E&P Exploration and production. The "upstream" sector of the oil and gas industry. E85 An alcohol fuel mixture containing 85 percent ethanol and 15 percent gasoline by volume, and the current alternative fuel of choice of the U.S. government. E95 A fuel containing a mixture of 95 percent ethanol and 5 percent gasoline. Emissions Substances discharged into the air during combustion, e.g., all that stuff that comes out of your car. Ending stocks Primary stocks of crude oil and petroleum products held in storage as of 12 midnight on the last day of the month. Primary stocks include crude oil or petroleum products held in storage at (or in) leases, refineries, natural gas processing plants, pipelines, tank farms, and bulk terminals that can store at least 50,000 barrels of petroleum products or that can receive petroleum products by tanker, barge, or pipeline. Crude oil that is in-transit by water from Alaska or that is stored on Federal leases or in the Strategic Petroleum Reserve is included. Primary Stocks exclude stocks of foreign origin that are held in bonded warehouse storage. Energy balance The difference between the energy produced by a fuel and the energy required to obtain it through agricultural processes, drilling, refining, and transportation. Energy crops Agricultural crops grown specifically for their energy value. Energy-efficiency ratio A number representing the energy stored in a fuel as compared to the energy required to produce, process, transport, and distribute that fuel. EOR Enhanced Oil Recovery Equity Share or interest in an oil or gas licence or field. ERR Economically Recoverable Reserves Field: area in which a well or a group of wells is found. Esters Methyl and ethyl esters produced from any vegetable (hemp, corn, soybean, sunflower) or tree (almond, walnut, palm, coconut) oils, animal fats (beef tallow), used oils (recycled fryer oils) or other fat sources from organic compounds. Esters are formed by combining an acid with an alcohol and eliminating the water. In the biodiesel reaction, esters are formed as a result of combining fatty acids and methanol or ethanol. Ethanol Ethyl alcohol, also known as "grain alcohol." Not commonly used in making biodiesel because of its low reactivity (higher quantity required) than menthanol. Usually made from corn as a by-product of the feed industry, but can be produced from numerous other feedstocks (i.e. hemp or artichoke). There is a lot of interest in commercial biodiesel from ethanol because it can be produced more sustainably. Today ethanol is blended with gasoline as an "extender" and "octane enhancer". E10 is 10% ethanol. Ethanol can replace more harmful gasoline additives such as MTBE. Ethylene An olefinic hydrocarbon recovered from refinery processes or petrochemical processes. Ethylene is used as a petrochemical feedstock for numerous chemical applications and the production of consumer goods. Exchange, natural gas A type of energy exchange in which one company agrees to deliver gas, either directly or through intermediaries, to another company at one location or in one time period in exchange for the delivery by the second company to the first company of an equivalent volume or heat content at a different location or time period. Note: Such agreements may or may not include the payment of fees in dollar or volumetric amounts. Exchange, petroleum A type of energy exchange in which quantities of crude oil or any petroleum product(s) are received or given up in return for other crude oil or petroleum products. It includes reciprocal sales and purchases. Expenditures per million Btu The aggregate ratio of a group of buildings' total expenditures for a given fuel to the total consumption of that fuel. Exploratory well A hole drilled: a) to find oil or gas in an area previously considered unproductive; b) to find a new reservoir in a known field, i.e., one previously producing oil and gas from another reservoir, or c) to extend the limit of a known oil or gas reservoir. 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.