The pores where the oil and gas could reach are all effective flow channel and the heat conduction in the formation is faster than that in the surrounding mudstones. Heat can conduct gradually from the bottom to the top and be kept effectively by the surrounding mudstone so that the "centrally heating" can be realized in the whole reservoir.
[10] 2.Reservoirs can be categorized into 10 types according to the distribution of oil, gas and water, such as block bottom-water oil reservoirs, layer-structure block bottom-water oil reservoirs, block edge-bottom and top-water oil reservoirs, layer-structure edge-water oil reservoir, block gas-cap (bottom-water) oil and gas reservoirs, block gas-cap and bottom-water oil and gas reservoirs, layer-structure gas-cap and bottom-water oil and gas reservoirs, layer-structure gas-cap oil and gas reservoirs, pure oil reservoirs, and pure gas reservoirs. Except for the pure oil reservoir, pure gas reservoir and layer-structure gas-cap oil and gas reservoir, most of the reservoirs develop edge and bottom water and contain adequate formation water resources, which provides sufficient material for electrically heating edge-bottom water layers with horizontal wells drilled in water layer.
[11] 3. Under the condition of a geothermal gradient between 2.5 C and 4.5 C/100m, the temperature of middle-deep layers and super-deep layers is between 35 C and 103.5 C although it can also be higher. The temperature difference is about 23.5-47.5 C for electrically heating the formation water from the initial formation temperature to the temperature of the reservoir at a range of 80-150 C under which in-place oil would be in a movable state. The deeper the formation water layer is, the less electric energy is needed. The higher the power of the electric heater is, the faster the water temperature rises. On the other hand, several electric heaters could be used simultaneously so that the formation temperature can be increased quickly;
[12] 4. Fora sealed reservoir heated as a whole, the characteristics of formation temperature and formation pressure rising is similar to that of a pressure cooker being heated. Under high pressure conditions, the boiling temperature of formation water is higher than 100 C. The relationship between water melting and boiling point and pressure demonstrates that when the formation pressure is between 3MPa and 20MPa, the water boiling temperature ranges from 132.9 C
to 211.4 C. The higher the pressure is, the higher the boiling point is. When the temperature is below the boiling point, the temperature in the reservoir could be raised up to the point at which the crude oil transitions to a movable state.
Therefore, it is feasible to control the lifting range of formation water temperature and pressure by keeping heating the formation water under high temperature and high pressure, as long as the temperature and pressure test is monitored reasonably in combination with of the blowdown of production well and pressure release.
[13] 5. At present, all these techniques are relatively mature in pipeline skin effect current tracing system, borehole or pumping rod electrically heated system, in which the temperature can be controlled and the material has high temperature resistance, that can satisfy the long-distance transportation of electrical energy, so that problems, such as heating the production oil, heat dissipation of conductor, can be addressed and overcome.
[14] 6. When "immersion heater" is immersed in the liquid, heat energy can conduct outside quickly through the liquid and the liquid can be heated quickly, and simultaneously the electric wire will not be burned, which is safe, environmental, economical and effective.
[15] 7. The technique of electrically heating magnet descaling can effectively solve the scaling problem arising during electrically heating. The scale originates from hard water. Magnets can soften the water, which is environmental, economical, convenient and safe. Ferrite permanent magnets are widely used, and their components mainly include BaFe12019 and SrFe12019. They are made by ceramic technology, and have the characteristics of temperature resistance, moderate price and are suitable for wide application.
Solutions for the Problems Schemes of Technical Solutions [16] 1) According to the size of the reservoir, horizontal wells are drilled in the upper water layer of the edge-bottom water reservoir, 20-30m away from the oil layer. An electric heater is installed in the sieve pipe of the horizontal well to conduct electric heat to the water layer.
[17] 2) the structure of the electric heater of the horizontal well is shown in Fig.1. The liner of the horizontal-well is divided into upper and lower parts by a heat insulation board. The upper part is slotted, in which several spiral electric heaters with series connection are set on the board which is set at the horizontal diameter of the liner. In the lower part, the liner is sealed in vacuum by a liner sealing board to insulate heat transferred downward in combination with the insulation board.
