A thermal storage system and method utilizing abandoned oil fields

Abstract

This invention relates to the field of abandoned oilfield technology and discloses a thermal storage system utilizing abandoned oilfields, including an abandoned oil well, an abandoned oilfield, a boiler, a warm water module, and a heating module. The abandoned oil well is used to connect to water and is connected to the abandoned oilfield. The abandoned oilfield is connected to the boiler and equipped with a first electric pump. The boiler outlet is connected to both the warm water module and the heating module. A thermal storage method is also provided, in which water is heated through the abandoned oil well and then flows into the abandoned oilfield for insulation. The insulated water then flows into the boiler for heating. When T1 < T0, a control component controls the opening of a first throttle valve, and the heated water from the boiler provides hot water to the warm water module. When T1 ≥ T0, the control component controls the closing of the first throttle valve. T0 is the standard temperature at the user end of the warm water module, and T1 is the temperature detected by a first temperature detection device. This reduces heat energy waste caused by seasonal fluctuations and extends the project cycle of the oilfield.

Description

Technical Field

[0001] This invention relates to the field of abandoned oilfield technology, and in particular to a thermal storage system and method for utilizing abandoned oilfields. Background Technology

[0002] Warm water and heating are basic necessities for residents in northern China. Winter is the peak season for heat demand, leading to seasonal fluctuations and instability. Currently, two problems exist: first, heating systems built to meet the average annual heat demand suffer from insufficient supply during peak winter periods; second, systems built to meet only the peak winter demand often result in supply far exceeding demand in other seasons, leading to resource waste.

[0003] The solution to these two major problems lies in storing thermal energy to adapt to seasonal fluctuations and instabilities. Deep underground strata contain abundant geothermal resources, and the geothermal gradient is an indicator of the amount of geothermal resources. In areas with normal geothermal gradients, geothermal wells needed for development must be sufficiently deep. In the later stages of oilfield development, some wells are abandoned; these abandoned wells can be slightly modified for geothermal energy development. Since geothermal resources are renewable and clean energy, their clean and low-carbon characteristics align with the main theme of the energy industry. To solve the winter heating problem and extend the oilfield project cycle, this invention provides a thermal storage system utilizing abandoned oilfields to address the issues of energy collection, storage, and utilization. Summary of the Invention

[0004] The purpose of this invention is, on the one hand, to provide a thermal storage system that utilizes abandoned oil fields to meet the demand for peak winter heating and to reuse the geothermal energy of abandoned oil fields.

[0005] A thermal storage system utilizing an abandoned oil field includes an abandoned oil well, an abandoned oil field, a boiler, a warm water module, and a heating module. One end of the abandoned oil well is connected to water, and the other end of the abandoned oil well is connected to the abandoned oil field. The abandoned oil field is connected to the boiler and equipped with a first electric pump. The boiler's outlet is connected to both the warm water module and the heating module.

[0006] Preferably, the warm water module includes a first connecting pipe, a first heat exchanger, a warm water user terminal, a second electric pump, and a first throttling valve. The first heat exchanger includes a first heat exchange channel and a second heat exchange channel that are not interconnected.

[0007] The boiler outlet is connected to one end of the first heat exchange channel via the first connecting pipe. A return pipe is provided between the other end of the first heat exchange channel and the abandoned oil field. One end of the second heat exchange channel is used to connect to tap water, and the other end of the second heat exchange channel is connected to the warm water user end. The first throttle valve is installed on the first connecting pipe, and the second electric pump is installed on the return pipe.

[0008] Preferably, the heating module includes a second connecting pipe, a second heat exchanger, a heating user terminal, a third electric pump, a fourth electric pump, a water supply pipe, and a water return pipe. The second heat exchanger includes a third heat exchange channel and a fourth heat exchange channel that are not interconnected.

[0009] The boiler outlet is connected to one end of the third heat exchange channel via a second connecting pipe. The other end of the third heat exchange channel is connected to an abandoned oil field. One end of the fourth heat exchange channel is connected to the water inlet of the heating user via a water supply pipe. A return water pipe is connected between the water outlet of the heating user and the other end of the fourth heat exchange channel. A third electric pump is installed on the water supply pipe, and a fourth electric pump is installed on the return water pipe. A second throttle valve is installed on the second connecting pipe.

