Table 1.

Details of formation conditions simulated in high-pressure experiments. Experiments were designed to mimic the pressure (P) of hydraulic fracturing, and the pressure and temperature (T) conditions of hydraulically fractured shales, as well as controls to test the effects of each in isolation.

Setup	Conditions simulated	Pressure/temp.
1	Hydraulic fracturing pressure+fractured shale T and P	70 MPa (15 min) and 35 MPa/50 °C
2	Fractured shale T and P	35 MPa/50 °C
3	Fractured shale P only	35 MPa/22 °C
4	Fractured shale T only	0.1 MPa/50 °C
5	Ambient T and P control	0.1 MPa/22 °C