[18] 3) Several ferrite permanent magnet bars are fixed at the top of the inner upper limit to prevent scaling.
Beneficial Effect of the Invention Beneficial Effect [19] Middle deep¨super-deep heavy oil reservoirs and high pour-point oil reservoirs can be recovered safely, environmentally, economically and efficiently so that the development effect can be improved and the final recovery can be promoted.
This method can be widely applied in thermal recovery of other similar types of mineral resources.
Brief description to the Figure Figure Description Figure 1 shows:
[20] 0 Upper slotted and lower vacuum-sealed liner;
[21] Ferrite permanent magnet bar;
[22] Waterproof spiral electric heating bar;
[23] Heat insulation board;
[24] Liner sealing board.
Best Example about Applying the Invention Best Application Method about the Invention [25] 1) According to the size of the reservoir, horizontal wells are drilled in the
7 Date Recue/Date Received 2020-04-17 7a Best Example about Applying the Invention Best Application Method about the Invention [25] 1) According to the size of a reservoir, horizontal wells are drilled in the upper water layer of the edge-bottom water reservoir, 20-30m away from the oil layer, which can store enough thermal energy to raise the temperature of the whole oil layer and delay the formation fracture due to premature boiling of the formation water and overpressure.
[26] 2) The number, length and trend of horizontal well are determined by the size of the water body and reservoir volume. Gravel packed open hole completion works well.
[27] 3) If the horizontal well is sidetrack drilled from an oil production well, the conducting wire can be used as borehole or pumping rod electrical heater so that the effect of cooling and heating can be realized; if the horizontal well is drilled individually, a skin heat tracing device needs to be applied to the conducting wire. High temperature resistant materials should be optimized to prevent the conducting wire from overheating in the borehole.
Application Example of the Invention Application Method of the Invention [28] Electric heaters are configured to be positioned in several horizontal wells drilled in an upper water layer of the reservoir, near the oil layers. The electric heaters heat the edge-bottom water layer of the reservoir so that the temperature of the whole reservoir is increased. Several mechanisms are applied to recover oil efficiently, such as, the effect of heat transfer, the effect of steam flooding produced by water soluble gas overflow, the thermal expansion pressure from water formations and oil layers as well as the viscosity-reduction effect / wax-precipitation effect of in-place oil under high temperature.
Industrial Applicability [29] It can be applied to thermally recover heavy oil and high pour-point oil reservoirs with edge-bottom water layers, especially for those heavy oil reservoirs of middle-super deep depth which are difficult to recover.
[26] 2) The number, length and trend of horizontal well are determined by the size of the water body and reservoir volume. Gravel packed open hole completion works well.
[27] 3) If the horizontal well is sidetrack drilled from an oil production well, the conducting wire can be used as borehole or pumping rod electrical heater so that the effect of cooling and heating can be realized; if the horizontal well is drilled individually, a skin heat tracing device needs to be applied to the conducting wire. High temperature resistant materials should be optimized to prevent the conducting wire from overheating in the borehole.
Application Example of the Invention Application Method of the Invention [28] Electric heaters are configured to be positioned in several horizontal wells drilled in an upper water layer of the reservoir, near the oil layers. The electric heaters heat the edge-bottom water layer of the reservoir so that the temperature of the whole reservoir is increased. Several mechanisms are applied to recover oil efficiently, such as, the effect of heat transfer, the effect of steam flooding produced by water soluble gas overflow, the thermal expansion pressure from water formations and oil layers as well as the viscosity-reduction effect / wax-precipitation effect of in-place oil under high temperature.
Industrial Applicability [29] It can be applied to thermally recover heavy oil and high pour-point oil reservoirs with edge-bottom water layers, especially for those heavy oil reservoirs of middle-super deep depth which are difficult to recover.
