What Does Intersect Method Mean?
The intersect method of drilling uses two drills, one at each end of the bore's design path. One of which has a magnetic source mounted on the assembly (BHA) instead of a steering tool. The magnetic source allows the rig without the magnet to determine the distance and azimuth to the source.
Both rigs drill pilot bores toward each other until the bores intersect. The drill with the magnetic source then continues the bore to the end of the design path.
Trenchlesspedia Explains Intersect Method
The intersect method may sound as if two drilling rigs are playing "which will blink first," but the intersect method has advantages in trenchless work.
- On-site drilling fluid samples to discover the effect of each design parameter on the overall design
- You determine the actual drill pressure to avoid water hammer and hydrofracture
Drill pressure is often calculated by the design engineer; using the intersect method in the field, knowing the actual pressure may help prevent frac-out, which is what happens when mud moves into cracks in the bedrock and leaches toward the surface, as the drill without the magnetic locator source is returns to its point of entry.