Horizontal Directional Drilling (HDD) is a method of installing underground pipelines, cables and service conduit through trenchless methods. It involves the use of a directional drilling machine, and associated attachments, to accurately drill along the chosen bore path and back ream the required pipe.
General description of the technology
Horizontal Directional Drilling is based on using the drilling equipment. The general technology of puncturing comes to the following manipulations:
Project documentation with calculations is prepared for accurate horizontal drilling in the soil. The projects are compliant with local authority and landowners. Two basins are digged out at the site of works start and communications exit in the location, where the drilling will take place. Laying of necessary pipelines are carried out with the help of drilling tools. Completion of work, removal of basins, restoration of sites at their location if necessary.
The above description is brief, currently several types of HDD have been developed. The application of a certain type of horizontal drilling is carried out depending on the soil type, laying communication lines and other factors. Drilling equipment
Various drilling tools are used in drilling technology:
Drilling machine. It is an industrial equipment run on diesel fuel. Operation and movement are carried out by the operator. Drilling is based on functional components of such machines as carriage, hydraulic power station, control panels. Accessory tools. Various tools are used for the soil puncturing and punching as hoses, reamers, pumps, screw elements with thread and so on. Based on type and stages of the works carried out, the team set a different tool on the drilling rig. Navigation system. It is important to observe the trajectory of transmitter housing (drill head) passing, the accuracy of outlet (output) at the second basin during HDD works. In order to do that, a probe is mounted into the transmitter housing, and the workers follow the movement of the tool with the help of a locator.
Each part of industrial equipment for HDD takes on an important role, requires professional handling and routine maintenance.
Directional drilling is a three stage process:
Pilot Hole
The first stage consists of drilling a small diameter pilot hole. Drilling fluid is pumped through the drill pipe to the drill bit where high pressure jets and the bit will grind the soils ahead of the drill stem. The drilling fluid will also carry the cuttings back to the entrance pit at the drill rig. Tracking of the pilot hole can be done in several ways depending on the size and complexity of the shot. There is a transmitter or steering tool located near the drill head which sends a signal to the location engineer giving the exact coordinates of the drill stem. Readings are constantly taken which check the depth, alignment and percent slope of the drill head. Corrections will be made by the operator and locator to keep the pilot hole along the predetermined bore path. The speed of the pilot hole will vary upon existing soil conditions and the amount of steering which is required. Upon reaching the exit point, the beacon housing and bit is detached and replaced with a reamer.
Pre-Reaming
The second step is to pre-ream the pilot hole and enlarge it to a size sufficient to safely install the product lines. A reamer is pulled back and rotated while pumping drilling fluid to cut and remove solids to enlarge the hole. Pre-reaming speeds will vary depending on existing soil conditions and the amount of cuttings that are removed from the hole. If required Additives are being used to ensure a clean and stable hole. Bentonite may be t9 used to create a “cake layer” around the outside of the hole during pre-reaming. This will help with the stability of the bore hole and with fluid loss or infiltration. Additives such as polymers are used to help break up the clay soils. A more evenly mixed drilling fluid will prevent any blockages inside of the bore hole.
Pipe Pullback
The final step is the pullback of the pipe within the pre-reamed hole. The drill rod and reamer will be attached to a swivel, which is utilized between the product line and the reamer to prevent any torsional stress from the rotating drill string being transferred to the product pipe. As the product pipe is pulled into the drill hole, drilling fluid is pumped downhole to provide lubrication to the product pipe.
Advantages Less waste of resources, finance, labour and time Costs for laying communications are reduced due to the lack of the need to restore the environment. You can work in any areas, including historical places, high-voltage stations, unfavourable climatic conditions; The soil structure is preserved; the fertile soil layers are not disturbed; The usual urban rhythm is also not disturbed, there is no need to stop the road traffic.
Why Choose MEC for Execution –
Huge Fleet of Equipment and highly skilled and experienced staff having experience in laying of underground Pipe Line for various utilities. Proven experience of 20 years, technocrats and the experienced human resources. Management team is an interfusion of leaders having an experience of 30 - 40 years, and young budding leaders having graduated from one of the best Business Schools of the Globe & Highly Trained, Experienced Project Managers. Having Experience of completion of Various crossing for laying pipeline of various DIA staring from 200 MM to 600 MM . All required equipment are company owned , no dependency on any external agency
