Optical Televiewer

Parameters Logged:

360° RGB oriented optical image

CCD Camera

45mm to 600mm hole sizes with vertical resolution of 1.0mm and horizontal resolution of 720 pixels

Borehole azimuth and dip

Tri axial magnetometers
and accelerometers.

+/- 1.0° Az, +/-0.2° Dip

The Optical Televiewer (OTV) generates a continuous, 360° orientated image of the borehole wall, using an optical imaging system. The tool includes an orientation package consisting of a precision 3 axis magnetometer and 3 axis accelerometer package allowing for both accurate borehole deviation data to be recorded as well as accurate and precise image orientation in the same log.

Televiewers (both Optical and Acoustic) can reduce the reliance on coring for geotechnical observation by obtaining structural information from less expensive percussion holes. They can also give more detailed structural information than traditional orientated core and can provide orientation data in vertical holes.

Applications:

The tool provides detailed, oriented structural information particularly in applications where an Acoustic Televiewer cannot be utilised (when holes are air filled). The tool must be run centralised and operates in air or (clean) water filled holes.

The most common applications are:

• fracture detection and evaluation
• detection of thin beds and bedding dip and orientation
• lithological characterisation
• casing inspection

Example Log Image: