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U.S. Crude Oil and Natural Gas Proved Reserves

With Data for 2014   |  Release Date:  November 23, 2015   |  
Next Release Date: December 2016   |   full report

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In 2014, U.S. crude oil and lease condensate proved reserves increased to 39.9 billion barrels—an increase of 3.4 billion barrels (9.3%) from 2013. U.S. proved reserves of crude oil and lease condensate have risen for six consecutive years, and exceeded 39 billion barrels for the first time since 1972.1 Proved reserves of U.S. total natural gas2 increased 34.8 trillion cubic feet (Tcf) to 388.8 Tcf in 2014. This increase (9.8%) boosts the national total of proved natural gas reserves to a record-high level for the second consecutive year.

Sustained low prices for oil and natural gas are anticipated to reduce the reserves in EIA’s next report (for year-end 2015). Lower prices have curtailed drilling and made recovery economics more challenging. Although resource estimates are not necessarily reduced by lower prices, the calculation of proved reserves is sensitive to price.

Oil highlights

  • U.S. proved reserves of crude oil and lease condensate increased for the sixth year in a row in 2014, and exceeded 39 billion barrels for the first time since 1972 (2014 is now the fourth-highest year on record).
  • Texas added 2.1 billion barrels of crude oil and lease condensate proved reserves (the largest increase of any state in 2014), mostly located within the Texas portion of the Permian Basin and the Eagle Ford Shale play.
  • North Dakota added 0.4 billion barrels of crude oil and lease condensate proved reserves (the second-largest increase in 2014) mostly from the Bakken Shale play.

Natural gas highlights

  • U.S. proved natural gas reserves set a record3 (exceeding 388 trillion cubic feet) in 2014.
  • Proved reserves additions of natural gas were highest in Pennsylvania, where operators added a net 10.4 trillion cubic feet of natural gas proved reserves in Pennsylvania’s portion of the Marcellus Shale play.
  • In 2014, West Virginia surpassed Wyoming and Colorado to become the fourth-largest state for natural gas proved reserves (behind Texas, Pennsylvania, and Oklahoma).
  • Proved natural gas reserves in Ohio more than doubled as a result of development of the Utica Shale play, and Idaho4 in 2014 reported proved natural gas reserves for the first time.

Proved reserves are estimated volumes of hydrocarbon resources that analysis of geologic and engineering data demonstrates with reasonable certainty5 are recoverable under existing economic and operating conditions. Reserves estimates change from year to year as new discoveries are made, as existing fields are more thoroughly appraised, as existing reserves are produced, and as prices and technologies change.

National summary

In 2014, U.S. crude oil and lease condensate proved reserves increased to 39.9 billion barrels—an increase of 3.4 billion barrels (9.3%) from 2013 (Table 1). U.S. proved reserves of crude oil and lease condensate have risen for six consecutive years (Figure 1), and exceeded 39 billion barrels for the Figure 1. U.S. oil and natural gas proved reserves, 1973-2013
figure data
first time since 1972.6 Proved reserves of U.S. total natural gas7 increased 34.8 trillion cubic feet (Tcf) to 388.8 Tcf in 2014 (Table 1). This increase (9.8%) boosts the national total of proved natural gas reserves to a record-high level for the second consecutive year.

Table 1. U.S. proved reserves, and reserves changes, 2013-14
  Crude oil and lease condensate
     billion barrels
Total natural gas
  trillion cubic feet
U.S. proved reserves at December 31, 2013 36.5 354.0
Total discoveries 5.4 50.5
Net revisions 0.4 1.0
Net adjustments, sales, acquisitions 0.8 11.4
Production -3.2 -28.1
Net additions to U.S. proved reserves 3.4 34.8
U.S. proved reserves at December 31, 2014 39.9 388.8
Percent change in U.S. proved reserves 9.3% 9.8%
Notes: Total natural gas includes natural gas plant liquids. Columns may not add to total because of independent rounding.
Source: U.S. Energy Information Administration, Form EIA-23L, Annual Survey of Domestic Oil and Gas Reserves

Proved reserves of crude oil and lease condensate increased in two of the top five states for crude oil and lease condensate reserves in 2014 (Figure 2). Figure 2. Proved reserves of the top five U.S. oil reserve states, 2007-12
figure data
In 2014, Texas had the largest increase in proved reserves, 2,054 million barrels (60% of the nation's total net increase in 2014). This increase was driven by development of tight oil plays (e.g., Wolfcamp, Bone Spring) in the Permian Basin and the Eagle Ford Shale play. North Dakota had the second-largest increase, 362 million barrels, which came mostly from the Bakken tight oil play in the Williston Basin. New Mexico had the third-largest increase in crude oil and lease condensate proved reserves in 2014, as it benefitted from the same Permian Basin developments as Texas, if not to the same degree. Colorado had the fourth-largest increase in crude oil and lease condensate reserves in 2014, where both vertical and horizontal drilling were used to develop the Niobrara/Codell tight oil play in the Denver Basin.

