Emerging Stratigraphic Play Opportunities of the Jurassic of Saudi Arabia through from Enhanced Workflow

Abstract

The search for stratigraphic traps especially in carbonates is a challenging task and requires careful detailed analysis of the petroleum system elements. Understanding the spatial relation between source, reservoir and seal layers constitutes a critical success factor. Building a workflow that transforms well and seismic data into 3D models allows stratigraphic traps prediction and better understanding of the stratigraphic trapping components. With the acquisition of modern 3D seismic data and the advancement in data analysis software, we are able to build 3D seismic and electrofacies and porosity models that are tied to well based information such as cores and well logs. The built 3D models allow the investigation of the spatial relations of source, reservoir and seal units. A corner stone of our workflow for targeting carbonate stratigraphic traps is to integrate all available data into 3D models of seismic facies, electrofacies and core data. These models were also transformed to porosity models using relations from seismic (AI), core measured and well log derived porosities. This allows analysis of the stratigraphic trap in great details. Highly detailed core data and well log defined electrofacies, are upscaled and used to calibrate seismic waveform based facies. The seismic facies volume generated from a combination of seismic attributes allowed lateral stratigraphic prediction. A workflow for the deliberate search for carbonate stratigraphic traps includes: ● Stratigraphic and sedimentologic analysis from cores and well-logs and building of depositional architecture. ● Stratigraphic modeling and Wheeler diagram construction to track lateral and temporal shifts of depositional facies and electrofacies modeling, which uses a combined analysis of well logs and cores, for facies definition. ● Seismic modeling and analysis to investigate the link of the facies response to seismic. ● Hybrid clustering classification. ● Seismic trace based 3D model integration of the core lithofacies, the electrofacies, and the seismic facies to produce facies and porosity models. ● Integration of other petroleum systems elements and visualization of the results. Application of this workflow to a Jurassic interval in an area in the eastern Saudi Arabia have proven that carbonate stratigraphic trap can be predicted thus giving us confidence in pursuing these type of traps.