Method and apparatus for investigating a borehole using an array of elements.

摘要

A method and apparatus investigation a circumferential segment of a borehole with an array of elements, which in effect spatially samples the segment, is described whereby, with a single circumferentially oriented array of spaced-apart elements sufficient overlap can be synthesized so as to reduce artifacts attributable to the spatial sampling. Measurements derived from circumferentially successive elements are combined, such as by summing to establish a desired overlap. In the described embodiment a single lateral array of small electrodes is used to inject survey currents into the borehole wall and each current is measured. Measurements derived from pairs of successive survey currents are then summed to provide the desired overlap.