Effects of Low-
and High-Resolution
Fault Interpretations on Simulated Pressure Distributions:
An Example from the
Lothe, Ane E.1, Øyvind Sylta1, Susanne Sperrevik2, Olav Lauvrak2 (1) SINTEF Petroleum Research, Trondheim, Norway (2) Norsk Hydro, Bergen, Norway
The lateral
pressure distributions in many sedimentary basins
are mainly dependent on the sealing properties of the faults that define
pressure compartments. Faults are typically interpreted from 2D or 3D seismic
datasets. The input fault interpretation will therefore have a fundamental influence
on the final pressure distribution results.
The effects of low- and high-resolution
fault interpretations on
simulated pressure distribution are tested on a dataset from the Tune Field,
northern
The simulations show high overpressures generated in the deeper
western parts of the Viking Graben and hydrostatic
pressures in the shallow eastern area. The low-resolution
fault map gives a
sharp change in the simulated overpressures between the two regions, while
using a high-
resolution
fault map results in a more gradual transition zone. A
pressure difference of 14 MPa is measured between
wells in the Tune field and a well east of Tune. To be able to match the
observed pressure difference, the small N-S striking faults situated in between
the wells require higher sealing capacities than expected from juxtaposition
analysis alone. A reason could be that the reservoir is in contact with deeper
burial parts of the sedimentary column east of Tune, than what is used as input
in the simulator.