Despite the tales you have heard
about pools of "black gold", oil is actually found in rock. The oil
resides in the small spaces, the pores, that exist between the solid
particles that form the rock. The area where oil exists in the rock is
called the reservoir. In order for the oil to be produced there has to
be a fluid available to displace the oil and a force to push the oil
through the rock to the well bore. In primary
production nature supplies the force and fluid to move the oil. Gas
associated with oil or water from an aquifer is the driving force and
fluid that moves the oil through the rock, and all that has to be done
is pump the oil to the surface. When the cost of pumping the oil
exceeds the value of the oil due to the loss of the driving force, then
another method has to be selected to produce the oil.
In secondary
recovery, water is injected into the reservoir under pressure to move
the oil. This process is called waterflooding and is economical because
water is more efficient than gas in displacing the oil. However, after
primary and secondary recovery methods have both reached their economic
limits, typically about two-thirds of the original oil still remains in
the reservoir. This unrecovered oil amounts to 300 billion barrels
nationally; 10 billion in the State of Kansas.
The Tertiary Oil Recovery Project
was created to conduct research to find an economic tertiary
(third) method to obtain additional oil from the reservoir. Tertiary
oil production is also known as IOR
or EOR.
