Structural Properties Measurements in Deepwater Oil and Gas Fields using an Advanced Fiber-optic Sensor Monitoring System

摘要

Deepwater fields in the Gulf of Mexico, West Africa, Offshore Brazil, and elsewhere has undergone a significant increase in oil and gas exploration and production activities. Discovery and development of deepwater oil and gas fields is made possible, in part, due to the application and advancement of new technologies that can detect important engineering properties of subsea equipment and environmentally induced conditions. Such technology advancements results in operational assurance, cost reduction, and greatly reduced risk of system failure. Described herein is an advanced instrumentation method developed for deepwater risers and pipelines. Fiber-optic sensors have been developed and implemented as a means to provide real-time strain, temperature, vibration, and flow monitoring for pipelines in deepwater. Fiber-optic sensors are attractive in deepwater applications because of their multiplexing capability, immunity to electro-magnetic interference, ruggedness and long distance signal transmission ability. Design maturity of a complete fiber-optic sensor system has been achieved through full scale riser deployment in actual deepwater fields. Two major areas of concern exist for deepwater riser structural integrity. The first concern involves high mechanical loads in the touch down area where the riser sits on the ocean floor and transitions from horizontal to vertical leading to topside. Secondly, vortex induced vibration that is caused primarily by high rate ocean currents. Both areas are susceptible to rapid fatigue failure.