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：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.

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：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：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：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：Gas lift is particularly applicable for lifting wells where high-pressure gas is available.Gas compressors may have been installed for gas injection, or high-pressure gas wells may be nearby. Since the cost of compression far exceeds the cost of down hole gas lift equipment, gas lift always should be considered when an adequate volume of high-pressure gas is available for wells requiring artificial lift. Most wells can be depleted by gas lift,which is particularly true since the implementation of reservoir pressure maintenance programs in most major oil fields.

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：Classification of reservoirs can be made on the basis of the texture, composition, and origin of the containing rock or the geometric configuration of the reservoir trap. Classification of reservoirs in the basis of rock texture and composition can assist in the prediction of reservoir performance. Variations in the mineralogy of reservoir rocks can be as important in reservoir performance as structural configuration or areal extent of the reservoir rock.

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.