By Don Shafer, Athens Group
Many drillers encounter thousands or tens of thousands of alarms per day – far more than recommended. When alarms are displayed at this frequency, it is difficult for even the most experienced driller to keep pace. Other times, alarms may be inaccurately mapped, causing them to appear incorrectly on the driller’s screen or, in some cases, to not appear at all.
The good news is that drilling contractors and operators can implement practices to help ensure that their alarm system is functioning correctly and is in compliance with regulatory standards. This reduces the risk that an improperly annunciated or missing alarm will result in nonproductive time (NPT), HSE incidents or citations from regional authorities.
FACTS AND FIGURES
Recommendations from the Engineering Equipment and Materials Users’ Association (EEMUA), the International Society of Automation (ISA) and the Norwegian Petroleum Directorate (NPD) set manageable alarm rates at about one alarm every five minutes and approximately 10 alarms or less every 10 minutes during peak operating conditions.
The Abnormal Situation Management Consortium found that 95% of the unique consoles observed during a study on alarm frequency received a peak of 31 to 50 alarms every 10 minutes during non-normal operations, such as in the case of an equipment failure or other emergency. That’s three to five times more alarms than are deemed manageable by the EEMUA, ISA and NPD.
A recent FMECA revealed that vital alarms might not be acted on in time because they were not categorized by priority amid the tens of thousands of alarms being displayed every day. During another project, we created an inventory of all alarms produced by drill floor equipment. The final list was more than 90 pages long and contained more than 2,700 alarms.
WHY SO MANY ALARMS?
Today, it’s easy to add an alarm, but historically it hasn’t always been simple. When alarm systems were hardwired, the installation of new alarms was expensive and carefully planned. Because offshore assets are becoming increasingly dependent on control systems software, it is now relatively quick, easy and inexpensive to add thousands of alarms.
The downside is that the complexity of control systems makes it difficult for staff without extensive software engineering experience to verify that alarms are interfacing correctly with each component. The High-Level Composite Systems Interface Diagram (Figure 2) illustrates the numerous systems that come together at the driller’s chair.
THE ALARMING SITUATION
Alarm mapping involves so many control system components that improper alarm calibration and mapping errors often occur. Early warnings may not be given if, for example, an alarm is not calibrated to pick up a temperature increase that is indicative of an equipment failure. Mapping errors can also prevent early mitigation efforts if an alarm is mapped to the wrong piece of equipment. For instance, a mapping error could prevent the discovery of a problem with a pipe handler if the alarm meant for that pipe handler had been mistakenly mapped to a mud pump.
Even if alarms are mapped correctly, they can still be improperly annunciated. An alarm system must be consciously designed to help prevent ambiguous alarm messages and to help ensure that alarms are prioritized correctly; otherwise, drillers can end up viewing hundreds of alarms nearly simultaneously.
7 PRACTICES TO HELP
Alarm system errors have led to issues ranging from trip tank overloads to unnecessary replacement of drilling equipment to compressor fires. To help prevent such circumstances, drilling contractors and operators can implement practices to help increase alarm system reliability.
1. Define requirements. Having an alarm philosophy in place for every drilling asset is essential. The first step in evaluating an alarm system is to determine objectives and any applicable regulatory requirements. The output from this exercise should serve as input for the creation or reassessment of alarm philosophy documentation and can also help determine if tools such as alarm management software are appropriate.
2. Take inventory. Is the alarm philosophy reflected in the system itself? A review of the alarm database helps to make this determination. This review should check for correct prioritization and life span, relevance, appropriate annunciation points, consistency, single points of failure in the alarm communication path, and compliance with industry and regulatory requirements.
3. Document. After the alarm database has been examined, the next step is to create a master alarm document. This will help to ensure that the information necessary to effectively respond to alarms, correct any issues that have been identified and to perform ongoing maintenance of your alarm system has been logged in a central location. The master alarm document should contain the tag, text, priority, significance and annunciation point for each alarm; any related equipment; detailed action required of the operator; remediation and mitigation plans; and emergency and maintenance contacts.
4. Benchmark. Benchmarking will help ensure that, if alarm system performance changes, the appropriate personnel will be alerted. The first step in monitoring an alarm system is to choose the system metrics to be captured and to determine time intervals for collecting this data. Next, an analysis tool, such as an alarm management software package or a custom reporting application, should be selected.
According to a recent industry survey, 67% of drilling contractors plan to implement alarm management software in 2010. Once these software are established, alarm system performance metrics can be reviewed and appropriate benchmarks can be established.
5. Train. Providing personnel with the appropriate training helps to ensure that they can effectively monitor, fine-tune and maintain the alarm system. A syllabus and course handouts should be developed using the established alarm philosophy, master alarm document and any related vendor documentation.
6. Audit. Regular audits help to ensure that alarm management processes are being followed. They are also needed to ensure compliance whenever equipment is changed, software is updated or reconfigured, operating requirements or standards change, or crew members are added.
Audits should consist of the following steps:
• Review and recommend improvements to existing alarm philosophy documentation;
• Review alarm database changes for priority, relevance, annunciation points and consistency;
• Recommend updates as needed;
• Examine alarm logs;
• Identify any process gaps and recommend improvements;
• Update existing training material or prepare a syllabus and course handouts for a “train the trainer” session;
• Provide staff with refresher training as needed.
7. Continually improve. Implementing recommended changes and regularly monitoring key performance indicators help to ensure continued high performance.
The seven practices outlined here are proven to help drilling contractors and operators take effective action in these areas.
This article is based on a presentation at the IADC World Drilling 2010 Conference & Exhibition, 16-17 June 2010 in Budapest, Hungary.
For more information, visit www.athensgroup.com.
1. Abnormal Situation Management (ASM) Consortium, “Achieving Effective Alarm System Performance: Results of ASM Consortium Benchmarking against the EEMUA Guide for Alarm Systems.”
2. Norwegian Petroleum Directorate, “NPD YA-711: Principles for Alarm System Design.”
3. Engineering Equipment and Materials Users’ Association, “EEMUA 191: Alarm Systems: A Guide to Design, Management and Procurement.”
4. The International Society of Automation, “ISA 18.2: Management of Alarm Systems for the Process Industries.”
5. Athens Group and ModuSpec. The State of NPT on High-Specification Offshore Assets: Second Annual Benchmarking Report: Focus on Commissioning and Human Resources. 2010.