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U.S. Crude Oil and Natural Gas Proved Reserves, Year-end 2021

With Data for 2021   |  Release Date:  December 30, 2022   |   Next Release Date: March 2024   |   full report

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In 2021, U.S. energy demand rebounded from its 2020 lows caused by the COVID-19 pandemic. The average prices of both crude oil and natural gas in the United States rose to the highest levels since 2014. Proved reserves of natural gas reported by operators established a new record in the United States in 2021, while proved U.S. reserves of oil increased but did not quite return to pre-pandemic levels.

Proved reserves are estimated volumes of hydrocarbon resources that analysis of geologic and engineering data demonstrates with reasonable certainty1 are recoverable under existing economic and operating conditions. Reserves estimates change from year to year because of:

  • New discoveries
  • Thorough appraisals of existing fields
  • Production of existing reserves
  • Changes in prices and costs
  • New and improved techniques and technologies

To prepare this report, we collect independently developed estimates of proved reserves from a sample of operators of U.S. oil and natural gas fields with Form EIA-23L. We use this sample to further estimate the portion of proved reserves from operators who do not report. This year, we received responses from 392 of 411 sampled operators, which provided coverage of about 90% of proved reserves of oil and 93% of proved reserves of natural gas at the national level. We develop estimates for reserves located in the United States, each state individually, and some state subdivisions. States and regions with subdivisions are:

  • California
  • Louisiana
  • New Mexico
  • Texas
  • Federal Offshore Gulf of Mexico

Oil highlights

  • Proved reserves of U.S. crude oil and lease condensate increased by 6.2 billion barrels (16%), from 38.2 billion barrels to 44.4 billion barrels at year-end 2021 (Table 1).
  • U.S. domestic production of crude oil and lease condensate decreased 1% in 2021.
  • Texas, where more proved reserves of crude oil and lease condensate are located than any other, saw the largest net increase in proved reserves in 2021 (1.9 billion barrels, 12%) (Table 6).
  • New Mexico saw the second-largest net increase of proved reserves of crude oil and lease condensate (1.4 billion barrels, 39%), and Alaska the third-largest (0.7 billion barrels, 31%).
  • The largest net decrease in proved reserves of crude oil and lease condensate in 2021 was reported by operators in Oklahoma (-19 million barrels, 1%) (Table 6).
  • The 12-month, first-day-of-the-month average spot price for West Texas Intermediate (WTI) crude oil at Cushing, Oklahoma, increased by 67% from $39.66 per barrel in 2020 to $66.26/barrel in 2021 (Figure 6).

Natural gas highlights

  • Proved reserves of U.S. natural gas increased by 152.1 trillion cubic feet (Tcf) (32%), from 473.3 Tcf at year-end 2020 to 625.4 Tcf at year-end 2021 (Table 10), establishing a new record for natural gas proved reserves in the United States.
  • Alaska (for the second consecutive year) saw a substantial volume of proved natural gas reserves added in 2021. The annual total of natural gas proved reserves in Alaska increased in 2021 by 63.3 Tcf, almost tripling the state’s total from 36.5 Tcf to 99.8 Tcf—the largest increase of all states in 2021.
  • Texas saw the second-largest increase in proved reserves of natural gas in 2021 (34.3 Tcf, 30%), and New Mexico the third-largest increase (10 Tcf, 38%).
  • The 12-month, first day-of-the-month average spot price for natural gas at the Louisiana Henry Hub increased by 84% from $1.99 per million British thermal units (MMBtu) in 2020 to $3.67/MMBtu in 2021 (Figure 7), which was the highest annual average price since 2014.

National summary

Table 1. U.S. proved reserves, and reserves changes, 2020–21
  Crude oil
billion barrels
Crude oil and lease condensate
billion barrels
Total natural gas
trillion cubic feet
U.S. proved reserves as of December 31, 2021 35.8 38.2 473.3
Extensions and discoveries 5.7 6.3 67.6
Net revisions 1.6 2.3 100.0
Net adjustments, sales, and acquisitions 1.8 1.8 22.6
Estimated production -3.8 -4.1 -38.1
Net additions to U.S. proved reserves 5.3 6.2 152.1
U.S. proved reserves as of December 31, 2021 41.2 44.4 625.4
Percentage change in U.S. proved reserves 14.8% 16.2% 32.1%
Source: U.S. Energy Information Administration, Form EIA-23L, Annual Report of Domestic Oil and Gas Reserves
Notes: Total natural gas includes natural gas plant liquids. Columns may not add to total because of independent rounding.

From 1981 to 1996, U.S. reserves of natural gas and crude oil steadily declined (Figure 1). In 1997, the downward trend for natural gas reversed as operators began introducing innovations including horizontal drilling2 and hydraulic fracturing techniques that successfully increased proved reserves and production of natural gas from shale formations. The downward trend for crude oil reversed beginning in 2008 when operators also applied these innovations to tight oil-bearing formations, such as the Bakken shale of the Williston Basin.

