Schlumberger Releases World's 1st In-Riser System with SIL 2 Certification

Schlumberger announced at the 2009 SPE Offshore Europe Oil and Gas Conference the release of its SenTURIAN subsea landing string electrohydraulic operating system. Technological advances have resulted in an innovative, shorter modular system, which allows safe, reliable, and efficient completion installation, well cleanup and well testing from a dynamically positioned vessel in water depths to 15,000 ft (4,572 m).

SenTURIAN is the world's first and only in-riser system designed and certified in accordance with the International Electrotechnical Commission's IEC 61508 SIL 2 reliability specifications for safety-related systems. IEC is the international standards and conformity assessment body for all fields of electrotechnology. In addition, the design enables compliance with ISO 13628-7 standards by providing electronic redundancy and pressure readout for each subsea function.

"The short and compact system is easy to handle and to operate, which saves rig time," said Shehryar Lodhi, marketing manager, Schlumberger Testing Services. "It delivers reliable verification of equipment integrity and well control with state-of-the-art circuitry and accumulator technology."

SenTURIAN is the first landing string system to use interchangeable mandrels and pressure-balanced accumulators. This unique technological advance allows both subsea control and accumulator modules to be combined in a single assembly, which is 50% shorter than other systems, while providing the tensile strength, pressure rating and hydraulic output needed for operations in shallow to ultra deepwater.

The system was used in the first-ever deepwater well completed offshore India, and on a total of 28 successful completions in India and the Gulf of Mexico.

SenTURIAN operates the family of SenTREE subsea test trees, tubing hanger running tools, and completion equipment. It enables the closing of all subsea test tree valves and disconnection of a landing string in less than 15 seconds. Qualified to 275 degF (135 degC) and 15,000 psi (1,034 Bar), the system has an interchangeable mandrel to increase the pressure rating above 15,000 psi for project specific requirements.