Internal architectural analysis of mass transport deposits to unravel deepwater dispersal fairways; a novel approach to an old challenge

Summary

High resolution borehole images were used to study the internal architecture of mass transport deposits (MTD units) in a well drilled in offshore deepwater Borneo. The main objective was to utilize information from bedding orientations within MTDs to infer the direction of sediment transport which can in turn imply the distribution of reservoir facies. In this work, we first subdivided the deepwater package into turbidite and MTD deposits. Then, we utilized the dip attributes of bedding features in the deposits interpreted as moderately deformed slumps to identify the folding within the MTD packages. We utilized the geometry of these folds to infer the paleoslope trend which is NE-SW with overall MTD transport direction almost perpendicular to that, i.e. northeast. This trend direction corresponds to fairways along which reservoir facies sands have been transported and deposited in deepwater depocenters. Therefore, using this approach, we can provide vital clues to one of the most persistent exploration challenges in the energy industry, which is to identify main sediment transport directions in deepwater environments.

• mass transport deposit
• borehole image
• dispersal fairways