Horizontal directional drilling (HDD) machines are steerable, trenchless drilling rigs for the installation of pipes, conduits, and cables underground in a shallow arc. They are commonly used for installations below waterways and roadways to avoid disturbing the ground above.
Horizontal drilling machines are typically heavy-duty vehicles fitted with track drives, operator controls, and drilling machinery. Materials used for pipes include PVC, polyethylene, polypropylene, ductile iron, and steel.
Directional drilling machines install both small and large diameter lines (3 to 48 inches). Installation is typically a two-step process. The first step is to use a drill head to drill a one- to five-inch pilot hole at an angle, using the ground as reference. The second step involves replacing the drill head with a reaming device such as a fluid-assisted drill, a high pressure fluid jetting system, or a dry bore system to enlarge the hole to the desired size. As the reamer is pulled back the pilot hole is enlarged and pulls the pipe or conduit back with it. For larger pipes an additional step of reaming will be required. The final size of the drilled hole is 50% larger than the pipe diameter to drain drilling fluids and to accommodate the bend radius of the pipe.
Directional drilling machines come in a range of sizes, with the largest machines capable of drilling to depths of 200 ft. and lengths of 6,000 ft. Horizontal directional drilling machines are divided into three categories large-diameter HDD (maxi-HDD), medium-diameter HDD (midi-HDD), and small-diameter HDD (mini-HDD). There is no significant difference in the operation of these systems. The categories represent the drive length, depth, torque and pullback capabilities of each system.
Guiding the drill head is an important part of the drilling operation. There are three types of guiding systems for locating and steering the drill head.
Walk-over locating system: A sonde or transmitter located behind the drill head registers angle,
rotation, direction, and temperature data. This information is encoded into an electro-magnetic signal and transmitted to the surface. A handheld receiver is manually positioned over the transmitter where the signal is decoded and steering directions are given to the machine operator.
Wire-line locating system: With a Magnetic Guidance System (MGS) the tool reads inclination and azimuth. The guidance system also has a secondary means of location verification that utilizes wire grids laid on the ground surface. This information is transmitted through a wire-line fitted within the drill string. At the drilling machine, a navigator performs calculations to confirm the direction and location of the drill head.
Gyro-based locating system: The gyro-based locating system is considered one of the most accurate systems available. These locating systems are free of some of the limitations inherent in other systems. such as vulnerability to magnetic disturbance, inability to access areas above a drill path, and a large tolerance of trajectory.
Amid the previous six years, Horizontal Directional Drilling (HDD) has changed the industry of underground utility installation. Today, HDD is a common and well-known technique for introducing a wide range of underground utilities, for example, water, telephone, sewer, electric and gas. HDD is likewise appropriate for introducing natural remediation wells.
HDD is basically a procedure by which it is conceivable to introduce utilities underground with insignificant disturbance to the ground surface. This is cultivated by making a bore into the ground and after that leveling out at a predefined depth. When the best possible depth has been achieved, it is then conceivable to propel the bore horizontally to a goal point where the drill is diverted so it leaves the ground. When it leaves the ground, the bore head is evacuated and a back expander or reamer is connected alongside a swivel and the product that will be installed. It is then pulled back to the drilling unit through the pilot bore.
To perform different directional drilling projects, directional drilling machines are accessible in numerous sizes. Notwithstanding the size, they all have three principal functions: forward push, rotation as well as a pullback. The business wide standard for rating the measure of a machine is the aggregate pounds of pullback ability. In any case, more accentuation is being set on the rotational torque rating of machines. Directional drilling machines can likewise be part into two different classifications: independent or remote units.
An independent Horizontal Directional Drilling unit alludes to a machine that has the power unit, bore pipe, and rack on board while a remote unit comprises of a power unit that is permanently attached to a trailer, truck bed, or is slide mounted and has water powered hoses rushing to the bore rack. Independent machines are very prominent in view of the decreased setup time and on the grounds that the additional weight holds the machine set up.
The drilling or boring pipe is also known as drill stem and it is accessible in various widths and lengths, depending on the span of the bore fix that it is to be utilized on. Measurements of bore pipe can extend in size from a little more than one inch up to six inches. These pipes are empty to enable drilling liquids to go from the boring apparatus to the bore head.
When the pilot bore is finished, the drill head is evacuated and a back reamer is connected to the drill string. Back reamers also called expanders or the hole openers, are able to perform two main functions.
The first and most clear is to broaden the opening to a size sufficiently expansive to enable space for the item to be introduced The other capacity is to mix the cuttings with the drilling liquids to make a slurry down gap, in this way making a superior situation for product installation .Due to easy and simple working, Horizontal Directional Drilling (HDD) is one the most preferred ways for pipe laying and such other things.
Max thrust force
Max pullback force
Dia.of drilling rod
Length of drilling rod
Max rotary speed
Max Dia.of pullback pipe
Max carriage speed
Max construction length
Max mud pump flow
Max mud pressure
Power divider/Swivel 250T
Protection joint/Sub saver
Male-female connector/Pull eyes