Seismic Modelling of Deepwater Depositional Architectures to Validate Static Model Characterization

Seismically consistent static models of hydrocarbon reservoirs contribute to the effective estimation of potential reserves and dynamic characterisation that subsequently guide decision making for well placement and production planning in a field development. This paper presents an example of an integrated static model that utilises reflectivity and inversion data to characterise the static model both structurally and stratigraphically for a deepwater turbidite field in offshore Sabah, Malaysia. The deepwater field has three well penetrations; the discovery well (Well-A), drilled in the late 1998 and appraisal well (Well-B) and geological sidetrack (Well-B ST) drilled in 2013. The reservoir is characterized by excellent net-to-gross thickness and reservoir properties deposited in a channel and levee overbank setting. A 3D Closing- the-Loop (CtL) exercise was undertaken to validate the appropriate characterisation of static models and improve understanding on compartmentalisation, a primary uncertainty for this field. Evidence of seismic discontinuities in reflectivity data suggests the potential of dynamically significant lateral boundaries that may be represented by localised shale drapes at the base of channel meander belt systems or more regionally extensive levee systems. Static models for both scenarios were built to address the issue of compartmentalisation which was observed in Well-B ST.