Heat-exchanging horizontal well, heat-exchanging cross orthogonal horizontal well factory and construction method

Abstract

The invention discloses a heat-exchanging horizontal well, a heat-exchanging cross orthogonal horizontal well factory and a construction method. A first opening well section includes a first verticalwell section, a second opening well section includes a second vertical well section connected to the bottom of the first vertical well section and a well section deflecting to the horizontal section connected to the bottom of the second vertical well section, and a third opening well section includes a horizontal well section connected to the well section deflecting to the horizontal section; a surface casing is arranged in the first vertical well section; a first technical casing is arranged in the surface casing, the second vertical well section and the well section deflecting to the horizontal section; a second technical casing is arranged in the horizontal well section; the first technical casing is connected to the second technical casing; the end of the second technical casing away from the first technical casing is sealed; the second technical casing is a heat-exchanging technical casing; a central tube is arranged in the first technical casing and the second technical casing; and one end of the central pipe is spaced from the end of the second technical casing. The heat exchange efficiency is greatly improved, no refilling is required, and the geothermal energy can be developed and utilized efficiently and cleanly.

Description

technical field [0001] The invention belongs to the technical field of development and utilization of geothermal resources, and in particular relates to a heat exchange type horizontal well, a heat exchange type cross orthogonal horizontal well factory and a construction method. Background technique [0002] my country's Guanzhong Basin is rich in geothermal resources, and has a long history of development and utilization of mid- to deep-layer geothermal resources, mainly using hydrothermal geothermal energy. Common 1500-3000m medium-deep geothermal energy utilization currently has four utilization methods: (1) Drilling a single vertical well, directly extracting hot water without recharging; (2) Drilling a group of vertical wells, one well extracts hot water, Recharge tail water from one or more wells; (3) Drill a single vertical well, use concentric pipes to circulate hot and cold water to extract thermal energy from the reservoir; (4) Drill a pair of well groups, a vertic...

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Problems solved by technology

[0003] The above four utilization methods have the following problems: one is to take the hot water from the ground hydrothermal reservoir (sandstone reservoir) and use the geothermal water for direct heating. The geothermal water after heating and cooling is sent to the recharge well for recharge through the water pipeline network. The geological conditions of the recharge to the sandstone hot water reservoir often encounter problems such as scaling and blockage, which restricts 100% of the water supply. Geothermal water recharge and clean utilization; second, vertical well concentric tube heat transfer technology is limited by the thickness of the hydrothermal reservoir and the size of the wellbore structure. The third is the horizontal well docking technology. Although it can achieve relatively efficient clean utilization of geothermal energy, the horizontal well docking method requires a higher level of drilling technology and higher drilling costs. Popularization and commercial utilization more difficult

Generally speaking, the current development and utilization technology of mid-deep geothermal energy has not achieved clean utilization in the main, and a small part has achieved clean utilization. However, its heat exchange efficiency and well construction cost are relatively high, and it is difficult to be widely promoted and commercialized.

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