Proved natural gas reserves increased in four of the top five U.S. gas reserves states (Texas, Pennsylvania, Oklahoma, and West Virginia) in 2014 (Figure 3). Figure 3. Proved reserves of the top five U.S. gas reserve states, 2009-2013
figure data
Texas remains the largest natural gas reserves state, but the second-largest, Pennsylvania, had the largest net increase (10.4 Tcf) in 2014—largely the result of extensions to fields in the Marcellus Shale play. The reserves additions in Texas and Oklahoma were mostly from extensions in shale natural gas plays. West Virginia added enough Marcellus natural gas proved reserves to surpass Wyoming and Colorado to become the fourth-largest natural gas reserves state.

Official EIA Oil and Gas Production Data

The production numbers in the tables and figures of this report are offered only as an indicator of production trends and may differ from EIA's official production numbers based on state-reported data, which are provided on the EIA website for oil and natural gas. Specifically, the production estimates in this report are based on data reported on Form EIA-23L, Annual Survey of Domestic Oil and Gas Reserves. They may differ from estimates published by EIA in the Petroleum Supply Annual 2014, DOE/EIA-0340(14) or the Natural Gas Annual 2014, DOE/EIA-0131(14).


As U.S. oil reserves and production increased in 2014, imports of crude oil declined 5% from the 2013 level. Crude oil imports declined for the fourth consecutive year (Figure 4).

Figure 4. U.S. crude oil and lease condensate proved reserves, production, and imports, 1981-2013

U.S. natural gas proved reserves and production increased in 2014, and natural gas imports declined by 6% (Figure 5), the seventh consecutive year of import declines.

Figure 5. U.S. totalnatural gas reserves, production, and imports, 1981-2013

 

Background

This report provides estimates of U.S. proved reserves of crude oil and lease condensate and proved reserves of natural gas at year-end 2014. The U.S. Energy Information Administration (EIA) starts with the data filed on Form EIA-23L, Annual Survey of Domestic Oil and Gas Reserves, which was submitted by 459 of 467 sampled operators of U.S. oil and natural gas fields. EIA then estimated the U.S. total proved reserves and the subtotal for individual states and state subdivisions. Results are summarized and tabulated in this report.

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 as new discoveries are made, as existing fields are more thoroughly appraised, as existing reserves are produced, and as prices and technologies change.

Discoveries include new fields, identification of new reservoirs in previously discovered fields, and extensions, which are additions to reserves that result from additional drilling and exploration in previously discovered reservoirs. In a given year, extensions are typically the largest percentage of total discoveries. Although discoveries of new fields and reservoirs are important indicators of new resources, they generally account for a small percentage of overall annual reserve additions.

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 or improvements in technology. Higher fuel prices typically increase estimates (positive revisions) as operators consider a broader portion of the resource base economically producible, or proved. Lower prices, on the other hand, generally reduce estimates (negative revisions) as the economically producible base diminishes. Because actual prices received by operators depend on their contractual arrangements, location, hydrocarbon quality, and other factors, spot market prices are not necessarily the prices used by operators in their reserve estimates for EIA. They do, however, provide a benchmark or trend indicator. The 12-month, first-day-of-the-month, average West Texas Intermediate (WTI) crude oil spot price for 2014 was $94.56 per barrel, a 3% decrease from 2013 (Figure 6).

Figure 6. WTI crude oil spot price, 2008-14

The 12-month, first-day-of-the-month average natural gas spot price at the Louisiana Henry Hub for 2014 was $4.55 per million British thermal units (MMBtu), representing a 24% increase over the previous year’s average spot price of $3.66 per MMBtu (Figure 7).

