Solids characterisation forms an integral part of many studies related to petroleum engineering, e.g., coreflood evaluation assessment of fines migration and characterisation of precipitates; and is often completed using routine analytical methods such as Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). These methods, however, cannot provide sub-micron detail of morphology and chemistry of solids and cannot be applied readily to characterise non-crystalline solids or solids present in low quantities. In this study, ATEM has been applied to examine solids isolated from produced fluids from an oilfied. The method has the potential to give early indication of production problems like sands production and scaling. It has also been used effectively to characterise scale inhibitor precipitates, which are non-crystalline, from corefloods and ‘batch’ experiments. Although ATEM cannot be viewed as a routine method since it requires specialised equipment and expertise, it can provide critical information.