Time-lapse (4D) seismic is often used for monitoring hydrocarbon fields during depletion and injection processes (hydrocarbon production, enhanced oil recovery, or CO₂ storage operations). When the reservoir pore pressure changes during production or injection, the formation stresses in reservoir an...

Depletion or injection into a reservoir implies stress and strain changes in the reservoir and its surroundings. This may lead to measurable time-shifts for seismic waves propagating in the subsurface. We have measured multi-directional ultrasonic P-wave velocity changes for three different field ...

Fluid production from or injection into a subsurface reservoir leads to stress pressure changes inside and outside the reservoir. The overburden often consists of low permeability shale, and the undrained pore pressure response may be estimated from Skempton’s empirical equations. The key parameters...

Since shales are the far most abundant overburden formation, understanding the geomechanical and rock physics behavior of shales is essential. We discuss a particular deep overburden shale in light of a thorough static and dynamic multi-directional data acquisition, as a basis for complete static ...

Shale rock physics may be used for improved monitoring of subsurface changes in and around a depleting reservoir. It is shown how rock physics plays a key role in interpreting time-lapse (4D) seismic into geomechanical attributes as changed stresses, strains and pore pressure. This knowledge is...

Since shales are the far most abundant overburden formation, understanding the geomechanical and rock physics behavior of shales is essential. We discuss a particular deep overburden shale in light of a thorough static and dynamic multi-directional data acquisition, as a basis for complete static an...