Figure 1. U.S. proved reserves, 1981–2021
figure data

Steady increases in oil and natural gas reserves continued until 2015, when the industry experienced a large price drop (-47% for crude oil and -42% for natural gas), and proved reserves were revised downward because these lower prices did not support operators’ projections of resource development. From 2016 to 2018, U.S. oil and natural gas prices and reserves increased by at least 9% each year. That trend was again interrupted in 2019 by declining oil and natural gas prices (-15% for crude oil; -20% for natural gas) and in 2020, demand and proved reserves declined for both fuels. In 2021, demand for petroleum and natural gas increased 5% from 20203, prices rose, and proved reserves increased for both fuels, setting a new U.S. record for natural gas.

In 2021, proved U.S. reserves of combined crude oil and lease condensate increased in seven of the eight states with the most oil reserves states (Figure 2). In 2021, operators in Texas reported the largest net increase in the state’s proved reserves of crude oil and lease condensate—an increase of 1,931 million barrels.

Operators in New Mexico had the second-largest increase of proved crude oil and lease condensate reserves—a net increase of 1,370 million barrels. The third-largest net increase in proved reserves of crude oil and lease condensate occurred in Alaska, a net increase of 754 million barrels.

Figure 2. Proved reserves of the top eight U.S. oil reserves states and regions, 2017–21
figure data

Proved U.S. natural gas reserves increased in each of the eight states with the most natural gas reserves in 2021 (Figure 3). Alaska, for the second year in a row, saw operators add the most proved reserves of natural gas. In the previous year, the Alaska LNG project pipeline allowed operators to book previously stranded natural gas from the north slope of Alaska as proved reserves. The continuing development of that project and rising natural gas prices caused operators to revise their reserves estimates up yet again in 2021. The annual total of natural gas proved reserves in Alaska increased in 2021 by 63.3 trillion cubic feet (Tcf), almost tripling the state’s total natural gas reserves from 36.5 Tcf to 99.8 Tcf.

Operators in Texas reported the second-largest net increase in proved natural gas reserves in any state, a net increase of 34.3 Tcf. Operators in New Mexico reported the third-largest net increase in proved natural gas reserves in 2021, increasing by 10 Tcf. These increases resulted from extensions and discoveries in the Permian and Delaware Basins and also from net revision increases due to rising natural gas prices.

Figure 3. Proved reserves of the top eight U.S. natural gas reserves states, 2017–21
figure data

Official oil and natural gas production data

We publish official production volumes in the Petroleum Supply Annual 2021, DOE/EIA-0340(20), and the Natural Gas Annual 2021, DOE/EIA-0131(20). We base these volumes on the Form EIA-914, Monthly Crude Oil and Lease Condensate, and Natural Gas Production, report data. The production numbers in the tables and figures of this report represent data reported on Form EIA-23L, Annual Report of Domestic Oil and Gas Reserves. We use these numbers because they are consistent with our calculations of U.S. reserves. The data may differ from our official production numbers; this report includes them as an indicator of production trends. So, they should not be cited as our official production statistics. Figures 4 and 5 display both the official EIA and the EIA-23L production data series.

In 2021, annual production of crude oil and lease condensate decreased in the United States by 1% (-35 million barrels). Annual U.S. imports of crude oil increased 4% (80 million barrels) (Figure 4).

Figure 4. Proved reserves, production, and imports of U.S. crude oil and lease condensate, 1988–2021
figure data

U.S. natural gas production increased 3% (1,126 billion cubic feet [Bcf]) in 2021, and natural gas imports increased 10% (256 Bcf) (Figure 5).

Figure 5. Proved reserves, production, and imports of U.S. natural gas, 1988–2021
figure data

Background

This report provides estimates of proved reserves of crude oil and lease condensate and proved reserves of natural gas located within the United States at the end of 2021. We measured changes for 2021 as the difference between year-end 2020 and year-end 2021 estimates. We processed data filed on Form EIA-23L, Annual Report of Domestic Oil and Gas Reserves, submitted by 392 of 411 sampled operators of U.S. oil and natural gas fields. We then estimated the remaining portion of U.S. proved reserves that is not reported for the United States, each state, and some federal offshore and state subdivisions. State subdivisions (for example, California Coastal Region Onshore, Louisiana North, and Texas Railroad Commission District 1) are defined geographic areas within a large producing state or offshore area. State subdivision boundaries typically align with the boundaries of internal state conservation commission districts that collect production data. Within this report, we publish proved reserves for state subdivisions in California, Louisiana, New Mexico, Texas, and the Federal Offshore Gulf of Mexico.

Proved reserves are estimated volumes of hydrocarbon resources that analysis of geologic and engineering data demonstrates with reasonable certainty are recoverable under existing economic and operating conditions. Reserves estimates change from year to year because of:

  • New discoveries
  • Thorough appraisals of existing fields
  • Production of existing reserves
  • Changes in prices and costs
  • New and improved techniques and technologies

Discoveries include new fields, new reservoirs in previously discovered fields, and extensions, which are additional reserves that resulted from drilling and exploration in previously discovered reservoirs. Extensions typically make up the largest share of total discoveries. Beginning with the 2016 report, operators reported to us on Form EIA-23L their discoveries as a single, combined category—extensions and discoveries. Totals for that category are presented in one column on the data tables in this report.

