What Does Directional Survey Station Mean?
A directional survey station is a reference point that corresponds to a measured depth along the (typically actual) well path where well bore inclination and azimuth are observed/measured and recorded. In horizontal directional drilling, this reference point is used to survey below the surface of the ground for the purpose of exploring, tunneling, constructing structures or laying pipeline at a certain depth. This process is vital in planning sub-surface trenchless construction.
Trenchlesspedia Explains Directional Survey Station
There are various methods used to determine the bore path between survey stations. These methods include:
- The tangential method
- The radius of curvature method
- The average Angle method
- Driller bias
Factors including measured distance, vertical depth, inclination, entry and exit points and the horizontal plane must be taken into account when employing the use of a directional survey station. Accuracy depends on the frequency of the survey station. Underground surveys differ from surface surveys due to conditions such as humidity, darkness and cramped work space, However, using this kind of survey enables carrying out underground work without the need for open excavation, which can disrupt surface activity and landscape.