Deep-sea safety: New SIL-3 controller certified for underwater applications

Growing importance of offshore drilling for oil and gas expands demand for pressure monitoring and protection systems to prevent injuries and environmental disasters.

By Control Engineering Staff November 3, 2008

With the growing sophistication and integration of process safety systems, safety-related PLCs (programmable logic controllers) are being deployed in more demanding applications. HIMA has now released its latest HIMatrix F35 controller for subsea applications, which it says is one of the first safety PLCs for use at up to SIL-3.

Working with its Norwegian representative Bjørge Saas System , HIMA has developed a HIPPS (high integrity pressure protection system) that monitors excess wellhead pressure and partially isolates pipe pressure by closing off effected pipeline segments. The HIMatrix F35 subsea controller meets the rigorous demands of the growing off-shore oil and gas drilling market, and is one of the first safety-related programmable logic controllers for use at up to SIL 3.

“Development of deep-sea oil and gas reserves has become increasingly attractive due to global energy demand. However, deep-sea applications are subject to increased environmental protection requirements due to the considerable impact of an equipment failure, as well as the challenges involved in localizing and addressing any failure,” says Rolf Hafner, head of product management. “For that reason, there is keen interest for deployed systems to offer the highest level of safety and availability, and the HIMatrix F35 subsea controller is the ideal solution for today’s complex underwater applications.”

HIMA says the subsea system incorporates a redundancy design where dual HIMatrix F35 controllers are used, together with two safety-related HIMatrix F3 AIO subsea remote I/O modules. The HIMatrix controllers are connected via safe Ethernet, and the link to the SEM (subsea electronic module) is made through Modbus RTU.

HIPPS can be used at depths down to 4,000 m, and the first projects using these capabilities have been successfully completed. The system was built for deep-sea applications in accordance with IEC 61508/SIL 3 and ISO/DIS 13628-6 (“Control Systems for Underwater Production”). Pressure is monitored by three or more pressure meters, with pulse-to-trip and partial stroke tests used to control the HIPPS valves.

HIMA’s products have been tested for meeting high mechanical demands of subsea applications (vibration testing in the spectral range of 0 to 2,000 Hz/6 G), and the extended operating temperature range from -20 to 60 °C, have been verified in extensive testing by TÜV Produkt Service GmbH, Unternehmensgruppe TÜV Süddeutschland (Mannheim, Germany) and the Teknologisk Institutt TI (Kongsberg, Norway).

—Edited by Peter Welander, process industries editor, PWelander@cfemedia.com , Process & Advanced Control Monthly Register here and scroll down to select your choice of free eNewsletters .