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：After the casing string is run, the next task is cementing the casing in place. An oil well cementing service company is usually called in for this job although, as when casing is run,the rig crew is available to lend assistance.

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 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 total quantity of petroleum now thought to exist on Earth is about 14 trillion gallons. In weight that is only one-ninth as much as the total existing quantity of coal and ,at the present moment, petroleum is being used up much more quickly. At the present rate of used, the worlds supply of petroleum may last for only thirty years or so.

翻譯：This chapter deals with the fundamental properties of reservoir rocks. The properties discussed are (1) porosity - a measure of the void space in a rock; (2) Permeability - a measure of the fluid transmissivity of a rock; and (3) fluid saturation - a measure of the gross void space occupied by a fluid. These properties constitute a set of fundamental parameters by which the rock may be described quantitatively.

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：The primary limitations for gas lift operations are the lack of formation gas of an outside source of gas, wide well spacing, and available space for compressors on off-shore plat forms. Generally, gas lift is not applicable to single-well installations and widely spaced wells that are not suited for a centrally located power system.

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：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.