The GHT emits low energy gamma rays from a small 3 milli Curie Cobalt-57 source inside the tool, the gamma rays undergo a variety of interactions with wellbore fluids surrounding the tool; these include back scattering, photoelectron absorption and Compton scattering. A sodium-iodide scintillation detector in the tool is positioned a short distance away from the source such that it will detect back scattered gamma rays. Less dense fluids, such as gas, produce less back scatter, hence detailed count rate is low in gas and high in liquids.
The short source-detector spacing reduces statistical errors associated with gamma ray detection as a result of Compton Scattering or photo-electron absorption. Calibration checks are carried out in air and water to ensure the tool is reading correctly before running in hole.
The tool is supplied with a shielded carrying case that alleviates the need for source insertion/removal.
- Multi-phase flow profiling
- Fluid Identification
- Bubble Point Determination
- Gas Entry Detection
- Combinable with other Ultrawire productlion logging tools
- Surface readout or memory operation
- Calibration jig (part number 07416)
- Wellsite Verifier (part number 07415)