Experimental Study and Numerical Modeling of Boron Transport in Reservoir and Its Influence on Seawater-Breakthrough Calculation

Abstract

Summary Seawater injection is widely used to maintain offshore-oil-reservoir pressure and improve oil recovery. However, injecting seawater into reservoirs can cause many issues, such as reservoir souring and scaling, which are strongly related to the seawater-breakthrough percentage. Accurately calculating the seawater-breakthrough percentage is important for estimating the severity of those problems and further developing effective strategies to mitigate those issues. The validation of using natural-ion boron as a tracer to calculate seawater-breakthrough percentage was investigated. Boron can interact with clays, which can influence the accuracy in seawater-breakthrough calculation. Therefore, the interaction between boron and different clays at various conditions was first studied, and the Freundlich adsorption equation was used to describe the boron-adsorption isotherms. Then, the boron-adsorption isotherms were coupled into the reservoir simulator to investigate the boron transport in porous media, and the results in turn were further analyzed to calculate the accurate seawater-breakthrough percentage. Results indicated that boron adsorption by different clays varied. pH value of solution can significantly influence the amount of boron adsorbed. As a result, the boron-concentration profile was delayed in coreflood tests. The accuracy of the new model was verified by convergence rate tests and comparison with analytical results. Furthermore, model results fit well with experimental data. On the basis of the reservoir-simulation results, the boron-concentration profile in produced water can be used to calculate the seawater-breakthrough percentage by considering the clay-content distribution. However, the seawater-breakthrough point cannot be determined by boron because the boron concentration is still at the formation level after seawater breakthrough due to boron desorption.

Impact of Sodium Dodecyl Benzene Sulfonate Concentration on the Stability of the Crude Oil–Mineral Water Interfacial Film: A Molecular Dynamics Simulation Study

“…The comparison of the interfacial formation energy of the simulation systems with the experimental results of interfacial tension for different SDBS concentrations is shown in Figure . It can be found that in the process of describing the impact of SDBS concentration on the stability of the crude oil–water interface, the results of molecular dynamics simulation are basically consistent with the experimental results of interface tension, which further confirmed the reliability of the simulation calculation and experimental results in this paper. , …”

“…It can be found that in the process of describing the impact of SDBS concentration on the stability of the crude oil−water interface, the results of molecular dynamics simulation are basically consistent with the experimental results of interface tension, which further confirmed the reliability of the simulation calculation and experimental results in this paper. 53,54 5. CONCLUSIONS In this paper, to break through the limitations of model simplification and single-factor simulation in previous molecular dynamics studies, different oil−water interface system models were constructed according to the actual component composition of crude oil and water to investigate the impact of the concentration of surfactant SDBS on the stability of the crude oil−mineral water interface by molecular dynamics simulation.…”

Effect of Interface Structure and Behavior on the Fluid Flow Characteristics and Phase Interaction in the Petroleum Industry: State of the Art Review and Outlook

“…Therefore, new EOR technologies have been continuously developed. The primary and secondary recovery technologies provide recovery rates of 20–40%, whereas tertiary recovery technologies can afford recovery rates of 30–60%, greatly improving the oil recovery capacity. , EOR technology has evolved from the steam-assisted gravity drainage technology pioneered by Roger Butler to today’s chemically enhanced oil recovery technology, where displacement efficiency is continuously improved and chemical components such as alkalis, surfactants, and polymers are continuously injected in the rock formation. ,, However, there is a consensus that these chemical components will change the interface structure and behavior through the formation of adsorption layers, thus making the field of interface studies in the petroleum industry complex and diverse. , …”