Contemporary methods for the creation of geomechanical parameters in a subsurface play are able to produce indications of deformations, stress & strain change and fracture probability-all vital to the efficient and safe development of a reservoir and also to understand how it was created as part of a restoration workflow.
However the robustness of these techniques and the reliability of the output properties and 4D models so created are heavily dependent upon both the accuracy of the input data and the sophistication and application of the modeling analysis. We describe an innovative solution which from the outset ensures that-regardless of the reservoir's tectonic complexity and history-a true volumetric restoration may be ultimately produced.
We create an accurate, sealed structural model by representing horizons as chronostratigraphic surfaces and ensuring that all paleo-distances are preserved using a proprietary technology to transform data between xyz space and paleospace. Stress / strain information including curvature, cubic dilatation, dip and azimuth may then be directly computed and populated within a geomechanical mesh. Our workflow allows direct integration of reservoir facies in order to constrain the distribution of the geomechnical properties and we show further extension to include DPDP fracture modelling via the incorporation of microseismic data.
This high accuracy, pillar less structural model may then undergo a mechanical restoration and back-stripping process to sequentially uncompact and unerode the layers. Outputs are predicted stress ellipsoids and high confidence information on paleo-prospect size, closure and age. Those aspects of a contemporary geomechanics and restoration workflow usually rendered problematic and inaccurate by virtue of play complexity are shown to be easily handled.