Pgs Geophysical As

Pos Geophysical As

Mattias Südow

Robert Andras Juhasz

Kenneth Karlsen

Peter Lindqvist

Martin Austad

Øyvind Hillesund

Frederick James Barr

Bergur Vinther

Claus Clausen Petersen

Andre Stenzel

Geir Andre Motzfeldt Drange

Philip Heelan

Einar Nielsen

Oliver Colin Peppe

Matthew Eric Lyssy

Toralf Lund

Joel Skogman

Clet Antoine Landry

Dougal Kennedy

Jon Magnus Sorli

Jan-Allan Muller

Panagiotis Verras

Jan-Allen Muller

Roll data can be acquired from a magnetometer and an accelerometer of a towed object telemetry unit coupled to a towed object during rolls of the towed object in two or more different headings. The magnetometer can be calibrated based on the roll data. Turn data can be acquired from the magnetometer and the accelerometer during a turn of the towed object from a first heading to a second heading. The magnetometer can be further calibrated based on the turn data.

Calibration of a magnetometer in a towed object telemetry unit based on turn data

An apparatus can include a base assembly and a pivot assembly coupled to the base assembly. The apparatus can include a carriage coupled to the pivot assembly. The carriage can be shaped to receive a compass streamer telemetry unit (CSTU). The carriage can be configured to secure the CSTU. The pivot assembly can be rotatably coupled to the base assembly to adjust a pitch of the carriage. The carriage can be rotatably coupled to the pivot assembly to adjust roll of the carriage.

Calibration of streamer navigation equipment

A system can include a head connector, a stress member connector, and a tail connector. The system can include a first plurality of stress members coupled to the head connector and to the stress member connector. The first plurality of stress members can enter through a first side of the stress member connector. The system can include a second plurality of stress members coupled to the tail connector and to the stress member connector. The second plurality of stress members can exit through a second side of the stress member connector. The second plurality of stress members can be axially nonaligned with the first plurality of stress member connectors.

Stress member connector

Disclosed are methods and systems for controlling spread and/or depth in a geophysical survey. An embodiment discloses a submersible deflector, comprising: an upper portion comprising an upper fin section and upper foils disposed below the upper fin section, wherein at least one slot is defined between the upper foils; and a lower portion coupled to the upper portion and disposed below the upper portion, wherein the lower portion comprises a lower fin section and lower foils disposed above the lower fin section, wherein at least one slot is defined between the lower foils. Also disclosed are marine geophysical survey systems and methods of performing geophysical surveys.

Towing methods and systems for geophysical surveys

This disclosure is related to the field of streamers. In one embodiment, a streamer may include a group of particle motion sensors. In some embodiments, at least two of the particle motion sensors in the group are movable relative to one another within the streamer, and the two particle motion sensors are configured to measure motion along a particular axis. In some embodiments, the streamer may additionally include a plurality of pressure sensors.

Distributed multi-sensor streamer

A method and apparatus for generating an electromagnetic (EM) field from a sub-sea source is disclosed. In one embodiment, a sub-sea source includes a step-down transformer coupled to receive a sinusoidal source wave via a tow cable, and is further coupled to output a sinusoidal wave to a silicon-controlled rectifier (SCR) circuit. A control circuit coupled to the SCR circuit is configured to selectively activate various ones of the SCRs therein in order to control a portion of the sinusoidal wave that is rectified. The output current provided by the SCR is determined by the portion of the sinusoidal wave that is rectified thereby. The output current is provided to electrodes coupled to the sub-sea source, and the output current is passed therebetween. The strength of the EM field is based on the output current.

Silicon controlled rectifier control of sub-sea towed electromagnetic source

An apparatus is disclosed that includes a solid-core streamer with particle motion sensors disposed within the solid core. Some embodiments may additionally include one or more pressure sensors that are disposed outside of the solid core. In some embodiments, the apparatus may also include one or more electromagnetic sensors. Also disclosed are various methods of operating an apparatus that includes a streamer with particle motion sensors disposed within the solid core of the streamer.

Streamer design for geophysical prospecting

Disclosed are methods and systems for controlling spread and/or depth in a geophysical survey. An embodiment discloses a method for geophysical surveying, comprising: towing two streamers laterally spaced apart through a body of water at a depth of at least about 25 meters, each of the streamers comprising geophysical sensors disposed thereon at spaced apart locations; maintaining lateral separation of at least about 150 meters between the two streamers using at least two submersible deflectors, the two submersible deflectors being individually coupled to one of the two streamers; and detecting signals using the two geophysical sensors while the two streamers are towed at the depth of at least about 25 meters.

The present disclosure describes various geophysical survey systems and methods for mapping an electric potential field. At least one illustrative embodiment includes an electromagnetic (EM) source and geophysical survey cables that each includes multiple electrodes spaced apart along each geophysical survey cable's length, and multiple data acquisition units that each obtains measurements indicative of an electric potential between two the electrodes. A modeling module is included and configured to calculate a reference potential at a selected electrode for each of the plurality of geophysical survey cables, as well as a calculation module to combine signals representative of the measurements to produce signals indicative of the electric potential of each electrode relative to the reference potential.

Electromagnetic geophysical survey systems and methods employing electric potential mapping

Disclosed are methods and apparatus for adaptive source electromagnetic (EM) surveying. In accordance with one embodiment, a source waveform signal is generated, and an outgoing EM signal which is based on the source waveform signal is transmitted using an antenna. A responsive electromagnetic signal is detected using at least one electromagnetic sensor, and a receiver waveform signal based on the responsive electromagnetic signal is obtained. A feedback control signal which depends on at least one input signal is determined. Based on the feedback control signal, the source waveform signal is adapted. Other embodiments, aspects, and features are also disclosed.

Methods and apparatus for adaptive source electromagnetic surveying

The present disclosure describes various geophysical survey systems and methods for mapping an electric potential field. At least one illustrative embodiment includes an electromagnetic (EM) source and geophysical survey cables that each includes multiple electrodes spaced apart along each geophysical survey cable's length, and multiple data acquisition units that each obtains measurements indicative of an electric potential between two the electrodes. A calculation module is included and configured to combine signals representative of the measurements to produce signals indicative of the electric potential of each electrode relative to a reference potential assumed to be present at a selected electrode for each of the plurality of geophysical survey cables. Each reference potential is assumed to be of a magnitude that is within a tolerance range of a common reference potential.

A disclosed geophysical survey cable includes a signal amplifier coupled between two electrodes spaced apart along the length of the geophysical survey cable (the electrodes being coupled to the signal amplifier by a first conductor pair), and a noise amplifier coupled to a second conductor pair positioned substantially parallel to the first conductor pair. The geophysical survey cable further includes a combiner that combines a noise signal provided by the noise amplifier with a sensor signal provided by the signal amplifier to provide a sensor signal with a reduced noise component.

Noise reduction systems and methods for a geophysical survey cable

Disclosed are methods and systems for controlling depth profiles of marine geophysical sensor streamers as they are towed in a body of water. An embodiment discloses a method for marine geophysical surveying, the method comprising: towing a geophysical sensor streamer in a body of water having a surface and a floor, the geophysical sensor streamer being coupled to a survey vessel by a lead-in cable, the lead-in cable having a length that extends from the survey vessel; adjusting the length of the lead-in cable to cause a forward end of the geophysical sensor streamer to follow a depth profile; and deflecting the geophysical sensor streamer in the vertical plane at one or more spaced apart locations.

Growing community of inventors

Solna, Sweden

Mattias Südow