The method was applied to cores from Niobrara and Codell formations in the DJ basin. In summary, we present a novel method to measure osmotic pressure in core samples. We also recognize that a fraction of the imbibition into the cores is due to capillary pressure while much of the imbibition results from capillary osmosis. Even in oil-wet shale reservoirs, osmotic pressure prevails-leading to brine imbibition into the matrix and generating a counter-current flow of oil from the matrix into the fractures. However, when low-salinity water enters the stimulated reservoir micro-fractures an osmotic pressure gradient forms because of the salinity contrast between fracture and matrix and the nanometer size of pore throats (nano- and micro-fractures are a consequence of rock deformation instigated by hydraulic fracturing in shale reservoirs). Classical waterflooding in unconventional reservoirs is not plausible because of the small pore sizes and low permeability of shale reservoirs. The ultimate oil recovery from liquid-rich unconventional reservoirs is less than ten percent, thus a great interest in developing enhanced oil recovery (EOR) methods that can increase oil production from such reservoirs economically. These include the analysis of heat engines, heat pumps (refrigerators), turbines, fuel cells, and understanding and predicting phase transitions among the solid, liquid, and vapor phases in both pure fluids and mixtures and chemical equilibria.Keywords:thermodynamics mass balance energy balance first law internal energy enthalpy entropy balance second law property relations Gibbs energy Helmholtz energy heat engine heat pump turbine equation of state phase equilibrium vapor–liquid transition fugacity solid–liquid transition solid–vapor transition partial molar property chemical reaction chemical equilibrium standard state ideal mixture activity activity coefficient Gibbs’ phase rule bubble point dew point flash vapor–liquid equilibrium liquid–liquid equilibrium vapor–liquid–liquid equilibrium It is shown here how these principles lead to a broad range of applications. Thermodynamics is a discipline with broad applications based on three basic principles: Conservation of mass, conservation of energy (first law), and isolated systems evolve toward an equilibrium, time-invariant state in which temperature and pressure are spatially uniform, and in composition is uniform in each phase (ie, vapor, liquid, or solid).
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