[0010] Preferably, the heat storage system utilizing the abandoned oil field also includes a control component, a first temperature detection device is installed on the second heat exchange channel, a second temperature detection device is installed on the fourth heat exchange channel, and the first temperature detection device, the second temperature detection device, the first throttle valve, the second throttle valve, the boiler, and the control component are electrically connected.

[0011] Preferably, the heat storage system utilizing the abandoned oil field further includes a first flow detection device and a second flow detection device. The first flow detection device is located on the second heat exchange channel, and the second flow detection device is located on the fourth heat exchange channel. Both the first flow detection device and the second flow detection device are electrically connected to the control component.

[0012] Preferably, both the first heat exchanger and the second heat exchanger are indirect heat exchangers.

[0013] On the other hand, a method for utilizing abandoned oil fields for thermal storage is provided, including the use of a thermal storage system for utilizing abandoned oil fields as described above, comprising the following steps:

[0014] Water is heated through abandoned oil wells and then flowed into the abandoned oil field for insulation.

[0015] The insulated water flows into the boiler for heating;

[0016] The control component controls the opening and closing of the first throttle valve based on the relationship between the temperature detected by the first temperature detection device and the standard temperature at the user end of the warm water module.

[0017] When T1 < T0, the control component controls the first throttle valve to open, and the water heated by the boiler supplies hot water to the hot water module.

[0018] When T1≥T0, the control component controls the first throttle valve to close;

[0019] Where T0 is the standard temperature at the user end of the warm water module, and T1 is the temperature detected by the first temperature detection device.

[0020] Preferably, the method of utilizing abandoned oilfields for thermal storage further includes the following steps:

[0021] The control component controls the opening and closing of the second throttle valve based on the relationship between the temperature detected by the second temperature detection device and the standard temperature at the user end of the heating module.

[0022] When T3 < T2, the control component controls the second throttle valve, the second electric pump, the third electric pump, and the fourth electric pump to all open, and the water heated by the boiler provides hot water to the heating module.

[0023] When T3≥T2, the control component controls the second throttle valve, the second electric pump, the third electric pump, and the fourth electric pump to all shut down;

[0024] Where T2 is the standard temperature at the user end of the heating module, and T3 is the temperature detected by the second temperature detection device.

[0025] This invention discloses a thermal storage system and method utilizing abandoned oil fields. Compared with existing technologies, its advantages lie in the following: abandoned oil wells and abandoned oil fields contain abundant geothermal energy. Water is added to these wells and fields and heated by geothermal energy. The water is then further heated by a boiler and supplied to the warm water module and heating module. During peak winter heating seasons, this thermal storage system utilizes abandoned oil fields to compensate for the difference between the annual average heating demand and the winter peak demand. Therefore, heating systems can be built according to the annual average heat energy demand, reducing the impact of seasonality on urban heating systems and ensuring optimal operation, thus minimizing seasonal heat waste. Using abandoned oil fields for thermal storage can also extend the project cycle, making it environmentally friendly. Attached Figure Description

[0026] Figure 1 This is a system diagram of an embodiment of the present invention;

[0027] Figure 2 This is a partially enlarged view of the first heat exchanger in an embodiment of the present invention;

[0028] Figure 3 This is a partially enlarged view of the second heat exchanger according to an embodiment of the present invention;

[0029] Figure 4 This is a flowchart of a method according to an embodiment of the present invention.

[0030] In the image, 1. abandoned oil well; 2. abandoned oil field; 3. boiler;

[0031] 4. Warm water module; 41. First connecting pipe; 42. First heat exchanger; 421. First heat exchange channel; 422. Second heat exchange channel; 43. Warm water user end; 44. First electric pump; 45. Second electric pump; 46. First throttle valve; 47. Return pipe;

[0032] 5. Heating module; 51. Second connecting pipe; 52. Second heat exchanger; 521. Third heat exchange channel; 522. Fourth heat exchange channel; 53. Heating user end; 54. Third electric pump; 55. Fourth electric pump; 56. Water supply pipe; 57. Water return pipe; 58. Second throttle valve. Detailed Implementation

[0033] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0034] In the description of this invention, it should be understood that the terms "longitudinal," "lateral," "vertical," "horizontal," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., used to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0035] In the description of the invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] like Figures 1-2 As shown, a preferred embodiment of the present invention provides a thermal storage system utilizing an abandoned oil field, comprising an abandoned oil well 1, an abandoned oil field 2, a boiler 3, a warm water module 4, and a heating module 5. Preferably, the abandoned oil well 1 and the abandoned oil field 2 are arranged side by side. One end of the abandoned oil well 1 is used to connect to water, and the other end of the abandoned oil well 1 is used to connect to the abandoned oil field 2. The abandoned oil field 2 is connected to the boiler 3 and is equipped with a first electric pump 44. The outlet of the boiler 3 is connected to the warm water module 4 and the heating module 5 respectively.

