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：There are two approaches to the problem of determining the fluid saturation within a reservoir rock. The direct approach is to measure, in the laboratory, the saturation of selected rock samples recovered from the parent formation. The indirect approach is to determine the fluid saturation by measuring some related physical property of the rock.

翻譯：The HF-HCI mixture (usually 3-percent HF and 12-percent HCI) then is injected. The HF reacts with calys, sand, drilling mud, or cement filtrate to improve permeability near the well-bore.The HCI will not react and is present to keep the PH low, preventing precipitation of HF reaction products. Sent to keep the PH low, preventing precipitation of HF reaction products.

翻譯：A reservoir trap is a combination of physical conditions that will cause hydrocarbon liquids and/or gases and water to accumulate in porous and permeable rock and prevent them from escaping either laterally or vertically because of differences in specific gravity, pressure, fluid/gas characteristics, and/or lithology. It has the capability of collection, holding, and yielding hydrocarbon fluids and water.

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：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 OPEC oil cartel is about to turn 40, and the mood in the run-up to the grand heads-of-state party in Venezuela in less than three weeks time is jubilant. Not quite two years ago,oil was $10 a barrel and the cartel was on the brink of collapse. Now the oil price is well above $30 a barrel, and it shows little sign of coming down.

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：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.