Water Saturation Modeling Using Modified J-Function Constrained by Rock Typing Method in Bioclastic Limestone
Y. Deng, R. Guo, L. Zhao, J. Chen and Z. Tian
Event name: 80th EAGE Conference and Exhibition 2018
Session: Fluid Characterization Activiation
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 507.45Kb )
Price: € 20
Combining both geological and petrophysical properties, a reliable rock typing scheme can be achieved. Two steps are included in rock typing. Step 1: rocks are classified into lithofacies based on core observations and thin sections; Step 2: lithofacies are further subdivided into rock types according to petrophysical properties such as MICP and K-Phi relationships. By correlating rock types to electrofacies (clusters of log data), we can group the target formation into 15 rock types. Then it is possible to predict the distributions of rock types laterally and vertically using wireline logs. To avoid the defect of the classical J-function saturation model that includes permeability which is quite uncertain especially in carbonate rocks, a modified J function was created and used in the paper. In this function, water saturation is simply expressed as a function of height above free water level for a specific rock type. Different water saturation model is established for different rock type. Finally, the water saturation model is successfully constructed and verified to be appropriate.