Input/output, Inc.

I/o Exploration Products (u.s.a.), Inc.

Lee E Siems

John L Maida

Han-Sun Choi

Greyson Orval Knapp

Reinis Kanders

Grevson Knapp

Tom O'Brien

Gary L Scott

A fiber optic acoustic sensor system including an optical conductor having low reflectivity mirrors is provided. Optical sensors are provided by sections of the optical conductor bounded by pairs of the low reflectivity mirrors. Pulses of light are injected into the optical conductor and reflected by the low reflectivity mirrors. The reflected pulses of light are processed using a compensating interferometer to generate interference patterns representative of the environmental conditions acting upon the optical conductor.

Optical sensing system

A marine seismic fiber optic acoustic sensor system having internal mirrors with a low reflectivity written into the fiber to form a series of continuous, linear sensors incorporated in a single fiber, each sensor bounded by a pair of internal mirrors. A pulsed laser provides optical signals to the fiber at a pulse width less than twice the travel time to assure that there will be no phase or frequency modulation of signals returned from the sensors and reflected optical energy is returned through the same fiber to an optical coupler where it is input to a compensating interferometer to produce interference signals which are then time division multiplexed to produce signals corresponding to acoustic signals received by each mirror bound sensor. Calibration to remove local temperature effects is provided by using a desensitized reference fiber with internal mirrors identical to the sensitized fiber, by a piezoelectric stretcher built into the fiber or any other conventional calibration technique.

Seismic optical acoustic recursive sensor system

The invention is a seismic acquisition system for communicating seismic sensor signals to a recording unit, including a control unit and analog-to-digital conveyer units connected to the control unit. The conveyer units each include integral interconnecting cables having an hermaphroditic connector at each end, analog seismic sensor inputs and signal processing circuitry disposed within a watertight housing forming part of the cables. The circuitry includes analog-to-digital conveyers connected to the analog inputs, a buffer for digitized signals transmitted to one converter unit from other converter units interconnected to the conveyer unit opposite to the control unit connection, a digital transceiver for retransmission of digitized sensor signals and the buffered signals at a first data rate to the control unit. The control unit includes a second buffer for signals from the conveyer unit and for signals retransmitted from other control units serially codected to the control unit. The control unit further includes a second transceiver for retransmitting buffered signals from the conveyer units and from other control units to the recording unit at a second data rate higher than the first data rate. A preferred embodiment includes a data buffering unit interconnected between the recording unit and the control unit. The buffering unit comprises another digital transceiver for communicating control signals from the recording unit and sending digited signals to the recording unit, and a buffer for storing digitized signals from the control unit and from other ones of the buffering units interconnected to the one buffering unit.

Hierarchical telemetry system for seismic acquisition

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Simonton, TX, United States of America

Lee E Siems