Abstract
Black Powder is a common corrosion related contaminant causing operational issues in gas pipeline networks. Some of these networks large amounts of black powder or debris can be present as a result of many years of operation. In addition to the years of uncertainty, the presumption is all internal integrity threats were previously managed due to the conveyance of sales grade dry gas, which is not always the case. In aging and complex gas distribution networks, due to the difficulty of conducting inspection, the magnitude of deposit accumulation is unknown.
Operators therefore have a problem when it comes to validating the internal condition of their gas distribution networks, usually only being able to perform intrusive inspection at huge cost. To overcome this, ROSEN has developed an approach similar to ICDA in order to identify hotspots and buildup areas within city gas distribution networks without the need for intrusive inspection. hotspot areas were identified using advance flow modelling and are then confirmed by non-intrusive NDT methods. This paper goes through a case study of the approach and how it was confirmed to be accurate to pipeline conditions with only a 4% error. In addition, areas of black powder build-up were also identified and validated to be within a 15% error band. These factors together enabled the operator to prove the condition of their network and gain an estimated remaining life, additionally the requirement for pipeline pigging, both operational and intelligent was assessed and deemed not required, saving significant costs both directly and in supply disruption.
