CN108756821B - Oil well down-hole thermoelectric power generation system and method - Google Patents
Oil well down-hole thermoelectric power generation system and method Download PDFInfo
- Publication number
- CN108756821B CN108756821B CN201810525009.2A CN201810525009A CN108756821B CN 108756821 B CN108756821 B CN 108756821B CN 201810525009 A CN201810525009 A CN 201810525009A CN 108756821 B CN108756821 B CN 108756821B
- Authority
- CN
- China
- Prior art keywords
- cold fluid
- oil
- fluid
- pipeline
- power generation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
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
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03G—SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR
- F03G7/00—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for
- F03G7/04—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using pressure differences or thermal differences occurring in nature
Abstract
The invention relates to an oil well underground thermoelectric power generation system and method. The system includes a wellbore, a fluid circulation module, and an electrical energy export module. The shaft comprises a casing, an oil pipe, a thermoelectric power generation module and a cold fluid injection pipe. And an oil sleeve annular flow channel is formed in a space between the inner wall of the sleeve and the outer wall of the thermoelectric power generation module. The inner space of the oil pipe forms a flow passage in the oil pipe. The cold fluid injection pipe is embedded in the oil sleeve annular flow channel. The fluid circulation module comprises a cold fluid injection pipeline, a cold fluid injection pump, a cold fluid outflow pipeline, a cold fluid storage container, a cold fluid inflow pipeline, an oil sleeve annulus circulating outflow hot fluid utilization module, an oil sleeve annulus circulating outflow fluid flow pipeline, a stratum output hot fluid outflow pipeline, a stratum output hot fluid utilization module and a stratum output liquid flow pipeline after heat utilization. The invention can save a large amount of construction cost and operation cost, ensure stable electric energy supply and cannot influence the subsequent utilization of the produced water of the oil well.
Description
Technical Field
The invention belongs to the technical field of geothermal power generation, and particularly relates to an oil well underground thermoelectric power generation system and method.
Background
At present, a large number of oil fields enter a high water content stage, and some oil wells have to be shut down due to too high water content. In such wells, the production zone provides not only a large amount of fluid, but also a large amount of thermal energy. How to fully utilize the existing resources of the oil well and prolong the production life of the oil well has become a key point of attention in the industry. The method mainly focuses on producing geothermal energy of oil wells in a co-production mode, and provides a heat source for the fields of oil field pipeline gathering and transportation, plant area heating and the like. The China North China oil field utilizes the produced water of the oil well to perform ground medium-low temperature geothermal power generation, and certain achievements are achieved.
With the recent progress of semiconductor materials, thermoelectric power generation technology has been gradually developed. When different temperatures are applied to both sides of the semiconductor, respectively, an electromotive force is generated between the high temperature side and the low temperature side due to the seebeck effect. By utilizing this phenomenon, thermal energy can be directly converted into electric energy using the thermoelectric power generation element. The thermoelectric power generation technology is widely applied to the fields of automobile exhaust waste heat power generation, industrial waste heat power generation, solar power generation, intelligent wearing and the like.
Disclosure of Invention
Aiming at the production characteristics of high water content oil wells, such as large water yield and high heat carrying capacity, the invention provides an underground thermoelectric power generation system and method for an oil well by combining a thermoelectric power generation technology.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention relates to an oil well down-hole thermoelectric power generation system, comprising: the system comprises a well bore, a fluid circulation module and an electric energy output module.
Specifically, the shaft comprises a casing, an oil pipe, a thermoelectric generation module and a cold fluid injection pipe, wherein the casing penetrates through an overburden stratum and a production layer of the production layer from top to bottom in sequence; the part of the sleeve positioned on the production layer is provided with a perforation section; the top of the oil pipe is flush with the top of the casing pipe, and the bottom of the oil pipe is positioned at the junction of the overburden and the production layer on the production layer; the outer side of the lower end of the oil pipe is seated on the inner wall of the casing through a packer; the thermoelectric power generation module is arranged on an oil pipe above the packer and is connected with the electric energy output module through a connecting cable; an oil sleeve annulus flow channel is formed in a space between the inner wall of the sleeve and the outer wall of the thermoelectric power generation module; the inner space of the oil pipe forms an inner flow channel of the oil pipe; the cold fluid injection pipe is embedded into the oil sleeve annular flow channel, and a gap is reserved between the bottom of the cold fluid injection pipe and the top of the packer.
Further, the fluid circulation module comprises a cold fluid injection pipeline, a cold fluid injection pump, a cold fluid outflow pipeline, a cold fluid storage container, a cold fluid inflow pipeline, an oil sleeve annulus circulating outflow hot fluid utilization module, an oil sleeve annulus circulating outflow fluid flow pipeline, a formation produced hot fluid outflow pipeline, a formation produced hot fluid utilization module and a formation produced fluid flow pipeline after heat utilization; the outlet of the cold fluid injection pipeline is connected with the cold fluid injection pipe or the oil sleeve annulus flow channel, the inlet of the cold fluid injection pipeline is connected with the outlet of the cold fluid injection pump, the inlet of the cold fluid injection pump is connected with the outlet of the cold fluid storage container through a cold fluid outflow pipeline, and the inlet of the cold fluid storage container is connected with the outlet of the oil sleeve annulus circulating outflow hot fluid utilization module through a cold fluid inflow pipeline; when the outlet of the cold fluid injection pipeline is connected with the cold fluid injection pipe, the inlet of the oil sleeve annulus circulating outflow hot fluid utilization module is connected with the oil sleeve annulus circulating outflow fluid flow channel through the oil sleeve annulus circulating outflow fluid flow pipeline; when the outlet of the cold fluid injection pipeline is connected with the oil sleeve annulus flow channel, the inlet of the oil sleeve annulus circulating outflow hot fluid utilization module is connected with the cold fluid injection pipe through the oil sleeve annulus circulating outflow fluid flow pipeline.
