Seals can be breached in several ways – membrane failure and hydraulic or mechanically. It is expensive to drill a trap that has previously leaked.
Ikon Science uses geomechanical and petrophysical data and seismic inversion to understand the lithology variation in top seals which inform on the likelihood of membrane failure. Gas chimney location can aid this understanding.
We also provide risking schemes for hydraulic failure, where pore pressure is sufficiently high (as top seal permeability is very low) such that is exceeds minimum stress. In combination, the above approaches can be used to mitigate exploration risk by reducing the drilling dry holes;
- Improving understanding of the regional pressure regime and its part in controlling aspects of the petroleum system, particularly trap integrity
- Utilising the Mohr diagram approach used to assess cap rock integrity using geomechanical consideration of all modes of failure within the host rock and with respect to reactivation of pre-existing structural elements such as fractures (and the calculation of their likely permeability).
- Building a database to provide a future source of quality, reliable pressure data to help solve other exploration and drilling challenges
Seal breach analysis also provides information for estimating hydrocarbon column heights, and detecting protected traps.
An integral part of our analysis is to establish the validity of the relationship between overpressure and seal breach in a study area, as it is not universally applicable. Lateral seal can also be assessed via the integration of geomechanics, pressure data, Shale Gouge Ratio, Allen diagrams and a structural interpretation.
Ikon Science has extensive experience evaluating seal breach risk and can conduct studies on a well-by-well basis and/or on a regional basis, either as a single-company consultancy or as a multi-company project