石油地质学英文课件Chapter 1.ppt

Chapter 1 Crude Oil, Natural Gas, Oilfield Water Crude oils Natural gases Oil-field waters 1 Crude oils 1.1 Definition 1.2 Chemical properties 1.3 Distillation 1.4 Classification 1.5 The differences between marine and terrigenous oils 1.6 Physical properties 1.1 Definition Crude oil is defined as a mixture of hydrocarbons and non-hydrocarbons that exists predominantly as liquid, with varying amounts of dissolved gases and/or semisolid hydrocarbons in natural underground reservoirs. 1.1 Definition The word petroleum originates from the Latin words petra(“rock and stone”) and oleum(“oil”), just like its Chinese word, 石油 means “石” and “油”. Petroleum is a kind of mineral resources that occurs in the earth as gas, liquid, semi-solids or in more then one of these states. Liquid petroleum is called crude oil that consists chiefly of the liquid hydrocarbons, with varying amounts of dissolved gases, bitumens, and impurities, which can be produced from underground reservoir rocks through a drill pipe. General Features Chemically any liquid petroleum is an extremely complex mixture of hydrocarbon compounds, with varying amounts of non-hydrocarbon compounds of nitrogen, sulfur, oxygen and also vanadium(V) and nickel(Ni) as impurities. The proportions of the hydrocarbon constituents and the contaminants are different in various petroleum accumulations or oil fields. The physical properties of petroleum are different in various accumulations/fields. 1.2 Chemical properties (1) Elemental composition The main elements are Carbon and Hydrogen; The minor elements are Sulfur,Nitrogen and Oxygen (normally less than 3%); Trace elements are heavy metals,such as V and Ni. (2) Alkane series — Paraffins The general formula is CnH2n+2. C1-4 are gases. methane/CH4, ethane/C2H6， propane/ C3H8, butane/C4H10 C5-20 are liquids. C20+ are usually waxy solids. In CnH2n+2 in crude oil, usually n≤80. Alkane series can be divided into 2 types: a. the normal alkanes: