Petroleum: generic name for certain combustible hydrocarbon compounds found in the earth
A commercial oil deposit requires the presence of a porous, permeable rock formation containing oil of a marketable A.P.I. gravity and of producible viscosity.
Three fundamental properties of petroleum (for oil and gas production):
1. state (gaseous, liquid or solid)
2. specific gravity or density = the ratio between the weights of equal volumes of water and another substance measured at a standard temperature
The specific gravity of oil is expressed as A.P.I degrees, oil with the least specific gravity has the highest A.P.I. gravity (inverse relationship)
3. Viscosity = inverse measure of the ability of a liquid to flow (the less viscous the fluid the greater its mobility)
Nearly all commercial oil and gas production is from some form of sedimentary rock due to the porosity and permeability of such rocks.
There is no way of finding oil and gas short of drilling wells. Geologists look for reservoir traps = underground formations favorable to the accumulation of oil and gas.
Oil and gas exploration is the search for reservoir traps. There are two types of reservoir traps: Structural and stratigraphic
Geophysical survey: an exploration method whereby devices, such as a seismograph is used to develop a contour map of an area in order to determine which land to lease and where to locate an exploratory well
There are two main methods of oil well drilling:
Cable tool drilling: an older method that operates on a hammer principle to pulverize the rock
Rotary drilling rig: the more widely used method, operates on the principle of boring a hole by the continuous turning of a bit
Three fluids may be found singly or in combination in a