Figure 7. Henry Hub natural gas spot prices, 2008-14
figure data

Price outlook for 2015. In July 2014, the price of WTI crude oil reached the highest recorded first-of-the-month price of the year ($106.06 per barrel). After that, the price declined, reaching $68.98 per barrel on December 1, 2014. The price continued to decline throughout 2015 and was $44.75 per barrel on October 1, 2015.8

EIA forecasts in its Short-Term Energy Outlook that WTI oil prices should be approximately $46 per barrel by the end of 2015. Compared with the 12-month, first-of-the-month 2014 average of $94.56 per barrel, EIA expects that the 12-month, first-of-the-month 2015 average WTI spot oil price will decrease 47% to $50.36 per barrel. As a result, EIA anticipates net downward revisions in U.S. crude oil proved reserves in 2015.

The 12-month, first-of-the-month average natural gas spot price at the Henry Hub in Louisiana in 2014 was $4.55 per MMBtu. After January 2015, when the first-of-the-month average spot gas price at the Henry Hub was $3.01 per MMBtu, natural gas prices remained below $3.00 on average throughout 2015. Compared to $4.55 per MMBtu in 2014, the average 12-month, first-of-the-month spot natural gas price at the Henry Hub is expected to decrease 39% in 2015, to $2.76 per MMBtu. As a result, EIA anticipates net downward revisions in U.S. natural gas proved reserves in 2015.

Sustained and much lower prices for both crude oil and natural gas throughout 2015 have curtailed exploration activity, as evidenced by statistics published by the U.S. Bureau of Economic Analysis and EIA (e.g., Today in Energy, September 24, 2015). Fewer new discoveries and extensions of existing fields, combined with the anticipated net downward revisions, are also expected to negatively affect both crude oil and natural gas proved reserves in 2015.

Crude oil and lease condensate proved reserves

Overview

U.S. crude oil and lease condensate proved reserves increased for the sixth consecutive year in 2014 (Figure 8). Figure 8. U.S. crude oil and lease condensate proved reserves, 1983-2013
figure data
These reserves exceeded 39 billion barrels for the first time since 1972, and this level makes 2014 the fourth-highest year on record.

U.S. crude oil and lease condensate proved reserves rose by 3.4 billion barrels in 2014, attributable primarily to 5 billion barrels of extensions to existing fields (Figure 9a).

Figure 9a. U.S. crude oil and lease condensate proved reserves changes, 2012-13

Proved reserves additions of crude oil and lease condensate were highest in Texas, which added 2.1 billion barrels of crude oil and lease condensate proved reserves in 2014. Texas Railroad Commission (RRC) District 8 (abutting southern New Mexico) added the most oil reserves of all 12 Texas RRC districts (0.8 billion barrels) in 2014. Horizontal drilling was used in this district within the Permian Basin—targeting stacked tight oil-bearing formations such as the Spraberry, the Clearfork, the Wolfcamp Shale, the Strawn sand, and the Bone Spring formation. Reserves additions in the Permian Basin accounted for about half of the Texas crude oil and lease condensate proved reserves additions—and roughly one-third of the net proved reserves additions in the entire United States for the year.

For the past three years, most oil reserves have been added by extensions to existing fields (Figure 9b).

Figure 9b. Components of U.S. crude oil and lease condensate reserves changes, 2003-13
figure data

North Dakota had the second-largest increase in crude oil and lease condensate proved reserves in 2014, adding 0.4 billion barrels. Extensions to fields producing tight oil from the Bakken formation provided the largest percentage of North Dakota’s new proved oil reserves.

As of December 31, 2014, tight oil9 plays accounted for 33% of all U.S. crude oil and lease condensate proved reserves. Most (95%) U.S. tight oil proved reserves in 2014 came from six tight oil plays (Table 2). The Bakken/Three Forks play in the Williston Basin retained its rank as the largest tight oil play in the United States in 2014. EIA has a series of maps and animations showing the nation's shale and other tight oil (and natural gas) resources.

Table 2. U.S. tight oil plays: production and proved reserves, 2013-14
million barrels
Basin Play State(s) 2013
Production
2013
Reserves
2014
Production
2014
Reserves
Change 2013-14 Reserves
Williston Bakken/Three Forks ND, MT, SD 270 4,844 387 5,972 1,128
Western Gulf Eagle Ford TX 351 4,177 497 5,172 995
Permian Bone Spring, Wolfcamp NM, TX 21 335 53 722 387
Denver-Julesberg Niobrara CO, KS, NE, WY 2 17 42 512 495
Appalachian Marcellus* PA, WV 7 89 13 232 143
Fort Worth Barnett TX 9 58 9 47 -11
Subtotal 660 9,520 1,001 12,657 3,137
Other tight oil 41 523 56 708 185
U.S. tight oil 701 10,043 1,057 13,365 3,322
Notes: Includes lease condensate. Bakken/Three Forks tight oil includes proved reserves from shale or low permeability formations reported on Form EIA-23L; Other tight oil includes proved reserves from shale formations reported on Form EIA-23L not assigned by EIA to the Bakken/Three Forks, Barnett, Bone Spring, Eagle Ford, Marcellus, Niobrara, or Wolfcamp tight oil plays. * The Marcellus Shale play in this table refers only to portions within Pennsylvania and West Virginia.
Source: U.S. Energy Information Administration, Form EIA-23L, Annual Survey of Domestic Oil and Gas Reserves, 2013 and 2014

Total discoveries. Total discoveries added 5.4 billion barrels to U.S. crude oil and lease condensate reserves in 2014. Total discoveries consist of discoveries of new fields, identification of new reservoirs in fields discovered in prior years, and extensions (reserve additions that result from the additional drilling and exploration in previously discovered reservoirs).

Geographically, the largest total discoveries of crude oil and lease condensate proved reserves in 2014 were in Texas, North Dakota, and Oklahoma. Texas had total discoveries of 2.3 billion barrels, North Dakota had 1.3 billion barrels, and Oklahoma had 0.4 billion barrels in 2014. Total discoveries in the federal Gulf of Mexico were 234 million barrels, 140 million barrels of which came from new field discoveries. In 2014, 85% of the nation’s reserves additions from new field discoveries were from the federal Gulf of Mexico.

Net revisions and other changes. Revisions to reserves occur primarily when operators change their estimates of what they are able to economically produce from the properties they operate using existing technology and current economic conditions. Thus, current prices are critical in estimating economically producible reserves.

Other changes occur when operators buy and sell properties (revaluing the proved reserves in the process), and as various adjustments are made to reconcile estimated volumes.

Net revisions added 416 million barrels to U.S. crude oil and lease condensate proved reserves in 2014. Texas had the largest positive net revision in 2014—405 million barrels of crude oil and lease condensate proved reserves—as operators developed existing fields in the Permian Basin and the Eagle Ford Shale play. The largest negative net revision was in North Dakota, with a decline of 186 million barrels.

The net change to U.S. crude oil and lease condensate proved reserves associated with buying and selling properties was 353 million barrels in 2014. Adjustments (positive and negative reserves changes that EIA cannot attribute to any other category) increased U.S. proved oil reserves by 440 million barrels.

Production. The United States produced an estimated 3.2 billion barrels10 of crude oil and lease condensate in 2014, an increase of about 17% from 2013. This level represents the country's sixth consecutive annual production increase. Production from the Lower 48 states was 19% above the 2013 level. Alaska experienced a 2% production decline.

Natural gas proved reserves

Overview

U.S. proved reserves of total natural gas (including natural gas plant liquids) increased by 10% (34.8 Tcf) in 2014 and reached a record high for the United States of 388.8 Tcf (Figure 10). Figure 10. U.S. total natural gas proved reserves, 1983-2013
figure data
The reserves were added onshore in the Lower 48 states from ongoing exploration and development in several of the nation's shale formations, particularly the Marcellus Shale play in Pennsylvania and West Virginia, the Eagle Ford Shale play in Texas, the Woodford Shale play in Oklahoma, and the Utica Shale play in Ohio. In contrast to these 2014 gains in shale natural gas, there were declines in the Rocky Mountain natural gas reserves in 2014. Operators curtailed development of (and in some cases, sold outright11) their mature dry natural gas fields in Wyoming and Colorado in order to pursue preferential liquids-rich targets in other states.

At the state level, operators in Pennsylvania reported the largest net increase in natural gas proved reserves in 2014 (10.4 Tcf), driven by continued development of the Marcellus Shale gas play. Texas added the second-highest volume of natural gas proved reserves (8.0 Tcf), followed by West Virginia (7.9 Tcf). Oklahoma added the fourth-largest volume of new natural gas proved reserves (5.4 Tcf), and Ohio had the fifth-largest increase, adding almost 4 Tcf of natural gas proved reserves in 2014.

