The portion of natural gas that is stripped out as liquids by special processing facilities at the surface.

Pumpable fluids circulated in a drill hole to remove rock cuttings and coll the bit Mud is normally a mixture of water, clay, and chemical additives.

A large high pressure pump used to circulate the mud on a drilling rig.

One thousand cubic feet. The Mcf is a standard measure of natural gas volume. One Mcf is equal to one million BTU of energy at one atmosphere of pressure. MMCF represents one million cubic feet.

A type of mobile offshore drilling rig capable of working in water up to 400 feet deep.

The ownership rights of oil, gas, and other minerals under a given tract. These include the right to explore, drill, and produce the minerals or assign such rights to another party in the form of a lease.

A well that contains no oil or gas, too little of either to make an adequate return on investment.

A drilling method where a vertical drilling hole is redirected so as to be parallel to oil formation.

A mobile offshore drilling unit that floats and is not secured to the seafloor when it is in drilling mode. Floating units include inland barge rigs, drill ships, ship-shaped barges, and semi-submersibles.

The identification and examination of areas that could potentially contain oil and gas reserves.

Expenses incurred in identifying new exploration activities. This includes equipment, support personnel, facilities, depreciation, and other applicable costs.

The sum paid to a drilling contractor for each 24 hours of operation under a daywork contract. Under these agreements, contractors are paid on the basis of time worked, not footage drilled. Day rates can generally range from $45,000 to $80,000 per day.

A common unit of liquid measure in the petroleum industry. One barrel of oil equals 42 standard U.S. gallons or 35 British imperial gallon.

The cutting or boring element used to penetrate the earth in the digging of the well.

Heavy seamless tubing used to rotate the bit and circulate the drilling fluid. Lengths of pipe approximately 30 feet long are coupled together by means of tool joints.

a self propelled floating vessel that specializes in penetrating deepwater and ultra deepwater formations.

An uncontrolled flow of gas, oil, or other well fluids into the atmosphere or into an underground formation that is extremely wasteful of reservoir fluids. This is also called a gusher since it can occur when formation pressure exceeds the pressure applied to it by the column of drilling fluid.

The drilling of new wells to increase production in a field. There are legal spacing standards between wells.

Injecting water under pressure into a depleted well to force out remaining oil.

Expenses incurred to obtain access to proven reserves and to provide facilities for extracting , treating, gathering, and storing oil and gas.

The rate at which a reserve of natural resource is exploited, calculated as the inverse of the years of reserve remaining and expressed as a percentage.