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The Norwegian Oil Strike is not a big impact upon World Oil supplies by itself...


Strike Cuts Norway Oil, Gas Output by 40,000 boe/d     
Friday, June 30, 2006

A strike by the Norwegian oil service union has so far cut oil and gas output by around 40,000 barrels of oil equivalent, the Oil Industry Association, or OLF, said Friday.

The Norwegian Oil and Petrochemical Workers Union, or NOPEF, began the conflict June 21, with 87 members striking following failed wage negotiations.

Industry insiders expect the strike to last several weeks, if not months.
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Was wondering if someone can clarify/confirm how oil quality is defined... I read announcements all the time so I think I've got it right in the following; The higher the API the better the quality? What ranges are considered good refinery quality? For example HDR's latest announcements have 2 zones of 33.8 API and one of 18.5 API. 33.8 from my understanding is on not too bad but not great and 18.5 is not really good. As such am I correct in assuming that the 18.5 will have a very heavy discount to market rate as it will require a lot more refining (or is it worse in that its simply not suitable as fuel oil and only has limited industrial use?)



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In reply to: swandc on Thursday 06/07/06 09:51am



You pretty much nailed it, but lets go to the source






Basically, I wouldnt expect them to be producing the heavy crap - it's about the same standard as the stuff the Venezualans have and havent produced.


The 33.8 API stuff looks acceptable, assuming it isnt packed with sulfer.


Ian Whitchurch



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In reply to: swandc on Thursday 06/07/06 10:51am

API gravity is an inverse density scale. From Wikipedia:


"API Gravity is a specific gravity scale developed by the American Petroleum Institute (API) for measuring the relative density of various petroleum liquids. API gravity is graduated in degrees on a hydrometer instrument and was designed so that most values would fall between 10 and 70 API gravity degrees.


The U.S. National Bureau of Standards established the BaumÃÆâ€â„¢ÃƒÆ’ƒâ€Â ÃƒÆ’¢Ã¢Ã¢â‚¬Å¡Ã‚¬Ãƒ¢Ã¢â‚¬Å¾Ã‚¢ÃƒÆ’ƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚© scale (see degrees BaumÃÆâ€â„¢ÃƒÆ’ƒâ€Â ÃƒÆ’¢Ã¢Ã¢â‚¬Å¡Ã‚¬Ãƒ¢Ã¢â‚¬Å¾Ã‚¢ÃƒÆ’ƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚©) as the standard for measuring specific gravity of liquids less dense than water in 1916. Investigation by the U.S. National Academy of Sciences found major errors in salinity and temperature controls that had caused serious variations in published values. Hydrometers in the U.S. had been manufactured and distributed widely with a modulus of 141.5 instead of the BaumÃÆâ€â„¢ÃƒÆ’ƒâ€Â ÃƒÆ’¢Ã¢Ã¢â‚¬Å¡Ã‚¬Ãƒ¢Ã¢â‚¬Å¾Ã‚¢ÃƒÆ’ƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚© scale modulus of 140. The scale was so firmly established that by 1921 the remedy implemented by the American Petroleum Institute was to create the API Gravity scale recognizing the scale that was actually being used.


The formula used to obtain the API gravity of petroleum liquids is thus:


API gravity = (141.5/SG at 60 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°F) - 131.5


Conversely, the specific gravity of petroleum liquids can be derived from the API gravity value as


SG at 60 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°F = 141.5/(API gravity + 131.5)


60ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°F (or 15 5/9 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°C) is used as the normal value for measurements and further tables give adjustments for temperature.


(See ASTM D1298)


Thus, a heavy oil with a specific gravity of 1.0 (i.e., with the same density as pure water at 60ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°F) would have an API gravity of:


(141.5/1.0) - 131.5 = 10.0 degrees API.


Generally speaking higher API gravity degree oil values have a greater commercial value and lower degree values have lower commercial value. This general rule only holds up to 45 degrees API gravity as beyond this value the molecular chains become shorter and less valuable to a refinery.


Crude oil is classified as light, medium or heavy, according to its measured API gravity.


Light crude oil is defined as having an API gravity higher than 31.1 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°API


Medium oil is defined as having an API gravity between 22.3 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°API and 31.1 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°API


Heavy oil is defined as having an API gravity below 22.3 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°API.


Oil which will not flow at normal temperatures or without dilution is named bitumen and the API gravity is generally less than 10 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°API. Bitumen derived from the oil sands deposits in the Alberta, Canada area has an API gravity of around 8 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°API. It is 'upgraded' to an API gravity of 31 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°API to 33 ÃÆâ€â„¢ÃƒÆ’ƒÂ¢Ãƒ¢Ã¢Ã¢â€š¬Ã…¡Ãƒâ€šÃ‚¬ÃƒÆ’…¡ÃƒÆ’â€Å¡Ãƒƒâہ¡ÃƒÆ’‚°API and the upgraded oil is known as synthetic oil."



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In reply to: swandc on Thursday 06/07/06 12:48pm

Depends how waxy. Specific gravity is just one physical measure of crude quality. Another key measure is viscosity and waxes (heavy paraffins) can have a mjor impact on viscosity without a major impact on gravity.


Waxes can precipitate and the crude exhibit non Newtonian (thixotropic mainly) properties, i.e. can give rise to some very serious production problems in the extreme, even rendering an oil discovery uncommercial, like Wichian Buri in Thailand .....aarrrggg ....why did I mention that?

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In reply to: swandc on Thursday 06/07/06 11:18am

Waxy oil contains large amounts of waxy organic molecules which require more complex processing and make the oil less valuable to the refinery. It can also cause problems in production equipment. Ian has been around longer than myself I suspect and may know more about if it has ever stopped a development, I would be surprised to hear if it had, maybe back in the $8 days?


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In reply to: monkey man on Thursday 06/07/06 12:22pm

Yeah,very waxy oil has stopped developments. At least when oil was $40 a barrel.


CVN's Wichian Buri is possibly the poster child for waxy oil, but Maari in NZ has got high wax content as well.


Generally speaking, a rule of thumb is that heavy, waxy, sulferous and a long way from anywhere will each lose you a third of the value of oil.


Ian Whitchurch

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