Core pipeline for middle-deep geothermal well

Abstract

The utility model discloses a core pipeline for a middle-deep geothermal well, and belongs to the technical field of geothermal well pipelines. The pipeline adopts a segmented assembly structure and comprises a high-temperature section pipeline with the applicable temperature higher than 100 DEG C, a medium-temperature section pipeline with the applicable temperature ranging from 40 DEG C to 80 DEG C and a low-temperature section pipeline with the applicable temperature lower than 40 DEG C, and the pipelines are sequentially arranged and fixedly connected through connecting sections to form a complete assembly pipeline; and the lengths of the high-temperature section pipeline, the medium-temperature section pipeline and the low-temperature section pipeline correspond to the depths of all temperature sections in the geothermal well. The pipeline adopts a segmented assembly structure, the high-temperature section adopts the high-temperature-resistant pipe, and the wall thickness of the pipe is small, so that heat exchange between water and high-temperature geology can be enhanced, and the temperature of the water is increased; the medium-temperature section is large in wall thickness and high in strength, and can be used for a long time in the temperature section; the medium-temperature section pipeline is made of a heat-insulating pipe which is large in wall thickness and high in strength; the low-temperature section is large in wall thickness, high in strength and good in heat preservation effect.

Description

Technical Field

[0001] The utility model belongs to the technical field of geothermal well pipelines, and in particular relates to a core pipeline for a medium-deep geothermal well. Background Art

[0002] As human demand for energy continues to grow, traditional energy resources are gradually decreasing, and environmental protection and sustainable development have become the focus of global attention. In this case, the use of geothermal energy as a clean and renewable energy has become the choice of more and more countries and regions. And deep geothermal heating technology is one of them. Deep geothermal energy refers to geothermal resources located within 1,000 meters below the earth's surface, and its temperature range is usually between 70℃ and 200℃. Compared with shallow geothermal energy, deep geothermal energy has higher temperature and wider distribution range, and can provide energy support for various purposes such as heating, power generation, and refrigeration. The heat pump system is a way to transfer heat between deep geothermal energy and ambient temperature through circulating working fluid. Through the heat pump system, the low-temperature heat in the deep geothermal energy can be extracted, and then heated up through compression and expansion processes, and finally used for heating or other purposes. The advantage of this method is that it does not require direct contact with geothermal water, avoiding the risk of groundwater pollution and geological disasters, and can also achieve efficient use of energy and reduce the impact on the environment.

[0003] At present, the core pipe of geothermal wells generally adopts insulated steel pipe and ordinary PE pipe. The steel pipe has good insulation effect, but it is heavy and inconvenient to construct. The wellhead needs to be equipped with a lifting device, which is difficult and expensive, and the total cost is high. PE plastic pipes have poor temperature resistance and are not suitable for deep geothermal wells. They also have poor insulation effect and low outlet water temperature. Utility Model Content

[0004] In view of the above problems existing in the prior art, the purpose of the utility model is to provide a core pipe for medium-deep geothermal wells, which has the functions of adapting to different temperature ranges, being resistant to high temperatures, having good thermal insulation performance and low water resistance.

[0005] The utility model provides the following technical solution: a core pipeline for medium-deep geothermal wells, which adopts a segmented assembly structure, including a high-temperature segment pipeline with an applicable temperature greater than 100°C, a medium-temperature segment pipeline with an applicable temperature of 40-80°C, and a low-temperature segment pipeline with an applicable temperature less than 40°C. The pipelines are arranged in sequence and fixedly connected through connecting segments to form a complete assembled pipeline; the lengths of the high-temperature segment pipeline, the medium-temperature segment pipeline, and the low-temperature segment pipeline are set corresponding to the depths of each temperature segment in the geothermal well.

[0006] Furthermore, the high temperature section pipeline is made of high temperature resistant pipe material with a wall thickness of 7-10 mm.

[0007] Furthermore, the outer diameter of the medium temperature section pipeline is 100-110 mm, and the wall thickness ranges from 8-12 mm.

[0008] Furthermore, the low-temperature section pipeline adopts thermal insulation pipe material, and its outer diameter ranges from 100-110 and the wall thickness ranges from 8-12.

[0009] Furthermore, two adjacent sections of the pipeline are made of plastic material and are connected by hot-melt butt welding or electric heating.

[0010] Furthermore, two adjacent sections of the pipeline, one is made of plastic material and the other is made of steel pipe material, and the two are connected by a crimping connection or a threaded connection.

