A down-the-hole drill, usually called DTH by most professionals, is basically a jackhammer screwed on the bottom of a drill string. The fast hammer action breaks hard rock into small cuttings and dust that are evacuated by a fluid (air, water or drilling mud). The DTH hammer is one of the fastest ways to drill hard rock. The system is thought to have been invented independently by Stenuick. Origin of the nameDTH is short for “down-the-hole”. Since the DTH method was originally developed to drill large-diameter holes downwards in surface-drilling applications, its name originated from the fact that the percussion mechanis. .
In DTH drilling, the percussion mechanism – commonly called the hammer – is located directly above the drill bit. The drill pipes transmit the necessary feed force and rotation to the hammer and the bit, along with the flui.
[pdf] A screw compressor is a type of positive displacement compressorthat uses two spiral screws to compress the gas. It uses a positive displacement rotary mechanism for the compression of gas. The scre.
[pdf] 
On April 20, 2010, an explosion and fire occurred on the Deepwater Horizon semi-submersible mobile offshore drilling unit, which was owned and operated by Transocean and drilling for BP in the Macondo Prospect oil field about 40 miles (64 km) southeast off the Louisiana coast. The explosion and. .
Deepwater HorizonDeepwater Horizon was a floating —a fifth-generation, ultra-deepwater, ,. .
On the morning of April 22, Coast Guard Petty Officer Ashley Butler stated that "oil was leaking from the rig at the rate of about 8,000 barrels [1,300 cubic meters] of crude per day." That. .
In June, the said BP should have tested cement at the well, which would have cost them $128,000 and taken no more than 12 hours. .
Documentaries• In 2011, aired March 28, 2011, a documentary by , BP: In Deep Water,. .
The fire aboard the Deepwater Horizon reportedly started at 9:56 p.m. on April 20.Transocean employees on the vessel stated that the. .
SurvivorsAccording to officials, 127 people were on board, of whom 79 were Transocean employees, seven were from BP, and 40 were contracted; several of the BP and Transocean executives were on board for a tour of the rig,. .
On April 21, 2011, BP filed $40 billion worth of lawsuits against rig owner Transocean, cementer Halliburton and blowout-preventer manufacturer . The oil firm alleged that failed safety systems and irresponsible behavior of contractors had led.
[pdf] 
