Early April saw yet another fatal accident at a U.S. refinery. Seven workers were reported killed in an explosion and fire in a naphtha hydrotreater unit during routine maintenance at the Tesoro refinery in Anacortes, 70 miles north of Seattle, Washington. Of the 18 on-going investigations at the U.S. Chemical Safety Board (CSB), seven concern accidents at refineries, and the CSB sees this as a significant and disturbing trend that should be addressed immediately by the industry.
The Washington Department of Labor & Industries inspected the Anacortes refinery last year, under the OSHA program of increased refinery inspections initiated after the BP Texas City explosion. This resulted in 17 serious violations being identified at the refinery, mainly for the same unit where the fire occurred.
The CSB investigation at Tesoro will hold up work on other important CSB investigations. These include the Caribbean Petroleum fuel terminal fire near San Juan, Puerto Rico; the CITGO refinery hydrogen fluoride release and fire in Corpus Christi, Texas; the Goodyear heat exchanger rupture and ammonia release in Houston, Texas; and the Exxon Mobil refinery hydrogen fluoride release in Joliet, Illinois.
Echoing comments made by Ian Nimmo of User Centered Design Services on the establishment of national and industry standards for process plant alarm systems after the Texas City explosion and investigations, the guidelines from the Norwegian Petroleum Directorate for petroleum production installations, and the Norsok standards in use in Norway, were highlighted in another recent paper presented at the ISA's 65th Annual Instrumentation Symposium for the Process Industries, in January of this year. Norsok Standard 1-002 defines an overall Safety and Automation System (SAS), incorporating process control, process shutdown, Emergency Shutdown (ESD), Fire & Gas, power distribution and control, plus information management systems. It thus implies commonality in the HMIs for all the individual systems within the SAS, as it treats all the units as an entire system. It also allows the use of Large Screen Displays (LSDs) and Video Walls with a common HMI, so it is important that each of these systems is controlled by a common philosophy and style guide.
Ten Years Behind?
This is a major step forward from practices in the rest of the industry, which have allowed project integration after placing orders on different vendors and accepting their style for each of the individual system solutions. The Norsok Standard (revised in 2001) addressed all these issues and even defines a testing strategy and the required display and system time responses. In addressing the ISA January conference Nimmo pointed out that "With a track record of catastrophic disasters, to drive out human error there must be workable standards written by our country and our industry." He felt that the United States was 10 years behind the Norwegian industry in this respect, a view confirmed by the fact, in a review of refinery accidents conducted after Texas City, insurer Swiss Re found "significantly higher" accident-related losses for U.S. refineries compared with those in the rest of the world.
Exemplifying the Norwegian approach is the Ormen Lange gas field which came on stream in 2007 and is expected, at full production, to account for 20% of the U.K. gas requirement of 70 million cubic meters a day from a reservoir 120 km off the Norwegian coast. Operator Norske Shell uses three video walls to help control the export of gas down the pipeline across the North Sea to the U.K. Barco supplied the video walls to ABB, who were contracted to deliver the control, safety and information management systems for the gas processing plant. "Ormen Lange needed a visualization solution to monitor the plant and the flow of gas through the pipelines, plus display solutions for the simulation and collaboration rooms," said Morten Hansen, sales manager of Barco's Norwegian distributor, VideoSystem: "The human aspect and ergonomics were of key importance for the control room."
ABB designed an ergonomically optimized room with a 14 x 50 in. central Barco video wall system with rear projection, plus a simulator room, with a video wall made up of a 4 x 2 format of 50 in. cubes and mounted on casters to allow front projection.
During normal operations, the video wall displays process overviews, live CCTV camera feeds, an alarm list and a fire and gas overview, but during an emergency shutdown, the on-screen content can be changed to zoom in on safety and security relevant information. "The operators have an easy, unifying overview of operational as well as security aspects of their operations. In case of a problem, they can spot it straight away, as the alarm is clearly visible, and then look at the desktop for more details," said Hansen.