Revisions primarily occur when operators change their estimates of what they will be able to produce from the properties they operate in response to changing prices, costs, or improvements in technology. Higher fuel prices typically increase estimates of proved reserves as operators consider more of the resource base economically producible with reasonable certainty. Lower prices, on the other hand, generally reduce estimates as operators estimate that less of their resource base is economically producible.

The U.S. Securities and Exchange Commission (SEC) revised its procedure for determining the prices it has operators use to estimate proved reserves in 2008 to reduce their sensitivity to price fluctuations. SEC rules require companies to use an average of the 12 first-day-of-the-month prices. We require companies to follow the same procedure. SEC and EIA estimates are not exactly the same; SEC requires companies to report their owned reserves, and EIA requires companies to report their operated reserves.

National or regional spot market prices are not necessarily the prices used by operators in their reserve estimates for us because actual prices received by operators depend on their particular contractual arrangements, location, and hydrocarbon quality, among other factors. However, spot prices do provide a benchmark or trend indicator. The 12-month, first-day-of-the-month average spot price for West Texas Intermediate (WTI) crude oil (the U.S. benchmark price for crude oil) in 2021 was $66.26 per barrel—a price increase of 67% from 2020 (Figure 6).

Figure 6. WTI crude oil spot prices, first day of the month, 2013–22
figure data

The 12-month, first-day-of-the-month average natural gas spot price at Louisiana’s Henry Hub (the U.S. benchmark location for natural gas) for 2021 was $3.67 per million British thermal units (MMBtu)—an 84% increase from the previous year’s average spot price of $1.99/MMBtu (Figure 7).

Figure 7. Henry Hub natural gas spot prices, first day of the month, 2013–22
figure data

Proved reserves outlook for EIA’s next report (2022)
On February 24, 2022, Russian Federation President Vladimir Putin announced that Russia was initiating a "special military operation"4 in the Donbass and launched a full-scale invasion into Ukraine5. The invasion caused international crude oil prices to rise above $100 a barrel, before ultimately reaching $120 a barrel a few months later as the United States and other countries imposed economic sanctions on Russia.

In 2022, the 12-month, first-of-the-month average crude oil spot price for WTI at Cushing, Oklahoma, and the natural gas spot price at the Henry Hub in Louisiana both have increased from 2021. The oil price rose 43% (from $66.26 per barrel to $94.67 per barrel), and the natural gas price rose 90% (from $3.67/MMBtu to $6.69/MMBtu). On November 3, 2022, the WTI daily spot price was $86.12 per barrel, and the natural gas daily spot price at the Henry Hub was $5.02/MMBtu. During the summer months of 2022, the price of U.S. retail regular gasoline set a new record high average of $4.93 cents per gallon.

In January 2021, only 374 rotary rigs were operating in the United States.6 One year later, in January 2022, the number of operating rigs totaled 481. As of November 11, 2022, the number of rigs operating in the United States had risen to 7797 due to higher prices for oil and natural gas. As a result, we expect operators to report an increase in additions of proved reserves from extensions and discoveries in the 2022 reserves report.

According to estimates published in our Short-Term Energy Outlook (STEO) forecast, U.S. production in 2022 will increase 4% for crude oil and 9% for natural gas. When combined with higher prices, increased rig counts, and more annual production, we anticipate that total U.S. proved reserves will increase again in 2022 for both crude oil and natural gas.

Proved reserves of crude oil and lease condensate

We estimate that the United States had 44,418 million barrels of proved reserves of crude oil and lease condensate as of December 31, 2021—an increase of 16% from year-end 2020. Proved reserves increased 31% in Alaska, 17% onshore in the Lower 48 states (excluding Federal Offshore of the Pacific and the Gulf of Mexico), and 6% in the Federal Offshore (Figure 8).

Figure 8. Proved reserves of U.S. crude oil and lease condensate, 1991–2021
figure data

U.S. proved reserves of crude oil and lease condensate increased by over 6 billion barrels (16%) in 2021. Extensions and discoveries alone, a component of total proved reserves additions, exceeded U.S. annual production for the year (Figure 9a).

Figure 9a. Changes in the proved reserves of U.S. crude oil and lease condensate, 2020–21

Operators in Texas reported the largest increase in total proved crude oil and lease condensate reserves (1,931 million barrels) of all states in 2021—an increase of 12% from 2020.

Operators in New Mexico had the second-largest net increase in 2021 of proved crude oil and lease condensate reserves (1,370 million barrels)—an increase of 39% from 2020.

Operators in Alaska reported the third-largest net increase in proved crude oil and lease condensate reserves (754 million barrels) in 2021—an increase of 31% from 2020.

