Borehole image logs

Borehole imaging logs are logging and data-processing methods used to produce two-dimensional, centimeter-scale images of a borehole wall and the rocks that make it up .These tools are limited to the open-hole environment. The applications where images are useful cover the full range the exploration and production (E&P) cycle from exploration through appraisal, development, and production to abandonment.

Specific applications are sedimentology, structural geology/tectonics, reservoir geomechanics and drilling, reservoir engineering.

The tools can be categorized a number of ways: energy source (electrical, acoustic, or nuclear); conveyance (wireline or logging while drilling (LWD)); and mud type (water-based mud (WMD) or oil-based mud (OBM)).

Image basics

What 2 dimensional means

File:2DArrayToTadpoles.jpg

Image logs are 2D data sets meaning that there are multiple values recorded at each depth and at different positions around the borehole. When projected onto a plane (like a computer screen or sheet of paper a 2D image is created.

Tadpoles

File:Tadpoles2.jpg

The planar features are quantified with a tadpole map that relates depth with the dip angle and dip direction of the plane.

Image normalization

File:StaticDynamicImages.jpg

The images can be normalized to a local color map to bring out hidden or subtle features.

See also

List of acronyms in oil and gas exploration and production