4 Initial pressure

Initial pressure in the reservoir, seal, and base

Hydrostatic pressure gradient (p_grad)

Gradient used to set the initial hydrostatic pressure. See Figure 1
p(z) = p_grad * z + p_offset
Default value 10.5 MPa/km

Figure 1 Hydrostatic pressure gradient specified by p_grad and p_offset

Offset of hydrostatic pressure gradient (p_offset)

Pressure offsetting the hydrostatic gradient. See Figure 1
Pressure offset can be positive or negative.
Default value 0 MPa.

Pressure gradient within the reservoir (p_grad_res)

In some cases a hydrocarbon is present in the reservoir formation, e.g. oil or gas. A different pressure gradient can be prescribed within the reservoir interval, p_grad_res. At the base of the reservoir this will connect to the water pressure gradient. Within the reservoir, the water pressure is also computed, assuming a mobile water phase. Optionally, the water pressure can be assumed in the fault, rather than the gas pressure (REF). <br > At the moment, it is assumed the reservoir fluid occupies the entire reservoir height. In a future release, it will be possible to specify a reservoir fluid-water contact depth within the reservoir. <br >

<br > Figure 3 Pressure gradient for a different reservoir fluid density. Note that the water pressure gradient will also be present in the reservoir (dotted line)