Figure 9b summarizes the components of U.S. crude oil and lease condensate annual reserve changes since 2010:

Figure 9b. Components of U.S. crude oil and lease condensate annual reserve changes, 2011–21
figure data

Extensions and discoveries
Exploration including the discovery of new fields, identification of new reservoirs in fields discovered in previous years, and extensions, the addition of reserves that result from more drilling in previously discovered reservoirs, added 6.3 billion barrels to U.S. crude oil and lease condensate reserves in 2021. Extensions and discoveries in 2021—typically the largest component of proved reserves change in a given year—returned to pre-pandemic volumes (Figure 9b).

The largest extensions and discoveries of proved reserves of crude oil and lease condensate in 2021 were in Texas, New Mexico, and North Dakota. Operators reported 3.1 billion barrels of extensions and discoveries in Texas, 1.4 billion barrels in New Mexico, and 0.8 billion barrels in North Dakota.

Net revisions and other changes
Revisions to reserves occur primarily when operators change their estimates of what they are able to produce economically using existing technology and under current economic conditions. Current prices are critical in estimating economically producible reserves. Other changes occur when operators acquire (buy) and divest (sell) properties, consequently revaluing the proved reserves in the process, and when various adjustments are made to reconcile estimated volumes.

Revisions increased proved reserves of U.S. crude oil and lease condensate by 2.3 billion barrels in 2021. The largest increases of proved reserves of crude oil and lease condensate due to revisions were in Alaska. Net revisions of proved reserves of crude oil and lease condensate accounted for an increase of 1.0 billion barrels in 2021 in Alaska.

The proved reserves of U.S. crude oil and lease condensate associated with buying and selling properties8 increased by 2.9 billion barrels in 2021. Texas reported the most transactions in 2021.

Adjustments
Adjustments are yearly changes in the published reserve estimates that cannot be attributed to the estimates for other reserve change categories because of the survey and statistical estimation methods employed. For example, if last year’s year-end reserves for a state or state subdivision don’t match this year’s beginning year reserves, we must make an adjustment to account for that difference. Other examples that contribute to adjustments include changes in the selected reporting companies from the previous year and imputations for missing or unreported reserve changes.

In 2021, the sum of all of our adjustments for U.S. proved oil reserves was -1,159 million barrels.

Production
In general, production of crude oil and lease condensate in 2021 was not much changed from 2020. Our official published estimate of total U.S. crude oil production(including lease condensate) is 4,108 million barrels for 2021, down 1% from 2020 (4,142 million barrels). As estimated using Form EIA-23L responses, 4,129 million barrels of crude oil and lease condensate were produced in the United States produced during 2021, also down 1% from 2020 (Tables 5 and 6).9

Production of crude oil and lease condensate onshore in the Lower 48 states in 2021 (3,335 million barrels) was 1% lower than in 2020 (3,371 million barrels), but Federal Offshore (both Pacific and Gulf of Mexico) production increased by 1%, based on Form EIA-23L data, increasing from 621 million barrels in 2020 to 627 million barrels in 2021.

Crude oil and lease condensate from U.S. shale plays
As of December 31, 2021, seven major shale plays accounted for 54% of all proved reserves of U.S. crude oil and lease condensate (Table 2). The Wolfcamp/Bone Spring shale play in the Permian Basin remains the largest oil-producing shale play in the United States. We publish a series of maps showing major U.S. shale plays.

Table 2. Crude oil production and proved reserves from selected U.S. tight plays, 2020–21
million barrels
Basin Play State(s) 2020
production
2020
proved
reserves
2021
production
2021
proved
reserves
2020–21
reserves
change
Permian Wolfcamp/Bone Spring New Mexico and Texas 1,322 11,870 1,421 14,803 2,933
Williston Bakken/Three Forks North Dakota and Montana 431 3,685 398 4,379 694
Western Gulf Eagle Ford Texas 399 3,246 363 3,602 356
Denver Niobrara Colorado, Kansas, Nebraska and Wyoming 16 218 43 479 261
Anadarko, S. Oklahoma Woodford Oklahoma 46 378 42 433 55
Appalachian Marcellus* Pennsylvania and West Virginia 23 247 23 278 31
Fort Worth Barnett Texas 1 15 1 26 11
Subtotal     2,238 19,659 2,291 24,000 4,341
Data source: U.S. Energy Information Administration, Form EIA-23L, Annual Report of Domestic Oil and Gas Reserves, 2020 and 2021
Note: Includes lease condensate. Bakken/Three Forks oil includes proved reserves from shale or low-permeability formations reported on Form EIA-23L.
Wolfcamp/Bone Spring includes proved reserves from shale or low-permeability formations reported on Form EIA-23L in TX RRC 7C, TX RRC 8, TX RRC 8A, and NME.
*The Marcellus play in this table refers only to portions within Pennsylvania and West Virginia.

Proved reserves of natural gas

The United States had 625.4 trillion cubic feet (Tcf) of proved natural gas and natural gas plant liquids (NGPLs) reserves as of December 31, 2021, up 32% (152.1 Tcf) from 2020 (Figure 10).

