Directional Survey Data Mean?
Directional survey data, in context of trenchless technology, concerns the process of horizontal directional drilling (HDD) and refers to the raw data gathered from surveys conducted using survey stations along the path of the bore hole, such as azimuth and inclination, which are analyzed mathematically to arrive at required calculations. In trenchless technology, a directional survey is used to determine the feasibility of a path for laying pipelines or other underground structures.
Trenchlesspedia Explains Directional Survey Data
The directional survey uses methods such as the tangential method, the average angle method, the radius of curvature method and driller bias in its calculations. The angular position is determined for every foot drilled, after which necessary corrections are made. Usually an inclination target is given to the driller, which he needs to hit at the end of the joint to be drilled. The survey data can be used to monitor the path to ensure that the target exit is reached, to orient tools used for deflecting the path, to ensure that the drill path does not intersect other underground structures or pipelines, and to map the underground for future reference. Magnetic interference can affect the reading of a survey station, which can result in inaccurate data. An artificial magnetic field on the surface can often compensate for this potential.