ExxonMobil Oil Corporation © 2006 Exxon Mobil Corporation. All rights reserved. 3225 Gallows Road Fairfax, VA 22037 ® ExxonMobil, Exxon and the ExxonMobil Logotype are registered trademarks of Exxon Mobil Corporation. ENCYCLOPEDIA FOR THE USER OF PETROLEUM PRODUCTS K B 4 7 www.exxonmobil.com 6 0 M 1-800-MOBIL-25 M PREFACE Hydrogen and carbon atoms, the principal components of crude oil and natural gas, can combine in virtually countless ways to make a diversity of petroleum products, including gasoline, diesel fuel, heating oil, lubricating oils and greases, solvents, waxes, process oils, electrical insulating oils, heat treating oils, and asphalts. Petroleum hydrocarbons are also the source of the petrochemicals that are widely used in the manufacture of such products as plastics, fertilizers, paints, pesticides, and synthetic rubber and fiber. In view of the indispensable role of petroleum products in our lives, this Encyclopedia is offered as a concise source of basic information about these products — their properties, the processes by which they are made, the test methods used to assess product characteristics and assure consistent quality, and health and safety issues. The types of equipment and materials that rely on petroleum products for their operation or manufacture are also discussed. This edition of the Encyclopedia has been extensively revised and expanded with more than 140 new definitions. Two recurring aspects of this encyclopedia require explanation: • In most of the definitions, certain words and phrases are in italics; others are in boldface. Italics indicate that the term is defined separately under its own heading; boldface indicates either that the term is of key importance in the definition or that it is a commonly used alternative to the word or phrase being described. • In numerous definitions, reference is made to ASTM test methods. These are carefully controlled tests developed by the American Society for Testing and Materials (ASTM), a scientific and technical organization founded in 1898 to establish standards for various petroleum and non-petroleum products, systems, and services. A abandon — when a well is depleted and no longer capable of Petroleum hydrocarbons, in the presence of oxygen and heat, producing oil and gas profitably. All equipment and material is can oxidize to form weak acids, which attack metals. See salvaged. A cement plug is placed in the borehole to prevent corrosion, oxidation. fluids from reaching the surface. Also called Plug and Abandon. acidizing — treatment of underground oil-bearing absolute humidity — see humidity. formations with acid in order to increase production. Hydrochloric or other acid is injected into the formation and absolute pressure — see pressure. held there under pressure until it etches the rock, thereby Absolute scale — see temperature scales. enlarging the pore spaces and passages through which the oil flows. The acid is then pumped out and the well is absolute viscosity — also referred to as dynamic viscosity. The swabbed and put back into production. ratio of shear stress to shear rate. It is a fluid’s internal resistance to flow. The common unit of absolute viscosity is the Poise or acid number — see neutralization number. centiPoise (see viscosity). Absolute viscosity divided by the fluid’s acid treating — refining process for improving the color, odor, density equals kinematic viscosity (in Stokes or centiStokes). and other properties of white oils or lube stocks, whereby the absorber oil — oil used to selectively absorb heavier unfinished product is contacted with sulfuric acid to remove hydrocarbon components from a gas mixture. Also called the less stable hydrocarbon molecules. wash oil or scrubber oil. acid wash color — an indication of the presence of olefins absorption — the assimilation of one material into another; in and polar compounds in petroleum solvents. A sample of petroleum refining, the use of an absorptive liquid to selectively solvent is mixed with sulfuric acid and let stand until formation remove components from a process stream. of an acid layer, the color of which is compared against color standards. The test is described in ASTM D 848. AC — see asphalt cement. acrylic resin — any of a group of resins formed from the ACC — see American Chemistry Council. polymerization of acrylic acid, methacrylic acid, esters of accumulator — in a hydraulic system, a device used to store these acids, acrylonitrile, and other monomers. It is used energy, here liquid under pressure for future conversion into in the manufacture of lightweight, weather resistant, useful work. As such, it acts as a flow control mechanism. exceptionally clear plastics and various coatings and inks. It is also used to absorb system shocks, smooth