Method and system for testing a fiber optic monitoring system in a conduit

A method for verifying an event detection system, comprising:

• interrogating optical fiber positioned alongside a conduit by sending one or more light pulses along the optical fiber and receiving reflections of the one or more light pulses;
• and
• using an event verification device housed within an enclosure through which passes the optical fiber to generate one or more interference signals so as to alter an optical path length of the optical fiber and modify the received reflections,
• wherein the strain actuator comprises a motor operable to drive rotation of a rotatable element such that the rotatable element periodically displaces the optical fiber, and wherein the optical fiber is wound about a resilient bias configured to bias the optical fiber against displacement from the rotatable element.

An event detection system comprising:

• a conduit;
• optical fiber positioned alongside the conduit;
• an interrogator optically coupled to the optical fiber and configured to interrogate the optical fiber by sending one or more light pulses along the optical fiber and receiving reflections of the one or more light pulses;
• an event verification device comprising an enclosure through which passes the optical fiber, wherein the event verification device is configured to generate one or more interference signals for interfering with the optical fiber within the enclosure such that an optical path length of the optical fiber is altered;
• and
• an optical circulator optically coupled to the optical fiber and comprising first, second, and third ports configured such that light entering the first port via a first portion of the optical fiber is sent out of the second port toward the event verification device via a second portion of the optical fiber, and light entering the second port from the event verification device via a third portion of the optical fiber is sent out of the third port via a fourth portion of the optical fiber.

An apparatus for use with an event detection system, comprising:

• an enclosure comprising one or more apertures for receiving optical fiber therethrough;
• and
• one or more actuators housed within the enclosure and configured to generate one or more interference signals for interfering with optical fiber within the enclosure such that an optical path length of the optical fiber is altered,
• wherein the one or more actuators comprise a strain actuator configured to move between first and second positions for displacing optical fiber within the enclosure, and
• wherein the strain actuator comprises one or more of a piston, an inflatable member, and a gear motor.