Total discoveries. The U.S. total of natural gas discoveries was 50.5 Tcf in 2014 (Table 3), of which 93% were extensions to existing natural gas fields (Figures 11a and 11b). Figure 11a. U.S. total natural gas proved reserves changes, 2012-13
Figure 11b. Components of U.S. total natural gas proved reserves changes, 2003-13
figure data
New field discoveries and new reservoir discoveries in previously discovered fields were 0.7 Tcf and 2.7 Tcf, respectively. Total discoveries of natural gas reserves were highest in Pennsylvania, at 11.3 Tcf. West Virginia had the second-largest total discoveries, at 10.2 Tcf. Texas was third with approximately 9.5 Tcf of natural gas discoveries, and fourth-ranked Ohio had 4.7 Tcf of discoveries. Total discoveries in each of these states were driven principally by shale gas developments; Marcellus Shale in Pennsylvania and West Virginia, Eagle Ford Shale and Wolfcamp Shale in Texas, and Utica Shale in Ohio.

 

Table 3. Changes to proved reserves of U.S. natural gas by source, 2013-14
trillion cubic feet
Source
of gas
Year-end 2013 proved reserves 2014 discoveries 2014 revisions & other changes 2014 production Year-end 2014 proved reserves
Coalbed Methane 12.4 0.4 4.3 -1.4 15.7
Shale 159.1 37.8 16.2 -13.4 199.7
Other U.S. natural gas
Lower 48 Onshore 166.0 11.4 -8.4 -11.7 157.2
Lower 48 Offshore 9.1 0.8 0.8 -1.3 9.4
Alaska 7.4 0.1 -0.4 -0.3 6.8
U.S. TOTAL 354.0 50.5 12.4 -28.1 388.8
Note: Lower 48 offshore includes state offshore and Federal offshore. Components may not add to total because of independent rounding.
Source: U.S. Energy Information Administration, Form EIA-23L, Annual Survey of Domestic Oil and Gas Reserves, 2013 and 2014

In 2014, operators in Idaho reported natural gas proved reserves for the first time. However, to prevent the disclosure of individual company data (because only one operator reported), Idaho’s proved reserves will be included in the group of miscellaneous states in this report.

Net revisions and other changes. Net revisions added 1.0 Tcf to U.S. total natural gas proved reserves in 2014. The following states had the largest changes (positive and negative) in 2014 as a result of net revisions:

  • Texas had the largest positive net revision of natural gas proved reserves in 2014, an increase of 4.7 Tcf, 3.3 Tcf of which was from RRC District 1 (Eagle Ford Shale play).
  • Oklahoma had positive net revisions of 2.1 Tcf in 2014.
  • Wyoming had the largest negative net revision in 2014, a decrease of 4.5 Tcf, a result of negative net revisions to its nonassociated natural gas proved reserves. (Operators are shifting their attention from large dry natural gas fields in the Rockies to liquids-rich developments elsewhere in the United States.)

The net change to natural gas proved reserves from the purchase and sale of properties resulted in an additional gain of 6.6 Tcf in 2014. The largest net acquisition of natural gas proved reserves in 2014 was in northern Louisiana—where an operator that acquired properties in the Haynesville Shale play expects better results than the previous owner. Adjustments (annual reserves changes that EIA cannot attribute to any other category) to U.S. total natural gas proved reserves totaled 4.9 Tcf.

Production. This report's estimate of U.S. production of total natural gas in 2014 was 28.1 Tcf, an increase of 6% from 2013.12 EIA's official published estimate of marketed natural gas production was 27.3 Tcf in 2014, an increase of 7% from 2013. For both estimates, this sets a record high for the United States and is the ninth consecutive year that natural gas production (total or marketed) increased. In Pennsylvania, 0.9 Tcf of additional production boosted that state's production by 28%, the nation's largest increase. The state with the largest estimated decline in natural gas production in 2014 was Louisiana (-0.4 Tcf, a drop of 16%).

Shale natural gas

Shale natural gas is a type of natural gas where a shale formation is both the source rock and the production zone. Proved reserves of U.S. shale natural gas increased from 159.1 Tcf in 2013 to 199.7 Tcf in 2014 (an increase of 40.6 Tcf, 25% higher than in 2013).

The share of shale gas compared with total U.S. natural gas proved reserves increased from 45% in 2013 to 51% in 2014 (Figure 12). Figure 12. U.S. total natural gas proved reserves (shale and other sources), 2006-13
figure data

Estimated production of shale natural gas increased 18%—from 11.4 Tcf in 2013 to 13.4 Tcf in 2014.

