Oil Series Part 3- Locating and Extracting
At this stage you have a complete petroleum system. Over thousands of years the trap accumulates more and more petroleum becoming what is known as “charged”. This is what petroleum geologists want! Other geological processes such as plate tectonics and sea level rise/fall going on throughout this period means that the systems can be found on land or at sea today.
The first thing geologists look for is what’s known as sedimentary basins (sites of large sediment accumulation and burial) where vast reservoir rocks are found. The petroleum systems in these more modern times are located by a whole arsenal of quite complex tools such as geological mapping, satellite imagery, wire logging, core sampling, gravity, magnetic and seismic surveys (see links for more on this). Once data has been collected through these tools it is fed through powerful computers and their software modeling programs, which are able to transform the numerical and 2D data into a 3D model of the area below the surface.
Calculations such STOIIP (see links) can be made to determine the size of each system and whether it is cost effective to continue. Also depending on how remote the area and/or how deep the water is can dramatically affect the future profit. Should the oil company deem it sufficiently profitable they normally bid on government owned blocks to acquire drilling rights to that area. Infrastructure such as pipelines, roads drilling platforms and workers accommodation must be designed and built around the area before full scale drilling can begin.
By this point other companies would be onto the find and be moving into the areas nearby. If the company can set up a pipeline first they can charge others for use and regain some of the initial costs. Once everything has been set up and a workforce established drilling begins, bringing the endeavor into the stage known as production.
Part 4 will focus on declining extraction rates, peak oil and other petroleum-based alternatives.
-Matt J
This is part 3 of a mini series on oil, if you haven’t already please read part 1 and 2 of the story. Part 2 is here and links to part 1:
http://www.facebook.com/photo.php?fbid=426164590777924&set=a.352867368107647.80532.352857924775258&type=1&theater
More on techniques used to locate the oil:
http://science.howstuffworks.com/environmental/energy/oil-drilling2.htm
STOIIP calculation:
http://en.wikipedia.org/wiki/Oil_in_place
Photo courtesy of
http://gazprom-sh.nl/sakhalin-2/