Key Definitions Flashcards
NGL
Natural Gas Liquid -Ethane, propane, butane, isobutane, and pentane
Natural Gas
Gaseous mixture of hydrocarbon compounds, primarily methane.
Base Gas
Natural gas needed to maintain adequate reservoir pressures during withdrawal - remains in the reservoir.
Citygate
Point or measuring station where a gas utility receives gas from a pipeline company or transmission system.
Coke oven gas
Mixture of permanent gases produced by the carbonization of coal in a coke oven at high temperatures.
Condensate
Light liquid hydrocarbons (primarily pentane and heavy hydrocarbons) recovered from lease separators or field facilities.
Dry natural gas
Natural gas which remains after most of the liquefiable hydrocarbons and gaseous nonhydrocarbons are removed.
Consumer-grade natural gas
Dry natural gas
Flare
Tall stack with burners to combust and dispose of combustible gases. Natural gas (typically when produced as a byproduct of oil production) is flared when it is uneconomical/impractical to process/sell/transport the gas after it is obtained.
Gas Well
A well that is built for the extraction of natural gas exclusively - i.e. is not suitable for oil extraction.
Lease and plant fuel
Natural gas used in well, field, and leasing operations, and as fuel in natural gas processing plants.
LNG
Liquefied natural gas that has been liquefied by reducing its temperature to -260 degrees Fahrenheit at atmospheric pressure.
Marketed production
Gross withdrawals minus the gas used for re-pressuring, gas that is vented/flared, and nonhydrocarbon gases removed during treatment/processing.
Native gas.
Gas that was already in place when a reservoir was converted for storage.
Natural gas field facility
A field facility used to process natural gas from more than one lease.
NGL Production
The volume of NGLs removed from natural gas in lease separators, field facilities, processing plants, or cycling plants.
Pipeline fuel
Gas consumed in the operation of pipelines, primarily in compressors.
Re-pressuring
The injection of gas into oil or gas formations to generate greater ultimate recovery.
Shale
A fine-grained, clastic sedimentary rock that forms when mud, silt, and clay-sized mineral particles are compacted into relatively impermeable layers.
Clastic
Denoting rocks composed of broken pieces of older rocks.
Hydraulic Fracturing
Hydraulic fracturing, or fracking, is a well-stimulation method, used commonly in low-permeability rocks like tight sandstone, shale, and some coal beds, to extract oil or natural gas from deep in the Earth. In the fracking process, cracks in and below the Earth’s surface are opened and widened by injecting water, chemicals, and sand at high pressure.
Fracking
Hydraulic fracturing, or fracking, is a drilling method, used commonly in low-permeability rocks like tight sandstone, shale, and some coal beds, to extract oil or natural gas from deep in the Earth. In the fracking process, cracks in and below the Earth’s surface are opened and widened by injecting water, chemicals, and sand at high pressure.
Source rock
Rock rich in organic matter that generates oil or natural gas. Typical source rocks include shales and limestones.
Synthetic/Substitute natural gas
A manufactured product resulting from the conversion of hydrocarbons that can be substituted with pipeline-quality natural gas.
Therm
100,000 Btu
Design capacity
The total maximum quantity of natural gas, including base and working gas, that can be stored in an underground storage facility.
Vented gas
Natural gas that is disposed of by release into the atmosphere.
Wellhead
The point at which crude oil and/or natural gas exits the ground.
Working gas
The quantity of natural gas in the reservoir in addition to the base gas. It may or may not be completely withdrawn during a specified withdrawal season.
Wet gas
Natural gas that contains a significant proportion of hydrocarbons heavier than methane.
Associated Gas
Natural gas produced as a result of oil production.
Casinghead Gas
Unprocessed natural gas - aka wet gas
Horizontal drilling
Also known as directional drilling, drilling method that involves drilling vertically till, typically, a few hundred feet above the target rock, after which a hydraulic motor is attached between the drill bit and drill pipe to rotate the drill bit without rotating the entire length of the drill pipe, which allows the drill bit to change orientation and drill horizontally.
This allows drillers to reach targets that are unfeasible through vertical drilling, as well as giving operators the ability to drain from a much broader area, which often substantially improves the productivity and profitability of wells. Horizontal drilling is also sometimes used to drill a relief well to relieve pressure from or seal a nearby out-of-control well.
Horizontal drilling is often used in conjunction with hydraulic fracturing as a form of “unconventional drilling” in low-permeability areas.
Conventional target
A conventional target is reached using conventional drilling methods aka exclusively vertical drilling.
Unconventional target
A target that is reached using unconventional drilling methods, using well stimulation and directional drilling. These targets are typically associated with difficult-to-access, impermeable, and/or non-porous geologic formations, such as shale and tight sands, and are more expensive to reach.
Play
An area of similar geological characteristics in which oil/gas hydrocarbon accumulations or prospects occur.
Basin
A depression in the Earth’s crust in which sediments can accumulate.
ROP
Rate of Penetration - drilling
Footage
The specified formation or depth in a drilling contract.
DLS
Dogleg Severity - the curvature/change in direction of a well bore over 100 feet of length; a more severe dogleg makes drilling more difficult.
WOB
Weight on Bit
Sweet gas
Natural gas with insignificant amounts of hydrogen sulfide - H2S is corrosive and undesirable.
Sour Gas
Natural gas with measurable levels of corrosive and undesirable hydrogen sulfide.
Compressor
Increases the pressure of natural gas to allow for its transportation.
Condensate
NGLs
Well stimulation
A process that improves oil/gas production by improving the flow through the rock formation - examples of well stimulation processes include fracking, acidizing, and the use of other chemicals.