[0011] By adopting the above technology, compared with the prior art, the beneficial effects of the utility model are as follows:

[0012] The utility model pipeline adopts a three-section assembly structure of a high-temperature section, a medium-temperature section and a low-temperature section. The high-temperature section adopts high-temperature resistant pipes with a small wall thickness, which can enhance the heat exchange between water and high-temperature geology and increase the water temperature; the medium-temperature section has a large wall thickness and high strength, and can be used for a long time within the temperature section; the medium-temperature section pipeline adopts thermal insulation pipes with a large wall thickness and high strength; the low-temperature section has a large wall thickness, high strength and good thermal insulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments of the specification. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0015] On the contrary, the present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention as defined by the claims. Further, in order to make the public have a better understanding of the present invention, some specific details are described in detail in the following detailed description of the present invention. Those skilled in the art can fully understand the present invention without the description of these details.

[0016] See also Figure 1A core pipe for medium-deep geothermal wells. The geothermal wells are divided into sections according to the use temperature of the pipes. The appropriate type of pipe is selected for each section. High-temperature resistant pipes are selected in the high-temperature zone, PE, PPR and reinforced pipes are selected in the medium-temperature zone, and thermal insulation pipes are selected in the low-temperature zone. It has strong adaptability and low cost. It ensures the service life of the pipes. The thermal insulation pipes can increase the outlet temperature and reduce the operating costs of subsequent heating.

[0017] Specifically, the high temperature section pipeline 1 uses high temperature resistant pipes, such as PPS pipes, MPPO pipes, POK pipes, etc. The use temperature of this type of pipe is above 100°C. The wall thickness of the high temperature resistant section pipe is relatively small, 7-10mm, which can enhance the heat exchange between water and high temperature geology and increase the water temperature.

[0018] The medium temperature section pipeline 2 (conventional section) uses PE-RT pipes, glass fiber reinforced PE pipes, PPR pipes, BFPP pipes and other pipes. The use temperature range is 80-40℃. The pipes in this section are low in cost and high in strength. They can be used for a long time in this temperature range. The outer diameter of the medium temperature section pipes ranges from 100-110mm, and the wall thickness ranges from 8-12mm. The wall thickness is large and the strength is high.

[0019] The low-temperature section pipeline 3 adopts thermal insulation pipes, such as glass bead reinforced PE pipes, PE foam pipes, aerogel felt reinforced PE pipes, etc. The thermal conductivity of such pipes is extremely small, far less than 0.1W / (m·K), which effectively enhances the thermal insulation effect and increases the outlet temperature.

[0020] The operating temperature range of the low-temperature section pipeline 3 is below 40°C, the outer diameter range of the medium-temperature section pipe is 100-110mm, and the wall thickness range is 8-12mm. The wall thickness is large, the strength is high, and the thermal insulation effect is good.

[0021] Adjacent pipes are connected in sequence through the connecting section 4. Due to the different types of pipes, different sections have a variety of connection methods. If the adjacent pipes are made of the same PE material, they can be connected by hot-melt butt, electric fusion connection, etc., which is convenient and fast. Conventional section pipes and high-temperature section pipes can be connected by crimping connection, threaded connection, etc. to achieve a stable and fast connection.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A core pipe for a medium-deep geothermal well, characterized in that: A segmented assembly structure is adopted, which includes a high-temperature section pipeline with an applicable temperature greater than 100°C, a medium-temperature section pipeline with an applicable temperature of 40-80°C, and a low-temperature section pipeline with an applicable temperature less than 40°C. The pipelines are arranged in sequence and fixedly connected through connecting sections to form a complete assembled pipeline; the lengths of the high-temperature section pipeline, the medium-temperature section pipeline, and the low-temperature section pipeline are set corresponding to the depths of each temperature section in the geothermal well.

2. A core pipe for a medium-deep geothermal well according to claim 1, characterized in that: The high temperature section pipeline is made of high temperature resistant pipe material with a wall thickness of 7-10mm.

3. A core pipe for a medium-deep geothermal well according to claim 2, characterized in that: The outer diameter of the medium temperature section pipeline is 100-110 mm, and the wall thickness ranges from 8-12 mm.

4. A core pipe for a medium-deep geothermal well according to claim 3, characterized in that: The low temperature section pipeline adopts thermal insulation pipe material, and its outer diameter ranges from 100 to 110, and the wall thickness ranges from 8 to 12.

5. The core pipe for a medium-deep geothermal well according to claim 4, characterized in that: The two adjacent sections of pipes are made of plastic material and are connected by hot-melt butt welding or electric heating.

6. The core pipe for a medium-deep geothermal well according to claim 4, characterized in that: Two adjacent pipe sections, one is made of plastic material and the other is made of steel pipe material, and the two are connected by means of a crimping connection or a threaded connection.

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