Guest Editorial: The State of the Units or the Units of the States

Autor: Klaus Potsch
Rok vydání: 2007
Předmět:
Zdroj: Journal of Petroleum Technology. 59:16-18
ISSN: 1944-978X
0149-2136
DOI: 10.2118/0707-0016-jpt
Popis: Opening the business section of my newspaper (a European one), my eyes spot an article on the oil price. It is over USD 60/bbl. In Europe, do we not measure amounts differently? Conveniently, the newspaper printed the conversion factor right along with the figure. So it is "just" a matter of a rough calculation to arrive at a number that I am used to. That is just an everyday example. Sitting in an oil conference, reading a technical article on petroleum engineering, or digging through a technical operations manual you may find ample opportunity for all kinds of unit conversions. Is that necessary? Can we not agree in our industry once and for all to use only one system of units? I still remember my years at the university when I had to fight with different systems of units, such as "cgs" or "mks" with "atm" or "at" as units for pressure. It took some time before the SI system (Le Système International d'Unités) began gaining recognition. Generally, this system is also called the metric system. The SI system was founded in 1960. Its roots date back to the French Revolution, when scientists like Lavoisier created a rational system of units. The numerical base was the number 10. Orders of magnitude are handled by prefixes, something that is missing in other systems. Seven basic units were singled out from which all other units of physical quantities can be derived. The units are not capitalized, except for some that are named after a person—K for Kelvin, Pa for Pascal. They are used only in the singular to avoid confusion with the unit "s" for seconds. In 1982, SPE issued a superb explanation of the SI system. Out of necessity, this SPE article is still my most frequently used article. Another detailed overview can be found at http://en.wikipedia.org/wiki/SI. The oil industry sticks to its favorite oilfield (OF) units. Some call it "practical units." But are they really practical? That depends probably on your point of view. The technology developed primarily in the US became so dominant in the industry that it also dictated how and in which system measurements have to be taken. The old countries, such as Azerbaijan, Poland, and Romania, where oil was produced even before the US, could not take over the technological lead. Now, people seem to use units as they please, even if it means mixing SI and OF units. Table 1 offers a glimpse of some units and terms found in a variety of journals and publications.
Databáze: OpenAIRE
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