This paper illustrates the process of erosion and erosion management during the UnderBalanced Drilling (UBD) of a series of gas wells in the Southern North Sea_ In this context, tonnes of solids can be brought to the surface in a short lime frame and induce erosion sufficient to threaten plant integrity. Preferred units for erosion are therefore mm/tonne of solids produced rather than the traditional units mm~vr derived from corrosion management. This paper presents: • the role of an erosion assessment in advance of drilling • the practical measures put in place to minimise the risk from erosion (likelihood and consequence) • examples of the erosion damage that occurred, and discussion of their likely cause
• steps implemented (and proposed) to reduce and manage erosion in future