Abstract
Abstract
It is suspected that some crude oils contain hydrate-active components that can render the hydrate surfaces from being water wetted to oil wetted. Water wetted hydrates are more prone to plugging and is sought to be avoided. In this work the aim was to accumulate naturally occurring hydrate-active components from a crude oil by a successive extraction and spiking process. The gas hydrates were formed by pressurizing and cooling crude oil, brine and a hydrocarbon gas in ahigh-pressure autoclave set-up. Conductivity and temperature measurements were used to determine hydrate formation, nature of the continuous phase and possible phase change upon hydrate formation. A successive extraction and spiking process with 4 "generations of spiking" was performed to accumulate possible hydrate active components in the respective crude oil. By using the last generation to spike a system with fresh oil and water it was shown that the spiked system increased the emulsion inversion point from to (at least) 80% water cut when compared with the fresh oil sample which inverted at a water cut of 70%. This result indicates strongly an effect of the accumulation procedure possible as a result of an increase in the amount of hydrate active components in the spiked system. Furthermore, PCA of the FT-ICR MS spectra indicated a large difference between the fresh crude oil and the oil extracted from the hydrate phases and a trend in the oil samples from the hydrate phases of the different "generations". Thus, the overall results indicate that the procedure managed to accumulate hydrate active components present in the selected crude oil.
It is suspected that some crude oils contain hydrate-active components that can render the hydrate surfaces from being water wetted to oil wetted. Water wetted hydrates are more prone to plugging and is sought to be avoided. In this work the aim was to accumulate naturally occurring hydrate-active components from a crude oil by a successive extraction and spiking process. The gas hydrates were formed by pressurizing and cooling crude oil, brine and a hydrocarbon gas in ahigh-pressure autoclave set-up. Conductivity and temperature measurements were used to determine hydrate formation, nature of the continuous phase and possible phase change upon hydrate formation. A successive extraction and spiking process with 4 "generations of spiking" was performed to accumulate possible hydrate active components in the respective crude oil. By using the last generation to spike a system with fresh oil and water it was shown that the spiked system increased the emulsion inversion point from to (at least) 80% water cut when compared with the fresh oil sample which inverted at a water cut of 70%. This result indicates strongly an effect of the accumulation procedure possible as a result of an increase in the amount of hydrate active components in the spiked system. Furthermore, PCA of the FT-ICR MS spectra indicated a large difference between the fresh crude oil and the oil extracted from the hydrate phases and a trend in the oil samples from the hydrate phases of the different "generations". Thus, the overall results indicate that the procedure managed to accumulate hydrate active components present in the selected crude oil.