Further, a downhole lift pump system is installed in the oil pipe.
Furthermore, the shaft is of an eyelet structure drilling through the stratum and is realized by adopting a method of casing pipe descending to shaft bottom cementing and well cementation; the casing is tightly cemented with the production layer and the upper covering layer of the production layer.
Further, the inner wall of the casing in the range of the overlying stratum of the production layer is coated with heat insulation materials.
Further, the thermoelectric power generation module comprises a plurality of groups of thermoelectric power generators which are connected in series; the thermoelectric generator comprises a plurality of groups of thermoelectric generating units; the thermoelectric power generation units comprise an N-type semiconductor and a P-type semiconductor, and the N-type semiconductor and the P-type semiconductor are alternately arranged between the adjacent thermoelectric power generation units.
Furthermore, the cross sections of the sleeve, the oil pipe and the cold fluid injection pipe are all circular; the oil pipe and the sleeve are coaxially arranged; the cross section of the thermoelectric power generation module is circular.
Further, the cold fluid injection pump and the cold fluid storage vessel are located on the ground.
The invention also relates to a thermoelectric power generation method adopting the oil well downhole thermoelectric power generation system, which comprises the following steps:
s1, when cold fluid is injected through the cold fluid injection pipe, the method comprises the steps of:
and S11, the cold fluid stored in the cold fluid storage container enters the cold fluid injection pump through the cold fluid outflow pipeline, is pressurized, and then enters the cold fluid injection pipe through the cold fluid injection pipeline.
S12, setting an opening at the bottom of the cold fluid injection pipe as a cold fluid reverse circulation point, enabling the cold fluid to enter an oil sleeve annulus flow channel from the cold fluid reverse circulation point at the bottom of the cold fluid injection pipe and flow out of the ground upwards, enabling the cold fluid to enter an oil sleeve annulus circulation outflow fluid flow pipeline, enabling the cold fluid to enter an oil sleeve annulus circulation outflow fluid utilization module, and returning the cold fluid to the cold fluid storage container through the cold fluid inflow pipeline after heat exchange and utilization.
S13, the hot fluid produced in the production zone enters the casing below the packer through the perforation section on the casing under the stratum driving pressure difference, the hot fluid enters the flow channel in the oil pipe under the action of residual pressure and is discharged out of the ground, the hot fluid enters the stratum produced hot fluid utilization module through the stratum produced hot fluid outflow pipeline, and the hot fluid enters the oil field produced fluid treatment system through the stratum produced fluid flow pipeline to be treated and utilized in the next stage after being subjected to heat exchange and utilization.
And S14, the thermoelectric power generation module generates electric energy under the action of temperature difference between hot fluid produced by the stratum in the flow channel in the oil pipe and circulating cold fluid in the annular flow channel of the oil sleeve, and the electric energy is input into the electric energy output module through the connecting cable.
S2, when cold fluid is injected through the oil jacket annulus flow channel, the method comprises the steps of:
and S21, allowing the cold fluid stored in the cold fluid storage container to enter a cold fluid injection pump through a cold fluid outflow pipeline, pressurizing the cold fluid, and allowing the cold fluid to enter an oil sleeve annulus flow channel through a cold fluid injection pipeline.
And S22, setting an opening at the bottom of the cold fluid injection pipe as a cold fluid reverse circulation point, enabling the cold fluid to enter the cold fluid injection pipe from the cold fluid reverse circulation point and flow out of the ground upwards, entering an oil sleeve annulus to circularly flow out of a fluid flow pipeline, then entering an oil sleeve annulus to circularly flow out of a hot fluid utilization module, and returning to the cold fluid storage container through a cold fluid flow pipeline after heat exchange and utilization.
S23, the hot fluid produced in the production zone enters the casing below the packer through the perforation section on the casing under the stratum driving pressure difference, the hot fluid enters the flow channel in the oil pipe under the action of residual pressure and is discharged out of the ground, the hot fluid enters the stratum produced hot fluid utilization module through the stratum produced hot fluid outflow pipeline, and the hot fluid enters the oil field produced fluid treatment system through the stratum produced fluid flow pipeline to be treated and utilized in the next stage after being subjected to heat exchange and utilization.
And S24, the thermoelectric power generation module generates electric energy under the action of temperature difference between hot fluid produced by the stratum in the flow channel in the oil pipe and circulating cold fluid in the annular flow channel of the oil sleeve, and the electric energy is input into the electric energy output module through the connecting cable.
Further, the cold fluid is any one of water, liquid carbon dioxide and liquid nitrogen.
Further, in steps S13 and S23, in case of sufficient formation energy, the hot fluid entering the flow channel in the oil pipe is directly discharged to the surface; under the condition of insufficient formation energy, the hot fluid entering the flow channel in the oil pipe is pressurized by the underground lifting pump system and then is discharged out of the ground.
Compared with the prior art, the invention has the beneficial effects that:
(1) the invention fully utilizes the existing oil well with high water content or the abandoned oil well with high water content, and prolongs the service life of the oil well.
(2) The invention realizes the downhole power generation of the oil well by utilizing the thermoelectric module arranged underground.
