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Monthly preliminary (from January 2006 to present) state-level data for the
production series, except marketed production, are not available until after the
final annual reports for these series are collected and processed. Final annual
data are generally available in the third quarter of the following year.
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For 1967 through 1970, Arizona, Florida, Missouri, and Tennessee are included in Alabama's volumes.
Beginning with monthly data for January 2006, "Other States" volumes include all
of the natural gas producing states except: Alaska, Louisiana, New Mexico,
Oklahoma, Texas, Wyoming, and the Gulf of Mexico. "Other States" volumes prior
to January 2006 include: Arkansas, Illinois, Kentucky, Maryland, Missouri,
Nebraska, Nevada, New York, Ohio, Pennsylvania, South Dakota, Tennessee,
Virginia, and West Virginia. Data for 2006 to the current month are estimated.
Federal Offshore Gulf of Mexico production volumes are presented as a separate data series
beginning in 2001. For Alabama, Louisiana and Texas all data through 2000 include
Federal Offshore production.
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Nonhydrocarbon gases removed increased significantly in 1996 due to production increases in the Bravo Dome.
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Beginning with 1965 data, all volumes are shown on a pressure base of 14.73 psia at 60 degres Fahrenheit.
For prior years, the pressure base is 14.65 psia at 60 degrees Fahrenheit.
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| Nonhydrocarbon Gases Removed |
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Annual data on nonhydrocarbon gases removed from marketed production-carbon dioxide, helium,
hydrogen sulfide, and nitrogen are reported by state agencies on the voluntary
Form EIA-895A.
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Beginning with report year 1990, states filing the Form EIA-627, "Annual Quantity and
Value of Natural Gas Report," were asked to supply monthly breakdowns of all data
previously reported on an annual basis. The sums of the reported figures were used to
calculate monthly volumes. In 1997 the Form EIA-627 was discontinued. States were
requested to file an annual schedule on the monthly Form EIA-895.
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| Marketed Production |
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Natural gas production annual data are collected from 33 gas-producing states on Form EIA-895A
which includes gross withdrawals, vented and flared, repressuring, nonhydrocarbon gases
removed, fuel used on leases, marketed production (wet), and extraction loss.
The U.S. Minerals Management Service (MMS) also supplies data on the quantity and
value of natural gas production on the Gulf of Mexico and Outer Continental Shelf. No
adjustments are made to the data.
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Average wellhead prices are calculated from volumes and values reported in Part IV of
the Form EIA-895A. These data are shown as "Reported Wellhead Value".
The volumes in this section refer to the actual amounts of natural gas reported to the states as sold.
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In many states, the marketed production volumes are larger than the reported wellhead
value volumes. Differences in these volumes generally result from differences in
definition and reporting requirements for separate data systems in the state. For
example, while production quantities of federal, tribal, and state royalty gas are
included in marketed production, some state reporting rules exclude these quantities
from reported wellhead value volumes.
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All monthly data are considered preliminary until after publication of the
Natural Gas Annual for the year in which the report month falls. Preliminary monthly data
are published from reports from the
Form EIA-914, "Monthly Natural Gas Production Report".
Volumetric data are converted, as necessary, to a standard 14.73 psia pressure base.
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Final monthly data are the sums of monthly data reported on the Form EIA-895A annual schedule.
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| Natural Gas Processed and Extraction Loss |
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Annual data on nonhydrocarbon gases removed from marketed production-carbon dioxide, helium,
hydrogen sulfide, and nitrogen are reported by state agencies on the voluntary
Form EIA-895A.
Latest data for nonhydrocarbon gases.
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Extraction loss is the reduction in the volume of natural gas available for disposition
resulting from the removal of natural gas liquid constituents at natural gas processing
plants. It represents that portion of the "raw" gas stream that is transferred from the
natural gas supply chain to the petroleum and natural gas liquids supply chain.
Extraction loss does not include the reduction in volume resulting from the removal of
nonhydrocarbon constituents or gas used as fuel, vented, flared, or otherwise disposed of
within natural gas processing plants. Extraction loss also results in a reduction in the
total heat (Btu) content of the natural gas stream equal to the heat content of the liquids
extracted.
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The Form EIA-64A "Annual Report of the Origin of Natural Gas Liquids Production,"
collects data on the volume of natural gas received for processing, the total quantity
of natural gas liquids produced, and the resulting shrinkage (defined as extraction loss
in this report) from all natural gas processing- and cycling-plant operators. The
quantity of natural gas received and liquids produced are reported by state of origin
of the natural gas. Shrinkage volumes are calculated and reported by plant operators
based upon the chemical composition of the liquids extracted using standard conversion
factors specified in the form instructions.
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To estimate the quantities of individual products extracted in each state, data from
the Form EIA-64A survey were used to determine the total liquids production, and data from the
Form EIA-816, "Monthly Natural Gas Liquids Report," survey were used to estimate the quantities
of the individual products contained in those total liquids.
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The Form EIA-816 captures information on the quantity of individual components (i.e., ethane, propane, normal
butane, isobutane, and pentanes plus) produced or contained in mixes of plant liquids as
determined by chemical analysis. The volumetric ratios of the individual components to the total
liquids, as calculated from the 12 monthly Form EIA-816
reports for each state, were applied to the annual total liquids production, as reported on the
Form EIA-64A, to estimate the quantities of individual components removed at gas-processing plants.
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The heat (Btu) content of liquids extracted is not reported on the Form EIA-64A.
Therefore, in order to estimate the extraction loss heat content, data reported on the
Form EIA-816 were used to determine the individual products contained in the total liquids reported on
Form EIA-64A.
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The heat (Btu) content of extracted liquids was estimated by applying conversion factors
to the estimated quantities of products extracted in each state. These conversion factors,
in million Btu per barrel of liquid produced, were ethane, 3.082; propane, 3.836; normal
butane, 4.326; isobutane,3.974; and pentane plus, 4.620. It should be noted that, at the
state level, extraction losses are not necessarily related to state production.
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Extraction loss annual data are calculated from filings of Form EIA-64A.
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Preliminary extraction loss data are derived from data reported on
Form EIA-816.
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Extraction loss volumes for Gulf of Mexico Federal production are included
in the total extraction loss volumes for the States of Alabama, Louisiana,
and Texas.
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Monthly data are revised after the publication of the Natural Gas Annual.
Final monthly data are estimated by allocating annual extraction loss data to each month
based on its total natural gas marketed production.
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