How to use directional drilling guide in oil field

Pipeline construction with directional drilling rig is generally divided into two stages: the first stage is to drill a pilot hole as accurately as possible according to the design curve; In the second stage, expand the pilot hole, and pull the product pipeline (generally PE pipeline, optical cable sleeve and steel pipe) back into the pilot hole along the expanded pilot hole to complete the pipeline crossing work.

1. 1 drilling pilot hole:

According to the geological conditions of crossing, select the appropriate drill bit and guide plate or downhole mud motor, start the mud pump drilling at the breakthrough point, and the drill bit is driven by the drill to rotate (or driven by the mud motor) to cut the stratum and move forward continuously under the thrust of the drill bit. Every time a drill pipe is drilled, it is necessary to measure the actual position of the drill bit, so as to adjust the drilling direction of the drill bit in time, ensure that the completed guide hole curve meets the design requirements, and so on, until the drill bit is unearthed at the predetermined position, and complete the whole guide.

1.2 Pre-reaming and back-dragging product pipeline:

In general, when using a small drilling rig, pre-reaming is needed when the diameter is greater than 200 mm. When using a large drilling rig, when the diameter of the product pipeline is greater than Dn350mm, pre-reaming is needed. The diameter and frequency of pre-reaming depend on the specific rig model and geological conditions.

When the product pipeline is towed back, firstly connect the reaming tool with the pipeline, and then start the towing operation. The drill pipe is driven by the rotary table of the drilling rig to rotate backwards to carry out reaming and towing. The product pipeline does not rotate during the dragging process. Because the expanding hole is full of mud, the product pipeline is suspended in the expanding hole, and the pipe wall and the periphery of the hole are lubricated by mud, which not only reduces the dragging resistance, but also protects the pipeline anticorrosion layer, and has been pre-reamed by the drilling machine for many times.