Scale build-up in petroleum production systems is a major impediment to efficient oil and gas production. Calcium carbonate is one of the most commonly occurring sources of scale, but the formation of gas hydrate is also a challenge, especially in offshore and subsea deep water production. Thermodynamic inhibitors like monoethylene glycol (MEG) are frequently used to prevent hydrate formation. This paper describes the influence of MEG on the calcium carbonate scaling time by using a Dynamic Scale Loop System (DSL). The study also examines the influence of temperature, pressure and salt concentration on the scaling time. Experiments were performed using a 25-1 fractional factorial experiment design. The experiments showed that as MEG content increases, the expected calcium carbonate scale decreases. In contrast, an increase in temperature, will increase the calcium carbornate scale, while pressure and salt concentration did not have a significant influence on their own. Furthermore, the paper describes the interaction between the variables under review. The interaction between pressure, temperature and MEG content results in an overall decrease in MEG performance to avoid scale build-up by changes in the system's viscosity. Finally, we determine that the increase of MEG content increases the time to reach full-scale blocking; thus, the results indicate that an inhibition of the calcium carbonate deposition occurs as the MEG content increases.

Keywords:
scale formation, wax inhibition, interaction, upstream oil & gas, production chemistry, meg content, scale remediation, hydrate remediation, paraffin remediation, scale inhibition
Subjects:
Production Chemistry, Metallurgy and Biology, Inhibition and remediation of hydrates, scale, paraffin / wax and asphaltene
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2017. Offshore Technology Conference
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