Report on Mowry Shale Thermal Maturity Mapping in the Powder River Basin, Wyoming

Thermal maturity, the degree to which the total organic carbon in a formation has been transformed from kerogen to producible hydrocarbons due to heat and pressure, is an important measure for not just the quality of a source rock, but also helps for delineating areas more favorable for unconventional drilling. EORI’s report of thermal maturity of the Mowry Shale in the Powder River Basin provides a detailed map based on a large public T_max data set.

Key observations include:

• Nearly all of the Mowry deeper than 8000’ currently generates hydrocarbons
• The basin axis has shifted slightly westward since the Mowry began generating hydrocarbons
• The Mowry 8000’ line plays an important role in demarcating the over-pressured Mowry and related clay diagenesis.
• The maximum maturity levels in the Mowry are in the “wet gas” stage