Lloyd's Register’s Brady Austin, Bill Mason, Garry Moon and Jarret Reeves consider the current state of gas detection and explore whether there are other areas that will increase risk management cost-effectively and, in turn, enhance operations onshore and offshore.
The thought of gas vapour leaking, escalating and finding an ignition source keeps the upstream, midstream and downstream businesses awake at night. It is a powder keg of a problem in terms of safety and environmental risk that needs addressing. It is also integral to a company’s commercial success. Recent industry fines associated with gas escapes have been hefty, as legislation finds its teeth in a number of regions. Given that unplanned shutdowns have proved even more costly, what else can be done in tackling this issue head-on? Are there other areas, away from gas detection systems, that will increase risk management cost-effectively and, in turn, enhance operations?
The current state of gas detection
Fixed and portable gas detection systems are relied on to prevent losses, forming an important part of formal risk management. But such devices cannot be designed to cover every probability and, now and again, a detector will fail. They are one link in a chain, as is the case for all preventive safety systems industry-wide. Gas detection systems also bring some unique challenges.
Increasingly, the reliability of conventional systems, which use catalytic sensors, are being questioned. Many now argue that these commonly found devices will not detect the majority of leaks until the escaped gas reaches a hazardous level. In addition, sufficient hazardous accumulations are unlikely to be detected in open areas or certain conditions, such as where there are high winds. There have been some promising advances in recent times, with open path gas beam detectors beginning to replace their catalytic counterparts. Advocates of these new systems claim they improve detection by covering a larger span. However, there are still occasions when a leak doesn’t break the infrared beam and will remain undetected. Elsewhere, acoustic systems are being championed as providing the most effective means of detecting high-pressure releases, even from pin-hole size leaks. Ultrasound is a well-established technology in many areas of engineering and, given that most leaks generate ultrasound, the signs are encouraging. For now though, these solutions remain on the horizon, with only hazardous accumulations really being detected. Added to all of this is another obstacle; it is often difficult to quantify the parameters involved with gas detection. Defining the required performance, and then relating that to safety requirements, is far from straightforward.
Returning to the source of the problem
Getting back to basics points an interesting way ahead. Let’s consider what causes a high percentage of gas leaks, onshore and offshore. Fugitive emissions from process equipment may be small-size releases individually, but they soon add up, forming the majority of the industry’s total emissions in fact. These types of emissions occur from non-point sources. Leaking pipe flanges, often as a result of poor bolting during operational maintenance, are a chief culprit, along with issues with pump seals, valves, damaged pipework, hoses, loss process couplings and other related components. With a modern refinery having kilometres of pipework, by way of example, we can start to picture the enormity of the scale of gas detection. There are also the end devices themselves to think about. Many of the process control and safety devices make use of gas to perform their functions, further releasing gases into the environment.
Improved gasket materials and bolting techniques have made some difference in preventing gas from escaping, and likewise making use of electronic control devices, as opposed to conventional gas and pneumatic control systems. By and large, however, it would be fair to say that the process of operational maintenance has not fundamentally changed for half a century or so. It is time then to explore a little wider.
A hole in the industry’s knowledge
Besides pinholes in pipes, there is a huge data gap when it comes to a company’s pipelines and pipework. The problem is not always the lack4 of data itself, which often exists in some form or another. The challenge is connecting this data up. The common industry practice is to use an Enterprise Asset Management (EAM) system, such as IBM Maximo or SAP, to schedule maintenance of physical assets across their lifecycle. These systems have tended to hold data on what have been defined as core elements. This invariably excludes the pipes that join up such elements, often with the plan to add information about these at a later time. We would estimate that around 10% of companies define their pipe in their planning system; the vast majority of related maintenance and procedures will therefore fall outside of the central system’s work order.