Borehole image logs have been around since the mid-1990s; they represent a well-understood technology. Recent technological advances have greatly expanded acquisition capabilities, data sensitivity, and the ability to apply borehole image data to complex reservoir systems. Borehole image logs have sub-centimeterscale resolution that can bring clarity to the structural and stratigraphic complexities of a field. As a result of the quantity of useful data collected by this technique, borehole imaging is becoming a more frequent component of standard logging runs on exploration and development wells.

The strength of borehole image data is that they reveal the spatial geometry of features such as bedding, channels, folds, faults, lithologic changes, and fracture networks. A borehole image provides data similar to that derived from a core without the time, expense, or other issues of coring.

There are four main components of borehole image analyses:. Structural Bedding determination is used to identify changes in the spatial geometry of rock masses due to tectonic deformation and the presence of unconformities and sequence boundaries . In-situ Present Day Stress determination derives the spatial geometry of maximum and minimum horizontal compressive stress trajectories – a crucial element in designing effective well stimulations. Fracture / Fault Characterization is necessary for understanding a dominant permeability element in a reservoir. Finally, Stratigraphic Analysis is used to reconstruct depositional environments and sediment dispersal patterns which govern the spatial distribution of sand bodies. An example of fluvial and shoreface environments will demonstrate the utility of core / image facies comparisons. Using the analysis of multiple image logs in a field improves understanding of sand body geometry and facies distribution which will deliver better well placement and more efficient field development.

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