OBMI
Oil-based microimager
Visualize the reservoir with microresistivity imaging in oil-based, nonconductive, and invert-emulsion mud systems.
Ultrasonic Borehole Imager
Acoustic imaging
Two operating frequencies for the image resolution you need
The UBI ultrasonic borehole imager has two operating frequencies measuring amplitude and transit time: standard and higher resolution. Image resolution is selected to correspond to the logging environment, such as the mud type and density. The higher frequency yields higher image resolution. The lower standard frequency gives a robust measurement in highly dispersive muds.
The imaging accuracy of both frequencies is supported by processing that avoids cycle skips and reduces echo losses.
Advanced images with 100% borehole coverage for analyzing fractures, understanding the stress regime, and determining borehole stability.
The rotating transducer subassembly is available in different sizes to provide optimal standoff from the casing or borehole wall.
How acoustic imaging works
The UBI imager’s sonde has a rotating transducer subassembly, which is available in different sizes to log all standard sizes of open boreholes.
The direction of rotation of the subassembly controls the orientation of the transducer. Counterclockwise rotation is used for the transducer facing the borehole wall. Clockwise is used with the transducer turned 180° within the subassembly to face a reflection plate for measuring downhole fluid properties.
The transducer is both a transmitter and receiver, transmitting ultrasonic pulses and receiving the pluses reflected by the borehole wall. Transit times are converted to borehole radius information using the velocity of the signal in the mud.
This sensitivity of the measurement to the surface variation of the borehole wall makes the UBI imager ideal for geomechanics applications related to fracturing, breakouts, and stability. Borehole anomalies such as keyhole wear are automatically diagnosed.
Interpretation
Our multidisciplinary interpretation experts work with you to determine structural information from image and dip analysis of measurements made with the UBI ultrasonic borehole imager.
Single-well cross sections can be generated to help identify complex folding and faulting. Fractures, faults, slumps, and other features can be identified and characterized. Textural information such as the porosity distribution in carbonates and the sorting index in sandstones can be obtained, along with net sand calculation in highly laminated reservoirs.
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