The article discusses that most of the shale formation contain kerogen and some bitumen (oil). Kerogen is simply a solid material that is insoluble organic matter which is a diagenetic alteration product of organic material laid down with sediments. Bitumen is the fraction of the organic matter in sedimentary rocks which is soluble in organic solvents. One of the diagrams below shows the three types of kerogen and different types of petroleum. The other one shows you relativily the amount of bitumen in a shale rock.
Therefore, to convert the the kerogen to bitumen it must be heated up or thermally matured. The petroleum industry is starting to find certain shale plays (such as the Eagle Ford) which contain a higher amount of bitumen than kerogen due to being at a deeper depth and mature level.
But, you also have to think about being over mature? If the formation is too deep, it could possibly pass the oil window and fall into a gas generation window. The Van Krevelen Diagram below shows the maturation paths of the three different types of kerogen. The diagram shows the path ways through Diagenesis-Catagenesis-Metagenesis of the three types of kerogen. (The diagrams were provided by Dr. Curtis, Colorado School of Mines)
With an understanding of oil generation, companies can target more oil prone shale formations while the price of oil is high.
Interesting. So shale is definitely on the table, and more companies are going for it. I wonder if this is going to be region dependent--a friend in o and g was telling me that they'll be able to go for shale in Nebraska where water rights are easy to obtain but that Colorado will be much harder to go after because water is hard to get (and shale is water intensive). Thoughts?
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