A pumpjack on an active oil or gas drilling site near Farmington, New Mexico. Photo by Mike Duniway, USGS, SBSC.
What is associated vs. non-associated natural gas?
Associated (or associated-dissolved) gas is natural gas that is produced along with crude oil, and typically separated from the oil at the wellhead. In contrast, non-associated gas is produced from a well in conventional gas fields that do not produce crude oil.
There is also a third category of natural gas production, continuous (or unconventional) gas, that occurs as basin-centered gas, coal-bed gas, shale gas, fractured-reservoir gas, and tight-reservoir gas.
Learn More:
Related Content
Why do USGS oil and gas resource assessments differ from other oil and gas assessments from other agencies or industry?
This question cannot be answered clearly because the methods used by those organizations to estimate oil and gas resource volumes are often not publicly available to compare step-by-step. One common reason different organizations get different results is based on what the assessments include. USGS estimates are for undiscovered, technically recoverable oil and gas resources. The USGS does not...
Why does the USGS decide to reassess oil and gas formations?
The USGS regularly re-examines our assessments to see if updated information warrants a reassessment. Sometimes more information is available either from USGS research or industry production, and the USGS decides to conduct a new assessment. Learn more: USGS Energy Assessments
Can the oil and gas that the USGS assesses be produced today?
USGS oil and gas assessments are for technically recoverable resources, meaning they can be produced using today’s technology and standard industry practices. However, our assessments do not look at what infrastructure would be required to produce these resources, nor does it look at whether it would be profitable to produce them. In addition, USGS assessments are for undiscovered resources, which...
What are the different columns on a USGS oil and gas resource assessment table?
Oil and gas estimates always involve some amounts of uncertainty. To account for this, the USGS presents its assessments of oil and gas potential in the form of a range based on how certain we are that this amount of oil and gas exist. The USGS uses a statistically based process (or model) to calculate the likely range of its estimates. The range of values extends from a 5% or greater likelihood...
What is the difference between assessed oil and gas “resources” and “reserves”?
“ Reserves ” are quantities of oil and gas that are already discovered, recoverable, and commercial. Domestic reserves are tracked by the U.S. Energy Information Administration . The USGS assesses “undiscovered, technically recoverable resources,” which are those that are estimated to exist based on geologic knowledge and theory. Learn more: USGS Energy Resource Assessments
A pumpjack on an active oil or gas drilling site in New Mexico
A pumpjack on an active oil or gas drilling site near Farmington, New Mexico. Photo by Mike Duniway, USGS, SBSC.
Well Drill in the Bakken Formation near Williston
Water truck in background is providing maintenance water to a producing well drilled in the Bakken Formation near Williston, North Dakota.
Water truck in background is providing maintenance water to a producing well drilled in the Bakken Formation near Williston, North Dakota.
Unconventional Oil and Gas—Fueling the Future
The Nation relies on oil and gas to power its economy, and unconventional gas is the fastest-growing energy resource in the United States. The U.S. Geological Survey is the authoritative, unbiased source for assessments of the world's oil and gas endowment. Come learn how these exciting new energy resources may contribute to the energy mix.
The Nation relies on oil and gas to power its economy, and unconventional gas is the fastest-growing energy resource in the United States. The U.S. Geological Survey is the authoritative, unbiased source for assessments of the world's oil and gas endowment. Come learn how these exciting new energy resources may contribute to the energy mix.
Gas Hydrate Drill Rig at the Mt. Elbert Test Site in Alaska
A drill rig at the Mount Elbert test site in Alaska's North Slope, just west of Prudhoe Bay. USGS joined BP Exploration (Alaska) and the U.S. Department of Energy to drill a test well to study natural gas production from gas hydrate deposits. Read more about the Mt.
A drill rig at the Mount Elbert test site in Alaska's North Slope, just west of Prudhoe Bay. USGS joined BP Exploration (Alaska) and the U.S. Department of Energy to drill a test well to study natural gas production from gas hydrate deposits. Read more about the Mt.
Test drilling in North Canadian River Valley, Canadian County, Oklahoma, by C.R. Frazier,
Test drilling in North Canadian River Valley, Canadian County, Oklahoma; Photograph by C.R. Frazier. A new length of drill-pipe is being raised into position so that hole can be deepened.
