Definitions, Sources and Explanatory Notes

 Category:   Natural Gas Summary
 Topic:   Summary

  Definitions

Key Terms Definition
Acquisitions (Proved Reserves) The volume of proved reserves gained by the purchase of an existing fields or properties, from the date of purchase or transfer.
Adjustments (Proved Reserves) The quantity which preserves an exact annual reserves balance within each State or State subdivision of the following form:

Adjustments + Revision Increases - Revision Decreases - Sales + Acquisitions + Extensions + New Field Discoveries + New Reservoir Discoveries in Old Fields - Report Year Production = Published Proved Reserves at End of Report Year

These adjustments are the 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, variations as a result of changes in the operator frame, different random samples or imputations for missing or unreported reserve changes, could contribute to adjustments.
Base (cushion) gas The volume of gas needed as a permanent inventory to maintain adequate reservoir pressures and deliverability rates throughout the withdrawal season. All native gas is included in the base gas volume.
Citygate A point or measuring station at which a distributing gas utility receives gas from a natural gas pipeline company or transmission system.
Coalbed Methane Methane is generated during coal formation and is contained in the coal microstructure. Typical recovery entails pumping water out of the coal to allow the gas to escape. Methane is the principal component of natural gas. Coalbed methane can be added to natural gas pipelines without any special treatment.
Commercial Price The price of gas used by nonmanufacturing establishments or agencies primarily engaged in the sale of goods or services such as hotels, restaurants, wholesale and retail stores and other service enterprises; and gas used by local, State and Federal agencies engaged in nonmanufacturing activities.
Delivered (Gas) The physical transfer of natural, synthetic, and/or supplemental gas from facilities operated by the responding company to facilities operated by others or to consumers.
Dry Natural Gas Natural gas which remains after: 1) the liquefiable hydrocarbon portion has been removed from the gas stream (i.e., gas after lease, field, and/or plant separation); and 2) any volumes of nonhydrocarbon gases have been removed where they occur in sufficient quantity to render the gas unmarketable. (Note: Dry natural gas is also known as consumer-grade natural gas. The parameters for measurement are cubic feet at 60 degrees Fahrenheit and 14.73 pounds per square inch absolute.)
Dry Natural Gas Production The process of producing consumer-grade natural gas. Natural gas withdrawn from reservoirs is reduced by volumes used at the production (lease) site and by processing losses. Volumes used at the production site include (1) the volume returned to reservoirs in cycling, repressuring of oil reservoirs, and conservation operations; and (2) gas vented and flared. Processing losses include (1) nonhydrocarbon gases (e.g., water vapor, carbon dioxide, helium, hydrogen sulfide, and nitrogen) removed from the gas stream; and (2) gas converted to liquid form, such as lease condensate and plant liquids. Volumes of dry gas withdrawn from gas storage reservoirs are not considered part of production. Dry natural gas production equals marketed production less extraction loss.
Electric Power Consumption Gas used as fuel in the electric power sector.
Electric Power Price The price of gas used by electricity generators (regulated utilities and non-regulated power producers) whose line of business is the generation of power.
Electric Power Sector An energy-consuming sector that consists of electricity-only and combined heat and power (CHP) plants whose primary business is to sell electricity, or electricity and heat, to the public -i.e., North American Industry Classification System code 22 for plants. Combined heat and power plants that identify themselves as primarily in the commercial or industrial sectors are reported in those sectors.
Exports Natural Gas deliveries out of the Continental United States and Alaska to foreign countries.
Extensions (Proved Reserves) The reserves credited to a reservoir because of enlargement of its proved area. Normally the ultimate size of newly discovered fields, or newly discovered reservoirs in old fields, is determined by wells drilled in years subsequent to discovery. When such wells add to the proved area of a previously discovered reservoir, the increase in proved reserves is classified as an extension.
Extraction Loss The reduction in volume of natural gas due to the removal of natural gas liquid constituents such as ethane, propane, and butane at natural gas processing plants.
Flared Gas disposed of by burning in flares usually at the production sites or at gas processing plants.
Gas in storage The sum of base gas plus working gas.
Gas Well A well completed for the production of natural gas from one or more gas zones or reservoirs. Such wells contain no completions for the production of crude oil.
