Other

Bp Corporation North America Inc.

Bg Transco Plc

Havsco Limited

Bp Corproation North America Inc.

Mark Harper

Martin Thompson

Joseph Anthony Dellinger

Graham Openshaw

Roger Philip Ashworth

Stuart C Moore

There is provided herein a method of seismic acquisition that utilizes an arrangement of marine sources where each source is positioned at a water depth shallow enough for the surface ghost notch to fall at a frequency greater than or equal to the maximum radiated frequency of interest. If the marine seismic source has a ratio of signal bandwidth to maximum frequency that is less than one half, then it is possible to deploy it at a greater depth at which ghost notches fall below and above its frequency band but not in it. Further, by placing two or more sources at different depths for the same frequency, any undesired nulls in the radiation pattern caused by the deeper tow can be filled in.

System and method for preventing cavitation in controlled-frequency marine seismic source arrays

A marine seismic source comprises a housing having a central axis, an open end, and a closed end opposite the open end. In addition, the source comprises a piston coaxially disposed within the housing. In addition, the source comprises a flywheel disposed within the housing and axially positioned between the closed end and the piston. The flywheel is configured to rotate about a rotational axis. Further, the source comprises a connecting rod moveably coupling the piston to the flywheel. The connecting rod has a first end pivotally coupled to the piston and a second end pivotally coupled to the flywheel. The second end of the connecting rod has a first position at a first distance measured radially from the rotational axis, and a second position at a second distance measured radially from the rotational axis. The first distance is less than the second distance.

Marine mechanical seismic source

A marine seismic source comprises a housing having a central axis, an open end, and a closed end opposite the open end. In addition, the seismic source includes a piston extending coaxially through the open end of the housing. The piston is adapted to axially reciprocate relative to the housing. Further, the piston has a first end distal the housing and a second end disposed within the housing.

Marine seismic source

A portable instrument, described in GB2413189, is held between the fingers of one hand and measures the cumulative exposure of a worker to vibration. However, this instrument will not comfortably fit the hands of all workers There is also an administrative problem in administering the allocation of different instruments to respective workers at the beginning of a shift, recording the measurements at the end of a shift and ensuring that instruments are adequately charged. The problem is solved by using a docking station () to receive the instruments before and after use, to receive information recorded by or stored within the units, to charge the batteries and to receive identity information concerning a worker requesting access, to a unit. When a worker returns an instrument to the docking station, a processing mechanism collects information about the identity of the worker, and the state of charge of the instrument's battery. It also informs a worker about to start work which instrument to take and records which worker has or has had which instrument.

System for monitoring exposure to vibration

An acoustic temperature measurement system for pipeline fluids comprises a loudspeaker ( ) with spaced microphone ( ) in a sealed pipe ( ) with end cap ( ). A computer arrangement ( ) provides a tone burst signal which drives the speaker via power amplifier ( ) and the outgoing and reflected signal is detected by the microphone ( ) and following amplification in amplifier ( ) passes to the computer ( ) for processing. The signals are processed to determine phase relationships indicative of temperature and can be used in correcting leakage measurement readings.

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Cambridge, United Kingdom

Mark Harper