Pennsylvania had the most shale gas proved reserves in 2014, surpassing Texas for the first time (Figure 13). West Virginia remained the third-largest shale gas reserves state. Oklahoma was the fourth-largest shale gas proved reserves state, and Louisiana and Arkansas were the fifth- and sixth-largest, respectively.

Figure 13.Proved shale gas reserve of the top six U.S. shale gas reserves states, 2008-13
figure data

Seven shale plays contained 90% of U.S. shale gas proved reserves at the end of 2014 (Table 4). The Marcellus Shale play remained the largest, and it added the most new shale gas reserves (22.1 Tcf) in 2014. The second-largest shale gas play was the Barnett Shale (the play that started the U.S. shale gas boom), where proved reserves declined 6% in 2014.

Table 4. U.S. shale gas plays: natural gas production and proved reserves, 2013-14
trillion cubic feet
          Change 2014-2013
Basin Shale Play State(s) 2013 production reserves 2014 production reserves Production Reserves
Appalachian Marcellus* PA, WV 3.6 62.4 4.9 84.5 1.3 22.1
Fort Worth Barnett TX 2.0 26.0 1.8 24.3 -0.2 -1.7
Western Gulf Eagle Ford TX 1.4 17.4 1.9 23.7 0.5 6.3
Texas-Louisiana Salt Haynesville/Bossier TX, LA 1.9 16.1 1.4 16.6 -0.5 0.5
Arkoma, Anadarko Woodford TX, OK 0.7 12.5 0.8 16.6 0.1 4.1
Arkoma Fayetteville AR 1.0 12.2 1.0 11.7 0.0 -0.5
Appalachian Utica OH 0.1 2.3 0.4 6.4 0.3 4.1
Subtotal 10.7 148.9 12.3 183.7 1.6 34.8
Other shale gas 0.7 10.2 1.1 15.9 0.4 5.7
All U.S. shale gas 11.4 159.1 13.4 199.7 2.0 40.6
Note: Table values are based on shale gas proved reserves and production volumes reported and imputed from data on Form EIA-23L. For certain reasons (e.g., incorrect or incomplete submissions, misidentification of shale versus nonshale reservoirs), the actual proved reserves and production of natural gas from shale plays may be higher or lower.
*The Marcellus shale play in this table refers only to portions within Pennsylvania and West Virginia. Other shale gas includes fields reported as shale on Form EIA-23L not assigned by EIA to the Marcellus, Barnett, Haynesville/Bossier, Eagle Ford, Woodford, Utica, or Fayetteville shale gas plays.
Columns may not add to subtotals due to independent rounding.
Sources: U.S. Energy Information Administration, Form EIA-23L, Annual Survey of Domestic Oil and Gas Reserves, 2013 and 2014.

Although the Eagle Ford Shale is primarily an oil and natural gas liquids play, it added 6.3 Tcf of shale natural gas reserves in 2014 and remains the third-largest shale gas play in the United States. Development of the Utica Shale play more than doubled the proved natural gas reserves of Ohio in 2014. EIA has a series of maps showing the nation’s shale gas resources for both shale plays and geologic basins.

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. EIA considers most shale natural gas and all coalbed natural gas to be nonassociated natural gas proved reserves. Proved reserves of U.S. nonassociated natural gas increased by 24.2 Tcf in 2014, an 8% increase from 2013 (Table 11). Estimated production of U.S. nonassociated natural gas increased 2%—from 22.3 Tcf in 2013 to 22.8 Tcf in 2014. The largest increase in nonassociated natural gas production was in Pennsylvania (Marcellus Shale)—where annual nonassociated natural gas production increased from 3.3 Tcf in 2013 to 4.2 Tcf in 2014.

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 gas (associated) or as gas in solution with crude oil (dissolved). Proved reserves of associated-dissolved natural gas rose from 58.5 Tcf in 2013 to 69.1 Tcf in 2014—an increase of 18% (10.6 Tcf) (Table 12). Estimated production of associated-dissolved natural gas increased 28%—from 4.1 Tcf in 2013 to 5.3 Tcf in 2014. The largest increase in associated-dissolved natural gas production in 2014 was in Texas, specifically in Texas Railroad Commission (RRC) Districts 1, 2, and 8, coinciding with the gains in oil production from the Eagle Ford Shale play and from the Permian Basin.

Coalbed natural gas

Coalbed natural gas, also called coalbed methane, is a type of natural gas contained in and removed from coal seams. Extraction requires drilling wells into the coal seams and removing water contained in the seam to reduce hydrostatic pressure and to release adsorbed (and free) natural gas out of the coal. Proved reserves of U.S. coalbed natural gas increased from 12.4 Tcf in 2013 to 15.7 Tcf in 2014, a 27% increase from 2013 (Tables 15 and 16). Estimated production of coalbed natural gas decreased 4%—from 1.47 Tcf in 2013 to 1.40 Tcf in 2014. Among individual states, New Mexico experienced the largest increase (1.3 Tcf) in proved reserves of coalbed methane, followed by Virginia and Colorado (adding 0.8 Tcf and 0.7 Tcf, respectively). Wyoming had the largest decrease in coalbed methane reserves, with proved reserves down 0.2 Tcf in 2014.

Dry natural gas

Dry natural gas is the volume of natural gas (primarily methane) that remains after natural gas liquids and non-hydrocarbon impurities are removed from the natural gas stream, initially at lease separation facilities near the producing well (lease condensate), and then downstream at a processing plant (natural gas plant liquids).

In 2014, the estimated U.S. total of dry natural gas content of total natural gas proved reserves increased from 338.3 Tcf in 2013 to 368.7 Tcf in 2014 (Table 17), a 9% increase from the 2013 level.

Lease condensate and natural gas plant liquids

Operators of natural gas fields report lease condensate reserves and production estimates to EIA on Form EIA-23L, Annual Survey of Domestic Oil and Gas Reserves. EIA calculates the expected yield of natural gas plant liquids using total natural gas reserves estimates and a recovery factor determined for each area of origin. Data from Form EIA-64A, Annual Report of the Origin of Natural Gas Liquids Production, are the basis of EIA's recovery factors.

Proved reserves of lease condensate have increased significantly in recent years as operators have focused their exploration and development on liquids-rich portions of natural gas plays to take advantage of relatively higher liquids prices. The annual crude oil-to-natural gas price ratio, which averaged about 8.0 from 2000 to 2008, was 26.6 in 2013 and 20.8 in 2014. The 2015 forecast for this ratio is 18.2 (based on average price estimates from figures 6 and 7). Producing liquids remains more economically favorable than producing dry natural gas alone, but the declining price of both fuels has operators curtailing their exploration activities.13

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 natural gas plant liquids, such as butane and propane, which are recovered at downstream natural gas processing plants or facilities. Lease condensate is often blended directly into crude oil to enhance quality.

U.S. lease condensate proved reserves increased from 3,149 million barrels in 2013 to 3,548 million barrels in 2014 (a 13% increase). Texas had the largest increase in lease condensate proved reserves at 250 million barrels, followed by West Virginia, which added 97 million barrels. Lease condensate accounted for 8.9% of the U.S. total crude oil and lease condensate proved reserves in 2014. U.S. lease condensate production increased 5%, from 311 million barrels in 2013 to 326 million barrels in 2014.

Natural gas plant liquids

Natural gas plant liquids (unlike lease condensate) remain within the natural gas after passing through lease separation equipment. These liquids can only be separated from the natural gas at processing plants, fractionating and cycling plants, and in some instances, field facilities. Products obtained include ethane, liquefied petroleum gases (propane, butane, and isobutane), and natural gasoline. Components may be further fractionated or mixed. Lease condensate is not a natural gas plant liquid and is not a component of the natural gas plant liquids total.

As with dry natural gas, the potential U.S. supply of natural gas plant liquids is not categorized as proved reserves because these liquids are extracted downstream of the producing wells at a natural gas processing plant. An estimate of the volume of these liquids that might be extracted from total natural gas reserves is presented in Table 17. The estimated volume of natural gas plant liquids contained in proved reserves of total natural gas increased from 11.9 billion barrels in 2013 to 15.0 billion barrels in 2014 (a 26% increase).

Reserves in nonproducing reservoirs

Not all proved reserves are contained in actively producing reservoirs. Examples of proved reserves in nonproducing reservoirs include existing producing wells that are shut in awaiting well workovers; drilled wells that await completion by hydraulic fracturing; sites that require installation of production equipment or pipeline facilities; or behind the pipe reserves that require the depletion of other zones or reservoirs before they can be placed on production (by recompleting the well).

Table 18 shows the estimated volumes of nonproducing proved reserves of crude oil, lease condensate, nonassociated natural gas, associated-dissolved natural gas, and total natural gas for 2014.

