Surface Scaling in the Oil and Gas Sector: Understanding the Process and Means of Management

Abstract

The oilfield scale is undoubtedly one of the most important flow assurance issues in the recovery of oil and gas. The formation of sparingly soluble salts of BaSO 4 and CaCO 3 when incompatible brines are mixed causes serious operational issues and imposes a large economic burden on operators. Scale management is principally by the deployment of oilfield chemicals, scale inhibitors, which work efficiently at sub-stoichiometric concentrations. Much of the research work in scale inhibitors has been directed toward (a) the deployment of chemicals through squeeze treatments and the adsorption and desorption (release) kinetics from the formation and (b) the determination of the minimum inhibitor concentration (MIC) to prevent bulk precipitation from bulk jar tests. Work carried out in the University of Leeds for the last 9 years has focused on understanding the deposition of scale on solid surfaces, and this paper summarizes some of the current thinking with respect to the importance of surfaces in scale management. The quantification of scale at the surface, the visualization of scale as it forms on the surface, and the notion of a different inhibition criterion (MIC) for surface and bulk scaling are all discussed in this paper. This paper is focused on the calcium carbonate system, but much of the discussion is also relevant to BaSO 4 and other common inorganic scales (e.g., CaSO 4 ).

Systematic Study of Barite Nucleation and Inhibition With Various Polymeric Scale Inhibitors by Novel Laser Apparatus

“…The SI coefficient b 3 is À1.4953. A negative b 3 means that as SI increases, the inhibition efficiency decreases, which is supported by classic nucleation theory (Mullin 1993) and often observed experimentally (Veter 1972;Van der Leeden et al 1992;He et al 1994).…”

“…Synchorotron X-ray diffraction was used to study barite formation and inhibition on surfaces (Mavredaki et al 2011). In addition, in-situ monitoring of both surface and bulk deposition of calcite was also reported (Chen et al 2005;Eroini et al 2012;Neville 2012). Currently, in the oil-and-gas industry, barite nucleation and inhibition are investigated mainly with both dynamic and static inhibitor testing under specific conditions (Fernandez-Diaz et al 1990;Yuan et al 1998).…”

Development of a novel once-through flow visualization technique for kinetic study of bulk and surface scaling

“…Improving the collective knowledge of surface deposition in terms of induction, nucleation, and growth processes will help in the application of an effective inhibition strategy and also in developing effective antifouling coatings to prevent scale formation on surfaces. [31][32][33] …”

Top-Down Model of Limescale Formation in Turbulent Pipe Flows

“…The spontaneous formation of calcium carbonate (CaCO 3 ) scale, also known as limescale, is an ordinary phenomenon long known to affect the efficiency of water supply networks, boilers and heat exchangers (Koutsoukos and Kontoyannis 1984;Lin et al 2020). Limescale formation is also a great source of worry in the oil industry, where it leads, from time to time, to operational issues that are commonly found from the deep production pipelines installed in oil reservoir cores up to topside facilities (Vetter and Farone 1987;Neville 2012;Olajire 2015). Particularly dramatic instances of calcium carbonate scale are those related to the exploration of carbonate reservoirs, which actually hold about 60% of all of the world oil reserves (Burchette 2012).…”