Apparatus and Method for Monitoring the Mechanical Properties of Subsea Longitudinal Vertical Components in Offshore Drilling and Production Applications

Abstract

An apparatus to monitor the loads and mechanical behavior of subsea longitudinal vertical components of off shore drilling and production platforms (SLVCs) uses sensors attached directly to the tendons by adhesive or by friction mount. The sensors are typically in a sensor ring assembly which is placed around the perimeter of the SLVC. Ruggedized cables carry the sensor reading from the ring assembly to the SLVC working platform and to a control center for monitoring the action and stresses on the tension legs. The system may be deployed on existing SLVCs or may be installed on new construction during initial assembly and installation.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The subject invention is generally related to measuring systems for monitoring the effect of environmental elements on subsea components in offshore oil and gas drilling and production and is specifically directed to fiber optic sensing systems employed as monitoring and measurement apparatus.

[0003] 2. Discussion of the Prior Art

[0004] Offshore drilling and production systems include a surface working platform in communication with a production field beneath the seafloor. All such systems have one feature in common, which is that a conduit of some sort is required to support drilling equipment and materials being delivered from the surface work platform to the subsea field, and / or a conduit for lifting oil and gas being produced from the subsea field to the surface work platform. In typical cases the conduit is a tubular pipe extending from the subsea field to the surface, generally referred to as a riser.

[0005] One such e...

Examples

Embodiment Construction

[0033]While the invention as described is illustrated using the sensor system 14 on the tension legs of a typical TLP 10, it should be understood that the system is readily adaptable to any SLVC incorporated in offshore drilling and production. The system is particularly useful, and similarly installed on risers, tension legs and other SLVC used during both the drilling and the production phase of the platform.

[0034]A TLP 10 with the sensor system 14 is shown in FIG. 1. In the preferred embodiment, the sensor system includes two groups of sensor assemblies 16 mounted on each tension leg 20. In the example, a first sensor ring 18 is mounted approximately thirty feet (eight to ten meters) from the mean sea surface and a second sensor ring 20 is mounted approximately sixty feet (sixteen to twenty meters from the surface. In some applications, it may be desirable to provide sensors strategically placed at intervals extending from the seafloor to a location near the surface platform. An ...

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The subject invention is generally related to measuring systems for monitoring the effect of environmental elements on subsea components in offshore oil and gas drilling and production and is specifically directed to fiber optic sensing systems employed as monitoring and measurement apparatus.

[0003] 2. Discussion of the Prior Art

[0004] Offshore drilling and production systems include a surface working platform in communication with a production field beneath the seafloor. All such systems have one feature in common, which is that a conduit of some sort is required to support drilling equipment and materials being delivered from the surface work platform to the subsea field, and / or a conduit for lifting oil and gas being produced from the subsea field to the surface work platform. In typical cases the conduit is a tubular pipe extending from the subsea field to the surface, generally referred to as a riser.

[0005] One such e...

Examples

Embodiment Construction

[0033]While the invention as described is illustrated using the sensor system 14 on the tension legs of a typical TLP 10, it should be understood that the system is readily adaptable to any SLVC incorporated in offshore drilling and production. The system is particularly useful, and similarly installed on risers, tension legs and other SLVC used during both the drilling and the production phase of the platform.

[0034]A TLP 10 with the sensor system 14 is shown in FIG. 1. In the preferred embodiment, the sensor system includes two groups of sensor assemblies 16 mounted on each tension leg 20. In the example, a first sensor ring 18 is mounted approximately thirty feet (eight to ten meters) from the mean sea surface and a second sensor ring 20 is mounted approximately sixty feet (sixteen to twenty meters from the surface. In some applications, it may be desirable to provide sensors strategically placed at intervals extending from the seafloor to a location near the surface platform. An ...

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