8
Claims (12)
1. A method for centrally thermal recovery of oil from an oil reservoir, said oil reservoir comprising an upper edge-bottom water layer proximal to oil layers within the oil reservoir, said oil reservoir is at a first temperature and comprises a quantity of in-place oil, said method comprising:
providing several horizontal wells extending into the oil reservoir, each horizontal well comprising an electric heater thermal recovery system comprising:
an electric heater comprising an inner liner comprising a slotted liner and a vacuum-sealed liner, said electric heater positioned in the upper edge-bottom water layer of the oil reservoir;
several ferrite permanent magnet bars fixed at a top of the slotted liner to protect the electric heater from scaling;
waterproof spring electrical heating bars in series connection in the slotted liner to generate heat; and a heat insulation board set in the inner liner;
wherein the vacuum-sealed liner, in cooperation with the heat insulation board insulates heat, and is vacuum-sealed to reduce downward transmission of thermal energy;
centrally electrically heating the edge-bottom water layer with the electric heaters until the temperature of the whole oil reservoir increases such that all of the in-place oil becomes mobile and flows; and centrally recovering the mobilized oil.
providing several horizontal wells extending into the oil reservoir, each horizontal well comprising an electric heater thermal recovery system comprising:
an electric heater comprising an inner liner comprising a slotted liner and a vacuum-sealed liner, said electric heater positioned in the upper edge-bottom water layer of the oil reservoir;
several ferrite permanent magnet bars fixed at a top of the slotted liner to protect the electric heater from scaling;
waterproof spring electrical heating bars in series connection in the slotted liner to generate heat; and a heat insulation board set in the inner liner;
wherein the vacuum-sealed liner, in cooperation with the heat insulation board insulates heat, and is vacuum-sealed to reduce downward transmission of thermal energy;
centrally electrically heating the edge-bottom water layer with the electric heaters until the temperature of the whole oil reservoir increases such that all of the in-place oil becomes mobile and flows; and centrally recovering the mobilized oil.
2. The method according to claim 1 wherein the edge-bottom water is treated as heat transfer medium;
the edge-bottom water is treated as a coolant of the electric heaters;
the edge-bottom water protects crude oil in oil layers from heat damage because of its stable boiling temperature, and sustains the increased temperature of the oil reservoir relatively stably; and the edge-bottom water coning is treated as a resource of bottom driving energies in process of central oil production.
the edge-bottom water is treated as a coolant of the electric heaters;
the edge-bottom water protects crude oil in oil layers from heat damage because of its stable boiling temperature, and sustains the increased temperature of the oil reservoir relatively stably; and the edge-bottom water coning is treated as a resource of bottom driving energies in process of central oil production.
3. The method according to claim 1 wherein the vertical position of the horizontal wells in the edge-bottom water layers is variable to save energy; and number, length and trend of horizontal wells are determined by the size of water body and reservoir volume.
4. The method according to claim 1 or 3 wherein each electric heater positioned in the horizontal well comprises the slotted liner and the vacuum-sealed liner, the several ferrite permanent bars, the waterproof spring electrical heating bar, the heat insulation board and a sealing board; wherein the electrical heating bar generates heat, and directly heats the edge-bottom water; water convection travels freely through the slotted liner; at least one of the several ferrite permanent bar protects the electric heater from scaling; the heat insulation board prohibits heat energy transferring downwards and seals the vacuum-sealed liner in vacuum together with the sealing board; and the vacuum-sealed liner sealed in vacuum prohibits heat energy transferring downwards.
5. The method according to claim 1 wherein increases in temperature and pressure in the oil reservoir are controlled by monitoring heating time, increases in temperature in top oil layers and oil production performance.
6. The method according to claim 1 wherein temperatures in all oil layers rise to the point needed by continuously electrically heating the upper edge-bottom water layer and wherein the temperature of the oil reservoir increases to at least 80°C to 150°C.
7. The method according to claim 5 wherein the pressure within the oil reservoir is between 3-20MPa and boiling temperature of water is between 132.9-211.4°C, and continuously heating edge-bottom water until top oil layers are mobilized;
wherein by heating under the conditions of pressure of 3-20 MPa in the formation and stable boiling temperature of edge-bottom water, the oil layers are protected from fracture and heat damage.
wherein by heating under the conditions of pressure of 3-20 MPa in the formation and stable boiling temperature of edge-bottom water, the oil layers are protected from fracture and heat damage.