Gross Withdrawals Full well-stream volume, including all natural gas plant liquids and all nonhydrocarbon gases, but excluding lease condensate. Also includes amounts delivered as royalty payments or consumed in field operations.
Heating Value The average number of British thermal units per cubic foot of natural gas as determined from tests of fuel samples.
Imports Natural Gas received in the Continental United States (including Alaska) from a foreign country.
Industrial Consumption Natural gas used for heat, power, or chemical feedstock by manufacturing establishments or those engaged in mining or other mineral extraction as well as consumers in agriculture, forestry, and fisheries. Also included in industrial consumption are generators that produce electricity and/or useful thermal output primarily to support the above-mentioned industrial activities.
Industrial Price The price of natural gas used for heat, power, or chemical feedstock by manufacturing establishments or those engaged in mining or other mineral extraction as well as consumers in agriculture, forestry, fisheries and construction.
Lease Fuel Natural gas used in well, field, and lease operations, such as gas used in drilling operations, heaters, dehydrators, and field compressors.
Liquefied Natural Gas Natural gas (primarily methane) that has been liquefied by reducing its temperature to -260 degrees Fahrenheit at atmospheric pressure.
Marketed Production Gross withdrawals less gas used for repressuring, quantities vented and flared, and nonhydrocarbon gases removed in treating or processing operations. Includes all quantities of gas used in field and processing plant operations.
Natural Gas A gaseous mixture of hydrocarbon compounds, the primary one being methane.
Natural Gas Processed Natural gas that has gone through a processing plant.
Natural Gas Processing Plant A facility designed to recover natural gas liquids from a stream of natural gas which may or may not have passed through lease separators and/or field separation facilities. These facilities also control the quality of the natural gas to be marketed. Cycling plants are classified as natural gas processing plants.
New Field Discoveries (Proved Reserves) The volumes of proved reserves of crude oil, natural gas and/or natural gas liquids discovered in new fields during the report year.
New Reservoir Discoveries in Old Fields (Proved Reserves) The volumes of proved reserves of crude oil, natural gas, and/or natural gas liquids discovered during the report year in new reservoir(s) located in old fields.
Nominal Price The price paid for a product or service at the time of the transaction. Nominal prices are those that have not been adjusted to remove the effect of changes in the purchasing power of the dollar; they reflect buying power in the year in which the transaction occurred.
Nonhydrocarbon Gases Typical nonhydrocarbon gases that may be present in reservoir natural gas, such as carbon dioxide, helium, hydrogen sulfide, and nitrogen.
Oil Well (Casinghead) Gas Natural gas produced along with crude oil from oil wells. It contains either dissolved or associated gas or both.
Pipeline A continuous pipe conduit, complete with such equipment as valves, compressor stations, communications systems, and meters, for transporting natural and/or supplemental gas from one point to another, usually from a point in or beyond the producing field or processing plant to another pipeline or to points of use. Also refers to a company operating such facilities.
Pipeline Fuel Gas consumed in the operation of pipelines, primarily in compressors.
Plant Fuel Natural gas used as fuel in natural gas processing plants.
Production The volume of natural gas withdrawn from reservoirs less (1) the volume returned to such reservoirs in cycling, repressuring of oil reservoirs, and conservation operations; less (2) shrinkage resulting from the removal of lease condensate; and less (3) nonhydrocarbon gases where they occur in sufficient quantity to render the gas unmarketable. Volumes of gas withdrawn from gas storage reservoirs and native gas, which has been transferred to the storage category, are not considered production. Flared and vented gas is also considered production. (This differs from "Marketed Production" which excludes flared and vented gas.)
Production of Natural Gas, Dry (Proved Reserves) The volume of natural gas withdrawn from reservoirs during the report year less (1) the volume returned to such reservoirs in cycling, repressuring of oil reservoirs, and conservation operations; less (2) shrinkage resulting from the removal of lease condensate and plant liquids; and less (3) nonhydrocarbon gases where they occur in sufficient quantity to render the gas unmarketable. Volumes of gas withdrawn from gas storage reservoirs and native gas, which has been transferred to the storage category, are not considered production. This is not the same as marketed production, because the latter also excludes vented and flared gas, but contains plant liquids.

For estimation methodology, see Estimation of Reserves and Resouces.
Proved Reserves Proved reserves of natural gas as of December 31 of the report year are the estimated quantities which analysis of geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions.

Reservoirs are considered proved if economic producibility is supported by actual production or conclusive formation test (drill stem or wire line), or if economic producibility is supported by core analyses and/or electric or other log interpretations.

The area of a gas reservoir considered proved includes: (1) that portion delineated by drilling and defined by gas -- oil and/or gas -- water contacts, if any; and (2) the immediately adjoining portions not yet drilled, but which can be reasonably judged as economically productive on the basis of available geological and engineering data. In the absence of information on fluid contacts, the lowest known structural occurrence of hydrocarbons is considered to be the lower proved limit of the reservoir.

Volumes of natural gas placed in underground storage are not to be considered proved reserves.

For natural gas, wet after lease seperation, an appropriate reduction in the reservoir gas volume has been made to cover the removal of the liquefiable portions of the gas in lease and/or field separation facilities and the exclusion of nonhydrocarbon gases where they occur in sufficient quantity to reder the gas unmarketable.

For dry natural gas, an appropriate reduction in the gas volume has been made to cover the removal of the liquefiable portions of the gas in lease and/or field separation facilities, and in natural gas processing plants, and the exclusion of nonhydrocarbon gases where they occur in sufficient quantity to render the gas unmarketable.

It is not necessary that production, gathering, or transportation facilities be installed or operative for a reservoir to be considered proved. It is to be assumed that compression will be initiated if and when economically justified.
Repressuring The injection of gas into oil or gas reservoir formations to effect greater ultimate recovery.
Residential Consumption Gas used in private dwellings, including apartments, for heating, air-conditioning, cooking, water heating, and other household uses.
Residential Price The price of gas used in private dwellings, including apartments, for heating, cooking, water heating, and other household uses.
Revisions (Proved Reserves) Changes to prior year-end proved reserves estimates, either positive or negative, resulting from new information other than an increase in proved acreage (extension). Revisions include increases of proved reserves associated with the installation of improved recovery techniques or equipment. They also include correction of prior report year arithmetical or clerical errors and adjustments to prior year-end production volumes to the extent that these alter reported prior year reserves estimates.
Sales (Proved Reserves) The volume of proved reserves deducted from an operator's total reserves when selling an existing field or property, during the calendar year.
Shale Gas Natural gas produced from organic (black) shale formations.
Storage Additions (LNG) Volumes of gas injected or otherwise added to underground natural gas reservoirs or liquefied natural gas storage.
Storage Capacity The present developed maximum operating capacity.
Storage Withdrawals (LNG) Total volume of gas withdrawn from underground storage or from liquefied natural gas storage over a specified amount of time.
Underground Gas Storage The use of sub-surface facilities for storing gas that has been transferred from its original location. The facilities are usually hollowed-out salt domes, natural geological reservoirs (depleted oil or gas fields) or water-bearing sands topped by an impermeable cap rock (aquifer).
Underground Storage Injections Gas from extraneous sources put into underground storage reservoirs.
Underground Storage Withdrawals Gas removed from underground storage reservoirs.
Vehicle Fuel Consumption The quantity of fuel used by vehicles. Vehicle fuel consumption is computed as the vehicle miles traveled divided by the fuel efficiency reported in miles per gallon (MPG). Vehicle fuel consumption is derived from the actual vehicle fuel mileage collected and the assigned MPGs obtained from EPA certification files adjusted for on-road driving.
Vented Gas released into the air on the production site or at processing plants.
Wellhead Price Price of natural gas calculated by dividing the total reported value at the wellhead by the total quantity produced as reported by the appropriate agencies of individual producing States and the U.S. Bureau of Ocean Energy Management, Regulation and Enforcement. The price includes all costs prior to shipment from the lease, including gathering and compression costs, in addition to State production, severance, and similar charges.
Working (top storage) gas The volume of total natural gas storage capacity that contains natural gas available for withdrawal.

