Dipmeter Application in Canadian Oil Sands Development – Evolution from Predicting Potential Block Slides to 3D Geological Interpretation and Modelling

Milovan Fustic¹, Ron Spencer², Steve Hubbard², Barry Bennett², and Steve Larter². (1) Alberta Ingenuity Centre for InSitu Energy, University Of Calgary, (presently with NEXEN Inc.), Department of Geology and Geophysics, 2500 University Drive NW, Calgary, AB T2N 1 N4, Canada, phone: (403) 262-3488, mfustic@ucalgary.ca, (2) Alberta Ingenuity Centre for InSitu Energy, University of Calgary, Department of Geology and Geophysics, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada

At the Athabasca Oil Sands, Canada, a majority of bitumen is hosted in clastic sediments of the Lower Cretaceous McMurray Formation, which is further informally divided into mappable units representing fluvial, open estuarine, tidally influenced estuarine channel complex (ECC), and shallow marine deposits. ECC deposits comprise facies assemblages that include point bar, abandoned channel-fill, and tidal flat deposits, which create complex internal geometries, architectures and associated reservoir properties. These complexities are associated with significant lateral and vertical bitumen grade/saturation variability (0-15 mass %). In order to resolve, or at least to minimize, some of the challenges in reservoir mapping, dipmeter logs are commonly employed to provide additional information. Case studies suggest that the dipmeter may be applied for:

1) Depth correction while describing cores; 2) Predicting the presence of steeply dipping layers (potential block slides in open pit mines); 3) Recognition of channel fill type (lateral versus vertical accretion); 4) Well to well correlation; 5) Estimation of vertical continuity (thickness) within channel fill; 6) Estimation of lateral extent of point bar deposits; 7) Prediction of bitumen grade; 8) 3D geological modelling

Despite this, the dipmeter commonly remains under-utilized by industry.

The intent of this review is not only to show the evolution of dipmeter applications, but also to demonstrate the advantages, simplicity, and additional potential utility in the mapping and extraction of bitumen in the Athabasca Oil Sands, as well as to provide insights for interpreting and modelling similar reservoir types elsewhere in the world.

Un-Conventional Heavy Oil Resources - Advances, Challenges and Case Studies
AAPG & AAPG European Region Energy Conference and Exhibition (November 18-21, 2007) Technical Program