8. The method according to claim 1 including a variety of thermal recovery methods selected from the group consisting of:
steam flooding produced by water soluble gas overflow;
thermal expansion pressure from water formations and oil layers;
the viscosity-reduction effect/ wax-precipitation effect of in-place oil under high temperature;
hot bottom water driving from bottom water coning during centrally thermal production;
gravity drainage of the heated crude oil;
gravity differentiation among fluids after first central thermal recovery of oil for another several times; and combinations thereof.
steam flooding produced by water soluble gas overflow;
thermal expansion pressure from water formations and oil layers;
the viscosity-reduction effect/ wax-precipitation effect of in-place oil under high temperature;
hot bottom water driving from bottom water coning during centrally thermal production;
gravity drainage of the heated crude oil;
gravity differentiation among fluids after first central thermal recovery of oil for another several times; and combinations thereof.
9. An electric heater thermal recovery system, comprising, an electric heater comprising an inner liner comprising a slotted liner and a vacuum-sealed liner divided into two parts by a heat insulation board;
the heat insulation board set in the inner liner;
waterproof spiral electrical heating bars in series connection provided on the heat insulation board in the slotted liner;
several ferrite permanent magnet bars fixed at a top of the slotted liner, a sealing board provided on either side of the vacuum-sealed liner;
wherein the vacuum-sealed liner, in cooperation with the heat insulation board insulates heat, and is vacuum-sealed by the sealing board and the heat insulation board to reduce downward transmission of thermal energy.
the heat insulation board set in the inner liner;
waterproof spiral electrical heating bars in series connection provided on the heat insulation board in the slotted liner;
several ferrite permanent magnet bars fixed at a top of the slotted liner, a sealing board provided on either side of the vacuum-sealed liner;
wherein the vacuum-sealed liner, in cooperation with the heat insulation board insulates heat, and is vacuum-sealed by the sealing board and the heat insulation board to reduce downward transmission of thermal energy.
10. The system according to claim 9 wherein the slotted liner allows fluid to transfer freely.
11. The system according to claim 9 wherein electrical heating bars generate heat and directly heat edge-bottom water.
12. The system according to claim 9 wherein at least one of the several ferrite permanent magnet bars is arranged to reduce scaling of the electric heaters.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310689685.0A CN103615215A (en) | 2013-12-12 | 2013-12-12 | Side and bottom water layer thermal recovery method allowing electrically heating oil deposit in horizontal well |
| CN201310689685.0 | 2013-12-12 | ||
| PCT/CN2014/072422 WO2015085674A1 (en) | 2013-12-12 | 2014-02-22 | Side and bottom water layer thermal recovery method allowing electrically heating oil deposit in horizontal well |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2933277A1 CA2933277A1 (en) | 2015-06-18 |
| CA2933277C true CA2933277C (en) | 2021-01-19 |
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| CA2933277A Active CA2933277C (en) | 2013-12-12 | 2014-02-22 | A centrally thermal recovery method for excavating oil from an oil reservoir by electrically heating edge-bottom water layer with horizontal wells |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US20170002637A1 (en) |
| CN (2) | CN103615215A (en) |
| CA (1) | CA2933277C (en) |
| RU (1) | RU2653203C2 (en) |
| WO (1) | WO2015085674A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106593379B (en) * | 2016-12-21 | 2019-06-11 | 中国石油天然气股份有限公司 | A kind of horizontal well steam assisted gravity drainage starting method and device |
