Determine the rock mechanic properties for paleo-times

Example from William Fork in Piceance Basin from Cumella and Scheevel, 2008

Evidences to determine the rock mechanic properties in paleo-times, whether it behaves elastically or not, can include:

• Present rock strain-recovery test see if it is elastic recovery.
• Determine the time span for the study, whether it is short or long time. For example, natural fractures generated during gas generation by coal.
• Low or negligible thermal effects

If the time span of the study in the paleo-times is relative short and present strain-recovery is elastic from core test, it can be assumed that the rock behaved elastically during that time span. Otherwise, non-elastic effects can play a role, such as pressure-solution, which can dissipate the stress during that process and result in non-elastic behavior.