Leak detection system and method for offshore hose lines

A fluid leak detector for a hose line segment of the type comprising at least an inner carcass and an outer containment carcass separated from the inner carcass by a collection space, the detector comprising:

• a sensor housing defined by sidewalls externally mounted to the hose line segment and having an internal housing chamber in communication with the collection space;
• an optical sensor extending through at least one of the sidewalls of the sensor housing;
• the optical sensor having an optical sensing element positioned within the sensor housing chamber for detecting a presence of fluid in the hose collection space, wherein the optical sensing element comprises an optical fiber disposed to contact fluid within the collection space;
• an analysis element connecting to the optical sensing element and positioned outside of the sensor housing sidewalls, the analysis element configured to generate data indicative of the fluid status within the hose collection space;
• a transmission element connecting to the analysis element for receiving data from the analysis element and transmitting the data to at least one remote receiver;
• an elongate duct extending from the housing chamber to the hose collection space, the duct having an axial passageway for conveying leakage fluid from the collection space to the housing chamber, wherein the optical fiber resides within the housing chamber;
• and
• an annular venting pipe extending circumferentially around the hose proximate to the sensor housing, the venting pipe having a central passageway communicating with the duct passageway for venting air from the duct passageway,
• wherein the optical sensing element is electrically isolated from the analysis element.

A fluid leak detector for a hose line segment of the type comprising at least an inner carcass and an outer containment carcass separated from the inner carcass by a collection space, the detector comprising:

• at least one elongate duct having an axial internal passageway, the duct disposed to extend parallel to a longitudinal axis of the hose line, the duct having an interior open duct end in communication with an annular collection space between the inner and outer carcasses and an exterior closed duct end and the duct having an opposite end terminating at a central chamber within a sensor housing;
• a fluid detection sensor extending through at least one sidewall of the sensor housing, the fluid detection sensor having an optical sensing element positioned within the sensor housing chamber for detecting a presence of fluid in the hose collection space;
• an analysis element connecting to the optical sensing element and positioned outside of the sensor housing sidewall, the analysis element generating data indicative of the fluid status within the hose collection space;
• and
• a transmission element connecting to the analysis element for receiving data from the analysis element and transmitting the data to at least one remote receiver,
• wherein the optical sensing element is electrically isolated from the analysis element.

A method for detecting leaks in a double carcass hose of the hose type having at least an inner carcass and an outer containment carcass separated from the inner carcass by a collection space, comprising:

• a. positioning at least one elongate duct between the inner and outer carcasses, the duct extending along the hose line and having an interior open duct end in communication with an annular space between the inner and outer carcasses and an exterior closed duct end;
• b. mounting a fluid detection sensor at the closed end of the duct, the sensor operationally utilizing the duct passageway for sensing the presence of fluid within the annular space between the inner and outer carcasses;
• c. positioning at least one optical fiber of the sensor axially into an elongate duct passageway;
• and
• d. protruding a remote end of the optical fiber from the duct into the collection space.