TY - BOOK

T1 - Explicit continuum-scale modelling of water-based IOR/EOR mechanisms

AU - Kurgyis, Kata

N1 - embargoed until null

PY - 1800

Y1 - 1800

N2 - A low-cost and environmentally friendly method of enhanced oil recovery is the reduction of the injection water salinity, which can lead to additional oil production. Understanding the influence of injection water composition on displacement efficiency has been a long-standing issue in reservoir engineering. While several underlying chemical mechanisms have been identified, identifying the governing mechanisms remains difficult and specific to the chemical setting of the reservoir and injection water composition. Two potential mechanisms are implemented in this work: double layer expansion and multicomponent ion exchange to achieve an explicit description of low-salinity effects in the open-source continuum-scale flow simulator DuMuX. The explicit description is achieved by linking measured relative permeability and capillary pressure saturation functions to the injection water composition with an interpolation scheme. This link is intended to model the ad/desorption of polar hydrocarbon molecules and therefore a change of wettability as a consequence of the injection water ionic composition. This ad/desorption processes are described by a set of equilibrium chemical reactions, which then directly links the wetting properties and brine compositions. The goal of the developed simulator is the design and interpretation of core-scale experiments and a potential upscaling of the results. For this purpose, first, the simulation results were benchmarked against analytical solutions. Since the simulation results produced front dispersion as opposed to the sharp front in the analytical solution, the benchmarking process was followed by an extensive sensitivity study on the influence of various dispersive mechanisms on the displacement fronts. These dispersive mechanisms were also numerically investigated on the experimental scale using typical input parameters. By these simulations, e.g., a minimum core length can be determined by utilizing tracer tests and by using the development of the oil bank in tertiary recovery as criterium. The numerical tool was developed in order to interpret and design experimental low salinity water flooding targeting two main questions: (1) what we can learn about the response time of the reservoir to the low salinity mechanisms, and (2) how an experiment must be performed in order to identify the leading mechanisms. For this purpose, the validated model has been used to interpret one of the few comprehensive experimental datasets that can be found in literature. The data from these measurements, which cover the full scope of salinity transition periods from the high- to the low-salinity environment, were successfully history matched and provided relative permeability and capillary pressure data for both conditions. These properties were then used for forward simulating low salinity coreflood under tertiary flood conditions. Comparing the simulated results to the corresponding experimental data provided meaningful insights about (1) the shape of the interpolation function, which reflects the salinity transition period, and (2) the response time of the reservoir to the low salinity water injection. Upon further analysing the effluent chemical composition from the reactive transport simulations a series of coreflood experiments is proposed with specific injection water compositions that show distinct production response. This, in conclusion, allows to distinguish between the show-cased implemented low salinity mechanisms.

AB - A low-cost and environmentally friendly method of enhanced oil recovery is the reduction of the injection water salinity, which can lead to additional oil production. Understanding the influence of injection water composition on displacement efficiency has been a long-standing issue in reservoir engineering. While several underlying chemical mechanisms have been identified, identifying the governing mechanisms remains difficult and specific to the chemical setting of the reservoir and injection water composition. Two potential mechanisms are implemented in this work: double layer expansion and multicomponent ion exchange to achieve an explicit description of low-salinity effects in the open-source continuum-scale flow simulator DuMuX. The explicit description is achieved by linking measured relative permeability and capillary pressure saturation functions to the injection water composition with an interpolation scheme. This link is intended to model the ad/desorption of polar hydrocarbon molecules and therefore a change of wettability as a consequence of the injection water ionic composition. This ad/desorption processes are described by a set of equilibrium chemical reactions, which then directly links the wetting properties and brine compositions. The goal of the developed simulator is the design and interpretation of core-scale experiments and a potential upscaling of the results. For this purpose, first, the simulation results were benchmarked against analytical solutions. Since the simulation results produced front dispersion as opposed to the sharp front in the analytical solution, the benchmarking process was followed by an extensive sensitivity study on the influence of various dispersive mechanisms on the displacement fronts. These dispersive mechanisms were also numerically investigated on the experimental scale using typical input parameters. By these simulations, e.g., a minimum core length can be determined by utilizing tracer tests and by using the development of the oil bank in tertiary recovery as criterium. The numerical tool was developed in order to interpret and design experimental low salinity water flooding targeting two main questions: (1) what we can learn about the response time of the reservoir to the low salinity mechanisms, and (2) how an experiment must be performed in order to identify the leading mechanisms. For this purpose, the validated model has been used to interpret one of the few comprehensive experimental datasets that can be found in literature. The data from these measurements, which cover the full scope of salinity transition periods from the high- to the low-salinity environment, were successfully history matched and provided relative permeability and capillary pressure data for both conditions. These properties were then used for forward simulating low salinity coreflood under tertiary flood conditions. Comparing the simulated results to the corresponding experimental data provided meaningful insights about (1) the shape of the interpolation function, which reflects the salinity transition period, and (2) the response time of the reservoir to the low salinity water injection. Upon further analysing the effluent chemical composition from the reactive transport simulations a series of coreflood experiments is proposed with specific injection water compositions that show distinct production response. This, in conclusion, allows to distinguish between the show-cased implemented low salinity mechanisms.

KW - Dumux

KW - low salinity mechanisms

KW - double layer expansion

KW - multi-component ion exchange

KW - low salinity coreflood

KW - Amott test

KW - dispersion

KW - low salinity experimental design

KW - Dumux

KW - Mechanismen mit niedrigem Salzgehalt

KW - Doppelschichtausdehnung

KW - Mehrkomponenten-Ionenaustausch

KW - salzarme Kern Flut

M3 - Doctoral Thesis

ER -