Gas Hold-up Tool (GHT)

The Gas Hold-up Tool provides a reliable full bore measurement of gas volume fraction, independent of flow regime or well deviation. The tool response is representative of the entire cross section of the well-bore within the casing and is almost completely independent of salinity, water cut oil/water densities and material outside the casing.

Description

The GHT emits low energy gamma rays from a small 3 milliCurie Cobalt-57 source inside the tool, the gamma rays undergo a variety of interactions with well-bore fluids surrounding the tool; these include backscattering, photo-electron 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 backscatter, hence detailed count rate is low in gas and high in water.

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 which alleviates the need for source insertion/removal.

Features

Multi-phase flow profiling.

Fluid Identification.

Bubble Point Determination.

Gas Entry Detection.

Combinable with other Ultrawire^TMPL tools.

Surface read-out or memory operation.

Optional Accessories

Calibration jig (part number 07416).

Wellsite Verifier (part number 07415).

Ver B Sept 2007

Gas Hold-up Tool (GHT)

Description

Features

Cased Hole