Petrophysical and Geological Model using Image Logs

This paper is a case study in Ecuador using 18 wells from two fields (Oso and Coca) that belong to Petroamazonas. It uses LWD (Shlumberger and Halliburton) and Wireline (Schlumberger) images. The main output of this work was to analyse facies in relationship with petrophysics (also using magnetic resonance and spectroscopy), and to analyse the paleocurrent direction using cross bedding analysis. In terms of petrophysics, we concluded that image logs are crucial for petrophysical analysis. It allows observing zones with lower resistivity due to facies changes, and also determining free water level. Image logs portray laminated zones, and Vsh from image logs is a more accurate input for petrophysical analysis in this kind of reservoirs. These techniques (also with magnetic resonance and spectroscopy) had been used in Oso and Coca becoming two of the most prolific fields in Ecuador in terms of oil production. Using the cross bedding from eighteen wells paleocurrent directions were determined. The paleocurrent direction has a SE-NW direction trend. This direction follows a precreataceous fault. The paleocurrent direction had been used for placing horizontal well directions. Those that follow a SE-NW direction have a better production than those drilled randomly.