A BOP relies on a sophisticated redundant control system to achieve desired reliability and safety. The BOP system software must work seamlessly integrating sensors, valves, and diagnostic feedback while being able to hot swap in a fully redundant environment. It is known that software errors may lead to nonproductive time, delays, compromise safety and potentially lead to an environmental disaster. Software failure risks can be mitigated by performing HIL testing which is a well-established test methodology in other industries such as automotive and aerospace, where high performing and robust control systems are essential, and has through the last decade been established also in the maritime and offshore industries. NOV Rig Systems and DNV GL Marine Cybernetics Advisory have together developed a test setup for HIL testing of BOP control systems by combining simulators from both parties.
Basic functionality of the BOP control system is tested through automatic scripts, allowing extensive testing and regression testing (to verify that software previously developed and tested still performs correctly after it has been changed during updates or retrofits based on customer requests). Often new functions are added or existing ones are modified and this could potentially lead to undesired errors. This paper demonstrates how this technology reduces the risk of adding software errors, by using a systematic and automatic testing approach.
This paper introduces HIL as a methodology for BOP control system software testing and shares the experiences from automated testing by using CyberSea Signature on the BOP Control System delivered by NOV Rig Systems.