Crude oils are extracted by fractioning crude oil in a fractioning tower. They are fractioned by heating to boiling point and rising up the tower where they condensate and come out in another form.
Waxes are separated from crude oils in a process called solvent dewaxing. A limited number of crude oils are suitable for processing in the lube oil refineries that run this process. These crude oils must have a high wax content in the original crude, resulting in a high pour point, making these types of crude oils difficult to extract and process in other refinery units. See the excellent link below entitled: "The Evolution of Base Oil Technology"
Crude oils
This is the possibility to extract crude oil for long time.
yes
viscosity. very viscose oils are considered "heavy", oils of low viscosity are considered "light". Oils with little sulfur are considered "sweet", oils with lots of sulfur are considered "sour". The most valuable crude oil is "light sweet".
To get lots of different oils from the main crude oil you must put it into a fractional distilaltion chamber.
Biofuels
What is the protective effect of the crude leaf extract of combretum racemosum on cyclosporin-A induced liver injury in rats?
There is no definite answer to your question. Every reservoir has its "Crude type" that is unique in composition. And that is the answer for "crude oils". Crude types has different viscosity - some flow easy, other can be used as roof covering once cooled down after it surface. The next is the sulfur content, and alphaltines. Crude oil is recovered with water and sand that is removed.
In the ground or under the ocean, by using oil pumps.
Margarine is not made of crude oil but it can be produced using vegetable oil or a combination of oils. Margarine is a spreadable butter substitute that is made through a process of hydrogenation to solidify the oils. Crude oil, on the other hand, is a fossil fuel used for energy production.
Brent crude oil is a "benchmark crude" oil agreed upon by various suppliers and traders of crude oil. Other crude oils are often priced based on the agreed upon benchmark crude which has a particular set of properties.