CN-121067474-B - Butt joint well structure for enhancing heat exchange efficiency of middle-deep geothermal well

CN121067474BCN 121067474 BCN121067474 BCN 121067474BCN-121067474-B

Abstract

The application relates to the field of geothermal exploitation and utilization, and provides a butt well structure for enhancing heat exchange efficiency of a middle-deep geothermal well, which comprises a water inlet well and a reflux well; the water inlet well is provided with a first vertical section and at least one heat exchange butt joint section, one end of the heat exchange butt joint section is communicated with the first vertical section, the backflow well is provided with a second vertical section and a heat exchange path extension section, the upper end of the heat exchange path extension section is communicated with the bottom of the second vertical section, the horizontal distance between any part of the heat exchange path extension section except the upper end and the first vertical section is larger than the horizontal distance between the upper end of the heat exchange path extension section and the first vertical section, and one end of the heat exchange butt joint section, which is away from the first vertical section, is communicated with the heat exchange path extension section. The application solves the problems of low heat exchange efficiency and large occupied area of the traditional butt joint well structure.

Inventors

CHEN GAOKAI
WU YANFEI
LI JI
WEI JINGWEN
ZHANG JIE
WANG SHUAIQI
ZHANG HONGXIA
MA XUHONG
FAN YUEHUA
WANG SHAOWEN

Assignees

万江新能源股份有限公司北京新能源科技分公司
万江新能源股份有限公司
中国建筑科学研究院有限公司

Dates

Publication Date: 20260512
Application Date: 20250910

Claims (5)

1. A butt well structure for enhancing heat exchange efficiency of a mid-deep geothermal well, comprising: The water inlet well (1) is provided with a first vertical section (11) and at least one heat exchange butt joint section (12), wherein one end of the heat exchange butt joint section (12) is communicated with the first vertical section (11); A return well (2) having a second vertical section (21) and a heat exchange path extension; the upper end of the heat exchange path extension section is communicated with the bottom of the second vertical section (21), and the horizontal distance between any part of the heat exchange path extension section except the upper end and the first vertical section (11) is larger than the horizontal distance between the upper end of the heat exchange path extension section and the first vertical section (11); Reinforcing sleeves (3) are arranged in the water inlet well (1) and the backflow well (2); The butt joint well structure for enhancing the heat exchange efficiency of the middle-deep geothermal well further comprises a supporting piece (4) and a plurality of separating pieces (5); the support (4) and the plurality of partitions (5) are arranged inside the reinforcement sleeve (3) in the return well (2); the support piece (4) extends along the axial direction corresponding to the reinforcement sleeve (3), the support piece (4) is positioned in the middle of the reinforcement sleeve (3), the plurality of partition pieces (5) are positioned in gaps between the support piece (4) and the inner wall of the reinforcement sleeve (3), the plurality of partition pieces (5) are arranged at intervals along the circumferential direction, the partition pieces (5) are respectively connected with the support piece (4) and the corresponding reinforcement sleeve (3), and the support piece (4) and the plurality of partition pieces (5) jointly divide the interior of the reinforcement sleeve (3) into a plurality of mutually independent fluid channels (31); the number of the heat exchange butt joint sections (12) is multiple, and two ends of at least one first heat exchange section (121) in the plurality of heat exchange butt joint sections (12) are respectively communicated with the middle area of the first vertical section (11) and the middle area of the heat exchange path extension section; The plurality of fluid channels (31) comprise at least one first fluid channel (311) and at least one second fluid channel (312), wherein the top of the first fluid channel (311) is communicated with the first heat exchange section (121), and the upper end and the lower end of the first fluid channel (311) are closed; The support piece (4) is an inner pipe, the lower end opening of the support piece (4) is closed, and a through hole (41) communicated with the first flow channel (311) is formed in the side wall of the lower end of the support piece (4).
2. The butt well structure for enhancing heat exchange efficiency of a mid-deep geothermal well according to claim 1, wherein the heat exchange path extension comprises a first extension (22) and a second extension (23), wherein the horizontal distance between the first extension (22) and the first vertical section (11) increases gradually from top to bottom; the top of the second extension section (23) is communicated with the bottom of the first extension section (22), and at least one heat exchange butt section (12) is communicated with the bottom of the second extension section (23).
3. A docking well structure for enhancing heat exchange efficiency of a mid-deep geothermal well as claimed in claim 2, wherein the first extension (22) is rectilinear and has an angle α with respect to the horizontal of 70 ° -80 °.
4. A docking well structure for enhancing heat exchange efficiency of a mid-deep geothermal well according to claim 1, wherein the partition (5) is elongated and extends in a spiral direction.
5. The butt well structure for enhancing heat exchange efficiency of a deep geothermal well according to claim 1, wherein the partition (5) is a heat conductive metal member, and the surface of the partition (5) has a convex portion.

