The Borehole Television Camera has been utilized successfully in the Appalachian Basin for the identification of natural fracturing and associated hydrocarbon production within the wellbore.

Many of the images recorded on the videotape at the time of logging are of less than optimum quality due to borehole conditions and camera lighting imbalances.

The on-board enhancement capability during logging is unfortunately limited to adjustments in light source intensity and the making of multiple passes over the zones of interest in order to get a better picture.

However, with the utilization of post logging computer processing, many of the downhole images can be enhanced visually, while at the same time, calibrated measurements can be made.

An image analysis and enhancement system consists of five components : the image source (which in this case is commonly a video cassette recorder (VCR); a video raster screen (RGB monitor); a video adapter board (frame-grabber); a computer with monitor (a coprocessed, 386-based machine with lots of memory); and, finally, a utile software package.

Having captured the image (using the frame-grabber board), the image is then processed and enhanced. The degree of resolution possible in an image is in part determined by the fineness of the pixel grid.

The image processing that can be performed includes the removal of artifacts and noise, contrast enhancement for easier viewing, object boundary determination so that objects may be counted and measured, and finally, image subtraction that can remove disruptive background shades.

Practical applications of the measurement techniques are in the estimation of: extent of corrosive pitting in casing, size of perforations after fracing, relative oil production from individual perforations based on oil globule size, and natural fracture width and fracture area measurements.

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