For definitions of related energy terms, refer to the EIA Energy Glossary.

  Sources

City Gate Price: Form EIA-857, "Monthly Report of Natural Gas Purchases and Deliveries to Consumers"; Form EIA-910, "Monthly Natural Gas Marketer Survey." .   Electric Utility Price: 1967-1977: Federal Power Commission (FPC). 1978-2001: Form EIA-759, "Monthly Power Plant Report" ; Federal Energy Regulatory Commission (FERC), Form-423, "Cost and Quality of Fuels for Electric Plants Report" ; Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition" ; Form EIA-910, "Monthly Natural Gas Marketer Survey" .    Electric Power Price: 2002-Present: Federal Energy Regulatory Commission (FERC), Form-423, "Cost and Quality of Fuels for Electric Plants Report" .   Other Prices: 1967-1975: Bureau of Mines, Minerals Yearbook, "Natural Gas" chapter. 1976-1978: EIA, Energy Data Report, Natural Gas Annual. 1979: EIA, Natural Gas Production and Consumption, 1979. Production: 1967-1975: Figures based on reports received from State agencies and Bureau of Mines estimates. 1976-1979: Appropriate State agencies' responses to informal data requests and the United state Geological Survey (USGS). 1980-1981: Form EIA-627, "Annual Quantity and Value of Natural Gas Report," and the USGS. 1982-1995: Form EIA-627, "Annual Quantity and Value of Natural Gas Report," and the United State Minerals Management Service; West Virginia, 1995: EIA, U.S. Crude Oil, natural Gas, and Natural Gas Liquids Reserves, 1996 Annual Report, and EIA computations. 1996-present: Form EIA-895, "Monthly and Annual Quantity and Value of Natural Gas Production Report" (2006 only), Form EIA-914, "Monthly Natural Gas Production Report" , and the U.S. Mineral Management Service; West Virginia, 2000: EIA, U.S. Crude Oil, Natural Gas Liquids Reserves, Annual Report.    Beginning in 2010: Form EIA-895, "Annual Quantity and Value of Natural Gas Production Report"; Form EIA-914, "Monthly Natural Gas Production Report"; Form EIA-816, "Monthly Natural Gas Liquids Report"; Form EIA-64A, "Annual Report of the Origin of Natural Gas Liquids Production"; the Bureau of Safety and Environmental Enforcement and predecessor agencies; state agencies; Form EIA-23, "Annual Survey of Domestic Oil and Gas Reserves"; LCI; Ventyx; BENTEK Energy; and EIA estimates based on historical data.    Imports and Exports: 1994 and earlier years: EIA, Form FPC-14, "Annual Report for Importers and Exporters of Natural Gas." 1995 to current: Office of Fossil Energy, U.S. Dept. of Energy, "Natural Gas Imports and Exports". Estimated pipeline data are from the National Energy Board of Canada. EIA reduced the reported volume of gas imported by pipeline from Canada by the amount of natural gas liquids removed from the saturated natural gas carried by Alliance Pipeline. Alliance moves saturated natural gas from the border to a processing plant in Illinois. After the adjustment, volumes of imported natural gas on this pipeline are on the same physical basis as other reported volumes of pipeline imports.    Underground Storage: 1979 and prior data from the American Gas Association, Committee on Underground Storage, The Storage of Gas in the United States and Canada. 1980 to current data from Form EIA-191M, "Monthly Underground Gas Storage Report" and Form EIA-191A, "Annual Underground Gas Storage Report" .   LNG Storage: Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition" Consumption: 1973-1975: Bureau of Mines, Minerals Yearbook, "Natural Gas" chapter. 1976-1978: EIA, Energy Data Reports, Natural Gas Annual. 1979: EIA, Natural Gas Production and Consumption, 1979. 1980-1989: Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition" and Form EIA-759, "Monthly Power Plant Report" . 1990: Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition" ,Form EIA-759, "Monthly Power Plant Report" and Form EIA-64A, "Annual Report of the Origin of Natural Gas Liquids Production" . 1991-1995: Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition" ,Form EIA-759, "Monthly Power Plant Report" Form EIA-64A, "Annual Report of the Origin of Natural Gas Liquids Production" and EIA-627, "Annual Quantity and Value of Natural Gas Report." 1996-2000: Form EIA-895, "Monthly and Annual Quantity and Value of Natural Gas Production Report" ,Form EIA-857, "Monthly Report of Natural Gas Purchases and Deliveries to Consumers"; Form EIA-910, "Monthly Natural Gas Marketer Survey." , Form EIA-759, "Monthly Power Plant Report" , EIA computations, and Natural Gas Annual 2000. 2001-current Form EIA-895, "Monthly and Annual Quantity and Value of Natural Gas Production Report" , Form EIA-857, "Monthly Report of Natural Gas Purchases and Deliveries to Consumers"; Form EIA-910, "Monthly Natural Gas Marketer Survey." , Form EIA-906, "Power Plant Report" and Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition" .  

