Oil and Gas Terms Beginning with “G” — Page 2

Hydrocarbon gas density expressed as the ratio of the molecular weight of the gas to the molecular weight of air. Read more →

What Is a Gas Hydrate? A gas hydrate is a crystalline solid clathrate compound in which water molecules form a hydrogen-bonded lattice cage that traps small gas molecules, principally methane, under conditions of low… Read more →

Gas that is dissolved in a liquid, such as water or oil. Read more →

What Is Gas Injection? Gas injection (also called gas flooding or pressure maintenance injection ) is an enhanced oil recovery and reservoir management method in which natural gas, CO2, nitrogen, or other gaseous fluids… Read more →

Gas interference is a sucker-rod pump performance problem that occurs when free gas enters the pump intake and compresses inside the pump barrel during the downstroke before the traveling valve can open to admit liquid… Read more →

What Is Gas Lift? Gas lift is an artificial lift method that injects compressed gas down the casing-tubing annulus and into the production tubing through a series of gas lift valves, aerating the produced fluid column… Read more →

What Is Gas Lock? Gas lock is a condition in artificial lift systems, particularly electric submersible pumps and sucker rod pumps, in which free gas accumulating at the pump intake occupies the pump chamber and… Read more →

Gas migration is the generic term for all the routes by which gas enters the wellbore annulus and propagates through and around the cement sheath, and it is also known as annular gas flow. It describes the unwanted… Read more →

What Is a Gas Processing Plant? Gas processing plant (also called a gas plant , gas treating facility , or natural gas processing facility ) is a surface facility that receives raw, or wellhead , natural gas from… Read more →

A poroussandlayer or sand body charged with natural gas. Read more →

A gas separator is a pressure vessel or surface equipment device that separates gas from liquid (oil or water) in a produced fluid stream by exploiting the density difference between the gas phase and the liquid phases,… Read more →

A gas show is the detection of natural gas in the drilling fluid returns, drill cuttings, or formation samples during the drilling of an oil or gas well — manifested as an increase in total gas units (TG) on the mud… Read more →

A gas well is a producing well whose primary commercial product is natural gas, the methane-rich hydrocarbon stream, as opposed to an oil well that produces crude as its main product. Most gas wells frequently bring up… Read more →

Gas-bearing describes a rock formation or interval that contains natural gas, either as free gas occupying the pore space or as gas dissolved in the formation liquids, and the term is occasionally extended to wellbore… Read more →

Gas-cap drive is a primary reservoir-drive mechanism in which the energy that pushes oil toward the wellbore comes from the expansion of free gas accumulated above the oil column. When a reservoir contains more gas than… Read more →

Gas-cut mud is drilling fluid that has been contaminated by formation gas (primarily methane, with minor amounts of ethane, propane, and heavier hydrocarbons) that entered the wellbore from gas-bearing formations during… Read more →

What Is a Gas Holdup Log? A gas holdup log is a production logging measurement that quantifies the volume fraction of gas in a multiphase flow stream within a producing or injecting wellbore as a function of depth.… Read more →

A gas-lift mandrel is a specialized completion tubing component assembled into the production tubing string at predetermined depth intervals to provide a housing and communication port for gas-lift valves used in… Read more →

What Is a Gas Lift Valve? Gas lift valve (also called a GLV or gas lift operating valve ) is a precisely calibrated, pressure-operated downhole valve installed in a mandrel on the production tubing string that opens at… Read more →

The gas-oil contact is the boundary surface in a reservoir that separates the gas cap above from the oil column below. Above the contact, the pore space is saturated predominantly with gas. Below it, the pore space… Read more →

The gas-oil contact (GOC) is the subsurface interface in a petroleum reservoir that separates the gas cap (free gas occupying the upper portion of the reservoir above the oil column) from the underlying oil zone,… Read more →

Gas-prone describes a source rock or kerogen type that preferentially generates natural gas (methane and light hydrocarbons) rather than liquid petroleum (crude oil) when subjected to elevated temperatures during burial… Read more →

The volume of gas (at standard conditions) liberated from a volume of oil (at standard conditions). Read more →

The gas-water contact (GWC) in a hydrocarbon reservoir is the subsurface depth at which the gas-saturated zone transitions downward to a water-saturated zone, representing the lower boundary of the gas accumulation… Read more →

The calculated or measured rate a gas well will produce for a given bottomhole or wellheadpressure. Read more →

The ratio of produced gas to produced liquids (oil and water), often abbreviated GLR. Read more →

What Is Gas-Oil Ratio (GOR)? The gas-oil ratio (GOR) is the volume of gas produced per unit volume of oil at standard surface conditions, expressed in standard cubic feet per barrel (scf/bbl) in the United States or… Read more →

The gas produced or separated at surface conditions from the full well stream produced from a natural gas reservoir. Read more →

The liquids separated at surface conditions from the full well stream produced from a natural gas reservoir. Read more →

A gate valve is a linear-motion isolation valve that uses a flat or wedge-shaped gate to block flow through the body bore, designed for fully-open or fully-closed service rather than throttling, and serves as the… Read more →