Open File Report 2018-10

This report documents the construction of Model 2019-01, a 3D property model of the Triassic aged Montney Formation, which is made up primarily of siltstone, with coquinas and turbidites also present. The model area is approximately 88,000 km2 and is bounded by the Alberta-British Columbia border in the west, the deformation edge associated with the Rocky Mountains to the southwest, and the erosional edge of the Montney Formation to the north and east. We defined the volume of the model by interpolating top and base surfaces from geological picks. We also interpolated internal surfaces representing the top and base of turbidite and coquina geobodies.

The model consists of three properties in a 3D grid generated from petrophysical well log analysis: gamma ray response, total porosity, and total organic carbon. We also modelled four properties in two dimensions (2D) based on data that is more sparse and uncertain: pressure gradient, temperature gradient, gas-oil ratio, and condensate-gas ratio. We modelled the 2D properties to align with the 3D grid to allow for calculations using all of the properties. We used the Gaussian Random Function Simulation (GRFS) algorithm in Schlumberger Petrel 2015 (Petrel) to model all of the properties. In total, we simulated 100 realizations for each of the properties to represent the range of uncertainty in the model.

We used Petrel to create the model and exported it to non-proprietary formats for use in other software. A series of datasets from the 3D model are available for download in the form of deconstructed model products and digital data including;
• the Petrel project files,
• a deconstructed model dataset composed of discrete and continuous model horizons as Esri format grids, and zone model extent shapefiles, 
• populated model properties as point data in ASCII format, and 
• an iMOD model dataset package.

All of the standard format digital datasets can be viewed in iMOD (see Section 7.2) an open source software and Petrel, enabling users to visualize rotate, slice, explode, and toggle data on and off in 3D. The iMOD software provides users with an interactive geospatial environment where end users can manipulate 3D geological models and import their own geospatially referenced subsurface and surface data..

NTS Keywords

Lyster, S., Marshall, F.H., Playter, T.L. and Berhane, H. (2019): Three-dimensional property modelling of the Montney Formation in Alberta; Alberta Energy Regulator / Alberta Geological Survey, AER/AGS Open File Report 2018-10, 45 p.