Schlumberger Technology Corporation

Prad Research and Development Nv

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Schlumberger Oilfield Assistance Limited

Patrick P Vessereau

Philip S Cheung

Andrew J Hayman

Gilles C Cantin

Daniel Codazzi

Olivier Faivre

Laurent J Aguesse

Philippe R Parent

Toshihiro Nomura

Charles Durbec

Nigel Greer

Systems, methods, and assemblies to provide clock signals to electrical components of downhole tools are provided. In one example, an oscillator assembly may include a silicon-based oscillator having a variable capacitor circuit. The silicon-based oscillator may provide an output signal at a frequency within a range of frequencies. The oscillator assembly may also include control circuitry electrically coupled to the silicon-based oscillator. Moreover, the control circuitry may include a temperature input that receives a temperature corresponding to the silicon-based oscillator. The control circuitry may also include a control signal output electrically coupled to the silicon-based oscillator. The control signal output may be used to change a capacitance of the variable capacitor circuit based on the temperature received by the temperature input to maintain the output signal of the silicon-based oscillator within the range of frequencies.

Silicon-based oscillator for a downhole tool

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.

Modular apparatus and method for making measurements in boreholes

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.

Apparatus and method for obtaining images of a borehole

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.

Borehole imaging

In a hydrocarbon well, a speed measurement is performed at substantially the same level as a determination of the proportions of the phases of the fluid flowing along the well in at least one local region. To this end, local sensors are placed on the hinged arms of a centering device, and a speed-measuring spinner is placed between the arms.

Method and apparatus for acquiring data in a hydrocarbon well

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Hericy, France

Patrick P Vessereau