In the early days of floating drilling it became apparent that a pivot point at the lower end of the marine riser next to the BOP stack was needed to reduce stress and fatigue in the marine riser. As water depths increased a new devise was needed. Lockheed Propulsion invented a pivot devise consisting of concentric spherical rings of steel separated and adhered to by elastomeric material that could withstand very large tensions and pressures. In 1976 the first subsea drilling “Flex Joint”TM was designed and manufactured by Oil States and used on a SEDCO rig. Following its successes in drilling, the technology was used in 1984 for the TLP tendons on the North Sea Conoco Hutton platform. In 1994 Shell used the device with steel catenary risers (SCR) on floating production systems. Since that time there has been over 700 versions of the Flex JointTM used in the offshore oil and gas industry.
Recognizing the pioneering efforts of the following individuals and organizations that contributed to this technology: Mark A. Childers, Mike Hogan, Frans Kopp, Craig Lang, Carl Langner, Charles Moses, Charles Reinhardt, Earl Shanks and Jim Slade Conoco (now ConocoPhillips), Kingsnorth Marine Drilling, Lockheed Propulsion, ODECO (now Diamond Offshore Drilling Inc.), Oil States (now Oil States International, Inc.), SEDCO (now Transocean), and Shell
The earliest floating drilling operations were carried out with direct control lines from the vessel to each function on the BOP stack. Many innovations were required to make these systems suitable for deeper water and separately retrievable. The pioneering innovators of subsea BOP control systems were individuals with Payne Manufacturing Co., Koomey Division of Stewart & Stevenson Distributing Co. and Hydril Co (now Tenaris). The following table summarizes important developments of these systems.
|1953||Submarex||Koomey||Directed connected control lines|
Air operated hydraulic plunger pumps
|1955||CUSS I||Hydril||Electric Hydraulic Plunger Pumps|
80 gallon, 1500 psi accumulators
|1961||Bluewater 1||Koomey||3000 psi accumulators with two pressure-reducing/regulating valves|
|1963||Ocean Driller||Payne||Bundled controlled hoses and retrievable control pods|
|1967||STAFLO||Koomey||SPM valves and choke & kill lines incorporated in control pods|
|Nuclear powered subsea hydraulic pumps and acoustic controls|
tested but non-commercial
|1968||Glomar V||Koomey||Compact design packer seal pods|
|1968||Sedco 445||Koomey||First electro-hydraulic controls and 6000-psi accumulators|
|1970||Discoverer||Koomey||First Multiplex (MUX) control system|
Floating drilling began in 1955 when Chevron’s “Western Explorer” used a subsea BOP controlled via individual control hoses from the surface; however, this resulted in the hoses becoming entangled and damaged even in these shallow water depths. Samuel Moore formed a small company in 1948 that developed the ability to bundle the hoses with an outer jacket. The first “bundled and jacketed” umbilical for the oilfield was 250 ft. long delivered in 1962 to the Global Marine (now Transocean) “CUSS II” under the name trade name “Synflex”. As water depths increased, the reaction time to close the BOPs became unacceptably long. The “pilot” control system was first developed by Hershel Payne using small plot hoses to shift pilot valves in a “pod” on the subsea BOP stack that directed power fluid to the proper function. This greatly decreased reaction times and was first used on the Ocean Drilling and Exploration Co. (ODECO and now Diamond Offshore) “Ocean Driller” in 1963 working for Texaco (now Chevron) in the Gulf of Mexico. The technology of “thermoplastic” pilot and power hoses encased in a polyurethane “jacket” or “out sheath” developed using different materials and weave patterns from short lengths to over 8,000 ft. lengths through the next decades. The number of pilot lines (usually 1/8 and/or 3/16 inch OD) increased from the original 22 to over 80 in some advanced bundles in the 1990s with the OD of the umbilical increasing from a few inches to over 5. Seismic and other segments of the oil and gas industry also adopted this new technology.
In 1977, umbilical technology was first used in the production mode offshore India for ONGC in the Bombay High Field to control a subsea Christmas tree. In the early 1980s, Phillips Petroleum used an umbilical from Multiflex (now Oceaneering) to control subsea Christmas trees half a mile from a platform in the North Sea. With the growth of subsea completions and the control point farther away, control systems went from all hydraulic, to electro-hydraulic to multiplex-hydraulic with other non-control functions required in the umbilical bundle. These may include thermoplastic hoses, stainless steel tubing, electric power cables, electronic wiring for control and monitoring, fluid injection and other items all encased in a weighted armor jacket. With advancements in control systems, production umbilical lengths have grown to over 50 miles long and weigh hundreds of tons.
Without the development of umbilical control technology in the drilling industry, deep water drilling in the 1960s – 2000s could not have been accomplished. With the development of armor cased umbilicals with multiple types of leads, production via satellite Christmas trees and production manifold could not have been achieved.
Recognizing the pioneering efforts of the following individuals and organizations that contributed to this technology:
Mark Childers, Hugh Elkins, Ed Greene, Samuel Moore, Hershel Payne, Emmett Richardson and Bill Savage, Multiflex (now Oceaneering), Payne Manufacture Co. (now Schlumberger), Samuel Moore & Co. (now Eaton) and Stewart & Stevenson (now Schlumberger)