  • Background on "Natural Gas Monthly" data
  • Background on "Natural Gas Annual" data
  • Natural Gas Survey Forms and Instructions
  • Electric Survey Forms and Instructions

  •   Explanatory Notes

  • Totals may not equal sum of components due to independent rounding.
    Production
  • Monthly extraction loss is derived from sample data reported by gas processing plants on Form EIA-816, "Monthly Natural Gas Liquids Report."
  • Shale production volumes are broken out separately using data from LCI Energy Insight (LCI). Natural gas production from coalbed methane is also derived from LCI.
    Storage
  • Net storage withdrawals data through 2006 include underground storage and liquefied natural gas storage. Data for January 2007 forward include underground storage only.
  • All monthly data concerning underground storage are published from the Form EIA-191M, "Monthly Underground Gas Storage Report." A new Form EIA-191 became effective in January 1994. Injection and withdrawal data are from the Form EIA-191M survey.
  • The final monthly and annual storage and withdrawal data include both underground and liquefied natural gas (LNG) storage. Annual data on LNG additions and withdrawals are taken from Form EIA-191M. Monthly data are estimated by computing the ratio of each month's underground storage additions and withdrawals to annual underground storage additions and withdrawals and applying it to annual LNG data.
  • There are three principal types of underground storage facilities in operation in the United States today: salt caverns (caverns hollowed out in salt "bed" or "dome" formations), depleted fields (depleted reservoirs in oil and/or gas fields), and aquifer reservoirs (water-only reservoirs conditioned to hold natural gas). A storage facility's daily deliverability or withdrawal capability is the amount of gas that can be withdrawn from it in a 24-hour period. Salt cavern storage facilities generally have high deliverability because all of the working gas in a given facility can be withdrawn in a relatively short period of time. (A typical salt cavern cycle is 10 days to deplete working gas, and 20 days to refill working gas.) By contrast, depleted field and aquifer reservoirs are designed and operated to withdraw all working gas over the course of an entire heating season (about 150 days). Further, while both traditional and salt cavern facilities can be switched from withdrawal to injection operations during the heating season, this is usually more quickly and easily done in salt cavern facilities, reflecting their greater operational flexibility.
    Imports and Exports
  • EIA reduced the reported volume of gas imported by pipeline from Canada by the amount of natural gas liquids removed from the saturated natural gas carried by Alliance Pipeline. Alliance moves saturated natural gas from the border to a processing plant in Illinois. After the adjustment, volumes of imported natural gas on this pipeline are on the same physical basis as other reported volumes of pipeline imports.
  • Prices for LNG imports are reported as “landed,” received at the terminal, or “tailgate,” after regasification at the terminal. Generally the reporting of LNG import prices varies by point of entry, and the average prices are calculated from a combination of both types of prices. The price of LNG exports to Japan is the “landed” price, defined as received at the terminal in Japan.
  • Annual and monthly data are published from the Office of Fossil Energy, U.S. Department of Energy, Natural Gas Imports and Exports.
  • Totals may not equal sum of components due to independent rounding.
    Prices
  • Prices are in nominal dollars.
  • Average Wellhead Value, Annual Data: Form EIA-895A, "Annual Quantity and Value of Natural Gas Report," requests state agencies to report the quantity and value of marketed production. When complete data are unavailable, the form instructs the state agency to report the available value and the quantity of marketed production associated with this value. A number of states reported volumes of production and associated values for other than marketed production. In addition, information for several states which were unable to provide data was obtained from Form EIA-176. It should be noted that Form EIA-176 reports a fraction of state production. The imputed value of marketed production in each state is calculated by dividing the state's reported value by its associated production. This unit price is then applied to the quantity of the state's marketed production to derive the imputed value of marketed production.
  • Average Wellhead Value, Preliminary Monthly Data: Preliminary values for the monthly U.S. natural gas wellhead price are estimated from the New York Mercantile Exchange (NYMEX) futures closing price for near-month delivery at the Henry Hub, and prevailing cash market prices (spot prices) at 5 major trading hubs: Henry Hub, LA; Carthage, TX; Katy, TX; Waha, TX; and Blanco, NM. The NYMEX price is reported in the trade publication, Gas Daily (published by Financial Times Energy). The spot prices are published in another trade publication, Natural Gas Week (Energy Intelligence Group), and they reflect the spot delivered-to-pipeline, volume-weighted average prices for natural gas bought and sold at the specified trading hubs. Prices include processing, gathering, and transportation fees to the hubs. The estimated wellhead prices are derived with a statistical procedure based on analysis of monthly time series data for the period 1995 through the present. A statistical procedure was adopted beginning with publication of the February 1999 issue of the Natural Gas Monthly. The preliminary estimates are replaced when annual survey data become available, usually about 10 months after the end of the report year.
  • Average Wellhead Value, Final Monthly Data: The Form EIA-895A requests state agencies to report monthly values of marketed production. Preliminary monthly gas price data are replaced by these final monthly data.
  • City gate prices are calculated from reports to the Form EIA-857 and represent the total cost paid by gas distribution companies for gas received at the point where the gas is physically transferred from a pipeline company or transmission system. This price is intended to reflect all charges for the acquisition, storage, and transportation of gas as well as other charges associated with the LDC's obtaining the gas for sale to consumers.
  • Published residential, commercial, and industrial prices are considered to be total prices paid by end-users per thousand cubic feet of natural gas in the respective sectors, inclusive of all tax, delivery, commodity, demand and other charges.
  • Volumes of natural gas reported for the commercial and industrial sectors include data for both sales and deliveries for the account of others.
  • The percentage of total volume delivered represents sales to the residential, commercial and industrial sectors. This information may be helpful in evaluating residential, commercial and industrial price data which are based on sales data only.
  • Beginning in 1987, prices for deliveries to consumers are calculated using only onsystem sales data. Due to large amounts of missing data for values of lease and plant fuel since 1987, prices are not estimated. In previous years, imputations were made for missing data and a price was calculated using reported and imputed data to derive a total value for gas consumed. Since total consumption value estimates were not made since 1987, no lease and plant fuel value estimate was made.
  • Beginning in 1996, consumption of natural gas for agricultural use was classified as industrial use. In 1995 and earlier years, agricultural use was classified as commercial use.
  • Average Price of Deliveries to Consumers: Price data are representative of prices for gas sold and delivered to residential, commercial, and industrial consumers. These prices do not reflect average prices of natural gas transported to consumers for the account of third parties or "spot-market" prices. Coverage for prices varies by consumer sector. All average prices , except electric power, are computed by dividing the reported revenue by its associated sales volume. Preliminary monthly prices for deliveries of natural gas to residential commercial and industrial consumers are calculated from reports to Form EIA-857, "Monthly Report of Natural Gas Purchases and Deliveries to Consumers." Final monthly data are calculated by allocating annual consumption data from the Form EIA-176, to each month in proportion to monthly volumes reported in Form EIA-857. In the States of Georgia, Maryland, New York, Ohio, Pennsylvania and Virginia, the residential and commercial sector prices, are collected on the Form EIA-910, "Monthly Natural Gas Marketer Survey," and include data on prices of gas sold to customers in those sectors by energy marketers. In the District of Columbia, Florida and Michigan, the commercial sector prices are also collected on the Form EIA-910. Additional states (Illinois, Massachusetts, New Jersey and West Virginia) may be added in the future as data quality becomes acceptable. In these States, prices in the residential and/or commercial sectors are calculated by combining the data from the Form EIA-910 with the EIA-857 (for preliminary monthly prices) and with the Form EIA-176 for final monthly prices. Beginning in January 2005, the EIA-910 added the States of Florida, Illinois, Massachusetts (which was dropped from the survey in 2008), Michigan, New Jersey, Virginia, West Virginia, and the District of Columbia. In 2011, the EIA-910 reduced the number of States for which it is used to collect data to Georgia, New York and Ohio only.
