Petrochemistry and Chemical Engineering

Biography

Biography: Vitaly Rogankov

Abstract

The search for the appropriate agent to solve a variety of problems in improved (or enhanced) oil recovery as well as to extract effectively the organic pollutants from the flow being restricted to the highly irregular geometric structure of channels within the permeable medium (PM) is long-standing but actual problem. As a rule, the chain of the specific assumptions and the limitations is necessary for a particular application. The most widespread statements are: (i) an agent to change desirably the crude oil pressure-temperature diagram by its dilution in a pseudo-continuum medium of PM should be a homogeneous, much more volatile fluid with the well-known properties and the well-established localization of a vapor-pressure curve; (ii) the representative elementary volume (REV) has to be determined as the boundary which separates the microscopic structure-dominated discrete system combined by pores and by their hard matrix from the macroscopic pseudo-continuum model of a PM; (iii) the cumulative porosity fluctuates normally (in according to the Gaussian distribution) in any REV within the pseudo-homogeneous PM-domains while its heterogeneous fluctuations could be arising, in principle, only within the macrovolumeslarger than REV. Recently author's poser was addressed (Phys.Rev.E87, â„–5, 2013;Fluid Phase Equilibria, 383, (2014), 115-125) to the pure near (super- and sub-) critical fluids in which the conventional concepts of above i-statement fail completely if the volume of observation is mesoscopic. More exactly, the range of mesoscopic scales, located between the microscopic molecular-based sizes and the macroscopic correlation-based sizes is negligible if the local equilibrium state occurs far away from the critical region. In this case, the respective correlation volume (CV) of a state is rather small and very similar to the above REV-definition because it separates just the micro- and macroscales. However, near the critical point CV becomes enormous and the steady distribution of mesoscopic local-equilibrium domains within it is the heterogeneous one by the physical nature. The unavoidable failure of any unified equation of state (widely usable in the enhanced oil recovery and in the supercritical extraction technologies)to represent such a behavior leads to the novel concept of the fluctuationnon-unified equation of state developed by author just for mesoscopic states. Its striking feature is the predicted split of the standard one-dimensional vapor-pressure curve for a pure fluid onto the two-dimensional coupling pair of bubble-point and dew-point curves (similar to ones in a binary mixture) at the subcritical temperatures within the mesoscopic volumes. Moreover, the additionally predicted specific range of the heterophase behavior located closely to but still under the critical temperature makes the mesoscopic subcritical states to be a serious competitor with conventional supercritical states for an extraction.In this work I intend to discuss the advantages of mesoscopic scales and the perspective interrelations between the standard REV- and CV-scales of volume as well as to point out the respective ranges of pressure and temperature for the oil flows in a PM which may provide the key to economic competitiveness of the propose approach. One of the relevant problems is the necessity to change the conventional term of a cumulative porosity by its counterpart (termed by me as actual porosity) defined, however, at the smaller mesoscopic volumes within REV. This modification can be quite useful in the frameworks of the mesoscopic approach to the problems of extraction and oil recovery.