This case study illustrates the success of comprehensive wireline logging acquisition and data analysis with an innovative rapid workflow performed in two development wells for characterizing complex thinly laminated clastic reservoirs under the petrophysical and geological viewpoints. This was followed by well testing to verify the productivity of the target intervals as well as validate the performance of the innovative workflow.
The first part of the proposed workflow is to integrate advanced petrophysical logs such as high-resolution resistivity and density, nuclear magnetic resonance, and dielectric dispersion measurements to generate a locally calibrated multi-mineral model. The petrophysical evaluation is integrated with the structural interpretation from high-definition borehole images to contextualize the rock properties and its behavior.
A novel solution for gas identification at high resolution using dielectric multifrequency dispersion logs is successfully introduced to identify gas in fresh mud invaded zone. With the high-resolution sampling rate at 1in, this new method enables gas identification in thin bed sequences; otherwise overlooked by conventional resolution logs.
The integrated log analysis confirmed the presence of gas-bearing intervals, with good producibility potential, and additional pay within finer layers. The evaluation results were used to optimize the well testing program and production test outcomes validated the log data interpretation.
