Development and identification of petrophysical rock typing for effective reservoir characterization

Abstract

Rock typing is considered one of the main requirements to distribute the classes of rocks in the reservoir model. This helps in more accurate estimates of oil reserves and reservoir forecasts. The rock typing is closely related to reservoir properties such as porosity, permeability, and shale volume which influence reservoir productivity. Field development plan (FDP) aim is to design appropriate development strategies to produce any commercial volume of hydrocarbons in the field and reduce any huge residual oil left in the reservoirs. However, any failure to integrate geological features with engineering attributes during model development, may limit geomodellers to distribute geological facies effectively in a field wide manner resulting in inaccurate inputs into simulators, and thus lessens the models' robustness. This study examines the petrophysical rock type classification scheme by comparing the different approaches using rock typing. Among the trimmed approaches are the hydraulic flow unit, the global hydraulic element, the Winland R35 Method. Also, electrical, and nuclear log data obtained from well as well as neutron-density to produce relationships that tie together pore geometric attributes, pore structures, and hydraulic flow characteristics. It was observed that hydraulic units (HU) concept among others was robust in rock typing based on consistencies established on porosity-permeability relationships in typical clastics. HU concepts reconcile hydraulic conductivity with geological concepts through employing reservoir quality index and flow zone indictors on core data. Consistency in saturation height model constructed from capillary pressure data were matched with the HU classes generated on the permeability - porosity cross plots.