The Carboniferous shales of the UK onshore area have become a major interest recently due to their potential to hold exploitable natural gas.
A key consideration in the exploitability of these natural gas assets is the current pore pressure regime within the shale. Knowledge of pore pressure is important in the process of hydraulically fracturing the shale to enhance permeability, and then to drive and enhance production of gas in place. However, traditional methods of pore pressure prediction within shales do not tend to work where effects of major uplift, diagenesis and hydrocarbon generation have eliminated usual porosity/effective stress relationships conventionally used to predict overpressure.
Our analysis addressed two challenges:
The techniques deployed included:
