TechFront New Developments in Manufacturing and Technology
ROVs Travel Deep in Subsea Energy Search
R
emotely operated vehicles (ROV) rose to the top of pub- lic consciousness with the Gulf oil spill disaster in April 2010. Streaming video from ROVs working to staunch the flow of oil from the Macondo well was seen on television screens around the world in real time after the Deepwater Horizon rig exploded, burned and sank. Before the oil surge was stopped, an estimated 5 million bar- rels of oil would be released before the well was brought under control three months later through ROV technology. Development of deepwater oil and gas fields at depths to 13,000+ ft (4000 m) has challenged the complexity and reliability of ROV technology required to meet all the require- ments of exploration, drilling, completion, and intervention. “In addition to trouble-shooting in the Gulf, ROVs are needed for every aspect of subsea oil and gas exploration and production,” said Tyler Schilling, regional manager, FMC Schil- ling Robotics (Davis, CAia). “ROVs map the sea floor, work in drilling and completion, construction and installation of trees, manifolds, and plumbing, perform workovers to restore the productivity of wells, and finally facilitate abandonment by cementing wells, removing equipment, and cutting off tubing below the sea floor.” Most of the robotic ma- nipulator arms and two of the ROVs used in the Gulf intervention were manufactured by FMC Schilling Robotics. Principal components of a ROV system are the submarine with two installed manipulators and a tether management system (TMS). The ROV is lowered into position under a TMS (Top Hat) and then released attached to the TMS by a tether which carries electric power, video and data signals necessary for monitoring and control. ROVs are equipped with a combination of video cameras, searchlights and sensors required for the tasks at hand. Launch and recovery systems and control vans are also needed.
An ROV submarine carries all the hydraulic power equipment, sensors, video and manipulator tools for performing operations in difficult deep sea environment. The manipulator arm on the right side is dexterous; the arm on the left side powerful.
Assembly of the ROV systems is done at FMC Schilling’s headquarters and assembly facility in Davis. Machining of components is performed in a separate machine shop using horizontal machining centers, the NH 5000 and the NH 6500, from DMG Mori Seiki USA (Hoffman Estates, IL). Components machined to exacting dimensions and accuracies include actuators, joints, robot arms and fluid sealing system com- ponents that are essential to keep sea water out and oil and fluids in the ROV systems.
“Our modular approach to system design encompasses mechanical, electrical, electronic and hydraulic sub-systems. But computer-crash-like events are a way of deep-ocean life