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Multi-Attribute Seismic Wheeler Volume Workflows, Illuminating Stratigraphy, Geomorphology, and Prospectivity Within a Mezardere Slope Fan Exploration Model, Thrace Basin, Turkey

Abstract

Evolving seismic interpretation technology has eased the ability of interpreters to quickly transform seismic time volumes into seismic wheeler or geologic time volumes. Integrating seismic attribute wheeler volumes early and iteratively into the interpretation workflow can aid in illuminating significant stratigraphic/geomorphologic features and accelerate understanding of depositional patterns and structural histories. This study utilizes recent 3D datasets located in the Thrace Basin of Turkey, with the zone of interest comprising prograding delta front to prodelta deposits of the Oligocene Mezardere formation. The workflows discussed here address the challenge of extracting seismic stratigraphic details from this particular geological setting, where events are faulted, structurally deformed, steeply dipping, and diverging and converging laterally within individual lobe shaped deposits. Dip volume data is utilized to accelerate horizon picking by steering the gridding of difficult to pick stratigraphic boundary horizons and then to generate dense sets of intervening systems tract horizons that closely follow seismic events. Desired seismic attributes, such as similarity and energy are extracted along the generated horizons, which are then essentially flattened, transforming data into a wheeler volumes. Animation of these volumes can quickly reveal important stratigraphic patterns and features. Key horizons can be extracted and used for the next stage of interpretation, including the application of more complex seismic attributes such as spectral decomposition. Rigorous testing and implementation of optimal parameters for horizon generation and attribute extraction/visualization is essential to achieving optimal images. By integrating this work with core, outcrop, and well log data, a slope fan model has been developed to describe the productive and prospective reservoir and source rock horizons of the Mezardere formation. Distinct clinoform packages and their geometries have been mapped, and numerous slope channel systems of varying sinuosity have been identified and tied to producing wells. Slope channel mapping has also aided structural interpretation and fault seal estimation by allowing the measurement of transverse fault movements. Stratigraphically trapped prospects have been successfully drilled and this mapping has led to further prospects that are currently being pursued by Valeura Energy.