Figure 10. Proved reserves of U.S. natural gas, 1991–2021
figure data

The average natural gas price used by operators to estimate reserves increased 84% in 2021, causing most operators to revise their proved reserves upwards. Increases in natural gas proved reserves arising from extensions and discoveries in 2021 (67.6 Tcf) significantly exceeded U.S. annual production of 38.1 Tcf (Figure 11a), and net upward revisions (100 Tcf) exceeded extensions and discoveries. As a result of these large additions, the United States established a new record for total proved natural gas reserves in 2021.

Operators in Alaska reported the largest net increase in proved natural gas reserves in 2021. Total natural gas proved reserves in Alaska increased for the second consecutive year in 2021 by an additional 63.2 Tcf, almost tripling the state’s total from 36.5 Tcf to 99.8 Tcf. In 2020, the proved reserves of Alaska had quadrupled from 9.4 Tcf to 36.5 Tcf—due to development of the Alaska LNG Project and its Mainline Pipeline connecting the North Slope to LNG facilities in the southern Alaska Cook Inlet Region. A large volume of previously strandedAlaskan natural gas resources can now be considered proved reserves.

Operators in Texas had the second-largest net increase in 2021 of proved natural gas reserves—proved reserves increased from 114.7 Tcf in 2020 to 149.1 Tcf in 2021 (34.3 Tcf, 30%). Operators in New Mexico reported the third-largest net increase in proved natural gas reserves—proved reserves increased from 26.1 Tcf in 2020 to 36.1 Tcf in 2021 (10.0 Tcf, 38%).

Figure 11a. Changes in the proved reserves of U.S. natural gas, 2020–21

Extensions and discoveries
Extensions and discoveries added 67.6 Tcf to U.S. natural gas proved reserves in 2021 (Table 3). Operators in Texas reported the most extensions and discoveries of proved natural gas reserves in the United States in 2021, totaling 17.8 Tcf (Table 10). The largest portion of these extensions and discoveries was from TX RRC Commission District 8 in the Delaware Basin (Wolfcamp/Bone Spring shale play).

Table 3. Changes to proved reserves of U.S. natural gas by source, 2020–2
trillion cubic feet
Source
of natural gas
Year-end 2020
proved reserves
2021
extensions and discoveries
2021
revisions and other changes
2021
estimated production
Year-end 2021
proved reserves
Shale 317.8 56.6 47.4 28.0 393.8
Other U.S. natural gas
Lower 48 states onshore 113.9 10.5 11.0 8.9 126.5
Lower 48 states offshore 5.1 0.3 0.7 0.8 5.2
Alaska 36.5 0.1 63.5 0.4 99.8
U.S. total 473.3 67.6 122.6 38.1 625.4
Data source: U.S. Energy Information Administration, Form EIA-23L, Annual Report of Domestic Oil and Gas Reserves, 2020 and 2021
Note: The Lower 48 states offshore subtotal in this table includes state offshore and Federal Offshore. Components may not add to total because of independent

Operators in Pennsylvania reported the second most extensions and discoveries in 2021 (15.9 Tcf), as a result of development of the Marcellus shale play in the Appalachian Basin.

Net revisions and other changes
Net revisions and other changes increased U.S. natural gas proved reserves by 122.6 Tcf in 2021. The most significant change of 2021 in proved natural gas reserves occurred in Alaska, where operators reported an increase due to net revisions of 63.6 Tcf (Table 3). In the Lower 48 states, the following states saw the largest net revisions of 2021:

  • Operators in Texas had the largest increase of proved natural gas reserves due to revisions of all states in the Lower 48 states in 2021 (18.5 Tcf).
  • Oklahoma saw the second-largest net revision increase in the Lower 48 states (4.7 Tcf).
  • Operators in New Mexico added the third most revision increase in the Lower 48 states (3.2 Tcf).

Adjustments
Adjustments are yearly changes in the published reserve estimates that we cannot attribute to other reserve change categories. In 2021, the sum of all of our adjustments for proved natural gas reserves was -8.6 Tcf..

Production
Our current published estimate of marketed natural gas production in 2021 is 37.3 Tcf, an increase of 3% from 2020 (36.2 Tcf). We estimate (using Form EIA-23L responses) that U.S. production of natural gas, wet after lease separation, was 38.1 Tcf in 2021—an increase of 3% from our 2020 estimate (37.1 Tcf).10 Figure 11b illustrates the components of U.S. natural gas annual reserve changes over time.

Figure 11b. Components of U.S. natural gas annual reserve changes, 2011–21
figure data

Nonassociated natural gas
Nonassociated natural gas, also called gas well gas, is defined as natural gas not in contact with significant quantities of crude oil in a reservoir. Nonassociated natural gas accounted for 64% of proved natural gas reserves in the United States in 2021. The U.S. total of proved reserves of nonassociated natural gas increased from 336.9 Tcf in 2020 to 398.1 Tcf in 2021—an increase of 18% (Table 11). The largest increase in 2021 proved nonassociated natural gas reserves was in Texas (22.6 Tcf, 21%). The second-largest increase in nonassociated natural gas reserves was in Pennsylvania (9.2 Tcf, 9%). We estimate that production of U.S. nonassociated natural gas increased by 2%, from 26.7 Tcf in 2020 to 27.2 Tcf in 2021.

