Geothermal wells refer to methods and devices that use geothermal energy with a depth of about 3,500 meters or hot springs whose water temperature is greater than 30°C to generate electricity. Geothermal can be divided into high temperature, medium low temperature and low temperature.
- Higher than 150℃, in the form of steam, belongs to high-temperature geothermal;
- 90℃ ~ 150℃, in the form of water and steam mixture, belongs to the medium temperature geothermal;
- Higher than 25℃ and lower than 90℃, belongs to low temperature geothermal.
Geothermal wellhead & x-mas tree equipment is the most basic wellhead & x-mas tree equipment in geothermal well development.
It is necessary to maintain the normal operation of geothermal well production, conduct dynamic monitoring of hot water, prevent accidents caused by well pipe expansion and ground descent, and reduce the corrosion effect of hot water.
With the gradual development of geothermal utilization, the wellhead & x-mas tree devices of geothermal wells are gradually standardized.
There are three kinds of wellhead & x-mas tree devices in geothermal wells: multifunctional wellhead & x-mas tree devices, wellhead & x-mas tree oxygen isolation devices and wellhead & x-mas tree desanding devices.
(1) Multifunctional wellhead device. Geothermal wellhead & x-mas tree equipment is the most basic wellhead & x-mas tree equipment in geothermal well development.
It is necessary to maintain the normal operation of geothermal well production, conduct dynamic monitoring of hot water, prevent accidents caused by well pipe expansion and ground drop, and reduce the corrosion of hot water.
With the gradual development of geothermal utilization, the wellhead & x-mas tree equipment of geothermal wells is gradually standardized.
One of the most widely used geothermal devices in China is the well head.
(2) wellhead & x-mas tree oxygen isolation device.
In order to prevent the geothermal water from contacting with the air at the wellhead & x-mas tree and reduce the corrosion damage of the water conveyance equipment caused by the combined action of oxygen and chloride ions in the geothermal water, oxygen isolation equipment is installed in some geothermal wells with corrosive effect.
One of the most commonly used methods is nitrogen protection.
(3) Cyclone desander for wellhead and Christmas tree.
Due to geological, construction and other factors, the sand content of some geothermal wells exceeds the national industrial water standard (sand content should be less than 1/2000), which affects the normal use of hot water.
If the geothermal water with high sand content is used for heating, the pipeline system will be blocked.
Therefore, the sand removal measures should be taken for the geothermal well with sand content exceeding the standard.
The cyclone desander designed in China is an ideal desander in geothermal utilization system.
The equipment is generally installed on the outlet pipe of hot water wellhead & x-mas tree.
|Working pressure psi||3000， 5000|
|Nominal main diameter (in)||13-5/8, 11, 7-1/16|
|Working temperature ℃||370|