HDD (Horizontal Directional Drilling) is a trenchless way to construct underground pipes, wires, and service conduits. It entails precisely boring all along desired bore route and reverse reaming the appropriate pipe with a directional drilling machine and accompanying equipment.
The Horizontal Directional Drilling Process has four stages.
Stage 1 – Drilling the Pilot Hole
Stage 2 – Horizontal Boring Pre-Reaming
Stage 3 – Pullback Operations
Stage 4 – Conduit Installation
1. Drilling the Pilot Hole
A pilot hole is drilled horizontally and follows a preset layout track below and across the barrier. An electrical transmitter is mounted in housing directly behind the directional drilling cutting head. The transmitter sends a message to the ground that the recipient reads and relays to the directional drill rig manager. The directional driller then can guide the hole route in any intended way that uses the communicated information.
2. Horizontal Boring Pre-Reaming
Following the completion of the pilot hole, the hole must always be extended to a diameter adequate for the development pipeline. This is performed by “pre-reaming” the horizontal drilling to gradually greater diameters in the second phase of the Horizontal Directional Drilling Operation. The reamer is usually connected to the drill string on the other side of the bore from the drill being dragged back into the pilot hole. To keep the hole clean and clean away cuttings, the slurry is poured into the directionally drilled hole. Based on the soil’s state, the reaming operation can take a long period.
3. Operation Pullback
A mud pass or packer reamer will be used after the preferred hole has now been accomplished and the reamer has transferred through it entirely to ensure that the hole is tidy of all eroded material and that the drilling liquid has totally filled the space, allowing for a seamless greased withdrawal of the pipe while trying to dodge tension in the pull segment.
4. Conduits are installed.
An aircraft wire is fitted into the horizontally bored conduit before it is pulled into alignment if it is to transport electricity lines, fibre optic cable, or another item. The directional drill rig is used to bring the product into place within the pipeline once the pipe has been installed. Pressure checking is performed at the end of the Horizontal Directional Drilling Process to confirm the pipe’s integrity.
The horizontal directional drilling (HDD) procedure evolved from the oil well boring agency’s tools and methods. A horizontal drilling rig used for pipeline construction has many of the same components as an oil well drilling rig, with the exception that a horizontal drilling rig has a slanted ramp instead of a vertical mast. The processes involved in drilling directional oil boreholes are similar to those required in HDD pilot hole drilling. Drill pipe and downhole equipment are often replaceable, and drilling fluid is utilized all through the procedure to carry drilled spoil, minimize friction, and stabilize the hole, among other things. Drilling, rather than boring, is the term used to describe the procedure due to the obvious connections.