The acquisition of triple-combo logging data, borehole imaging data, dipole sonic, and select magnetic resonance data, offered the unique opportunity to study a specific set of wells in the McMurray Formation of northeastern Alberta. Each one of the data sets provided valuable information about the geologic setting, fluid properties, or rock properties. The true value of the logging data comes from combining the analyses and interpretations to produce a complete picture of the geology, reservoir potential, and production potential. This integrated approach is based on the interpretation of results from the image data, while incorporating standard log data, including electric, nuclear, and acoustic measurements; dipole sonic data; and nuclear magnetic resonance data. Subsequently, shaly sand analysis from these measurements was added to provide key reservoir petrophysical information. Finally, the addition of nuclear magnetic resonance data supplied insight into the producibility of the reservoir.
Traditionally, dipmeter and image results are used for mapping of channel sands in the McMurray Formation. For this application, however, the image data provided high-resolution delineation of shale beds. This use of the image data leads to a critical reservoir heterogeneity description, which is required for vertical permeability information to optimize production. Shaly sand analysis results (volume of shale, sand calculations, water saturation, and permeability) are combined with core data, when available, and both the core and shaly sand analysis results were incorporated along with the image interpretations. Finally, nuclear magnetic resonance data was added for the key wells, providing comparison of bound to free water, as well as permeability and lithology-independent porosity. When combined, each data set adds either qualitative or quantitative information that is iteratively used to refine and complete the integrated petrophysical analysis.
In this investigation of the McMurray sand characteristics, initial interpretation of the image data revealed that the depositional environment does not match that of the typical fluvial-estuarine sands; subsequently, an interpretation of all wireline data was performed. The results of this interpretation indicate a shoreface environment. Integrating all petrophysical measurements enabled geoscientists to obtain a more complete picture of the subsurface.