Category: General

A technique used for cleaning core samples in which the water fraction is removed by distillation and the oil fraction is extracted by using solvents

Graph which plots the percentage (by volume) of a given grade of crude which boils off as a function of temperature. Since the boiling points of the various crude cuts are constant, the distillation curve shows the percentage of each compound in a given grade or batch of crude

High-compression, internal-combustion engine used extensively for powering drilling rigs. In a diesel engine, air is drawn into the cylinders and compressed to very high pressures; ignition occurs as fuel is injected into the compressed and heated air. Combustion takes place within the cylinder above the piston, and expansion of the combustion products imparts power to the piston. Diesel automatically ignites and burns when it is compressed to a very high pressure. The released energy is contained by the engine and powers the vehicle. The key difference between diesel and petrol engines is auto-ignition. A spark plug ignites the fuel in a petrol engine whereas a diesel engine auto-ignites. Diesel has a Cetane Index and Number rather than the Research Octane Number (RON) that petrol has.

Planning, implementation, and evaluation of utility-sponsored programs to influence the amount or timing of customers’ energy use.

Natural gas can also exist in Devonian shale deposits. Devonian shales are formed from the mud of shallow seas that existed about 350 million years ago (during the Devonian period of the Paleozoic era). These shales can contain natural gas, usually when two thick, black shale deposits ‘sandwich’ a thinner area of shale. Because of some of the properties of these shales, the extraction of natural gas from shale formations is more difficult (and thus expensive) than extraction of conventional natural gas. Most of the natural gas containing Devonian shale in the U.S. is located around the Appalachian Basin. Although estimates of the amount of natural gas contained in these shales are high, it is expected that only about 10 percent of the gas is recoverable. However, their potential as a natural gas supply is still very promising, given an adequate technological and economic environment. The EIA estimates that there are 55.42 Tcf of technically recoverable shale gas in the United States, representing just under 5 percent of total recoverable resources

Countries with a low level per capital national income but relatively high primary sectors (agriculture and natural resources)