Applications of the Normalized Pore Throat Radius Methodology for Improved Hydraulic Flow Unit Characterization Using the Niger Delta Field as Case Study

摘要

The relation between porosity, permeability and pore architecture in complex reservoir units, typical of the thin bedded canyon turbidite system within the clastic reservoir rocks is complicated and indistinct. The sedimentary architecture usually overprinted by late diagenesis results in the intrinsic complexities which pose major problems in modelling these systems. Detailed assessment of flow units is essential for a better understanding of the reservoir flow behavior and relation between storage and flow capacity. These units are zones composed of similar rock types that are in hydrodynamic communication, which possess stratigraphic continuity and have a strong relationship to pore geometries and rock type, but may not correspond exactly with the depositional facies. This paper presents the application of the normalized pore throat radius ( R_(tot)) methodology for improved hydraulic flow units characterization and production optimization in complex reservoir systems. A modification of the reservoir quality indicator (RQI), Stratigraphic Modified Lorenz Plot (SMLP) and Leverett J-Function methodologies for hydraulic flow unit characterization using the R_(tot) concept demonstrates improved calculation of hydraulic flow units using dataset from the Niger Delta deep water turbiditic system. Results of the analysis for the various genetic reservoir units demonstrate an improvement of 60% over existing methodologies with additional capability for delineating between zones with excellent high communicationand baffles. In addition, Correlation between the irreducible water saturation from mercury injection capillary pressures and FZI presents an improved efficacy of the R_(tot) model for hydraulic flow zone characterization.