US 11,977,195 B2Granted

Triggering distributed acoustic sensing downhole using an active fiber stretcher assembly

AssigneeHalliburton Energy Services, Inc.

InventorsAndreas Ellmauthaler, Henry Clifford Bland, Michel Joseph LeBlanc, Mark Elliott Willis, Xiang Wu

Life of this patent

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Abstract

An active fiber stretcher assembly can be used for data acquisition systems. A time-break signal can be detected that coincides with a seismic event emitted from a seismic controller. A predetermined waveform can be generated in response to detecting the time-break signal. The predetermined waveform may be encoded onto a fiber optic cable using a fiber stretcher. A data acquisition system connected to the fiber optic cable may detect the predetermined waveform on the fiber optic cable and initiate acquisition operations including: receiving, during the seismic event, light signals returning from a portion of the fiber optic cable in a subterranean environment; determining one or more characteristics of the subterranean environment from the light signals; and storing the one or more characteristics.

Claims18

Dependent claims

A system comprising:

an active fiber stretcher assembly including:
a trigger circuit to detect a time-break signal emitted from a seismic controller;
a function generator coupled to the trigger circuit to receive a signal from the trigger circuit that the time-break signal has been detected and, in response to receiving the signal from the trigger circuit, to generate a predetermined waveform;
and
a fiber stretcher unit coupled to the function generator to encode the predetermined waveform onto a fiber optic cable;
and
a data acquisition system communicatively coupled to the fiber optic cable, the data acquisition system including:
a light source to transmit light signals through the fiber optic cable into a subterranean environment;
a server communicatively coupled to the fiber stretcher unit, the server including a non-transitory computer-readable medium on which are instructions that are executable to identify a channel range of one or more fiber stretchers of the fiber stretcher unit and to transmit the channel range of the one or more fiber stretchers to the data acquisition system;
an optical receiver to receive the predetermined waveform from the active fiber stretcher assembly and a returning light signal from the subterranean environment;
and
a processor to detect the predetermined waveform, in response to detecting the predetermined waveform, to obtain one or more measurements from a returning light signal from the subterranean environment.

9 more elements

A method comprising:

detecting a time-break signal emitted from a seismic controller, the time-break signal being emitted substantially contemporaneously with a seismic event for a subterranean environment;
generating a predetermined waveform in response to detecting the time-break signal emitted from the seismic controller;
encoding, using a first fiber stretcher, the predetermined waveform onto a fiber optic cable communicatively coupled to a data acquisition system;
configuring the data acquisition system to detect encoded transmissions from the first fiber stretcher by:
transmitting, by a server, a carrier wave to the first fiber stretcher;
encoding, by the first fiber stretcher, the carrier wave onto the first fiber stretcher;
detecting, by the data acquisition system, the carrier wave on the fiber optic cable, wherein the carrier wave is detected on a particular channel range;
and
monitoring, by the data acquisition system, the particular channel range for the predetermined waveform;
detecting, by the data acquisition system, the predetermined waveform on the fiber optic cable;
and
initiating, in response to detecting the predetermined waveform by the data acquisition system, data acquisition operations including:
receiving, during the seismic event, light signals returning from a portion of the fiber optic cable in the subterranean environment;
determining one or more characteristics of the subterranean environment from the light signals;
and
storing the one or more characteristics.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/620,269Filed 20 Sep 2019
Published: US 2023/0020858 A119 Jan 2023
Granted: 7 May 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G01V 1/26
Recording seismic data: reference-signal-transmitting devices, e.g. indicating moment of firing of shot
G01D 5/3537
Influencing the transmission properties of an optical fibre: optical fibre sensor using a particular arrangement of the optical fibre itself
G01V 1/226
Transmitting seismic signals to recording or processing apparatus: optoseismic systems
G01V 1/46
Using generators and receivers in the same well: data acquisition