Marina Lima Publications

Marina Lima

PhD Student for Geothermal Energy and Geofluids

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Mailing Address
Marina Grimm Lima
Geothermal Energy & Geofluids
Institute of Geophysics
NO F 55
Sonneggstrasse 5
CH-8092 Zurich Switzerland

Contact
Phone +41 44 633 4041
Email marina.lima(at)erdw.ethz.ch

Administration
Dominique Ballarin Dolfin
Phone +41 44 632 3465
Email ballarin(at)ethz.ch

Publications

THESES

1.  Lima, M. The effect of sulfate ions on the performance of smartwater flooding applied to carbonate reservoirs, MSc Thesis University of Campinas, 197 pp., 2016. Abstract
The “low salinity water” technology is an enhanced oil recovery method that is gaining attention from researchers and the oil industry. For carbonate reservoirs, which are normally oil wet or mixed wet, this technique is even more attractive. Studies have shown that the sulfate ion plays a unique role on the technique, acting as a catalyzer for the multiple ion exchanges that promote the wettability alteration. The concentration of the ions Na+ and Cl-, as well as the temperature, are considered important parameters. In many cases, seawater is already an optimized water for the process. Traditionally, however, in the Brazilian pre-salt oil fields, the desulfated seawater is used as the injecting water ¿ as a precaution to avoid reservoir incrustation or souring. To justify the replacement of the injection water by seawater, substantial laboratory data using reservoir carbonate rocks are still required. The present work aims to evaluate the effect of the sulfate ion in the injection water using carbonate plugs, as well as to analyze the influence of the Na+ and Cl- ions and the temperature. At the laboratory, nine water-flooding tests, at 65°C and 100°C, and six spontaneous imbibition tests, at 65°C and 90°C, were performed with different water compositions. The water-flooding tests were divided in three groups. The first group contained four tests that were selected in order to investigate the effects of the initially chosen parameters (SO42-, Na+, Cl- and temperature). The second and third groups were elaborated because the injection rates and the rock samples¿ lithology could influence the oil recovery. Therefore, other five water-flooding tests were performed to study these new perceived variables. The results have shown that an increase in the sulfate concentration of the injection water, up to the amount present in seawater, can recover up to an additional 8% OOIP, after the injection of desulfated seawater. The effect of the non-active Na+ and Cl- ions was also observed. The influence of relatively small variations (less than an order of magnitude) of the flow capillary number on the remaining oil saturation in carbonate rocks was clearly observed, indicating a very small or even inexistent critical capillary number. It was noticed that the minimum temperature for the effect of the potential ions depends on the type of test performed. In spontaneous imbibition tests, it was not possible to distinguish the effect of increasing sulfate concentrations in water at 65°C ¿ which is in agreement with literature results. However, in the water-flooding tests, at 65°C it was already possible to notice the effect of the sulfate ion on the oil recovery. Finally, the overall results open up the suggestion to analyze the viability of changing the composition of the injection water currently being used in many Brazilian pre-salt oil fields, given the seawater’s potential of saving money by simplifying the operating plant and promoting oil production

show/hide list of publications

THESES

1.  Lima, M. The effect of sulfate ions on the performance of smartwater flooding applied to carbonate reservoirs, MSc Thesis University of Campinas, 197 pp., 2016. Abstract
The “low salinity water” technology is an enhanced oil recovery method that is gaining attention from researchers and the oil industry. For carbonate reservoirs, which are normally oil wet or mixed wet, this technique is even more attractive. Studies have shown that the sulfate ion plays a unique role on the technique, acting as a catalyzer for the multiple ion exchanges that promote the wettability alteration. The concentration of the ions Na+ and Cl-, as well as the temperature, are considered important parameters. In many cases, seawater is already an optimized water for the process. Traditionally, however, in the Brazilian pre-salt oil fields, the desulfated seawater is used as the injecting water ¿ as a precaution to avoid reservoir incrustation or souring. To justify the replacement of the injection water by seawater, substantial laboratory data using reservoir carbonate rocks are still required. The present work aims to evaluate the effect of the sulfate ion in the injection water using carbonate plugs, as well as to analyze the influence of the Na+ and Cl- ions and the temperature. At the laboratory, nine water-flooding tests, at 65°C and 100°C, and six spontaneous imbibition tests, at 65°C and 90°C, were performed with different water compositions. The water-flooding tests were divided in three groups. The first group contained four tests that were selected in order to investigate the effects of the initially chosen parameters (SO42-, Na+, Cl- and temperature). The second and third groups were elaborated because the injection rates and the rock samples¿ lithology could influence the oil recovery. Therefore, other five water-flooding tests were performed to study these new perceived variables. The results have shown that an increase in the sulfate concentration of the injection water, up to the amount present in seawater, can recover up to an additional 8% OOIP, after the injection of desulfated seawater. The effect of the non-active Na+ and Cl- ions was also observed. The influence of relatively small variations (less than an order of magnitude) of the flow capillary number on the remaining oil saturation in carbonate rocks was clearly observed, indicating a very small or even inexistent critical capillary number. It was noticed that the minimum temperature for the effect of the potential ions depends on the type of test performed. In spontaneous imbibition tests, it was not possible to distinguish the effect of increasing sulfate concentrations in water at 65°C ¿ which is in agreement with literature results. However, in the water-flooding tests, at 65°C it was already possible to notice the effect of the sulfate ion on the oil recovery. Finally, the overall results open up the suggestion to analyze the viability of changing the composition of the injection water currently being used in many Brazilian pre-salt oil fields, given the seawater’s potential of saving money by simplifying the operating plant and promoting oil production