Associated-dissolved natural gas
Associated-dissolved natural gas, also called casinghead gas, is defined as the combined volume of natural gas that occurs in crude oil reservoirs either as free, or associated natural gas, or in solution with crude oil, known as dissolved natural gas. Associated-dissolved natural gas accounted for 36% of proved natural gas reserves in the United States in 2021. The U.S. proved reserves of associated-dissolved natural gas increased from 136.4 Tcf in 2020 to 227.3 Tcf in 2021—up 67% (Table 12). The largest increase of proved reserves of associated-dissolved natural gas in 2021 occurred in Alaska (63.5 Tcf, 179%). The second-largest increase was in Texas (11.7 Tcf, 22%). Our estimate of production of associated-dissolved natural gas in the United States increased 4%—from 10.4 Tcf in 2020 to 10.8 Tcf in 2021.

Natural gas from U.S. shale plays
Shale formations can be both the source rock where the oil and natural gas are generated from organic matter in the rock, and the producing formation where the oil and natural gas are produced. When a sandstone or carbonate formation produces oil and natural gas, these rock layers are typically permeable enough to allow oil and natural gas to easily flow to a nearby wellbore. Shale formations have very low permeability and must typically be hydraulically fractured to produce natural gas at economical rates. Horizontally drilled wells perform substantially better than vertical wells because they allow more of the well bore to come in direct contact with the shale formation. However, horizontally drilled wells are more expensive to drill and complete at the same depth because they are longer and the drilling process is more complex11 Proved reserves of U.S. natural gas from shale increased 24%, from 317.8 Tcf in 2020 to 393.8 Tcf in 2021 (Table 13).

The share of total U.S. natural gas made up by natural gas from shale decreased from 67% in 2020 to 63% of proved natural gas reserves in 2021 (Figure 12). Estimated production of natural gas from shale increased 7%—from 26.1 Tcf in 2020 to 28.0 Tcf in 2021 (Table 13).

Figure 12. Proved reserves of U.S. natural gas (from shale and other sources), 2011–21
figure data

The eight states that reported the most proved reserves of natural gas from shale formations in 2021 are shown in Figure 13. Operators in Texas reported the most proved reserves of shale natural gas in 2021 with 116.8 Tcf. The second-largest reserves were reported in Pennsylvania, with 105.6 Tcf. In West Virginia, operators reported 39.2 Tcf—the state with the third largest shale natural gas proved reserves in 2021.

Figure 13. Proved shale gas reserves of the top eight U.S. shale gas reserves states, 2017–21
figure data

We collected production and proved reserves data for nine major U.S. shale plays in 2021 (Table 4). The Marcellus shale play remained the play with the largest amount of proved reserves of natural gas from shale in 2021. Proved reserves in the Marcellus increased by 15.7 Tcf (12%) in 2021. The second-largest shale play in 2021 was the Wolfcamp/Bone Spring shale play of the Permian Basin where proved natural gas reserves from shale increased by 22.5 Tcf (43%) in 2021.

Table 4. U.S. shale plays natural gas production and proved reserves, 2020–21
trillion cubic feet
Basin Shale play State(s) 2020 Production 2020 proved reserves 2021
Production
2021 proved reserves Change in production 2020-21 reserves change
Appalachian Marcellus* Pennsylvania and West Virginia 9.3 129.0 9.9 144.7 0.6 15.7
Permian Basin Wolfcamp/ Bone Spring New Mexico and Texas 5.2 52.5 5.8 75.0 0.6 22.5
Texas-Louisiana Salt Haynesville/Bossier Louisiana and Texas 3.6 44.8 4.3 56.2 0.7 11.4
Western Gulf Eagle Ford Texas 1.9 22.3 1.9 30.0 0.0 7.7
Appalachian Utica/Pt. Pleasant Ohio 2.3 27.8 2.2 31.8 -0.1 4.0
Anadarko, S. Oklahoma Woodford Oklahoma 1.2 15.5 1.2 20.8 0.0 5.3
Fort Worth Barnett Texas 1.0 10.8 0.9 13.6 -0.1 2.8
Williston Bakken/Three Forks Montana and North Dakota 1.0 8.6 1.1 11.4 0.1 2.8
Arkoma Fayetteville Arkansas 0.4 4.2 0.4 5.1 0.0 0.9
Sub-total 25.9 315.5 27.6 388.5 1.7 73.0
Other shale gas 0.2 2.2 0.4 5.2 0.2 3.0
All U.S. shale gas 26.1 317.7 28.0 393.8 1.9 76.1
Sources: U.S. Energy Information Administration, Form EIA-23L, Annual Report of Domestic Oil and Gas Reserves, 2019 and 2020
Note: Table values are based on natural gas proved reserves and production volumes from shale reported and imputed from data on Form EIA-23L. * In this table, the Marcellus shale play refers only to portions within Pennsylvania and West Virginia. Other shale includes proved reserves and production reported from shale on Form EIA-23L that we assign to the Niobrara, Antrim, and Monterey shale plays.
Columns may not add to subtotals because of independent rounding.

We publish a series of maps showing the nation’s shale natural gas resources for both shale plays and geologic basins.

Proved U.S. reserves of dry natural gas
Dry natural gas is the volume of natural gas that remains after natural gas plant liquids (NGPLs) and non-hydrocarbon impurities are removed from the natural gas stream downstream at natural gas processing plants. Not all produced natural gas has to be processed at a natural gas processing plant. Some produced natural gas is sufficiently dry and satisfies pipeline transportation standards without processing.

We calculate our estimate of the proved reserves of dry natural gas in the United States by first estimating the expected yield of NGPLs from natural gas proved reserves and by then subtracting the natural gas equivalent volume of the NGPLs from total natural gas proved reserves.

Proved reserves of dry natural gas in the United States increased by 32%, from an estimated 445.3 Tcf in 2020 to 589.2 Tcf in 2021.12

Proved reserves of lease condensate and NGPLs

Operators of natural gas fields report their estimates of lease condensate reserves and production to us on Form EIA-23L, Annual Report of Domestic Oil and Gas Reserves. We determine data for NGPLs from data reported on Form EIA-64A, Annual Report of the Origin of Natural Gas Liquids Production. We calculate the expected yield of NGPLs by using estimates of total natural gas reserves and a recovery factor determined for each area of origin based on Form EIA-64A data.

Lease condensate
Lease condensate is a mixture consisting primarily of hydrocarbons heavier than pentanes that is recovered as a liquid from natural gas in lease separation facilities. This category excludes NGPLs, such as propane, butane, and natural gasoline, which are recovered at downstream natural gas processing plants. Lease condensate usually enters the crude oil stream.

As of December 31, 2021, the United States had proved reserves of 3,267 million barrels of lease condensate, an increase of 880 million barrels from 2020 (37%) (Table 8). U.S. lease condensate production decreased 4%—from 308 million barrels in 2020 to 295 million barrels in 2021.

Natural gas plant liquids
Natural gas plant liquids (NGPLs) (unlike lease condensate) remain within natural gas after it passes through lease separation equipment. These liquids are normally separated from the natural gas at processing plants, fractionators, and cycling plants. NGPLs that are extracted include ethane, propane, butane, isobutane, natural gasoline, and plant condensate. Plant condensate is similar to lease condensate in that it usually enters the crude oil stream but is recovered at natural gas processing plants rather than lease separation facilities.

The estimated volume of NGPLs in proved reserves of total natural gas increased by 26%, from 20,695 million barrels in 2020 to 26,183 million barrels in 2021 (Table 15).13

Reserves in nonproducing reservoirs

Not all proved reserves are contained in actively producing reservoirs. Reserves within actively producing reservoirs are known as proved, developed, producing reserves. Two additional categories for proved reserves exist: proved, developed, nonproducing reserves (PDNPs) and proved, undeveloped reserves (PUDs).

Examples of PDNPs include existing producing wells that are shut in awaiting well workovers, drilled wells that await completion, drilled well sites that require installation of production equipment or pipeline facilities, and behind-the-pipe reserves that require the depletion of other zones or reservoirs before they can begin production (by recompleting the well).

An example of PUDs are undrilled offset well locations (acreage adjacent to an existing producing well that is scheduled to have wells drilled on it). However, additional conditions must be met to satisfy the definition of proved reserves. These locations must:

  • Be directly offset to wells that are producing in the objective formation
  • Be reasonably certain to be within the known proved productive limits of the objective formation
  • Conform to existing well spacing regulations where applicable
  • Be reasonably certain to be developed within a five-year period

Reserves from other locations beyond direct offset wells are categorized as proved, undeveloped reserves only where interpretations of geological and engineering data from wells indicate with reasonable certainty that the objective formation is laterally continuous and contains commercially recoverable petroleum at that location.

As of December 31, 2021, the United States had 11.3 billion barrels of crude oil proved reserves and 168.3 Tcf of natural gas proved reserves in nonproducing reservoirs (Table 16). These volumes are a 7% increase for crude oil and a 20% increase for total natural gas in nonproducing reservoirs from the 2020 levels published in our previous report. 14

Maps and additional data tables

Maps
Figure 14. Proved reserves of U.S. crude oil and lease condensate by state or area, 2021
Figure 15. Changes in proved reserves of crude oil and lease condensate by state or area, 2020–21
Figure 16. Proved reserves of U.S. natural gas by state or area, 2021
Figure 17. Changes in proved reserves of natural gas by state or area, 2020–21

Oil tables
Table 5. U.S. proved reserves of crude oil and lease condensate, crude oil, and lease condensate, 2011–21
Table 6. Proved reserves, reserve changes, and production of crude oil and lease condensate, 2021
Table 7. Proved reserves, reserve changes, and production of crude oil, 2021
Table 8. Proved reserves, reserve changes, and production of lease condensate, 2021

Natural gas tables

Table 9. U.S. proved reserves of total natural gas, wet after lease separation, 2001–21
Table 10. Proved reserves, reserve changes, and production of natural gas, wet after lease separation, 2021
Table 11. Proved reserves, reserve changes, and production of nonassociated natural gas, wet after lease separation, 2021
Table 12. Proved reserves, reserve changes, and production of associated-dissolved natural gas, wet after lease separation, 2021
Table 13. Proved reserves and production of shale natural gas, 2018–21
Table 14. Proved reserves, reserve changes, and production of shale natural gas, 2021
Table 15. Estimated proved reserves of natural gas plant liquids and dry natural gas, 2021

Miscellaneous/other tables
Table 16. Reported proved nonproducing reserves of crude oil, lease condensate, nonassociated gas, associated-dissolved gas, and total gas, wet after lease separation, 2021

Figure 14. Proved reserves of U.S. crude oil and lease condensate by state/area, 2020

Figure 15. Changes in proved reserves of crude oil and lease condensate by state/area, 2020–20

Figure 16. Proved reserves of U.S. natural gas by state/area, 2020

Figure 17. Changes in proved reserves of natural gas by state/area, 2019–20

 

Footnotes:

1Reasonable certainty assumes a probability of recovery of 90% or greater.

2.U.S. Energy Information Administration, Today in Energy, Hydraulically fractured horizontal wells account for most new oil and natural gas wells, January 30, 2018.

3U.S. Energy Information Administration, Monthly Energy Review, November 2022, Table 1.3, Primary Energy Consumption by Source.

4“Putin declares beginning of military operation in Ukraine.” TASS Russian News Agency, 24 February 2022. https://tass.com/politics/1409329

5“Ukraine Conflict: What we know about the Invasion.” BBC News, 24 February, 2022. https://www.bbc.com/news/world-europe-60504334

6U.S. Energy Information Administration, Crude Oil and Natural Gas Drilling Activity, Graph by U.S. Energy Information Administration, based on data from Baker Hughes, Inc.

7Baker Hughes, Inc. https://rigcount.bakerhughes.com/

8How can acquisitions in a given year exceed divestitures? When it comes to proved reserves, an exchange of properties is not a zero-sum game. Operators often have differing development plans for oil- and natural gas-bearing properties they purchase from or exchange with other operators. For example, when an operator purchases acreage that is adjacent to its producing wells, the operator can drill longer horizontal laterals and add more proved reserves.

9The oil production estimates in this report use data reported on Form EIA-23L, Annual Report of Domestic Oil and Gas Reserves. They are used to weight estimates used in developing total proved reserves, and they may differ slightly from the official EIA production data for crude oil and lease condensate for 2021 in the Petroleum Supply Annual 2021, DOE/EIA-0340(21).

10The natural gas production estimates in this report are based on data reported on Form EIA-23L, Annual Report of Domestic Oil and Gas Reserves. Estimates differ from our official production data for natural gas published in the Natural Gas Annual 2021, DOE/EIA-0131(21).

11U.S. Energy Information Administration, Today in Energy, Hydraulically fractured horizontal wells account for most new oil and natural gas wells, January 30, 2018.

12U.S. Energy Information Administration, U.S. Crude Oil and Natural Gas Proved Reserves, Year-End 2020, January 2022, Table 15.

13U.S. Energy Information Administration, U.S. Crude Oil and Natural Gas Proved Reserves, Year-End 2020, January 2022, Table 15.

14U.S. Energy Information Administration, U.S. Crude Oil and Natural Gas Proved Reserves, Year-End 2020, January 2022, Table 16.


Contact: Steven G. Grape or 202-586-1868


Data tables

1. U.S. proved reserves, and reserves changes, 2020–21 PDF XLS
2. Production and proved reserves of crude oil from selected U.S. shale plays, 2020–21 PDF XLS
3. Changes to proved reserves of U.S. natural gas by source, 2020–21 PDF XLS
4. U.S. shale plays: natural gas production and proved reserves, 2020–21 PDF XLS
5. U.S. proved reserves of crude oil and lease condensate, 2011–2021 PDF XLS
6. Proved reserves, reserve changes, and production of crude oil and lease condensate, 2021 PDF XLS
7. Proved reserves, reserve changes, and production of crude oil, 2021 PDF XLS
8. Proved reserves, reserve changes, and production of lease condensate, 2021 PDF XLS
9. U.S. proved reserves of total natural gas, wet after lease separation, 2001–20 PDF XLS
10. Proved reserves, reserve changes, and production of natural gas, wet after lease separation, 2021 PDF XLS
11. Proved reserves, reserve changes, and production of nonassociated natural gas, wet after lease separation, 2021 PDF XLS
12. Proved reserves, reserve changes, and production of associated-dissolved natural gas, wet after lease separation, 2021 PDF XLS
13. Proved reserves and production of shale natural gas, 2018–21 PDF XLS
14. Proved reserves, reserve changes, and production of shale natural gas, 2021 PDF XLS
15. Estimated proved reserves of natural gas plant liquids and dry natural gas, 2021 PDF XLS
16. Reported proved nonproducing reserves of crude oil, lease condensate, nonassociated gas, associated-dissolved gas, and total gas, wet after lease separation, 2021 PDF XLS