Advances in Sedimentary Facies and Depositional Environment Analysis of the Subsurface Late Miocene Offshore Borneo Using Oil-Based High Resolution

In this paper, borehole image are used for a sedimentological study. More than 3600ft of image log data is subdivided into image facies related to depositional processes from which the sub-environments of a shallow marine sequence is inferred. The borehole image provides excellent examples of sedimentary features such as cross bedding, flaser bedding, lenticular bedding, bioturbation, soft-sediment deformation, and de-watering structures; capturing the high heterogeneity of the formation. These features enable us to interpret sedimentary facies in detail and classify them in terms of their depositional processes. Vertical siccession of these sedimentary facies are then associated to infer their depositional environment such as shelf, shorefaces, and beach-foreshore environments.