翻譯：crude petroleum is not an equilibrium mixture, and on a geological time scale its composition is slowly changing. S.R.silverman found that heating at 121C for two weeks caused detectable changes, the low-molecular-weight components formed being isotopically lighter so far as the carbon was concerned, than the original.

翻譯：In the chapter and the next some aspects of rod pumping and of the instruments used to analyze pumping well behavior are discussed. Many different pumping systems are in current use , e.g. , conventional sucker rod pumping, long-stroke pumping , hydraulic ,centrifugal,and sonic pumping ,but no attempt is made to deal here with any other method than convention a sucker rod pumping.

翻譯：A porous medium has a permeability of one darcy when a single phase fluid of one centipoise viscosity that completely fills the voids of the medium, will flow through it under conditions of viscous flow at a rate of one cubic centimeter per second per square centimeter cross sectional area under a pressure or equivalent hydraulic gradient of one atmosphere per centimeter.

翻譯：The application of physics to the study of rocks (geophysics)is very important in petroleum geology. In its broadest application geophysics makes a major contribution to understanding the earths crust and, especially through the application of modern plate tectonic(板塊構(gòu)造)theory, the genesis and petroleum potential of sedimentary basins. More specially, physical concepts are required to understand folds（褶皺）, faults（斷層）, and diapers（底辟）, and hence their roles in petroleum entrapment.

翻譯：For example ,the determination of the pump-setting depth and size of plunger that will lead to the maximum pumping rate in a particular well is a problem of considerable difficulty, which even today has not been fully or saris factorial solved; another interesting problem is that of gas anchors(bottom-hole separators); yet another is the interpretation of the results obtained form devices for determining the depth of the fluid level in the annulus during pumping.

翻譯：The first step in planning a well should be the gathering of all available data on past wells. In this respect it is important to be completely familiar with all sources of information, the availability of the sources, and the information normally associated with each source.

翻譯：A paraffin base crude is an oil whose chief components are paraffins, and which completely distilled, leaves a solid residue of wax. An asphalt base crude is an oil composed primarily of cyclic compounds (mostly naphthenes) which, when distilled, leaves a solid residue of asphalt. Oils which fall in the middle of these categrories are classified as mixed base.

翻譯：In these early days, as lamp oil, was the important product and the main objects of refining was to extract as much of it as possible from the crude. Lubricants and some fuel oil were also sold, but gasoline was burnt off as unwanted and bitumen was also largely useless.

翻譯：The fluids of a petroleum reservoir are generally gas, oil, and water in varying proportions. Each phase can differ widely in composition and properties. Gas and oil, either as separate fluids or in mixtures, change their state or phase as reservoir pressure changes.

翻譯：The need for a greater understanding of the pumping process and for the ability to engineer pump installations to a close degree of tolerance is being accentuated by the trend to pump from greater and greater depths . Problems are relatively minor when the pump is at 10,000 ft.