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Estimation of pore‐pressure change in a compacting reservoir from time‐lapse seismic data
Author(s) -
Corzo Margarita,
MacBeth Colin,
Barkved Olav
Publication year - 2013
Publication title -
geophysical prospecting
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.735
H-Index - 79
eISSN - 1365-2478
pISSN - 0016-8025
DOI - 10.1111/1365-2478.12037
Subject(s) - geology , seismic to simulation , igneous petrology , compaction , geobiology , saturation (graph theory) , regional geology , reservoir modeling , engineering geology , petrophysics , characterisation of pore space in soil , porosity , economic geology , environmental geology , seismic inversion , pore water pressure , soil science , amplitude , petrology , hydrogeology , seismology , geotechnical engineering , volcanism , metamorphic petrology , geometry , combinatorics , azimuth , mathematics , tectonics , physics , quantum mechanics
An approach is developed to estimate pore‐pressure changes in a compacting chalk reservoir directly from time‐lapse seismic attributes. It is applied to data from the south‐east flank of the Valhall field. The time‐lapse seismic signal of the reservoir in this area is complex, despite the fact that saturation changes do not have an influence. This complexity reflects a combination of pressure depletion, compaction and stress re‐distribution throughout the reservoir and into the surrounding rocks. A simple relation is found to link the time‐lapse amplitude and time‐shift attributes to variations in the key controlling parameter of initial porosity. This relation is sufficient for an accurate estimation of pore‐pressure change in the inter‐well space. Although the time‐lapse seismic estimates mostly agree with reservoir simulation, unexplained mismatches are apparent at a small number of locations with lower porosities (less than 38%). The areas of difference between the observations and predictions suggest possibilities for simulation model updating or a better understanding of the physics of the reservoir.