Shale Gas Geochemistry Mythbusting

Dembicki, Harry

Our understanding of "unconventional" play types, such as shale gas, is still evolving. We have been developing our scientific concepts and methods for conventional petroleum exploration and development for over 100 years, but the investigation of the concepts and methods for unconventional petroleum has been going on for only about 15 years. As a result, there has been a rush by some to embrace ideas before they have been validated or, in some cases, even tested. This has led to a large portion of shale gas dogma being based on personal opinions that often reference others who share these beliefs, but are not necessarily supported by data. We need to guard against allowing such myths from sneaking into our understanding of unconventional plays. So let's do some Mythbusting to see if some of our beliefs are: Confirmed (valid and therefore not myths), Plausible (possible, but there's not enough evidence to validate), or Busted (false and they truly are myths). We will begin the process with these three concepts: The TOC Misunderstanding: "TOC, organic matter, kerogen -it's all the same stuff."; The Kerogen Type Conundrum: "What difference does it make if my shale had oil-prone or gas-prone kerogen in it, I'm looking for shale gas."; and The Maturity Debacle: "I only need to measure the vitrinite reflectance in the shale, that's the only maturity measurement that counts." The roots of these beliefs are examined as well as their validity.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013