[0037] The working process of this invention is as follows: Abandoned oil well 1 and abandoned oil field 2 contain abundant geothermal energy. Water is added to abandoned oil well 1, and the geothermal energy of abandoned oil well 1 heats the water. The water flows into abandoned oil field 2 for heat preservation, and is further heated by boiler 3. The hot water is then supplied to the warm water module 4 and the heating module 5. This invention provides a heat storage system utilizing abandoned oil field 2: Abandoned oil well 1 and abandoned oil field 2 contain abundant geothermal energy. Water is added to abandoned oil well 1 and abandoned oil field 2, and the water is heated by geothermal energy. It is then further heated by boiler 3. The hot water is then supplied to the warm water module 4 and the heating module 5. During the peak winter heating season, this heat storage system utilizing abandoned oil field 2 supplements the difference between the annual average heating consumption and the winter peak heating consumption. Therefore, when constructing a heating system, it can be built according to the annual average heat energy demand, reducing the impact of seasonality on the city's heating system and ensuring that the city's heating system operates at its optimal state, reducing heat energy waste caused by seasonality. Using abandoned oilfield 2 for thermal storage can also extend the cycle of oilfield projects, which is green and environmentally friendly.

[0038] More preferably, the input water can be not only ordinary unheated water, but also the unused electrical energy generated by the wind power plant during periods of strong winds, which is converted into heat energy. This portion of hot water is stored in the abandoned oil field 2. The abandoned oil field 2 reduces wind curtailment through geothermal heat storage, extends the oil field project cycle, and is more environmentally friendly.

[0039] More preferably, since solar power generation is also seasonal and fluctuating, this part of the electrical energy is converted into heat energy, and then this part of the hot water is stored in the abandoned oil field 2. The abandoned oil field 2 reduces the curtailment of solar power through geothermal heat storage, extends the oil field project cycle, and is more environmentally friendly.

[0040] The heating system is constructed based on the average annual heat energy demand. During peak winter heating seasons, the thermal storage system of the abandoned oilfield No. 2 is used to supplement the difference between the average annual heat consumption and the peak winter heating season. This reduces the impact of seasonality on the city's heating system and ensures that the system operates at its optimal state, minimizing heat waste caused by seasonality. Furthermore, the oilfield project is converted into a geothermal project, extending its lifespan and making it environmentally friendly.

[0041] Furthermore, the warm water module 4 includes a first connecting pipe 41, a first heat exchanger 42, a warm water user terminal 43, a second electric pump 45, and a first throttle valve 46. The first heat exchanger 42 includes a first heat exchange channel 421 and a second heat exchange channel 422 that are not interconnected.

[0042] The outlet of boiler 3 is connected to one end of the first heat exchange channel 421 via a first connecting pipe 41. A return pipe 47 is installed between the other end of the first heat exchange channel 421 and the abandoned oil field 2. One end of the second heat exchange channel 422 is connected to tap water, and the other end is connected to the warm water user terminal 43. A first throttle valve 46 is installed on the first connecting pipe 41, and a second electric pump 45 is installed on the return pipe 47. The first heat exchange channel 421 heats the second heat exchange channel 422, thus heating the water required by the warm water user terminal 43 from the geothermal energy of the abandoned oil field 2 and the thermal energy of boiler 3. Using the thermal storage system of this embodiment, since geothermal energy is a clean energy source and extends the project cycle of the oil field, it conforms to the clean and low-carbon trend of the energy industry.

[0043] Furthermore, the heating module 5 includes a second connecting pipe 51, a second heat exchanger 52, a heating user terminal 53, a third electric pump 54, a fourth electric pump 55, a water supply pipe 56, and a return water pipe 57. The second heat exchanger 52 includes a third heat exchange channel 521 and a fourth heat exchange channel 522 that are not interconnected.

