There are approximately 850 operational offshore oil rigs, or oil platforms around the world. These multipurpose structures support the process of well drilling, the extraction of either oil or natural gas, and the processing and storing of the product until it is transported to shore for refining and use. Many oil platforms contain extensive housing and transportation facilities for staff as well.
Depending on the type of oil platform and the environment, the structure may float or be fixed to the sea floor. In either case, the oil rig structure is typically assembled off site and must be installed on top of the anchoring structure at sea. Accurate measurement is essential for a successful installation at sea.
Engineer was tasked with the installation of an oil platform deck onto steel legs anchored directly into the seabed. This particular platform supports an enormous load with deck space sufficient to support drilling rigs, production facilities, and housing quarters. The challenge was to accurately measure these steel legs and determine the correct cut-off height to perfectly match the deck structure while at sea.
The time from set-up to final “pop” mark was about two hours. The set-up and data collection on the day of the installation took about 40 minutes, the office calculation took approximately 40 minutes, and the final set out of marks took another 40 minutes. The final installation proved the accuracy of the measurements when the platform fit within a millimeter of dead center.