Description

Butt joint well structure for enhancing heat exchange efficiency of middle-deep geothermal well Technical Field The application relates to the field of geothermal development and utilization, in particular to a butt joint well structure for enhancing heat exchange efficiency of a middle-deep geothermal well. Background In the field of geothermal energy development and utilization, medium-deep geothermal resources are becoming an important direction of global energy development as clean, stable and rich-reserve energy. With the continuous increase of energy demand and the improvement of environmental protection consciousness, the development and utilization of deep geothermal resources are of great significance for optimizing energy structures, reducing carbon emission and realizing sustainable development. The effective utilization of the medium-deep geothermal energy can provide stable heat energy supply for building heating, industrial production and the like, reduce the dependence on traditional fossil energy and promote the green transformation in the energy field. In the aspect of enhancing the heat exchange efficiency of the middle-deep geothermal well, the conventional technology generally adopts a horizontal well and a vertical well for heat exchange. The horizontal well is provided with a vertical section and a horizontal section, and the vertical section is communicated with the bottom of the vertical well through the horizontal section. The fluid is guided into the horizontal well to deeply exchange heat underground, and the fluid after heat absorption flows back through the vertical well. Wherein the horizontal segment is effective to enable the fluid to reside within the target depth zone for a long period of time to adequately exchange heat. However, due to the existence of the horizontal section, the horizontal well and the vertical well are usually far apart, the occupied area is large, and the management is inconvenient. Shortening the length of the horizontal segment in turn affects the heat transfer effect. Disclosure of Invention The application provides a butt joint well structure for enhancing the heat exchange efficiency of a middle-deep geothermal well, which aims to solve the problems of low heat exchange efficiency and large occupied area of the traditional butt joint well structure. The application provides a butt joint well structure for enhancing heat exchange efficiency of a middle-deep geothermal well, which adopts the following technical scheme: a docking well structure for enhancing heat exchange efficiency of a mid-deep geothermal well, comprising: The water inlet well is provided with a first vertical section and at least one heat exchange butt joint section, wherein one end of the heat exchange butt joint section is communicated with the first vertical section; A return well having a second vertical section and a heat exchange path extension section; the upper end of the heat exchange path extension section is communicated with the bottom of the second vertical section, the horizontal distance between any part of the heat exchange path extension section except the upper end and the first vertical section is larger than the horizontal distance between the upper end of the heat exchange path extension section and the first vertical section, and one end of the heat exchange butt joint section, which is away from the first vertical section, is communicated with the heat exchange path extension section. By adopting the technical scheme, the horizontal distance between any part of the heat exchange path extension section except the upper end and the first vertical section is larger than the horizontal distance between the upper end of the heat exchange path extension section and the first vertical section, so that the length of the heat exchange butt joint section in the horizontal direction is larger than the horizontal distance between the first vertical section and the second vertical section, further, even if the wellhead distance between the water inlet well and the reflux well is relatively short, the heat exchange butt joint section still has enough length so that the fluid can fully absorb geothermal heat, and in addition, compared with a vertical structure, the design of the heat exchange path extension section can prolong the heat exchange time of the fluid, and further improve the heat exchange effect. Optionally, the heat exchange path extension section comprises a first extension section and a second extension section, wherein the horizontal distance between the first extension section and the first vertical section is gradually increased from top to bottom; the top of the second extension section is communicated with the bottom of the first extension section, and at least one heat exchange butt joint section is communicated with the bottom of the second extension section. By adopting the technical scheme, the horizontal distance between the heat exchange path exte