The accurate and precise analysis of scale inhibitors—in conjunction with other field data such as ion analysis, total suspended solids, and productivity index—plays an important role in making decisions about the efficiency of scale squeeze and continuous chemical injection treatments. This paper presents a review of scale-inhibitor analysis techniques and describes how these techniques can be used to provide cost-effective scale management in simple and complex production scenarios.
Scale-Inhibitor Analysis Methods
This overview of scale-inhibitor detection methods is based on a database of analytical techniques previously developed through a joint industry project and expanded to cover alternative approaches and recent developments in high-performance liquid chromatography, recently developed C18 ion pair approaches, improved benchtop polymer analysis for sulfonated polymers, and more recent methods such as time-resolved fluorescence (TRF) and other fluorescence-based approaches.
The premise of this paper is that, although various methods are available for scale-inhibitor analysis, most are affected by interference of some degree and that, while a preferred method may be sensitive and accurate under a particular set of conditions, it is unlikely to be effective in all production environments. The scale-inhibitor analyst, therefore, requires a large toolbox of alternative approaches that can supplement original methodologies.
In many cases, inappropriate analysis techniques can render expensive coreflood testing and field trials ineffective, thereby leading to the risk of qualification and selection of inappropriate products in the laboratory or poor performance when applied in the field. For field returns, the use of an inappropriate method has obvious implications: an increased risk of well failures because of uninhibited scaling.
Sample preservation also is critical.
