The breakthrough of horizontal drilling has revolutionized the search for new reserves of oil and natural gas, enabling our industry to recover resources located under sensitive habitats without harm and produce more oil and natural gas from fewer wells.
The same basic principles also enable pipelines – essential in delivering the fuels you count on every day – to be laid underground without disrupting the lands or waterways above.
Here's how it works:
- A small diameter “pilot hole” is drilled using a steerable bit. A bit is a cutting devise that cuts rocks and makes the hole during drilling. A steerable bit is one that can be oriented in various directions, both up and down and in any compass direction.
- The bit and driller communicate using computers that can send and interpret vibrations sent through mud in the hole. Mud, used to lubricate and cool the bit during drilling, transfers vibrational signals much like coper wires transfer electronic signals in your personal computer.
- Mud vibrations sent from the surface tell a computer at the bit where it should point for drilling. The drill bit sends precise information on its depth, location and alignment back to the driller. In this way the operator can steer the bit and create a hole around sensitive features and environments without disturbing the surface.
- When the drill emerges at the other side of the pilot hole, it is replaced at the end of the drill string with a “reamer” that bores out a hole large enough to accommodate the pipeline. The drill string is pulled back through the pilot hole and the reamer widens the hole as it moves along.
- The drill string makes a third pass through the hole, this time pulling the pre-welded and tested pipe into place behind it.