sjavadi

• Dziadkowiec, Joanna; Javadi, Shaghayegh; Bratvold, Jon E.; Nilsen, Ola & Røyne, Anja (2018). Surface Forces Apparatus Measurements of Interactions between Rough and Reactive Calcite Surfaces. Langmuir.  ISSN 0743-7463.  34((25)), s 7248- 7263 . doi: 10.1021/acs.langmuir.8b00797 Fulltekst i vitenarkiv.
• Javadi, Shaghayegh & Røyne, Anja (2018). Adhesive forces between two cleaved calcite surfaces in NaCl solutions: The importance of ionic strength and normal loading. Journal of Colloid and Interface Science.  ISSN 0021-9797.  532, s 605- 613 . doi: 10.1016/j.jcis.2018.08.027 Fulltekst i vitenarkiv.

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• Dziadkowiec, Joanna; Javadi, Shaghayegh & Røyne, Anja (2019). Contacts between reactive surfaces.
• Dziadkowiec, Joanna; Javadi, Shaghayegh; Bratvold, Jon E.; Nilsen, Ola & Røyne, Anja (2018). Adhesive and repulsive forces between calcite surfaces.
• Dziadkowiec, Joanna; Javadi, Shaghayegh; Bratvold, Jon E.; Nilsen, Ola & Røyne, Anja (2018). Nucleation in solution confined between reactive surfaces can generate long-range repulsive forces.
• Javadi, Shaghayegh; Dziadkowiec, Joanna; Røyne, Anja; Bratvold, Jon E.; Nilsen, Ola & Hiorth, Aksel (2018). Synthetic CaCO3 surfaces in aqueous solutions – AFM and Surface Force Apparatus (SFA) measurements.
• Dziadkowiec, Joanna; Javadi, Shaghayegh; Bratvold, Jon E.; Nilsen, Ola & Røyne, Anja (2017). Interactions between reactive CaCO3 surfaces in aqueous solutions -Surface Forces Apparatus measurements.
• Dziadkowiec, Joanna; Javadi, Shaghayegh & Røyne, Anja (2017). Surface Forces Apparatus measurements of interactions between rough and reactive calcite surfaces.
• Javadi, Shaghayegh (2017). Interaction forces between two calcite surfaces as a function of ionic strength in NaCl solutions.
• Javadi, Shaghayegh; Røyne, Anja & Hiorth, Aksel (2017). AFM study of the adhesion of calcite surfaces in NaCl solutions.
• Røyne, Anja; Javadi, Shaghayegh & Dziadkowiec, Joanna (2017). Nanoscale forces between calcite surfaces and how they relate to fracturing and friction.
• Javadi, Shaghayegh (2016). Interaction forces between two calcite surfaces as a function of fluid composition. Vis sammendrag

  Upon interaction between two calcite crystals in the presence of fluid, repulsion and attraction forces are generated by the confined fluid film at the interface. It has been shown that these nano-scale forces impact the mechanical behavior of calcite-bearing rocks, e.g., [1] & [2]. The long-term deformation of calcite rocks induced by chemical mechanisms, such as dissolution and growth, occurs in the presence of pore fluid. This makes the interaction analysis more complicated [3]. We therefore need to find out not only the responsibility of chemistry fluid on mechanical behavior of calcite, but also to what extent calcite crystals grow or dissolve in pore fluid. Since calcite is the main component of chalk, the result of this study describes the compaction caused by injecting water into chalk reservoirs [1], through the Enhanced Oil Recovery (ERC) projects. In this work, we present an experimental method to study the interfacial forces between two calcite crystals in fluid, in nano-scale. We observed that changing the chemistry of pore fluid, will change the adhesion properties of calcite. In order to measure the adhesion force, we have developed a method using Atomic Force Microscopy (AFM) [3]. Through this method we investigate the nano-scale repulsion and attraction forces between two calcite grains in a liquid cell that are moving towards or apart from one another. Analyzing this experimental data gives us the adhesion force between two calcite grains for variation of ionic compound, ionic strength and salinity. The measured adhesion force depends on the area of contact, which is in turn affected by growth and dissolution of the crystal surfaces. We show that the short-range forces between calcite surfaces in salt water vary extensively as a function of fluid composition and time.

• Javadi, Shaghayegh; Røyne, Anja & Hiorth, Aksel (2016). Interaction between two calcite surfaces, in nano-scale, as a function of fluid composition. Vis sammendrag

  As one part of the Enhanced oil recovery (EOR) techniques, the injection of fluid into chalk reservoirs, specifically in the North sea, has been of interest for several years. Despite extensive research in this field, there are still many questions left to be answered. One such question is the compaction of chalk reservoirs as the impact of fluid injection. The cause of this process is not fully understood, but it is believed that the microscopic origin of this effect could reveal the secrets behind this phenomenon [1]. Recent experimental and theoretical works have shown, e.g., [1] & [2], that the mechanical strength of chalk rocks behave dependently on the chemistry of pore fluid. In particular, it may be the interfacial nano-forces near the grain boundaries that are responsible for mechanical behavior of two interacting calcite-bearing rocks. In this work, we present an experimental study, in which the hydration re- pulsion between two calcite surfaces is measured. We have developed an experimental method using Atomic Force Microscope (AFM), in which a tip- less AFM cantilever is glued to a calcite fragment, from a freshly cleaved calcite crystal [3]. We then investigate the interaction between these two cal- cite grains in a fluid cell containing salt water. We show the effect of ionic compound, ionic strength and salinity on the hydration short-range forces be- tween calcite surfaces over the time. The result of this study can help us to understand the mechanism behind the chalk-liquid interactions and so-called chalk water weakening due to water adsorption on calcite surfaces. Figure 1 shows a simple sketch of the AFM-tip modification (left), and a SEM image of one of the calcite grains attached to the AFM cantilever (right).

• Røyne, Anja; Bergsaker, Anne Schad; Javadi, Shaghayegh; Dziadkowiec, Joanna; Bratvold, Jon E. & Nilsen, Ola (2016). The role of surface forces and confined fluid films in the slow deformation of rocks.
• Javadi, Shaghayegh; Røyne, Anja & Hiorth, Aksel (2015). Experimental investigation of nano-scale interaction between two calcite grains.
• Javadi, Shaghayegh; Røyne, Anja & Hiorth, Aksel (2015). Experimental investigation of the effect of fluid chemistry on adhesive properties of calcite surfaces..
• Røyne, Anja; Hassenkam, Tue; Bergsaker, Anne Schad & Javadi, Shaghayegh (2015). The role of nanoconfined fluid films in fracture propagation and healing.
• Røyne, Anja & Javadi, Shaghayegh (2015). The role of surface forces in fluid-rock interactions.

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