Calculating overburden

Overburden stress, also called lithostatic pressure or vertical stress, is the stress imposed on a layer of soil or rock by the weight of overlying material. The vertical stress, Sv, is the maximum principal stress (S1) in normal faulting regimes, the intermediate principal stress (S2) in strike slip regimes and the least principal stress (S3) in reverse faulting regimes. For horizontally layered material, the magnitude of Sv is equivalent to the integration of rock densities from the surface to the depth of interest, z. Mathematically, the function can be expressed as:

where ρ(z) is the density as a function of depth and g is gravitational acceleration.

While this simplified calculation does not hold in very complex geological settings, for instance at a varying seafloor (canyon), or in mountain areas, it is a good approximation in many cases and is widely used.

The overburden calculation workflow is divided in two steps - calculating overburden density followed by the calculation of overburden stress profiles. Regional data tool can be used for the scenarios when you do not have well log data available. For more information, see: