Background
Geothermal heating is an important route to clean heating in northern China, and deep geothermal wells often exceed a thousand metres. The deeper the well and the more water-bearing layers, the higher the pressure needed — which is why geothermal drilling generally uses units above 30 bar.
Solution
The rated pressure was recalculated for depth and water back-pressure, and a two-stage unit above 30 bar was chosen with pressure margin for changing water inflow.
Results
No more flushing problems from low pressure in the water-bearing sections, and drilling pace stayed steady through the whole well.