(3) In the invention, the fluids produced by the low-temperature side and the high-temperature side of the thermoelectric power generation system can still be used for ground heating, cultivation, bathing and other applications.
In conclusion, the invention not only can save a large amount of construction cost and operation cost and ensure stable electric energy supply, but also can not influence the subsequent utilization of the produced water of the oil well.
Drawings
FIG. 1 is a schematic diagram of a downhole thermoelectric power generation system for an oil well with cold fluid injected from a cold fluid injection pipe;
FIG. 2 is a schematic view of the cross-sectional structure I-I' of FIG. 1;
FIG. 3 is a schematic diagram of the configuration of an oil well downhole thermoelectric generation system with cold fluid injected from the oil jacket annulus flow passage.
Wherein:
1. a production zone, 2, a well bottom, 3, a perforated section, 4, a packer, 5, a cold fluid reverse circulation point, 6, a cold fluid injection pipe, 7, an oil pipe, 8, a casing, 106, a wellbore, 9, a thermoelectric power generation module, 10, a cold fluid injection pump, 11, a cold fluid injection line, 12, a cold fluid storage vessel, 13, the system comprises a cold fluid outflow pipeline, 14 a formation produced hot fluid utilization module, 15 a formation produced hot fluid outflow pipeline, 16 an oil sleeve annulus circulating outflow hot fluid utilization module, 17 an oil sleeve annulus circulating outflow fluid flow pipeline, 18 a cold fluid inflow pipeline, 19 a formation produced fluid flow pipeline after heat utilization, 20 an underground lifting pump system, 21 an electric energy output module, 22 a connecting cable, 101 a production layer overlying formation, 102 a fluid circulation module, 201 an oil sleeve annulus flow channel, 202 and an oil pipe inner flow channel.
Detailed Description
The invention is further described below with reference to the accompanying drawings:
example one
An oil well downhole thermoelectric power generation system as shown in fig. 1 when cold fluid is injected from a cold fluid injection pipe, the system comprising: a wellbore 106, a fluid circulation module 102, and an electrical energy export module 21.
Specifically, the wellbore 106 includes a casing 8 drilled through the overburden 101 and the production zone 1 of the production zone, an oil pipe 7 embedded in the casing 8, a thermoelectric power generation module 9 disposed on an outer wall of the oil pipe 7, and a cold fluid injection pipe 6 disposed between the casing and the oil pipe in this order from top to bottom. The oil well production zone 1 is buried several kilometers deep; the overburden stratum 101 of the production layer is a heat insulation layer such as sedimentary rock or soil covered from the upper part of the production layer 1 to the ground surface, and the temperature of the stratum is gradually reduced from bottom to top and is lower than the temperature of the reservoir of the production layer 1. The wellbore 106 is a perforated structure drilled through the formation, sequentially penetrates the overburden 101 and the production zone 1 of the production zone, and is completed by cementing with the casing 8. The portion of casing 8 within the overburden 101 of the production zone is tightly cemented to the formation and fluidly isolated from the formation, and the inner wall surface is coated with an insulating material. The portion of the casing 8 within the zone 1 is completed by perforating the well to form a perforated section 3 providing a flow path for fluids in the zone 1 to enter the bottom of the well 2. An oil pipe 7 is arranged right above the production layer 1, the bottom of the oil pipe 7 is set on a sleeve 8 through a packer 4, and an oil sleeve annulus flow channel 201 is formed by the outer wall of the oil pipe 7 and the part of the sleeve 8 within the range of the overburden 101 of the production layer. The space inside the oil pipe 7 forms an in-oil-pipe flow passage 202. The thermoelectric generation module 9 is closely arranged on the outer wall of the oil pipe 7. The cold fluid injection pipe 6 is lowered through the oil jacket annulus flow passage 201 directly above the packer 4.
Further, the fluid circulation module 102 includes a cold fluid injection line 11, a cold fluid injection pump 10, a cold fluid outflow line 13, a cold fluid storage container 12, a cold fluid inflow line 18, an oil jacket annulus circulating outflow hot fluid utilization module 16, an oil jacket annulus circulating outflow fluid flow line 17, a formation produced hot fluid outflow line 15, a formation produced hot fluid utilization module 14, and a thermally utilized formation produced fluid flow line 19. The outlet of the cold fluid injection pipeline 11 is connected with the cold fluid injection pipe 6, the inlet of the cold fluid injection pipeline 11 is connected with the outlet of the cold fluid injection pump 10, the inlet of the cold fluid injection pump 10 is connected with the outlet of the cold fluid storage container 12 through the cold fluid outflow pipeline 13, and the inlet of the cold fluid storage container 12 is connected with the outlet of the oil jacket annular circulating outflow hot fluid utilization module 16 through the cold fluid inflow pipeline 18. The inlet of the oil casing annulus circulating outflow thermal fluid utilization module 16 is connected with the oil casing annulus flow channel 201 through an oil casing annulus circulating outflow fluid flow line 17.
Further, a downhole lift pump system 20 is installed in the oil pipe 7. A downhole lift pump system 20 is connected to the tubing 7 to provide energy to the formation fluid produced from the production zone 1 and lift to the surface. The downhole lift pump system 20 is a high displacement electrical submersible pump lift system, the location of which on the tubing 7 is determined by the residual pressure at the bottom of the well 2, the depth of the well 2 and the flow rate of the hot fluid produced by the producing formation 1.
