|  Definitions, Sources and Explanatory Notes |
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|  Category:   | Petroleum Refining & Processing   |
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|  Topic:      | Refinery Utilization and Capacity |
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|   Definitions |  |
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| Key Terms                                               | Definition                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
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| Atmospheric Crude Oil Distillation                      | The refining process of separating crude oil components at atmospheric pressure by heating to temperatures of about 600o to 750o F (depending on the nature of the crude oil and desired products) and subsequent condensing of the fractions by cooling.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| Barrel                                                  | A unit of volume equal to 42 U.S. gallons.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| Barrels Per Calendar Day                                | The amount of input that a distillation facility can process under usual operating conditions.  The amount is expressed in terms of capacity during a 24-hour period and reduces the maximum processing capability of all units at the facility under continuous operation (see Barrels per Stream Day) to account for the following limitations that may delay, interrupt, or slow down production:  the capability of downstream facilities to absorb the output of crude oil processing   facilities of a given refinery. No reduction is made when a planned distribution of   intermediate streams through other than downstream facilities is part of a refinery's normal operation;
the types and grades of inputs to be processed;
the environmental constraints associated with refinery operations;
the reduction of capacity for scheduled downtime due to such conditions as routine   inspection, maintenance, repairs, and turnaround; and
the reduction of capacity for unscheduled downtime due to such conditions as   mechanical problems, repairs, and slowdowns. |
| Barrels Per Stream Day                                  | The maximum number of barrels of input that a distillation facility can process within a 24-hour period when running at full capacity under optimal crude and product slate conditions with no allowance for downtime.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Gross Input to Atmospheric Crude Oil Distillation Units | Total input to atmospheric crude oil distillation units. Includes all crude oil, lease condensate, natural gas plant liquids, unfinished oils, liquefied refinery gases, slop oils, and other liquid hydrocarbons produced from tar sands, gilsonite, and oil shale.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Idle Capacity                                           | The component of operable capacity that is not in operation and not under active repair, but capable of being placed in operation within 30 days; and capacity not in operation but under active repair that can be completed within 90 days.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Operable Capacity                                       | The amount of capacity that, at the beginning of the period, is in operation; not in operation and not under active repair, but capable of being placed in operation within 30 days; or not in operation but under active repair that can be completed within 90 days. Operable capacity is the sum of the operating and idle capacity and is measured in barrels per calendar day or barrels per stream day.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Operable Utilization Rate                               | Represents the utilization of the atmospheric crude oil distillation units. The rate is calculated by dividing the gross input to these units by the operable calendar day refining capacity of the units.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| Operating Capacity                                      | The component of operable capacity that is in operation at the beginning of the period.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| Petroleum Administration for Defense (PAD) Districts    | Geographic aggregations of the 50 States and the District of Columbia into five districts by the Petroleum Administration for Defense in 1950. These districts were originally defined during World War II for purposes of administering oil allocation. Description and maps of PAD Districts and Refining Districts.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| Refinery                                                | An installation that manufactures finished petroleum products from crude oil, unfinished oils, natural gas liquids, other hydrocarbons, and oxygenates.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Refinery Input, Total                                   | The raw materials and intermediate materials processed at refineries to produce finished petroleum products. They include crude oil, products of natural gas processing plants, unfinished oils, other hydrocarbons and oxygenates, motor gasoline and aviation gasoline blending components and finished petroleum products.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
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| For definitions of related energy terms, refer to the   EIA Energy Glossary. |
|  	Sources |
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|  | Energy Information Administration, Form EIA-810, "Monthly Refinery Report".
EIA Forms & Instructions
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Background, Survey Methodology and Statistical Details
. |
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|  	Explanatory Notes |
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|  | Totals may not equal sum of components due to independent rounding.  
  Description and maps of PAD Districts and Refining Districts  from the Petroleum Supply Monthly. |
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