Borehole Size Monitoring

Measurements of borehole diameter are made using acoustic pulse-echo sensors. The sensors measure the transit time of acoustic waves between the sensor and the borehole wall and transmit the results to the surface in real time. The surface computer system uses this information to derive the corresponding stand-off distance and borehole diameter, based on the calculated acoustic velocity of the borehole fluid under downhole conditions. The acoustic sensors also record detailed data in memory, which is processed after the run to derive measures of borehole shape, ellipticity and ellipse orientation.

AcoustiCaliper™ MWD Tool
Provides borehole caliper measurements. Diameter can be used to calculate wellbore volume.
ALD™ Azimuthal Lithodensity Sensor
LWD tool combines azimuthal binning of data and an independent acoustic standoff sensor to provide azimuthally oriented density data and Pe logs in an enlarged borehole. In addition, images of the formation are provided, from which the formation dip can be estimated.

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