Schlumberger Technology Corporation

Renesas Electronics Corporation

Services Petroliers Schlumberger

Kenji Endo

Masahide Kobayashi

Tetsuro Okuda

Nalin Weerasinghe

Kazuo Fukagai

Motohiro Nakanouchi

Kentaro Tada

Kun Wang

Yuichi Kobayashi

David Santoso

Alex Olson

Hiroshi Hori

Milos Milosevic

Hiromasa Nishisaka

Tadashi Tajima

Mika Uno

A method can include, using a downhole tool, acquiring ultrasonic echo data of a borehole, where the ultrasonic echo data include echoes representative of material and borehole geometry responsive to reflection of ultrasonic energy that has a wide-band frequency range; filtering the ultrasonic echo data using at least one selected filter for multi-band frequency filtering corresponding to different frequency ranges of the wide-band frequency range to generate filtered data; and processing the filtered data to generate attribute values representative of physical characteristics the material, the borehole geometry, or the material and the borehole geometry.

Ultrasonic pulse-echo and caliper formation characterization

Methods and systems for failure point diagnostics in cable telemetry at a wellsite. The methods involve providing a system includes a cable operatively coupling between a surface modem and a downhole modem that is operatively coupled to a downhole toolstring of one or more downhole tools via a toolbus. The methods further involve generating a plurality of test signals, sequentially applying the test signals across one or more test loops in the cable telemetry system, and generating a failure point alert when at least one of the test signals fails in at least one of the test loops. The failure point alert identifies which component of the cable telemetry system caused the test signal to fail.

Failure point diagnostics in cable telemetry

Systems, apparatuses, and methods for hybrid cable telemetry. The methods can include positioning a toolstring in a wellbore. The toolstring can include an uphole telemetry cartridge and a downhole telemetry cartridge respectively adapted to send and receive telemetry data. The toolstring can also include a hybrid logging cable having optical fibers and copper conductors that can operatively couple the uphole telemetry cartridge to the downhole telemetry cartridge. The method can also include transferring data between the uphole telemetry cartridge and the downhole telemetry cartridge across the optical fibers and the copper conductors. The method can further include measuring a data transmission rate on the optical fibers and the copper conductors. The method can also include comparing the data transmission rate to a predetermined threshold. The method can further include detecting a data transmission failure when the data transmission rate falls below the predetermined threshold.

Systems and methods for hybrid cable telemetry

Provided is a semiconductor laser, wherein (&#x3bb;a&#x2212;&#x3bb;w)&#x3e;15 (nm) and Lt&#x3c;25 (&#x3bc;m), where &#x3bb;w is the wavelength of light corresponding to the band gap of the active layer disposed at a position within a distance of 2 &#x3bc;m from one end surface in a resonator direction, &#x3bb;a is the wavelength of light corresponding to the band gap of the active layer disposed at a position that is spaced a distance of equal to or more than ( 3/10)L and &#x2266;( 7/10)L from the one end surface in a resonator direction, 'L' is the resonator length, and 'Lt' is the length of a transition region provided between the position of the active layer with a band gap corresponding to a light wavelength of &#x3bb;w+2 (nm) and the position of the active layer with a band gap corresponding to a light wavelength of &#x3bb;a&#x2212;2 (nm) in the resonator direction.

Method of manufacturing a semiconductor laser

Provided is a semiconductor laser, wherein (&#x3bb;a&#x2212;&#x3bb;w)&#x3e;15 (nm) and Lt&#x3c;25 (&#x3bc;m), where &#x3bb;w is the wavelength of light corresponding to the band gap of the active layer disposed at a position within a distance of 2 &#x3bc;m from one end surface in a resonator direction, &#x3bb;a is the wavelength of light corresponding to the band gap of the active layer disposed at a position that is spaced a distance of equal to or more than ( 3/10)L and &#x3c;( 7/10)L from the one end surface in a resonator direction, 'L' is the resonator length, and 'Lt' is the length of a transition region provided between the position of the active layer with a band gap corresponding to a light wavelength of &#x3bb;w+2 (nm) and the position of the active layer with a band gap corresponding to a light wavelength of &#x3bb;a&#x2212;2 (nm) in the resonator direction.

Semiconductor laser and method of manufacturing semiconductor laser

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Kanagawa, Japan

Kenji Endo