Further, the thermoelectric generation module 9 is fastened on the outer wall of the oil pipe 7 and is arranged in the sleeve 8 along with the oil pipe 7. The electric energy generated by the thermoelectric power generation module 9 is connected with the electric energy output module 21 through the connecting cable 22, and the electric energy is provided for the user through the electric energy output module 21. The thermoelectric power generation module 9 is formed by connecting a plurality of groups of thermoelectric power generators in series; the plurality of groups of thermoelectric generators can be 1 group, 10 groups and 100 groups, and can also be any plurality of groups; the thermoelectric generator is formed by assembling a plurality of N-type semiconductors and a plurality of P-type semiconductors in an alternating and paired arrangement mode; an N-type semiconductor and a P-type semiconductor form a thermoelectric power generation unit; the number of the N-type semiconductors and the number of the P-type semiconductors can be 1, 10, 100 or any number; the number of the N-type semiconductors is equal to that of the P-type semiconductors.
Further, as shown in fig. 2, the cross sections of the casing 8, the oil pipe 7 and the cold fluid injection pipe 6 are all circular; the oil pipe 7 and the sleeve 8 are coaxially arranged; the cross section of the thermoelectric power generation module 9 is circular.
Further, the cold fluid injection pump 10 and the cold fluid storage vessel 12 are located at the surface.
Further, the cold fluid injection pipe 6 is made of heat insulating material, and the temperature of the cold fluid flowing out from the cold fluid reverse circulation point 5 at the bottom of the cold fluid injection pipe 6 is approximately equal to the temperature of the cold fluid entering the cold fluid injection pipe 6 at the ground surface.
The working principle of the system is as follows:
the hot fluid produced by the production layer 1 enters the well bottom 2 through the perforation section 3 under the stratum driving pressure difference, and then flows into the flow channel 202 in the oil pipe by utilizing the residual pressure after entering the well bottom 2 to form the high-temperature hot end of the thermoelectric power generation module 9. When the formation energy is sufficient, the hot fluid flowing out of the production layer is directly discharged to the surface; in the event that there is insufficient surface energy, i.e., the remaining pressure at the bottom of the well 2 is insufficient to flow the thermal fluid produced from the pay zone 1 to the surface, a downhole lift pump system 20 is installed at the tubing 7 at a depth that pressurizes the thermal fluid produced from the pay zone 1 for flow to the surface. The cold fluid injection pump 10 pressurizes cold fluid from the cold fluid storage vessel 12 and injects the pressurized cold fluid through the cold fluid injection line 11 into the cold fluid injection pipe 6, and the pressurized cold fluid flows along the cold fluid injection pipe 6 above the packer 4 and from the cold fluid reverse circulation point 5 into the oil jacket annulus flow channel 201. Under the action of ground injection pressure, cold fluid entering the oil sleeve annulus flow channel 201 from the cold fluid reverse circulation point 5 flows upwards along the oil sleeve annulus flow channel 201 to form a low-temperature cold end of the thermoelectric power generation module 9; during the process that the cold fluid flows upwards along the oil casing annulus flow channel 201, heat is absorbed from the surroundings to be changed into hot fluid, and the hot fluid is circulated out of the hot fluid utilization module 16 through the oil casing annulus circulating fluid flow line 17 and enters the oil casing annulus. The hot fluid flowing out of the oil jacket annulus flow channel 201 is changed into cold fluid after sufficient heat exchange and utilization in the oil jacket annulus circulating hot fluid utilization module 16, and then enters the cold fluid storage container 12 through the cold fluid inflow line 18. The cold fluid storage container 12, the cold fluid outflow pipeline 13, the cold fluid injection pump 10, the cold fluid injection pipeline 11, the cold fluid injection pipe 6, the oil jacket annulus flow channel 201, the oil jacket annulus circulating outflow fluid flow pipeline 17, the oil jacket annulus circulating outflow hot fluid utilization module 16 and the cold fluid inflow pipeline 18 form a closed cold fluid flow circulating system to provide continuous cold energy for the thermoelectric power generation module 9. The thermoelectric power generation module 9 realizes the downhole thermoelectric power generation under the action of the temperature difference between the high-temperature formation produced fluid in the oil pipe inner flow channel 202 and the low-temperature circulating fluid in the oil sleeve annulus flow channel 201. The hot fluid flowing from the in-tubing flow path 202 out of the surface enters the formation producing hot fluid utilization module 14 through the formation producing hot fluid outflow line 15. The heat carried by the hot fluid flowing out of the ground from the flow channel 202 in the oil pipe is fully exchanged and utilized by the formation produced hot fluid utilization module 14, and then enters the oil field produced fluid treatment system for the next-stage treatment and utilization through the formation produced fluid flow pipeline 19 after heat utilization. Preferably, the cold fluid is water, liquid carbon dioxide or liquid nitrogen.
The implementation method of the oil well downhole thermoelectric power generation system during cold fluid injection from the cold fluid injection pipe in the embodiment comprises the following steps:
(1) selecting a high water content oil well or an oil well which is abandoned due to high water content. Depending on the depth of its production zone 1, the tubing 7 with its outer wall consolidated with thermoelectric generation modules 9 is lowered above the production zone 1 and the tubing 7 is set on the casing 8 with the packer 4. A downhole lift pump system 20 is installed at the tubing 7 at a depth based on the residual pressure at the bottom hole 2, the depth of the bottom hole 2, and the flow rate of the hot fluid produced by the producing formation 1.
(2) A cold fluid injection pipe 6 is run into the oil jacket annulus flow passage 201 above the packer 4.
