The primary purpose of a drilling marine riser system is to allow circulation of fluids into and out of the wellbore, help maintain well control, and guide items into and out of the wellbore. The roots of riser analysis start with the Mohole project in 1950. The first floating drilling rigs to utilize a metal marine riser were the CUSS 1 (Continental, Union, Shell, and Superior Oil) and D-1 (Offshore Co.) in 1957. Initially for very shallow water, simple column analysis was considered adequate but as water depths increased the industry realized it was necessary to understand the physics, materials of the structure and operating parameters to recommend adequate top tension and vessel position limits.
The technology advanced slowly until floating drilling became a priority for several oil companies. In 1965, the CUSS 1, drilling for Humble Oil & Refining Co., set a world water depth record of 632 feet in the Santa Barbara Channel and was a precursor for the deepwater Santa Barbara Channel OCS lease sale in 1968. Key operators were Chevron, Shell Oil, and Humble Oil, each building and modifying floating rigs while developing proprietary technology. It was apparent to these companies and emerging riser manufacturers that more comprehensive riser analysis methods were needed for the static and dynamic issues in deepwater riser analysis, design and operation.
Between 1965 and 1973, several professional papers had been published, revealing much of the early analysis technology. The critical effect of mud density on required riser tension was discovered and named the effective tension principle. By 1973, riser analyses had incorporated dynamic behavior from wave-induced motions of the riser and the vessel.
This first phase in the ability to analyze, predict behavior and operate drilling risers was a key factor in the successful evolution of floating drilling to 1,500 feet of water, laying the foundation for future advances to greater water depths.
Recognizing the pioneering efforts of the following individuals and organizations that contributed to this technology:
Gerald L. Barksdale, Ben G. Burke, Mark A. Childers, William Fischer, Clinton Gosse, John Lacy, Milton Ludwig and Danny R. Tidwell,
Cameron Iron Works, Esso (now ExxonMobil), Shell, Standard Oil (now Chevron).