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：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：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.

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：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：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：It has been suggested that an effective oil source rock generates 10-40 bbl or oil per acre ft (0.0013-0.0052 cc/cc) for each one per cent of organic carbon. This is approximately 500-2000 ppm by weight.

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：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.