|  Definitions, Sources and Explanatory Notes |
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|  Category:   | Natural Gas Production |
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|  Topic:      | Plant Processing       |
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|   Definitions |  |
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| Key Terms                    | Definition                                                                                                                                                                                                                                                                                                                   |
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| Extraction Loss              | The extraction of gas plant liquids constituents such as ethane, propane, normal butane, isobutane, plant condensate, and natural gasoline, sometimes referred to as extraction loss. Usually reported in barrels or gallons, but may be reported in cubic feet for purposes of comparison with dry natural gas volumes.     |
| 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. |
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| For definitions of related energy terms, refer to the   EIA Energy Glossary. |
|  	Sources |
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|  | Natural Gas Processed, Liquids Extracted, and Extraction Loss Volume:Form EIA-64A, "Annual Report of the Origin of Natural Gas Liquids Production".Estimated Heat Content of Extraction Loss: Estimated, from the individual liquid components as reported on Form EIA-64A for each state, and applying the following conversion factors to the individual component and productproduction estimates (million Btu extraction loss per barrel of liquid produced): ethane - 3.082; propane - 3.836; normal butane - 4.326; isobutane - 3.974; pentanes plus - 4.620.Background on "Natural Gas Annual" data
- Natural Gas Survey Forms and Instructions       	Explanatory Notes        Through 2018, The Form EIA-64A 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.  
    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.  
    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.  
    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.  
    Beginning in 2019, the Form EIA-64A collects data by area of origin for inlet gas volumes and individual liquid components extracted (i.e., ethane, propane, normal butane, isobutene, natural gasoline, and plant condensate).  Form EIA-64A also collects total residue gas, gas used for plant fuel, gas sent to a pipeline, and purchased electricity by gas plant.  The individual liquid component volumes reported on Form EIA-64A by area of origin are used to calculate shrinkage (extraction loss) by state of origin and the heat content (Btu) of the extracted liquids  
    The shrinkage (extraction loss) was estimated by applying conversion factors to the volumes of the individual products extracted in each state.  These conversion factors, in Mcf/bbl, are ethane, 1.558; propane, 1.498; normal butane, 1.289; isobutane, 1.247; natural gasoline,1.050; and plant condensate, 0.811.  
    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.  
    Through 2011, extraction loss volumes for the Federal Offshore Gulf of Mexico are included in the total extraction loss volumes for the States of Alabama, Louisiana, and Texas.  
    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. |