Determining the spatial controls on lacustrine ‘microbial’ carbonate facies

Project Description

The challenge faced by BP is to predict the porosity and permeability of lacustrine carbonate reservoirs of Angola and Brazil. Key questions include 1) Is the spatial distribution of the porous and permeable framework facies controlled by the origin (meteoric "karst-like" versus "volcanic rift-like") of spring water, or do deposits reflect lake-margin processes remote from springs and stream influxes; 2) are the most porous and permeable facies restricted to shallow, oxic areas within the photic zone (photosynthetic) or to deeper settings (chemosynthetic) or are they produced without any biological involvement?; 3) how does porosity / permeability change during early diagenesis, and is this different between the depositional settings outlined above? Ultimately, the success of any approach, be it based on sequence stratigraphy or geostatistical inference of spatial trends from borehole and seismic exploration, depends on the quality of the depositional model underpinning it.