Hydraulic-Unit-Based Fuzzy Model to Predict Permeability from Well Logs and Core Data of a Multi-Layer Sandstone Reservoir in Ulleung Basin, South Korea

Abstract

This paper presents a method to predict permeability of an offset well using well logs and core data from a multi-layer sandstone reservoir with various depositional environments. Many studies have been conducted to predict permeability but limited to wells drilled in a formation with a single depositional environment. This study implements fuzzy models to predict the FZI (flow zone indicator) and permeability, and applied HU (hydraulic unit) grouping to classify the rock properties of various depositional environments in terms of the correlation between permeability and porosity. Then, an individual fuzzy model is developed for each HU group. A field application confirms that the method can be applied to permeability prediction using well data from various depositional environments. A comparative study shows that HU grouping plays a key role in grouping cores of similar flow characteristics in the case of core data from multiple layers with various depositional environments.