For those interested I'm just posting some brief details on API...

For those interested I'm just posting some brief details on API gravity and sulphur content. Remember our Panakawa seep is 35 API, not sure on Sulphur content or when that is determined. The chart below puts it into perspective -

Crude oil is classified into various grades according to density (heavy vs light) and sulphur content (sour vs sweet). The lighter and sweeter the crude, the higher the price it can be sold, because refiners can produce higher yield of high quality refined products from it.

Density is measured by API gravity, a measure developed to compare the density of petroleum with water (API > 10 means the liquid floats on water) but is now widely used to compare among crude oils. API degree is inversely related to the density of crude oil. In general, crudes of API between 40-45 degrees can be sold at greatest commercial values.

Sulphur content determines the quality of a crude oil. Sulphur is a corrosive material which decreases the purity of a crude oil. Therefore, a crude oil with high sulphur content (sour crude) should sell cheaper than one with low sulphur content (sweet crude).

WTI Crude

West Texas Intermediate (WTI) crude oil is of very high quality. It has API gravity of 39.6 and sulphur content of 0.24% only. Its low density and low sulphur content gave it the name 'light, sweet crude' and enabled refiners to produce high yield of gasoline. Most WTI crude oil gets refined in the Midwest region of the country, with some more refined within the Gulf Coast region.

This type of crude oil is used as a benchmark in oil pricing and the underlying commodity of NYMEX's oil futures contracts. Due to its 'lightness' and 'sweetness', WTI crude is normally selling at about $1-$2/ barrel premium to Brent.

Brent

Brent is actually a blend of crude oil from 15 different oil fields the North Sea. It has API gravity of 38.3 degrees and sulphur content of around 0.37%. From these 2 parameters, we can see that Brent crude oil is heavier and less sweet than WTI crude. Therefore, its price is generally lower. Brent is suitable for refinery of gasoline and middle distillates.

Brent was first traded on International Petroleum Exchange in London and then on IntercontinentalExchange (ICE) since 2005. Typically, price of Brent crude oil is around $1 lower than WTI. However, in 2007, due to the depletion of the North Sea Oil field, Brent Crude futures had traded at a premium to WTI of approximately $1 to $3 per barrel.