翻譯：A portion of the sample is used to determine the gravity of the oil expressed in AIP unit the lighter the oil, the higher the API gravity .In most cases the price paid for the coude is determined in prat by the API gravity, hence ,the importance of careful gravity determination in each instance.

翻譯：Nearly three-fifths of all known petroleum reserves on Earth is to be found in the territory of the various Arabic-speaking countries. Kuwait , for instance , which is a small nation at the head of the Persian Gulf , with an area only three-fourths that of Massachusetts and a population of about half a million , posseses about one-fifth of all the known petroleum reserves in the world.

翻譯：Other additives are often added to the fracturing fluids for special proposes. Corrosion inhibitors may be used if the fracturing fluids might cause corrosion in the tubular goods in the well.Other additives are used to make the part of the fracturing fluid which is moving against the pipe walls behave almost like lubricating oil while the remaining fracturing fluid take an almost solid form to carry the maximum amount of proppant.

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：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 major oil company usually initiates the sequence of events that leads to the drilling of oil and gas wells in foreign fields, but independent oil operators pay for most of the wells in the United States. In fact, about 80% of all wells drilled in the U.S. today are financed by independents.

翻譯：Land maps are essential in establishing control wells and provide fundamental orientation. As Fig.2 illustrates, land maps which are readily available within most companies as well as readily available commercially, provide offset operators, total depth, formation tops and development dates. The land map is essential in establishing orientation and control.

翻譯：In addition to being useful as an exploration tool, subsurface maps are a necessary part of any reservoir engineering study; and petroleum engineers, as well as geologists, must be completely familiar with their construction and interpretation.

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：An acidizing treatment for a sandstone formation normally will consist of sequentially injecting three fluids---a preflush, the hydrofluoric acid hydrochloric acid mixture, and an after flush. These fluids serve definite purposes.