[0044] The outlet of boiler 3 is connected to one end of the third heat exchange channel 521 via a second connecting pipe 51. The other end of the third heat exchange channel 521 is connected to the abandoned oil field 2. One end of the fourth heat exchange channel 522 is connected to the inlet of the heating user terminal 53 via a water supply pipe 56. The outlet of the heating user terminal 53 is connected to the other end of the fourth heat exchange channel 522 via a return water pipe 57. A third electric pump 54 is installed on the water supply pipe 56, and a fourth electric pump 55 is installed on the return water pipe 57. A second throttle valve 58 is installed on the second connecting pipe 51. The third heat exchange channel 521 heats the fourth heat exchange channel 522, that is, the geothermal energy of the abandoned oil field 2 and the heat energy of boiler 3 heat the heating user terminal 53. The heating module uses heat exchangers and electric pumps, which have low construction costs, are easy to construct, and have good heat transfer effects.

[0045] Furthermore, the thermal storage system utilizing the abandoned oil field 2 in this embodiment also includes a control component. A first temperature detection device is installed on the second heat exchange channel 422, and a second temperature detection device is installed on the fourth heat exchange channel 522. The first temperature detection device, the second temperature detection device, the first throttle valve 46, the second throttle valve 58, the boiler 3, and the control component are all electrically connected. The first temperature detection device detects the temperature of the warm water user terminal 43, and the second temperature detection device detects the temperature of the heating user terminal 53. The control component is configured to: open the first throttle valve 46 when the temperature detected by the first temperature detection device is lower than the rated value of the warm water module 4; and open the second throttle valve 58 when the temperature detected by the second temperature detection device is lower than the rated value of the heating module 5.

[0046] More preferably, the control component can be a PLC, a controller, etc., and is not limited here.

[0047] Furthermore, the thermal storage system utilizing abandoned oilfield 2 also includes a first flow detection device and a second flow detection device. The first flow detection device is located on the second heat exchange channel 422, and the second flow detection device is located on the fourth heat exchange channel 522. Both the first and second flow detection devices are electrically connected to the control component. The control component calculates the warm water heat load using the flow rate detected by the first flow detection device and the temperature detected by the first temperature detection device. The control component calculates the heating load using the flow rate detected by the second flow detection device and the temperature detected by the second temperature detection device.

[0048] Furthermore, both the first heat exchanger 42 and the second heat exchanger 52 are indirect heat exchangers. Indirect heat exchangers have the advantages of high heat exchange efficiency, low heat loss, compact and lightweight structure, small footprint, convenient installation and cleaning, wide application, and long service life.

[0049] On the other hand, embodiments of the present invention also provide a method for heat storage utilizing abandoned oil fields, using the heat storage system for utilizing abandoned oil fields as described above, which includes the following steps:

[0050] Water is heated through abandoned oil well 1 and then flows into abandoned oil field 2 for insulation.

[0051] The insulated water flows into boiler 3 for heating;

[0052] The control component controls the opening and closing of the first throttle valve 46 based on the relationship between the temperature detected by the first temperature detection device and the standard temperature at the user end of the warm water module 4.

[0053] When T1 < T0, the control component controls the first throttle valve 46 to open, and the water heated by the boiler 3 supplies hot water to the warm water module 4.

[0054] When T1≥T0, the control component controls the first throttle valve 46 to close;

[0055] Where T0 is the standard temperature at the user end of the warm water module 4, and T1 is the temperature detected by the first temperature detection device.

[0056] Furthermore, the method of utilizing abandoned oilfields for thermal storage also includes the following steps:

[0057] The control component controls the opening and closing of the second throttle valve 58 based on the relationship between the temperature detected by the second temperature detection device and the standard temperature at the user end of the heating module 5.

[0058] When T3 < T2, the control component controls the second throttle valve 58, the second electric pump 45, the third electric pump 54, and the fourth electric pump 55 to all open, and the water heated by the boiler 3 provides hot water to the heating module 5.

[0059] When T3≥T2, the control component controls the second throttle valve 58, the second electric pump 45, the third electric pump 54, and the fourth electric pump 55 to all close.

[0060] Where T2 is the standard temperature at the user end of heating module 5, and T3 is the temperature detected by the second temperature detection device.

[0061] Specifically, supplying geothermal energy from abandoned oilfield 2 to heating module 5 has the effect of extending the geothermal project cycle and meeting the heating needs of heating module 5.

[0062] More preferably, the boiler 3 and the abandoned oil field 2 provide heat energy to the hot water module 4 and the heating module 5. When the temperature supplied by the abandoned oil field 2 meets the needs of the hot water user terminal 43 and the heating user terminal 53, that is, when T1>T0 and T3>T2, the control component controls the boiler 3 to shut down, thereby further saving energy.

[0063] In summary, the embodiments of the present invention provide a thermal storage system and method for abandoned oil fields. Firstly, it solves the problem of insufficient or surplus heat production in heating systems caused by the seasonality of heat demand. Secondly, it extends the cycle of oil field projects. Through geothermal thermal storage, it is low-carbon and environmentally friendly, which is in line with the trend of the energy industry.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A thermal storage system utilizing abandoned oil fields, characterized by, The application relates to a heating system comprising a waste oil well, a waste oil field, a boiler, a warm water module and a heating module, one end of the waste oil well is used for connecting water, the other end of the waste oil well is connected with the waste oil field, the waste oil field is connected with the boiler and a first electric pump is arranged between the waste oil field and the boiler, and the water outlet of the boiler is connected with the warm water module and the heating module respectively. The warm water module comprises a first connecting pipe, a first heat exchanger, a warm water user end, a second electric pump and a first throttling valve, the first heat exchanger comprises a first heat exchange channel and a second heat exchange channel which are not communicated with each other. The water outlet of the boiler is connected with one end of the first heat exchange channel through the first connecting pipe, a backflow pipe is arranged between the other end of the first heat exchange channel and the waste oil field, one end of the second heat exchange channel is used for connecting tap water, the other end of the second heat exchange channel is connected with the warm water user end, the first throttling valve is arranged on the first connecting pipe, and the second electric pump is arranged on the backflow pipe.

2. The thermal storage system utilizing abandoned oil fields according to claim 1, wherein, The heating module comprises a second connecting pipe, a second heat exchanger, a heating user end, a third electric pump, a fourth electric pump, a water supply pipe, a backwater pipe and a second throttling valve, the second heat exchanger comprises a third heat exchange channel and a fourth heat exchange channel which are not communicated with each other. The outlet of the boiler is connected with one end of the third heat exchange channel through the second connecting pipe, the other end of the third heat exchange channel is connected with the waste oil field, one end of the fourth heat exchange channel is connected with the water inlet of the heating user end through the water supply pipe, the water outlet of the heating user end is connected with the other end of the fourth heat exchange channel through the backwater pipe, the third electric pump is arranged on the water supply pipe, the fourth electric pump is arranged on the backwater pipe, and the second throttling valve is arranged on the second connecting pipe.

3. The thermal storage system utilizing abandoned oil fields of claim 2, wherein, The application further comprises a control assembly, a first temperature detecting device is arranged on the second heat exchange channel, a second temperature detecting device is arranged on the fourth heat exchange channel, the first temperature detecting device, the second temperature detecting device, the first throttling valve, the second throttling valve and the boiler are electrically connected with the control assembly.

4. The thermal storage system utilizing abandoned oil fields according to claim 3, wherein, The application further comprises a first flow detecting device and a second flow detecting device, the first flow detecting device is arranged on the second heat exchange channel, the second flow detecting device is arranged on the fourth heat exchange channel, and the first flow detecting device and the second flow detecting device are electrically connected with the control assembly.

5. A thermal storage method using an abandoned oil field, which uses the thermal storage system using an abandoned oil field according to claim 4, characterized by, The application comprises the following steps: Water is heated through the waste oil well and then flows into the waste oil field for heat preservation; The heat-preserved water flows into the boiler for heating; The control assembly controls the opening and closing of the first throttling valve according to the size relationship between the temperature detected by the first temperature detecting device and the standard temperature of the warm water module user end: When T1 When T1 Wherein, T0 is the standard temperature of the warm water module user end, and T1 is the temperature detected by the first temperature detecting device.

6. The heat storage method according to claim 5, characterized by, The application further comprises the following steps: The control assembly controls opening and closing of the second throttle valve according to the size relationship between the temperature detected by the second temperature detecting device and the standard temperature of the user end of the heating module; When T3 When T3 When T3 T2 is the standard temperature of the user end of the heating module, and T3 is the temperature detected by the second temperature detecting device.

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