Geothermal Wells refer to methods and devices that generate electricity using geothermal energy at a depth of about 3,500 meters or hot springs whose water temperature is higher than 30 degrees Celsius. Geothermal energy can be divided into three categories: high temperature and low temperature.
- higher than 150℃, in the form of steam, belongs to the high-temperature geothermal;
- 90℃ ~ 150℃, in the form of water vapor mixture, belonging to the middle-temperature geothermal;
- Low temperature geothermal is higher than 25℃ and lower than 90℃.
Geothermal wellhead is the most basic wellhead in geothermal well development. To maintain the normal operation of geothermal well production, dynamic monitoring of hot water, prevent well tube expansion and ground drop caused by accidents, reduce the corrosive effect of hot water. With the gradual development of geothermal utilization, the wellhead device of geothermal well is gradually standardized.
There are three kinds of geothermal wellhead devices: multifunctional wellhead devices, wellhead oxygen isolation devices and wellhead sand removal devices.
(1) Multi-functional wellhead device. Geothermal wellhead is the most basic wellhead in geothermal well development. To maintain the normal operation of geothermal well production, hot water dynamic monitoring, prevent well tube expansion and ground subsidence caused by accidents, reduce the corrosion of hot water. With the gradual development of geothermal utilization, the wellhead equipment of geothermal Wells is gradually standardized. The wellhead is one of the most widely used geothermal facilities in China.
(2) Wellhead oxygen isolation unit. In order to prevent the contact between geothermal water and the air at the wellhead and reduce the corrosive damage caused by the combined action of oxygen and chloride ions in geothermal water to water transport equipment, oxygen isolation devices have been installed in some corrosive geothermal Wells. One of the most common methods is nitrogen protection.
(3) Wellhead cyclone desander. Due to geological and construction factors, the sand content in some geothermal Wells exceeds the national industrial water standard (the sand content should be less than 1/20,000), affecting the normal use of hot water. If hot geothermal water with high sand content is used, the piping system can become clogged. Therefore, for geothermal Wells with excessive sand content, sand removal measures should be taken. Cyclone desander designed by our country is an ideal desander in geothermal utilization system. The equipment is generally installed on the outlet pipe of the hot water wellhead.