Channel Complex Interpretation: Insights from Sand and Connectivity Prediction in West African Deep-Water Channel Complex Reservoirs Based from Wells, High-Resolution-3d Seismic, 4d Seismic and Production Performance
Gerrick Jensen, Matt Grove, and E-Chien Foo
ExxonMobil, Houston, TX
Channel Complexes are our fundamental production scale mapping unit for West African confined channel complex systems. Placing sands in the context of complex scale interpretation aids in sand and connectivity prediction. Aggregating complex level sand predictions to the reservoir level, typically Complex Systems, delivers more robust net sand predictions and consequently STOOIP assessments. Connectivity requires sand on sand juxtaposition therefore, more detailed sand prediction; sand amount and position is required. Sand and continuity understanding matures as out datasets grow. For wells drilled pre-production, static pressure measurements investigate geologic time scale continuity. For wells drilled early post production, static pressures measurements investigate pressure continuity. Our down-hole production surveillance data and 4D seismic data investigate reservoir sweep patterns. In some of our key reservoirs, connectivity challenges appear to be more dependent on stratigraphy than faults. Complex to complex juxtaposition provides a framework, but internal complex architecture is required for the best predictions. Axial sand on sand juxtaposition provides the best connections with marginal juxtapositions providing the most baffled connections. Internal complex interpretation is at the scale of individual channel fills and lobes which is frequently just at or below seismic resolution. In some cases the rock properties and sand/shale distribution are favorable and we have spectacular imaging of some of these units. Other times the interpretation is much more speculative or stochastic. This uncertainty is even greater in areas of poorer seismic data imaging where we have less confidence on Channel Complex architecture.
AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery