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：Practically every rig uses internal-combustion engines as its prime power source, or its prime mover.

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：A third means of assessing the maturity of rocks is by the pyrolysis of a small amount of the source rock. The temperature is raised rapidly and the material vaporized or formed by thermal breakdown of the kerogen is passed through a detector which records, on a temperature base, peaks representing these two bursts of volatile material. To a first approximation the peak at the lower temperature represents oil already generated; the peak at the higher temperature indicates oil capable of being generated at adequate maturity.

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：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 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：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：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：The transportation of oil has also led to the spectacular development of gait ships ,the largest ships that ever sailed the oceans of the world .in the last few years ,since it has been necessary to ship oil from middle East-one of the largest oil producing regions-around the cap of Good Hope in south Africa these tanks has grown to almost unblievable proportions.