What is a DTH drill?
It can be done on both hard and soft rock and is extensively used in the construction, oil and gas, and water well industries. DTH equipment consists of a drilling hammer and a piston-powered by compressed air. As the drill string rotates, the drilling hammer strikes down on the rock.
What is down-the-hole drilling?
Down-the-hole drilling (DTH) essentially involves a drilling hammer at the bottom of a drill string. It relies on three elements for drilling holes: bit loading (weight), rotation and air. These active elements combine to be efficient at crushing rock.
What is the direction of direction of thrust (DTH) drilling?
Applications were later found for the DTH method underground, where the direction of drilling is generally upwards instead of downwards. In DTH drilling, the percussion mechanism – commonly called the hammer – is located directly above the drill bit.
What is the DTH method?
Considering that the DTH method was initially designed to drill large-diameter holes in surface-drilling software, its title originated in the fact that the percussion mechanism adopted down the bit to the gap.
What is a DTH drill bit?
Down-the-hole (DTH) hammer bits are used with Down-the-hole hammers for drilling holes through a wide range of rocks types. In conjunction with DTH hammers, drill hammer bits are designed with a splined drive for rotating the bit in the ground.
What are the method of drilling?
Here are five of the most common drilling methods used in extracting oil and gas from beneath the earth: Percussion or Cable Drilling. Rotary Drilling. Dual-Wall Reverse-Circulation Drilling.
What is DTH equipment?
Down-the-Hole (DTH) Drilling Equipment DTH hammer drilling is the industry standard for the rapid drilling of boreholes for a variety of uses such as water wells, blasting and sub-surface void locations.
How do you use a DTH hammer?
The percussive mechanism begins to operate as the air supply is turned on and when the drill bit is pushed firmly into the hammer. Excessive pressure is not needed to initiate the hammer. Rotate the hammer clockwise at approximately 30-rpm. The DTH bit will now push into the Driver Sub and percussive action begins.
What is top hammer drilling?
In top hammer drilling, the activity is concentrated at the top of the drill string, above the hole, as a hammer transmits cyclical shock waves to the drill bit by applying a percussive force on the drill rods or tubes (With DTH drills, the hammer is placed down-the-hole at the bit).
What are the main types of drilling?
The two major types of the drill are manual and electric drills. The common features they have today include multi-function power, selection of driver bits, and varied drilling power.
How many types of drilling are there?
There are many different types or configurations of drilling machines, but most drilling machines will fall into four broad categories: upright sensitive, upright, radial, and special purpose.
What is DTH full form?
Description: In India, direct-to-home (DTH) Broadcasting Service refers to the distribution of multi channel TV programmes in Ku Band by using a satellite system by providing TV signals direct to subscribers' premises.
What is DTH system specification?
DTH is a new technology and it has matured to its full potential all parts of the world. Early satellite television was broadcast in C-band - radio in the 3.4 gigahertz (GHz) to 7-GHz frequency range. Digital broadcast satellite transmits programming in the Ku frequency range (10 GHz to 14 GHz).
What is DTH cable?
Direct-to-home (DTH) Broadcasting Service refers to the distribution of multi-channel TV programs by using a satellite system. The TV programs is encoded into a digital stream of “0” & “1” in binary data and provides TV signals direct to subscribers' premises.
Where are DTH drilling applicable?
Uses. DTH products can be used in the following applications: Mining- drill and blast holes in open pit mining, where the drill operator will drill several holes, then fill with explosives and detonate to lift rock allowing access to ore body.
Which drilling method is for rock?
2.1 Rock Drilling. Drilling of holes and wells can be divided into the four following application ranges: (1) rotary drilling and overburden drilling by use of cutters or bits; (2) percussive drilling; (3) rotary percussive drilling; and (4) rotary drilling by use of roller-cone bits.
What is odex drilling?
ODEX is an adaptation of the air-operated down-the-hole hammer. It uses a swing-out eccentric bit to ream the bottom of the casing. Cuttings blow up through the drive sub and casing annulus to a swivel conducting them to a sample collector or onto the ground. Rapid removal of cuttings. No use of drilling mud.
What is a top hammer used for?