Test drilling in North Canadian River Valley, Canadian County, Oklahoma; Photograph by C.R. Frazier. A new length of drill-pipe is being raised into position so that hole can be deepened.
Related Content
Why do USGS oil and gas resource assessments differ from other oil and gas assessments from other agencies or industry?
This question cannot be answered clearly because the methods used by those organizations to estimate oil and gas resource volumes are often not publicly available to compare step-by-step. One common reason different organizations get different results is based on what the assessments include. USGS estimates are for undiscovered, technically recoverable oil and gas resources. The USGS does not...
Why does the USGS decide to reassess oil and gas formations?
The USGS regularly re-examines our assessments to see if updated information warrants a reassessment. Sometimes more information is available either from USGS research or industry production, and the USGS decides to conduct a new assessment. Learn more: USGS Energy Assessments
Can the oil and gas that the USGS assesses be produced today?
USGS oil and gas assessments are for technically recoverable resources, meaning they can be produced using today’s technology and standard industry practices. However, our assessments do not look at what infrastructure would be required to produce these resources, nor does it look at whether it would be profitable to produce them. In addition, USGS assessments are for undiscovered resources, which...
What are the different columns on a USGS oil and gas resource assessment table?
Oil and gas estimates always involve some amounts of uncertainty. To account for this, the USGS presents its assessments of oil and gas potential in the form of a range based on how certain we are that this amount of oil and gas exist. The USGS uses a statistically based process (or model) to calculate the likely range of its estimates. The range of values extends from a 5% or greater likelihood...
What is the difference between assessed oil and gas “resources” and “reserves”?
“ Reserves ” are quantities of oil and gas that are already discovered, recoverable, and commercial. Domestic reserves are tracked by the U.S. Energy Information Administration . The USGS assesses “undiscovered, technically recoverable resources,” which are those that are estimated to exist based on geologic knowledge and theory. Learn more: USGS Energy Resource Assessments
A pumpjack on an active oil or gas drilling site in New Mexico
A pumpjack on an active oil or gas drilling site near Farmington, New Mexico. Photo by Mike Duniway, USGS, SBSC.
A pumpjack on an active oil or gas drilling site near Farmington, New Mexico. Photo by Mike Duniway, USGS, SBSC.
Well Drill in the Bakken Formation near Williston
Water truck in background is providing maintenance water to a producing well drilled in the Bakken Formation near Williston, North Dakota.
Water truck in background is providing maintenance water to a producing well drilled in the Bakken Formation near Williston, North Dakota.
Unconventional Oil and Gas—Fueling the Future
The Nation relies on oil and gas to power its economy, and unconventional gas is the fastest-growing energy resource in the United States. The U.S. Geological Survey is the authoritative, unbiased source for assessments of the world's oil and gas endowment. Come learn how these exciting new energy resources may contribute to the energy mix.
The Nation relies on oil and gas to power its economy, and unconventional gas is the fastest-growing energy resource in the United States. The U.S. Geological Survey is the authoritative, unbiased source for assessments of the world's oil and gas endowment. Come learn how these exciting new energy resources may contribute to the energy mix.
Gas Hydrate Drill Rig at the Mt. Elbert Test Site in Alaska
A drill rig at the Mount Elbert test site in Alaska's North Slope, just west of Prudhoe Bay. USGS joined BP Exploration (Alaska) and the U.S. Department of Energy to drill a test well to study natural gas production from gas hydrate deposits. Read more about the Mt.
A drill rig at the Mount Elbert test site in Alaska's North Slope, just west of Prudhoe Bay. USGS joined BP Exploration (Alaska) and the U.S. Department of Energy to drill a test well to study natural gas production from gas hydrate deposits. Read more about the Mt.
Test drilling in North Canadian River Valley, Canadian County, Oklahoma, by C.R. Frazier,
Test drilling in North Canadian River Valley, Canadian County, Oklahoma; Photograph by C.R. Frazier. A new length of drill-pipe is being raised into position so that hole can be deepened.
Test drilling in North Canadian River Valley, Canadian County, Oklahoma; Photograph by C.R. Frazier. A new length of drill-pipe is being raised into position so that hole can be deepened.