Geochemical analyses

Geologists work like detectives to determine the properties of rocks, characterise the conditions under which they were formed, and unearth any oil or gas reservoirs. One of the tools they use in their work is surface geochemistry. The theory behind this is that the pressure that exists below any oil or gas reservoirs forces oil and gas molecules to diffuse to the surface. The practical challenge is to find such anomalies.

Bacteria indicate oil or gas reservoirs

To this end, our geologists carry out micro-bacterial examinations of soil samples they have taken. If specific bacteria are found, it is reasonable to assume that underground oil or gas reservoirs do exist. Another technique these detectives use to unearth oil and gas anomalies is to bury special membranes that repel water but can be permeated by hydrocarbons – another means of identifying oil and gas anomalies.

The maturity of the rock provides the first indication of whether oil and gas have been formed.

Along with the surface geochemistry, pure geochemistry is also employed

Besides surface geochemistry, geologists also use purely geochemical tools in their detective work. In an area under investigation they will take samples from the source rock at intervals of between 50 and 1,000 metres. The samples are then sealed and sent for further analysis in our laboratory, where conclusions can be drawn about the maturity of the rock. Only if the maturity level is high can oil or gas be formed. Our specialists can also use such samples to forecast what quantities of hydrocarbons exist and whether the reservoirs are of oil or gas. The ideal temperature for the formation of oil is 50°-120°C. – temperatures that exist at depths of 2,000-4,000 metres. If the source rock is located at such depths, the reservoirs will be of oil. Gas, in contrast, is only generated at temperatures of over 120° C. so here the source rock will be deeper down.