Top hammer drills are primarily used in mining, construction and quarrying of rock material. Top hammer drilling, combined with the “drill and blast” method, makes the whole excavation process extremely efficient.
What is diamond drilling in mining?
Diamond drilling (or diamond core drilling) is the process of using a diamond-studded drill bit to drill down and withdraw a solid core sample from the ground rather than a chipped sample.
Is top hammer drilling vs down-the-hole drilling?
The primary difference between the top hammer and down-the-hole drilling methods is where the hammer is attached. The hammer in the industrial equipment makes contact with the bit during the down-the-hole drilling method. The top hammer drilling method's activity is concentrated at the very top of the drill string.
How does a DTH hammer work?
The DTH hammer is pneumatically powered, with the compressed air propelling it forward to impact and fracture rock. Compressed air also travels through the drill bit into the hole (air exhaust), which blows the chips and dust out of the hole.
What is down the hole drilling?
Down-the-hole drilling (DTH) essentially involves a drilling hammer at the bottom of a drill string. It relies on three elements for drilling holes: bit loading (weight), rotation and air. These active elements combine to be efficient at crushing rock.
What is a blasthole drill?
They’re used for drilling a hole into the surface of the rock, packing the hole with explosives and then detonating those explosives in the blasthole to break up rock and hard minerals to make it easier to remove.
Is DTH drilling good?
From environmental and social perspectives, DTH is a good option because it produces much less noise and vibration than many other drilling methods. Quieter drilling means it is often the preferred drilling method when used in cities and populated areas.
What is DTH drilling?
Down-the-hole (D TH) drilling has made it easier for contractors to drill wells faster and more efficiently, and to transition from dirt boring to rock boring just by adding a compressor and hammer to the drill bit. Usually, contractors working on a dirt bore would pack up and move on to the next dirt bore when they encountered rock, ...
When was DTH first used?
The Directional DTH system, patented by Atlas Copco, was first used successfully in 2012 by drilling crews in the Marcellus Shale region of the United States to steer percussive drilling.
What is the driving medium in a drill?
The driving medium i.e. compressed air is also the flushing medium. The flushing medium (in some cases, water is also used) is pressed down through the drill pipes, down-the-hole hammer and the drill bit. It is then forced back out of the borehole along with the cuttings through the annular gap between the drill pipe and the borehole.
Why is air drilling so cost effective?
The use of air makes this method very cost-effective as air does not have to be sourced, transported or treated. Less amount of drilling fluid and additives are required. Less weight-on-bit allows for lighter rigs that are easier to set up and takedown.
Is DTH drilling environmentally friendly?
The DTH method is the most productive and cost-effective method. It is environmentally friendly, as it produces lesser noise and vibration compared to other drilling methods making it ideal for cities.
Can you change a drill for a dirt bore?
Usually, contractors working on a dirt bore would pack up and move on to the next dirt bore when they encountered rock, leaving the rock boring for another contractor to complete. With DTH drilling, contractors can change the drill that they were using for the current directional bore to a rock drill when they encounter rock by connecting ...
How does a DTH drill work?
In DTH drilling, the drill string rotates while the drilling hammer continuously strikes down into the rock. Inside the hammer, a piston powered by compressed air gives the drill bit its striking power. This combined with the rotational movement means the rock is crushed in a very efficient manner.
How deep can you drill a hole with a DTH?
Because the power transfer takes place down in the hole when the piston strikes directly at the bit – hence the drilling method’s name – there is minimal energy losses along the drill string and holes can be drilled down to 6,000 meters in depth. DTH is a reliable method that drills stable holes with exceptional straightness.
What is the best way to drill a hole?
When you need to drill high quality holes with diameters between 100-254 mm , DTH (Down The Hole) drilling is by far the best and most effective method. DTH drilling can be performed in most types of rock, hard or soft. It's a commonly used method in the mining industry (blast hole drilling), waterwell drilling, construction, and in the oil and gas industry.
Is DTH drilling good?
DTH is a reliable method that drills stable holes with exceptional straightness. The method is also excellent both environmentally and socially because it produces far less noise and vibration than many other drilling methods, making it a widely used drilling method in cities and other populated areas.
