New approach for geomodeling and dynamic calibration of carbonate reservoirs using Porosity Determined System (PODS)

More than 50% of oil and gas resources are located in carbonate reservoirs in the world. In reservoir management purposes, it is very essential to have a reliable simulation model in order to understand the production phenomena for these reservoirs. In this work we are introducing a new concept for geological modeling and dynamic simulation of carbonate reservoirs. The distribution of porosity is often the only mappable property in the subsurface with uncertain geometry (i.e a pod). Permeability can be predicted from porosity if the nature of the porosity is understood and by utilising the right rock type(s) for each pod. This workflow is based on understanding and simulation of the heterogeneity of reservoir caused by porosity variations with permeability predicted from a rock typing approach. We have developed the workflow during a modeling study of the Algerita Escarpment outcrop located in NewMexico to show how dynamic data might be incorporated to reduce the uncertainty in subsurface property prediction and ultimately improve oil recovery. The approach termed (Porosity Derived System) has wide application to other systems where the reservoir flow dynamics are controlled by, likely poorly constrained, clusters of porosity creating pods of permeability, whether depositionally, diagenetically or fracture-controlled.