(3) A cold fluid storage vessel 12, a cold fluid outflow line 13, a cold fluid injection pump 10, and a cold fluid injection line 11 are connected in sequence, and the cold fluid injection line 11 is connected to the cold fluid injection pipe 6. The oil casing annulus flow channel 201 is connected with the oil casing annulus circulating outflow thermal fluid utilization module 16 through the oil casing annulus circulating outflow fluid flow line 17. The oil jacket annulus circulates hot fluid out of the use module 16 through the cold fluid inflow line 18 to the cold fluid storage vessel 12, thereby forming a closed cold fluid circulation system.
(4) The stratum produced hot fluid outflow pipeline 15 is connected with the flow channel 202 in the oil pipe, and then is sequentially connected with the stratum produced hot fluid utilization module 14 and the stratum produced fluid flow pipeline 19 to form a stratum produced fluid flow path.
(5) The thermoelectric power generation module 9 is connected with the electric energy output module 21 through a connecting cable 22 to form a circuit system.
(6) The cold fluid stored in the cold fluid storage vessel 12 enters the cold fluid injection pump 10 through the cold fluid outflow line 13, is pressurized, and then enters the cold fluid injection pipe 6 through the cold fluid injection line 11.
(7) The bottom opening of the cold fluid injection pipe 6 is set as a cold fluid reverse circulation point 5, cold fluid enters the oil sleeve annulus flow channel 201 from the cold fluid reverse circulation point 5 at the bottom of the cold fluid injection pipe 6 and flows upwards out of the ground, enters the oil sleeve annulus circular flow fluid flow pipeline 17, then enters the oil sleeve annulus circular flow hot fluid utilization module 16, and returns to the cold fluid storage container 12 through the cold fluid flow pipeline 18 after heat exchange and utilization.
(8) The hot fluid produced in the production layer 1 enters a sleeve 8 below a packer 4 through a perforation section 3 under the action of a stratum driving pressure difference, enters an oil pipe inner flow channel 202 under the action of residual pressure and is discharged out of the ground, enters a stratum produced hot fluid utilization module 14 through a stratum produced hot fluid outflow pipeline 15, and enters an oil field produced fluid treatment system through a stratum produced fluid flow pipeline 19 after heat exchange and utilization for next-stage treatment and utilization. When the stratum energy is sufficient, the hot fluid entering the flow channel in the oil pipe is directly discharged out of the ground; when the energy of the stratum is insufficient, the hot fluid entering the flow channel in the oil pipe is pressurized by the underground lifting pump system 20 and then discharged out of the ground.
(9) The thermoelectric power generation module 9 generates electric energy under the action of the temperature difference between the hot fluid produced by the formation in the oil pipe inner flow channel 202 and the circulating cold fluid in the oil sleeve annulus flow channel 201, and inputs the electric energy into the electric energy output module 21 through the connecting cable 22.
Example two
The oil well downhole thermoelectric power generation system when cold fluid is injected from the oil casing annulus flow channel as shown in fig. 3 is different from the shaft type heat exchange closed cycle downhole thermoelectric power generation system in the first embodiment in that: the outlet of the cold fluid injection pipeline is connected with the oil sleeve annulus flow channel, and the inlet of the oil sleeve annulus circulating outflow hot fluid utilization module is connected with the cold fluid injection pipe through the oil sleeve annulus circulating outflow fluid flow pipeline. The working principle of the system is as follows: the cold fluid stored in the cold fluid storage vessel 12 enters the cold fluid injection pump 10 through the cold fluid outflow line 13, is pressurized, and then enters the oil jacket annulus flow channel 201 through the cold fluid injection line 11. The bottom opening of the cold fluid injection pipe 6 is set as a cold fluid reverse circulation point 5, cold fluid enters the cold fluid injection pipe 6 from the cold fluid reverse circulation point 5 at the bottom of the cold fluid injection pipe 6 in the oil sleeve annulus flow channel 201 and flows upwards to the ground, enters the oil sleeve annulus circular flow fluid flow pipeline 17, then enters the oil sleeve annulus circular flow hot fluid utilization module 16, and returns to the cold fluid storage container 12 through the cold fluid flow pipeline 18 after heat exchange and utilization. The hot fluid produced in the production layer 1 enters the casing 8 below the packer 4 under the action of the formation driving pressure difference, enters the flow channel 202 in the oil pipe under the action of residual pressure and is discharged out of the ground, enters the formation produced hot fluid utilization module 14 through the formation produced hot fluid outflow pipeline 15, and enters the oil field produced fluid treatment system through the formation produced fluid flow pipeline 19 after heat exchange and utilization for next-stage treatment and utilization. The thermoelectric power generation module 9 arranged on the outer wall of the oil pipe 7 generates electric energy under the action of the temperature difference between the hot fluid produced by the stratum in the oil pipe inner flow channel 202 and the circulating cold fluid in the oil sleeve annulus flow channel 201, and the electric energy is input into the electric energy output module 21 through the connecting cable 22.
The other steps are the same as those of the first embodiment.
The implementation method of the oil well downhole thermoelectric power generation system when the cold fluid is injected from the oil sleeve annulus flow channel in the embodiment comprises the following steps:
(1) selecting a high water content oil well or an oil well which is abandoned due to high water content. Depending on the depth of its production zone 1, the tubing 7 with its outer wall consolidated with thermoelectric generation modules 9 is lowered above the production zone 1 and the tubing 7 is set on the casing 8 with the packer 4. A downhole lift pump system 20 is installed at the tubing 7 at a depth based on the residual pressure at the bottom hole 2, the depth of the bottom hole 2, and the flow rate of the hot fluid produced by the producing formation 1.
(2) A cold fluid injection pipe 6 is run into the oil jacket annulus flow passage 201 above the packer 4.
(3) A cold fluid storage vessel 12, a cold fluid outflow line 13, a cold fluid injection pump 10 and a cold fluid injection line 11 are connected in sequence, and the cold fluid injection line 11 is connected with the oil jacket annulus flow channel 201. Connecting the cold fluid injection pipe 6 with the oil sleeve annulus circulating outflow hot fluid utilization module 16 through an oil sleeve annulus circulating outflow fluid flow pipeline 17; the oil jacket annulus circulates hot fluid out of the use module 16 through the cold fluid inflow line 18 to the cold fluid storage vessel 12, thereby forming a closed cold fluid circulation system.
(4) The stratum produced hot fluid outflow pipeline 15 is connected with the flow channel 202 in the oil pipe, and then is sequentially connected with the stratum produced hot fluid utilization module 14 and the stratum produced fluid flow pipeline 19 to form a stratum produced fluid flow path.
(5) The thermoelectric power generation module 9 is connected with the electric energy output module 21 through a connecting cable 22 to form a circuit system.
(6) The cold fluid stored in the cold fluid storage vessel 12 enters the cold fluid injection pump 10 through the cold fluid outflow line 13, is pressurized, and then enters the oil jacket annular flow channel 201 through the cold fluid injection line 11.
(7) The bottom opening of the cold fluid injection pipe 6 is set as a cold fluid reverse circulation point 5, cold fluid enters the cold fluid injection pipe 6 from the cold fluid reverse circulation point 5 at the bottom of the cold fluid injection pipe 6 in the oil sleeve annulus flow channel 201 and flows upwards to the ground, enters the oil sleeve annulus circular flow fluid flow pipeline 17, then enters the oil sleeve annulus circular flow hot fluid utilization module 16, and returns to the cold fluid storage container 12 through the cold fluid flow pipeline 18 after heat exchange and utilization.
(8) The hot fluid produced in the production layer 1 enters the casing 8 below the packer 4 under the action of the stratum driving pressure difference, enters the flow channel 202 in the oil pipe under the action of residual pressure and is discharged out of the ground, enters the stratum produced hot fluid utilization module 14 through the stratum produced hot fluid outflow pipeline 15, and enters the oil field produced fluid treatment system through the stratum produced fluid flow pipeline 19 for next-stage treatment and utilization after heat exchange and utilization. When the stratum energy is sufficient, the hot fluid entering the flow channel 202 in the oil pipe is directly discharged out of the ground; when the formation energy is insufficient, the hot fluid entering the flow channel 202 in the tubing is pressurized by the downhole lift pump system 20 and then discharged to the surface.
(9) The thermoelectric power generation module 9 generates electric energy under the action of the temperature difference between the hot fluid produced by the formation in the oil pipe inner flow channel 202 and the circulating cold fluid in the oil sleeve annulus flow channel 201, and inputs the electric energy into the electric energy output module 21 through the connecting cable 22.
Claims (9)
1. A thermoelectric power generation method of an oil well downhole thermoelectric power generation system, characterized in that the thermoelectric power generation system comprises: the system comprises a shaft, a fluid circulation module and an electric energy output module;
the shaft comprises a sleeve, an oil pipe, a thermoelectric generation module and a cold fluid injection pipe, wherein the sleeve sequentially penetrates through an overburden layer and a production layer of the production layer from top to bottom; the part of the sleeve positioned on the production layer is provided with a perforation section; the top of the oil pipe is flush with the top of the casing pipe, and the bottom of the oil pipe is positioned at the junction of the overburden and the production layer on the production layer; the outer side of the lower end of the oil pipe is seated on the inner wall of the casing through a packer; the thermoelectric power generation module is arranged on an oil pipe above the packer and is connected with the electric energy output module through a connecting cable; an oil sleeve annulus flow channel is formed in a space between the inner wall of the sleeve and the outer wall of the thermoelectric power generation module; the inner space of the oil pipe forms an inner flow channel of the oil pipe; the cold fluid injection pipe is embedded in the oil sleeve annular flow channel, and a gap is formed between the bottom of the cold fluid injection pipe and the top of the packer;
the fluid circulation module comprises a cold fluid injection pipeline, a cold fluid injection pump, a cold fluid outflow pipeline, a cold fluid storage container, a cold fluid inflow pipeline, an oil sleeve annulus circulating outflow hot fluid utilization module, an oil sleeve annulus circulating outflow fluid flow pipeline, a stratum output hot fluid outflow pipeline, a stratum output hot fluid utilization module and a stratum output liquid flow pipeline after heat utilization; the outlet of the cold fluid injection pipeline is connected with the cold fluid injection pipe or the oil sleeve annulus flow channel, the inlet of the cold fluid injection pipeline is connected with the outlet of the cold fluid injection pump, the inlet of the cold fluid injection pump is connected with the outlet of the cold fluid storage container through a cold fluid outflow pipeline, and the inlet of the cold fluid storage container is connected with the outlet of the oil sleeve annulus circulating outflow hot fluid utilization module through a cold fluid inflow pipeline; when the outlet of the cold fluid injection pipeline is connected with the cold fluid injection pipe, the inlet of the oil sleeve annulus circulating outflow hot fluid utilization module is connected with the oil sleeve annulus circulating outflow fluid flow channel through the oil sleeve annulus circulating outflow fluid flow pipeline; when the outlet of the cold fluid injection pipeline is connected with the oil sleeve annulus flow channel, the inlet of the oil sleeve annulus circulating outflow hot fluid utilization module is connected with the cold fluid injection pipe through the oil sleeve annulus circulating outflow fluid flow pipeline;