| CN108505977B (en) * | 2018-04-18 | 2020-04-21 | 吉林大学 | Method for exploiting natural gas hydrate by using sleeve type heater |
| CN108487888B (en) * | 2018-05-24 | 2023-04-07 | 吉林大学 | Auxiliary heating device and method for improving oil gas recovery ratio of oil shale in-situ exploitation |
| CN108924974B (en) * | 2018-09-17 | 2020-10-13 | 中国石油大学(华东) | Electric heating material for thickened oil recovery and preparation method thereof |
| CN110080734A (en) * | 2019-04-17 | 2019-08-02 | 中国石油化工股份有限公司 | Method of Compound Development is let out in the drive of shallow-thin layer bottom water viscous crude |
| CN110905470B (en) * | 2019-12-17 | 2021-11-02 | 于文英 | Method for exploiting oil and gas by utilizing bottom water resources of oil and gas reservoir |
| CN112131704A (en) * | 2020-08-17 | 2020-12-25 | 长江大学 | Method for estimating reservoir of oil layer and predicting saturation of residual oil |
| CN112855079B (en) * | 2021-03-29 | 2023-01-17 | 北京红蓝黑能源科技有限公司 | Immersed horizontal well electric heater for heating formation water |
| CN113719261A (en) * | 2021-09-27 | 2021-11-30 | 北京红蓝黑能源科技有限公司 | Method for improving economic benefit of single well by exploiting oil gas through bottom water steam flooding |
| CN114016979A (en) * | 2021-11-05 | 2022-02-08 | 北京红蓝黑能源科技有限公司 | Oil and gas exploitation method for injecting water into water layer of oil and gas reservoir |
| CN114183108B (en) * | 2021-12-21 | 2023-02-21 | 北京红蓝黑能源科技有限公司 | Method for improving transverse driving force in bottom steam flooding oil gas production process |
| CN114183109B (en) * | 2021-12-23 | 2023-02-28 | 北京红蓝黑能源科技有限公司 | Method for exploiting oil gas by continuously heating formation water at temperature lower than boiling point of water |
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| RU2136858C1 (en) * | 1998-07-16 | 1999-09-10 | Открытое акционерное общество Научно-технологическая компания Российский межотраслевой научно-технический комплекс "НЕФТЕОТДАЧА" | Method for development of water-floating oil deposit |
| CN2458423Y (en) * | 2000-11-08 | 2001-11-07 | 关辅民 | Electromagnetic output increasing device for use in well |
| EA004696B1 (en) * | 2001-04-24 | 2004-06-24 | Шелл Интернэшнл Рисерч Маатсхаппий Б.В. | In-situ combustion for oil recovery |
| US7568526B2 (en) * | 2004-07-29 | 2009-08-04 | Tyco Thermal Controls Llc | Subterranean electro-thermal heating system and method |
| US7398823B2 (en) * | 2005-01-10 | 2008-07-15 | Conocophillips Company | Selective electromagnetic production tool |
| CA2672487C (en) * | 2006-12-13 | 2013-12-31 | Stephen Richard Larter | Preconditioning an oilfield reservoir |
| RU2419718C1 (en) * | 2009-11-02 | 2011-05-27 | Леонид Александрович Сорокин | Procedure for well operation |
| CA2792275A1 (en) * | 2010-04-09 | 2011-10-13 | Thomas David Fowler | Low temperature inductive heating of subsurface formations |
| CN202483541U (en) * | 2012-03-28 | 2012-10-10 | 周志斌 | Oil production system for heavy oil reservoir |
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2013
- 2013-12-12 CN CN201310689685.0A patent/CN103615215A/en active Pending
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2014
- 2014-02-22 RU RU2016122953A patent/RU2653203C2/en active
- 2014-02-22 US US15/039,454 patent/US20170002637A1/en not_active Abandoned
- 2014-02-22 CA CA2933277A patent/CA2933277C/en active Active
- 2014-02-22 WO PCT/CN2014/072422 patent/WO2015085674A1/en active Application Filing
- 2014-02-22 CN CN201480001286.3A patent/CN106062304A/en active Pending
Also Published As
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|---|---|
| WO2015085674A1 (en) | 2015-06-18 |
| RU2653203C2 (en) | 2018-05-07 |
| RU2016122953A (en) | 2017-12-12 |
| US20170002637A1 (en) | 2017-01-05 |
| CA2933277A1 (en) | 2015-06-18 |
| CN103615215A (en) | 2014-03-05 |
| CN106062304A (en) | 2016-10-26 |
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