Integration of borehole image log enhances conventional electrofacies analysis in dual porosity carbonate reservoirs
Authors: Perrin, C., Wani, M.R., Akbar, M. and Jain, S.
Journal: International Petroleum Technology Conference 2007, IPTC 2007
Volume: 3
Pages: 1406-1415
ISBN: 9781615673360
Abstract:Electrofacies based on conventional logs are found as strongly correlated to core lithofacies, thin section microfacies, and petrophysical measurements (φ/k and MICP) as long as the carbonate pore system remains simple. Once dual porosity is present, it is found that neural network using conventional logs can not distinguish 2 rock types having the same range of porosity but different porosity-permeability relation. The dual porosity system is illustrated by strong leaching (i.e. dissolution) overprinting the primary interparticle porosity of a grainstone, and responsible for an increase of one order of magnitude in permeability. The dissolution is observed by patchy feature on core. Similarly, this high level of heterogeneity can be observed downhole by borehole imaging tool. The heterogeneous porosity map from the image tool is then converted into a single curve representing the secondary porosity. This secondary porosity log is added to the conventional logs as input of the neural network model. Then, neural network can discriminate between 2 rock types with same range of porosity but different porosity-permeability relation. Copyright 2007, International Petroleum Technology Conference.
Source: Scopus
Preferred by: Mohammad Wani