|  Definitions, Sources and Explanatory Notes |
|--------------------------------------------------|
|  Category:   | Natural Gas Production               |
|-----------------------------|--------------------------------------|
|                             |
|  Topic:      | Wellhead Value & Marketed Production |
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|   Definitions |  |
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| Key Terms           | Definition                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|---------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 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.                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Production          | The volume of natural gas withdrawn from reservoirs less (1) the volume returned to such reservoirs in cycling, repressuring of oil reservoirs, and conservation operations; less (2) shrinkage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.) |
| 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.The Wellhead Price estimate has been discontinued as of January 2013.                                                                                                                                     |
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| For definitions of related energy terms, refer to the   EIA Energy Glossary. |
|  	Sources |
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|  |
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|  | **1967-1975:** Figures based on reports received from State agencies and Bureau of Minesestimates.**1976-1979:** State Conservation agencies.**1979:** State conservation agencies 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Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition"**1996-present:** Form EIA-895, "Monthly and Annual Quantity and Value of Natural Gas Production Report", Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition",EIA estimates, and the U.S. Mineral Management Service.Background on "Natural Gas Annual" data
- Natural Gas Survey Forms and Instructions       	Explanatory Notes    Average Wellhead Value    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. Because of data quality concerns, both monthly and annual wellhead prices were discontinued for January 2013 forward.  
  Average wellhead price times marketed production does not equal imputed  value of marketed production due to independent rounding.  
Marketed Production
    Marketed production is the sum of gross withdrawals less gas used for repressuring, quantities vented and flared, and nonhydrocarbon gases removed.      
    From 2017 forward, state monthly marketed production is estimated from gross withdrawals using historical relationships between the two. |