oa Fault Seal Risk Volumes – Assessing Uncertainty in Prospect and Field Development

Fault seals can be both beneficial and/or detrimental to the generation of traps and the economic extraction of hydrocarbons from reservoirs. From exploration to development, the resolution at which fault behaviour needs to be understood varies, as does the data available to determine that behaviour. In this contribution we present new methods for mapping the potential seal risk of a spatially variable stratigraphic sequence. Both exploration and production scenarios are investigated and probabilities for different seal types from juxtaposition to membrane seals are calculated and mapped. Where more data is available (in production settings) permeability retardation or enhancement risk can be mapped over the reservoir area and through the stratigraphic volume. Risk mapping allows rapid assessment of fault-related reservoir compartmentalisation, which is often critical in more complex structural settings. Risk map interpretations can then be used to generate new faults in the grid that better honour likely layer connections while honouring the information gathered from the dynamic data. Overall the technique allows for a better understanding of the uncertainty due to faulting and hence a greater ability to focus potential new data acquisition, to direct further interpretation and to rapidly generate multiple realistic scenarios to mitigate these risks.