Maps and additional data tables

For more detailed 2014 proved reserves information than discussed above, see maps below and tables for oil (5-8) and gas (9-17) top right.

Figure 14. Crude oil and lease condensate proved reserves by state/area, 2013

Figure 15. Changes in crude oil and lease condensate proved reserves by state/area, 2012 to 2013

Figure 16. Natural gas proved reserves by state/area, 2013

Figure 17. Changes in natural gas proved reserves by state/area, 2012 to 2013

 

Footnotes:

1The U.S. all-time high for crude oil and lease condensate proved reserves was 43.0 billion barrels in 1970.

2Total natural gas (also known as natural gas, wet after lease separation) includes natural gas liquids that have yet to be extracted downstream at a processing plant, but it does not include lease condensate.

3The previous U.S. record high for total natural gas proved reserves was 354 trillion cubic feet (Tcf) in 2013. (Source: EIA)

4Because there was only one operator reporting proved natural gas reserves in Idaho in 2014, the state’s total was included in the miscellaneous states subtotal.

5Reasonable certainty assumes a probability of recovery of 90% or greater.

6The U.S. all-time high for crude oil and lease condensate proved reserves was 43.0 billion barrels in 1970.

7Total natural gas (also known as natural gas, wet after lease separation) includes natural gas liquids that have yet to be extracted downstream at a processing plant, but it does not include lease condensate.

8The lowest recorded daily spot price of WTI crude oil in 2015 was $38.22 per barrel on August 24, 2015. (Thompson Reuters)

9Tight oil is oil produced from petroleum-bearing formations with low permeability such as the Eagle Ford, the Bakken, and other formations that must be hydraulically fractured to produce oil at commercial rates. A kerogen-bearing, thermally mature shale is the source rock, and typically lends its name to the play.

10The oil production estimates in this report are based on data reported on Form EIA-23L, Annual Survey of Domestic Oil and Gas Reserves. They may differ slightly from the official U.S. EIA production data for crude oil and lease condensate for 2013 contained in the Petroleum Supply Annual 2013, DOE/EIA-0340(13).

11"Encana to sell its Jonah field properties in Wyoming for $1.8 billion," Denver Post, March 31, 2014.

12The natural gas production estimates in this report are based on data reported on Form EIA-23L, Annual Survey of Domestic Oil and Gas Reserves. Estimates differ from the official U.S. EIA production data for natural gas published in the Natural Gas Annual 2013, DOE/EIA-0131(13).

13Sustained low oil prices could reduce exploration and production investment, EIA Today in Energy, September 24, 2015.

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

Data tables

1. U.S. proved reserves, and reserves changes, 2013-14 PDF XLS
2. U.S. tight oil plays: production and proved reserves, 2013-14 PDF XLS
3. Changes to proved reserves of U.S. natural gas by source, 2013-14 PDF XLS
4. U.S.shale gas plays: natural gas production and proved reserves, 2013-14 PDF XLS
5. U.S. proved reserves of crude oil and lease condensate, crude oil, and lease condensate, 2004-14 PDF XLS
6. Crude oil and lease condensate proved reserves, reserves changes, and production, 2014 PDF XLS
7. Crude oil proved reserves, reserves changes, and production, 2014 PDF XLS
8. Lease condensate proved reserves, reserves changes, and production, 2014 PDF XLS
9. U.S. proved reserves of total natural gas, wet after lease separation, 2001-14 PDF XLS
10. Total natural gas proved reserves, reserves changes, and production, wet after lease separation, 2014 PDF XLS
11. Nonassociated natural gas proved reserves, reserves changes, and production, wet after lease separation, 2014 PDF XLS
12. Associated-dissolved natural gas proved reserves, reserves changes, and production, wet after lease separation, 2014 PDF XLS
13. Shale natural gas proved reserves and production, 2011-14 PDF XLS
14. Shale natural gas proved reserves, reserves changes, and production, wet after lease separation, 2014 PDF XLS
15. Coalbed methane proved reserves and production, 2010-14 PDF XLS
16. Coalbed methane proved reserves, reserves changes, and production, 2014 PDF XLS
17. Estimated natural gas plant liquids and dry natural gas content of total natural gas proved reserves, 2014 PDF XLS
18. Reported proved nonproducing reserves of crude oil, lease condensate, nonassociated gas, associated dissolved gas, and total gas (wet after lease separation), 2014 PDF XLS

Supplement

Top 100 U.S. Oil and Gas Fields