  • The electric power sector comprises electricity-only and combined-heat-and-power plants within the NAICS 22 category whose primary business is to sell electricity, or electricity and heat, to the public. Through 2001, data are for regulated electric utilities only; beginning in 2002, data also include nonregulated members of the electric power sector. With the unbundling of services in the natural gas industry, pipeline and local distribution companies provide transportation service for their end-user customers. Those volumes are described as deliveries of gas for the account of others. When companies that deliver gas are the sellers of that gas, they are able to report the associated revenue to the EIA. Those volumes are described as onsystem sales. When the firm that physically delivers gas to the end user acts as a transportation agent, it does not know the sales price of the gas. Respondents, therefore, do not report a revenue amount associated with deliveries for the account of others in their submissions of the Form EIA-176.
  • Standard Error for Natural Gas Deliveries and Price to Consumers by State.
    Volumes and Prices to Residential, Commercial, and Industrial Consumers
  • Discussion of new definitions from Natural Gas Monthly (April 2003)
  • Statistical Considerations (Sample Design, Estimation Procedures, Final Revisions, Reliability of Monthly Data).
  • Beginning in 2009 , Pipeline and Distribution Use volumes now include Line Loss, defined as known volumes of natural gas that were the result of leaks, damage, accidents, migration and/or blow down.
    Consumption
  • Annual consumption volumes are available through the Natural Gas Navigator for the Total United States for 1949 forward. The volumes for 1949 forward represent the current sectoral concepts introduced in 2001 and used throughout the Energy Information Administration. A comprehensive description of the concepts and changes they imply may be found in the 2001 Annual Energy Review, Appendix H, Estimating and Presenting Power Sector Fuel Use in EIA Publications and Analysis.
  • Discussion of new definitions of industrial and electric power consumption from Natural Gas Monthly (April 2003)
  • Lease fuel quantities were estimated by assuming that the proportions of onsystem production used as lease fuel by respondents to the Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition," were the same as the proportions of gross withdrawals as reported on Form EIA-895, “Annual Quantity and Value of Natural Gas Production Report,” used as lease by all operators.
  • Monthly lease and plant fuel use is estimated from monthly marketed production by assuming that the preceding annual percentage remains constant for the next twelve months.
  • Monthly pipeline fuel use is estimated from monthly total consumption (excluding pipeline fuel) by assuming that the preceding annual percentage remains constant for the next twelve months.
  • Beginning in 1996, consumption of natural gas for agricultural use was classified as industrial use. In 1995 and earlier years, agricultural use was classified as commercial use.
  • Vehicle fuel in the monthly view is included in the annual total of deliveries to all consumers, but not in the State level monthly volumes.
  • Electric Utility includes all steam electric utility generating plants with a combined capacity of 50 megawatts or greater.
  • Beginning with 1965 data, all volumes are shown on a pressure base of 14.73 psia at 60 degrees Fahrenheit. For prior years, the pressure base is 14.65 psia at 60 degrees Fahrenheit.
  • From 1967 through 1979, data for the District of Columbia are included with data for Maryland.
  • From 1967 through 1979, data for New Hampshire and Vermont are included with data for Maine.
  • Beginning with data for August 2010, residential and commercial consumption is calculated using a methodology that more closely aligns these volumes with the calendar month. See Natural Gas Monthly, Appendix C, Estimation Procedures, for more details.
  • In December 2011, monthly and annual volumes of industrial gas in Maine were revised upward back to 2002 to correct a misclassification of gas reported on the Form EIA-176.
  • Standard Error for Natural Gas Deliveries and Price to Consumers by State.