when the cold fluid is injected through the cold fluid injection pipe, the thermoelectric generation method of the thermoelectric generation system comprises the following steps:
s11, the cold fluid stored in the cold fluid storage container enters a cold fluid injection pump through a cold fluid outflow pipeline to be pressurized, and then enters a cold fluid injection pipe through a cold fluid injection pipeline;
s12, setting an opening at the bottom of the cold fluid injection pipe as a cold fluid reverse circulation point, enabling the cold fluid to enter an oil sleeve annulus flow channel from the cold fluid reverse circulation point at the bottom of the cold fluid injection pipe and flow out of the ground upwards, entering an oil sleeve annulus circulating outflow fluid flow pipeline, then entering an oil sleeve annulus circulating outflow hot fluid utilization module, and returning to a cold fluid storage container through a cold fluid inflow pipeline after heat exchange and utilization;
s13, enabling hot fluid produced in a production zone to enter a casing below a packer through a perforation section on the casing under a stratum driving pressure difference, enabling the hot fluid to enter a flow channel in an oil pipe under the action of residual pressure and to be discharged out of the ground, enabling the hot fluid to enter a stratum produced hot fluid utilization module through a stratum produced hot fluid outflow pipeline, and enabling the hot fluid to enter an oil field produced fluid treatment system through a stratum produced fluid flow pipeline to be subjected to next-stage treatment and utilization after heat exchange and utilization;
s14, the thermoelectric power generation module generates electric energy under the action of temperature difference between hot fluid produced by the stratum in the flow channel in the oil pipe and circulating cold fluid in the annular flow channel of the oil sleeve, and the electric energy is input into the electric energy output module through the connecting cable;
when cold fluid is injected through the oil casing annulus flow channel, the thermoelectric power generation method of the thermoelectric power generation system comprises the following steps:
s21, after entering a cold fluid injection pump through a cold fluid outflow pipeline and being pressurized, the cold fluid stored in the cold fluid storage container enters an oil sleeve annular flow channel through a cold fluid injection pipeline;
s22, setting an opening at the bottom of the cold fluid injection pipe as a cold fluid reverse circulation point, enabling the cold fluid to enter the cold fluid injection pipe from the cold fluid reverse circulation point and flow out of the ground upwards, entering an oil sleeve annulus to circularly flow out of a fluid flow pipeline, then entering an oil sleeve annulus to circularly flow out of a hot fluid utilization module, and returning to a cold fluid storage container through a cold fluid flow pipeline after heat exchange and utilization;
s23, enabling hot fluid produced in a production zone to enter a casing below a packer through a perforation section on the casing under a stratum driving pressure difference, enabling the hot fluid to enter a flow channel in an oil pipe under the action of residual pressure and to be discharged out of the ground, enabling the hot fluid to enter a stratum produced hot fluid utilization module through a stratum produced hot fluid outflow pipeline, and enabling the hot fluid to enter an oil field produced fluid treatment system through a stratum produced fluid flow pipeline to be subjected to next-stage treatment and utilization after heat exchange and utilization;
and S24, the thermoelectric power generation module generates electric energy under the action of temperature difference between hot fluid produced by the stratum in the flow channel in the oil pipe and circulating cold fluid in the annular flow channel of the oil sleeve, and the electric energy is input into the electric energy output module through the connecting cable.
2. The method of claim 1, wherein a downhole lift pump system is installed in the tubing.
3. The method of claim 1, wherein the wellbore is a perforated structure drilled through a formation and cemented downhole; the casing is tightly cemented with the production layer and the upper covering layer of the production layer.
4. The method of claim 1, wherein the inner wall of the casing within the overburden of the production zone is coated with a thermally insulating material.
5. The method of thermoelectric power generation of an oil well downhole thermoelectric power generation system of claim 1, wherein the thermoelectric power generation module comprises a plurality of sets of thermoelectric power generators connected in series with each other; the thermoelectric generator comprises a plurality of groups of thermoelectric generating units; the thermoelectric power generation units comprise an N-type semiconductor and a P-type semiconductor, and the N-type semiconductor and the P-type semiconductor are alternately arranged between the adjacent thermoelectric power generation units.
6. The method of thermoelectric power generation of an oil well downhole thermoelectric power generation system of claim 1, wherein: the cross sections of the sleeve, the oil pipe and the cold fluid injection pipe are all circular; the oil pipe and the sleeve are coaxially arranged; the cross section of the thermoelectric power generation module is circular.
7. The method of thermoelectric power generation of an oil well downhole thermoelectric power generation system of claim 1, wherein the cold fluid injection pump and cold fluid storage vessel are both located on the surface.
8. The method of thermoelectric power generation of an oil well downhole thermoelectric power generation system of claim 1, wherein: the cold fluid is any one of water, liquid carbon dioxide and liquid nitrogen.
