In this post I will try to give an idea of how scientist, engineers and investors work together to find oil and gas (also known as hydrocarbon in the discipline of Chemistry ).
It is said that the first major production and commercial use of petroleum started with the well drilling in a place called Oil Creek in Pennsylvania, US. Prior to the success of this well, the site has been known to be flowing oil for some time. However, it was not immediately explored and commercialized because of 1) a practical use of petroleum was not well known at that point of time, 2) not many people would venture or invest into what was an unknown commodity market at that time, 3) lack of technology or knowledge to drill oil wells. In fact, the drive pipe or what is commonly known as conductor casing nowadays may have been first tried out in this particular oil well. The success of of this oil sparked off the petroleum industry to this day, starting with the application of well drilling design learned from this well nicknamed Drake’s Folly (a mock on the driller’s predicted failure).
The most accessible sites with oil visibly flowing would be the first to be discovered and claimed by explorationists (this is also applicable to exploration of other minerals). Over time, the easiest oil sites became less in numbers and exploration started to require more effort. More effort equals to a bigger initial investment, hence investors started to calculate their chance of success versus the amount of wealth required for a particular well. Basically, the oil businessman had to manage their exploration risks to ensure profit and sustainability.
Today, exploration geologists spend considerable time to investigate and calculate a number of parameters before deciding whether a well should be drilled or otherwise. The parameters may be quantitative (such as potential volume, temperature, rock porosity, rock permeability, pore pressure), or qualitative (presence of components that make up a working petroleum system that produces the hydrocarbon, type of play). Qualitative parameters cannot be directly measured, but may be inferred from observations, previous experience and studies done from many years of exploration. For example, modern geologists do look over satellite imagery to find oil slicks which indicate a general presence of oil in an area. They would also request for a seismic image acquisition, which is a technique to image the earth subsurface structure using sound wave, to be able to understand the oil reservoir and petroleum system better.