Microresistivity

Oil-based microimaging

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Image features in oil-based and nonconductive muds

The OBMI oil-based microimager performs microresistivity imaging in oil-based, nonconductive, and invert-emulsion mud systems.

For conventional microresistivity imagers, even a thin film of nonconductive mud is essentially an opaque curtain, preventing them from measuring the formation. The presence of nonconductive mudcake or mud filtrate further complicates the situation.

OBMI oil-based microimager.

You choose the mud—The OBMI microimager images features as small as 0.4 in.

How it works

The five pairs of voltage electrodes and two current electrodes on each of the four pads of the OBMI oil-based microimager (right) are applied to the borehole wall (left). The current (I) is passed between electrodes A and B with the potential difference measured between voltage electrodes C and D. The measurements are used to quantitatively determine the resistivity of the invaded zone.

The log image is oriented with respect to the geometry of the borehole. Structural and stratigraphic features as small as 0.4 in are visualized.

Interpretation

To obtain the highest value from measurements made with the OBMI oil-based microimager in oil-based, nonconductive, and invert-emulsion mud systems, our multidisciplinary interpretation specialists help you as needed with expert image and dip interpretation. Significant structural and stratigraphic information can be gained, including the identification and characterization of fractures, faults, slumps, and other features. 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.

A proprietary Petrel E&P software platform plug-in is used to facilitate well-to-well correlation and help improve your field development.