out flow by actuator — in a hydraulic system, a device used to convert absorbing pump pulsations, maintain constant pressures for hydraulic energy into mechanical energy and motion. It's long periods of time, and make up for system internal leakage. usually a hydraulic cylinder (the most common type), used Accumulators are of two main types, spring-loaded and gas- for linear action. It could also be a hydraulic motor which pressurized. The latter is the more common and can be either delivers rotary power. Effective sealing, including fluid of piston or bladder (also referred to as bag) design. Since the compatibility, is required for both types. bladder accumulator is typically made from rubber, hydraulic fluid compatibility is important. Accumulators help to reduce acute effect — toxic effect in mammals and aquatic life that the sizes of pumps and motors used in hydraulic systems. rapidly follows exposure to a toxic substance. An acute effect is usually evident after a single oral intake, a single contact ACEA — Association des Constructeurs Europeens d'Automobiles with the skin or eyes, or a single exposure to contaminated air (European Motor Manufacturers), represents the 13 major European lasting any period up to eight hours. Also known as acute car, truck and bus manufacturers in the European Union (EU). toxicity. See chronic effect, health hazard. acetylene — highly flammable hydrocarbon gas (C2H2), acute ecotoxicity — as defined in ASTM D 6046, propensity used in welding and cutting, and in plastics manufacture. of a material to produce adverse behavioral, biochemical, or Also a term for a series of unsaturated aliphatic hydrocarbons, physiological effects in non-human organisms or populations each containing at least one triple carbon bond, the simplest in a short period of time, usually not constituting a substantial member of the series being acetylene. The triple carbon bond portion of the life span of the organism. makes acetylenes highly reactive. See unsaturated hydrocarbon. acute toxicity — see acute effect. H C C H additive — chemical substance added to a petroleum product acetylene to impart or improve certain properties. Common petroleum product additives are: anti-foam agent, anti-icing additive, acid — hydrogen-containing compound that reacts with metals anti-wear additive, corrosion inhibitor, demulsifier, detergent, to form salts, and with metallic oxides and bases to form a dispersant, emulsifier, EP additive, fluidizer, friction salt and water. The strength of an acid depends on the extent modifier/reducer, oiliness agent, oxidation inhibitor, pour to which its molecules ionize, or dissociate, in water, and on point depressant, rust inhibitor, tackiness agent, viscosity the resulting concentration of hydrogen ions (H+) in solution. index (V.I.) improver. 3 ENCYCLOPEDIA FOR THE USER OF PETROLEUM PRODUCTS adiabatic compression — compression of a gas without (harmfulness to plants); this is accomplished by controlling extraction of heat, resulting in increased temperature. molecular weight within optimal limits and by maximizing The temperature developed in compression of a gas is an unsulfonated residue content. A crop oil is lower in quality important factor in lubrication since oil deteriorates more and commonly used as an adjuvant in herbicide spray rapidly at elevated temperatures. Oxidation inhibitors help formulations. prevent rapid lubricant breakdown under these conditions. air blowing — see air sparging. adjuvant — material added to a pesticide formulation that air entrainment — presence in an oil of minute bubbles in enhances the performance of the active ingredient. Petroleum colloidal-like suspension, giving the liquid a cloudy or hazy oils are commonly used as adjuvants. An adjuvant can appearance. The bubbles are difficult to expel, as distinct from improve pesticide effectiveness in a variety of ways, for example foam, which consists of relatively large bubbles that tend to rise by: reducing surface tension, which permits finer droplet and eventually escape from the oil. In a lubricating oil, entrained size and better surface coverage; reducing volatility, which air can disrupt the lubricating film and cause excessive surface minimizes evaporation to control spray drift and provide wear. Because entrained air is compressible, it can cause adequate surface residence time; lowering water solubility erratic and inefficient operation of hydraulic systems. A to resist rain washoff and weathering; and modifying plant common cause of air entrainment is excessive use of silicone or insect surfaces to improve pesticide uptake. in treating foaming problems. ASTM D 3427 Air Release See agricultural oil. Properties of Petroleum Oils measures the ability of an oil to adsorption — adhesion