AAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
Organic Matter, Kerogen, Bitumen, Petroleum, Generation, Sorption, Absorption, Adsorption, Expulsion and Migration: What’s the Difference and Why Does It Matter in Unconventional Resource Assessment?
(1) Hess, Houston, TX.
All source rocks are reservoirs for petroleum. In some cases these reservoirs are commercially producible - the so-called unconventional “Shale Gas”, “Shale Oil” or “Tight Oil” resource. In such rocks, petroleum is reservoired to varying degrees in the inorganic and the organic matrix framework; in the organic matter petroleum can exist in both an absorbed and adsorbed state. Therefore, traditional concepts of storage - and deliverability - derived from organic-lean reservoir rocks need to be modified.
Compared to conventional reservoir description, the industry’s approach to source rock description is extremely unsophisticated. Furthermore, loose and interchangeable usage of many terms confuses the description, which further acts to prevent a clear understanding of process.
This paper offers a physical description of the processes involved in storage and deliverability in such rocks and proposes a precise nomenclature to describe it. Following from this clarification, it becomes obvious that some current laboratory protocols are flawed; casting doubt on the validity of resource estimates derived from them.