9. The method of thermoelectric power generation of an oil well downhole thermoelectric power generation system of claim 1, wherein: in steps S13 and S23, the hot fluid entering the flow channel in the tubing is directly discharged to the surface in case of sufficient formation energy; under the condition of insufficient formation energy, the hot fluid entering the flow channel in the oil pipe is pressurized by the underground lifting pump system and then is discharged out of the ground.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810525009.2A CN108756821B (en) | 2018-05-28 | 2018-05-28 | Oil well down-hole thermoelectric power generation system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810525009.2A CN108756821B (en) | 2018-05-28 | 2018-05-28 | Oil well down-hole thermoelectric power generation system and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108756821A CN108756821A (en) | 2018-11-06 |
| CN108756821B true CN108756821B (en) | 2020-06-19 |
Family
ID=64002887
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810525009.2A Active CN108756821B (en) | 2018-05-28 | 2018-05-28 | Oil well down-hole thermoelectric power generation system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108756821B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO20220367A1 (en) * | 2022-03-28 | 2023-09-29 | Affin As | Assembly for generating electricity in a production well of a hot fluid |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20220059747A1 (en) * | 2018-12-27 | 2022-02-24 | National Oilwell Varco, L.P. | Systems and methods for electrical power generation |
| CN109681158B (en) * | 2019-03-04 | 2020-11-24 | 中国石油大学(华东) | Device for carbon dioxide flooding technology |
| CN112539045A (en) * | 2020-12-02 | 2021-03-23 | 中国石油大学(华东) | Underground temperature difference power generation system based on vortex tube and power generation method and design implementation method thereof |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201650630U (en) * | 2010-03-09 | 2010-11-24 | 上海海事大学 | Device generating electricity by solar energy and terrestrial heat |
| CN202215446U (en) * | 2011-09-06 | 2012-05-09 | 徐毅 | System using media with low boiling point in middle-low-temperature geothermal well to obtain heat |
| JP2014084857A (en) * | 2012-10-28 | 2014-05-12 | Yasuharu Kawabata | Binary power generation system |
| CN103225598B (en) * | 2013-04-27 | 2015-11-18 | 清华大学 | The method and system of a kind of pressurized air and heat-storage medium energy storage simultaneously |
| US9777562B2 (en) * | 2013-09-05 | 2017-10-03 | Saudi Arabian Oil Company | Method of using concentrated solar power (CSP) for thermal gas well deliquification |
| US10203162B2 (en) * | 2014-09-02 | 2019-02-12 | Japan New Energy Co., Ltd. | Geothermal heat exchanger, liquid transport pipe, liquid raising pipe, geothermal power generation facility, and geothermal power generation method |
| CN204572361U (en) * | 2015-03-27 | 2015-08-19 | 重庆天豪建材有限责任公司 | One is heat generating system cryogenically |
| CN105674608A (en) * | 2016-02-17 | 2016-06-15 | 姚国敏 | Device and method for extracting and utilizing geothermal energy |
| CN105863568A (en) * | 2016-04-14 | 2016-08-17 | 中国石油大学(华东) | Method for exploring dry-hot-rock geotherm through underground heat siphon self-circulation |
| CN105958870B (en) * | 2016-06-29 | 2017-11-21 | 中国石油大学(华东) | Compound low-temperature receiver hot dry rock thermoelectric heat generation system and method |
| CN107939621B (en) * | 2017-12-01 | 2024-04-02 | 西安交通大学 | S-CO based on geothermal energy of heating dry rock of fin sleeve 2 Power generation system and method |
-
2018
- 2018-05-28 CN CN201810525009.2A patent/CN108756821B/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO20220367A1 (en) * | 2022-03-28 | 2023-09-29 | Affin As | Assembly for generating electricity in a production well of a hot fluid |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108756821A (en) | 2018-11-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108756821B (en) | Oil well down-hole thermoelectric power generation system and method | |
| US10401056B2 (en) | Hydrothermal geothermal development method of multilateral well closed circulation | |
| CN108868723B (en) | Double-well closed circulation underground thermoelectric power generation system and method | |
| US7753122B2 (en) | Method of developing and producing deep geothermal reservoirs | |
| CN105840159B (en) | A kind of gas hydrate exploitation device and recovery method based on heliotechnics | |
| CN105840146A (en) | Method for self-circulation exploitation of geothermal energy of hot dry rock with multilateral well and volume fracturing technologies | |
| US20070245729A1 (en) | Directional geothermal energy system and method | |
| CN204252967U (en) | Hot dry rock multi cycle heating system | |
| CN105625993B (en) | Hot dry rock multi-cycle heating system and its production method | |
| CN103362442B (en) | Drilling well multiple spot communication loop gathers geothermal method | |
| CN109724275A (en) | Method and apparatus for recycling geothermal energy production well site | |
| CN105863568A (en) | Method for exploring dry-hot-rock geotherm through underground heat siphon self-circulation | |
| CN109505577A (en) | Hot dry rock recovery method | |
| CN105958870B (en) | Compound low-temperature receiver hot dry rock thermoelectric heat generation system and method | |
| CN113882836A (en) | Method for realizing geothermal power generation by double-working-medium underground heat exchange and heat exchange production structure | |
| CN108799024B (en) | U-shaped pipe heat exchange closed circulation underground thermoelectric power generation system and method | |
| CN108775275B (en) | Single-well closed circulation underground thermoelectric power generation system and method | |
| CN109458159B (en) | System and method for exploiting sea hydrate by thermoelectric power generation thermal shock method | |
| CN103512254A (en) | Deep well system used for enhanced geothermal system and boring method thereof | |
| Gosnold et al. | The potential for binary geothermal power in the Williston basin | |
| CN103114836B (en) | A kind of Apparatus for () and method therefor of steam heavy oil heat production | |
| CN108869207B (en) | Shaft type heat exchange closed circulation underground thermoelectric power generation system and method | |
| RU132127U1 (en) | IN-PLAST HEAT EXCHANGE DEVICE | |
| CN209877402U (en) | Underground heating well structure | |
| CN113846968A (en) | Lateral drilling branch well heat taking device and method suitable for hot dry rock development |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |