Abstract: An apparatus comprising a downhole tool operable to measure a characteristic of a subterranean formation from within a wellbore extending into the subterranean formation. The downhole tool may include a plurality of sensor devices each extendable from a body of the downhole tool by a corresponding pair of arms.

Abstract: A downhole imaging tool operable to obtain measurement data associated with a subterranean formation at a frequency above about 100 kHz. An application-specific integrated circuit (ASIC) is conveyable with the downhole imaging tool and operable to perform at least one of data acquisition, signal processing, and signal transmission utilizing the measurement data obtained by the downhole imaging tool.

Abstract: Apparatus for making measurements in boreholes comprising a sonde having a radial array of arms provided thereon; wherein the sonde is connectable to a cartridge containing electronic circuitry specific to a predetermined measurement to be made in the borehole, each arm is connectable to a sensor pad specific to the predetermined measurement; and the sonde provides electrical connectivity between the sensor pads and the cartridge that is substantially independent of the predetermined measurement.

Abstract: Apparatus for making measurements in boreholes comprising a sonde having a radial array of arms provided thereon; wherein the sonde is connectable to a cartridge containing electronic circuitry specific to a predetermined measurement to be made in the borehole, each arm is connectable to a sensor pad specific to the predetermined measurement; and the sonde provides electrical connectivity between the sensor pads and the cartridge that is substantially independent of the predetermined measurement.

Abstract: Apparatus for obtaining images of the wall of a borehole, comprises a tool body; a light source mounted on the tool body and arranged to illuminate the borehole wall; a camera mounted in the tool body; and a mirror moveably mounted on the tool body and spaced axially from the camera and arranged to reflect an image of the borehole wall at the camera, wherein the movement of the mirror allows images of different parts of the borehole wall to be reflected at the camera.

Abstract: Apparatus for imaging the wall of a borehole drilled through an underground formation, comprising: a light source; an optical detector device such as a CCD camera; a sensor head including a window for application against the wall of the borehole, the light source being connected to the sensor head so as to illuminate the region of the borehole wall when the sensor head is applied to the wall; and an optical fiber bundle connecting the window to the optical detector device so as to pass optical signals from the wall to the optical detector device; wherein the optical fiber bundle comprises a coherent bundle, each fiber of the coherent bundle providing one pixel of a two-dimensional, multi-pixel image of the borehole wall.

Abstract: Apparatus for obtaining images of the wall of a borehole, comprises a tool body; a light source mounted on the tool body and arranged to illuminate the borehole wall; a camera mounted in the tool body; and a mirror moveably mounted on the tool body and spaced axially from the camera and arranged to reflect an image of the borehole wall at the camera, wherein the movement of the mirror allows images of different parts of the borehole wall to be reflected at the camera.

Abstract: Apparatus for imaging the wall of a borehole drilled through an underground formation, comprising: a light source; an optical detector device such as a CCD camera; a sensor head including a window for application against the wall of the borehole, the light source being connected to the sensor head so as to illuminate the region of the borehole wall when the sensor head is applied to the wall; and an optical fibre bundle connecting the window to the optical detector device so as to pass optical signals from the wall to the optical detector device; wherein the optical fibre bundle comprises a coherent bundle, each fibre of the coherent bundle providing one pixel of a two-dimensional, multi-pixel image of the borehole wall.