US 6,636,046 B2 · Electrical resistivity probes

Abstract

A miniaturized electrical resistivity (ER) probe based on a known current-voltage (I-V) electrode structure, the Wenner array, is designed for local (point) measurement. A pair of voltage measuring electrodes are positioned between a pair of current carrying electrodes. The electrodes are typically about 1 cm long, separated by 1 cm, so the probe is only about 1 inch long. The electrodes are mounted to a rigid tube with electrical wires in the tube and a sand bag may be placed around the electrodes to protect the electrodes. The probes can be positioned in a borehole or on the surface. The electrodes make contact with the surrounding medium. In a dual mode system, individual probes of a plurality of spaced probes can be used to measure local resistance, i.e. point measurements, but the system can select different probes to make interval measurements between probes and between boreholes.

Claims16

Dependent claims

A dual mode distributed measurement system comprising:

a plurality of probes assembled in an array around a geophysical formation, each probe comprising a miniature electrical resistivity probe for geophysical measurements, comprising:
four miniature electrodes;
a mounting structure for mounting the four miniature electrodes in a spaced apart, centimeter-scale-size, parallel relation comprising an outer pair of current electrodes and an inner pair of potential electrodes;
wires connected to the four miniature electrodes and extending out of the mounting structure for connecting the outer pair of electrodes to a voltage source and the inner pair of electrodes to a voltage detector;
a data acquisition system connected to the probes;
wherein a point measurement can be made at each individual probe in utilizing the four electrodes as separate electrodes and interval measurements can be made between pairs of probes by utilizing the four electrodes as a single electrode.

3 more elements

Dependencies are inferred from the claim text.

Electrical resistivity probes

Life of this patent

Electrical resistivity probes

Life of this patent

Abstract

Claims16