When we evaluate the permanent reduction in the permeability of porous media, residual resistance factor (RRF) is utilized.
Nomenclature CD: Cyclodextrin e: Average hydrodynamic thickness of polymer layer, [micro]m EOR: Enhanced oil recovery K: Consistency index, mPa x [s.sup.n] k: Brine permeability, [micro][m.sup.2] L: Length of the core, cm n: Power-law index OOIP: Original oil in place [DELTA]P: Pressure drop across the core, MPa Q: Flow rate, [cm.sup.3]/s [r.sub.p]: Average pore radius for brine flow, [micro]m RF: Resistance factor RRF: Residual resistance factor [gamma]: Shear rate, [s.sup.-1] [eta]: Viscosity of the fluid, mPa x s [mu]: Shear viscosity, mPa x s v: Interstitial mean velocity, cm/s [phi]: Porosity, fraction.
Therefore, we designed a new fluid drive unit to assess the matching relationship of asphalt particle sizes with pore sizes by measuring the on-way resistance coefficient, residual resistance factor, and relative change of permeability in man-made cores after injecting asphalt .
At the same time, it can be seen from the table that when the permeability keeps constant (500 mD), residual resistance factor and plugging increase with the size change, which do not comply with certain rules.
Under the condition of the constant injection pore volume, when the concentration decreases and less particles enter into the core, the residual resistance factor and relative change of permeability become smaller.
Without considering the circumstances of the interaction between various factors, select the three parameters (resistance coefficient, residual resistance factor, and relative change of permeability) to study the matching relation between asphalt particle concentration and permeability.
In this experiment, the passage capacity of the profile control agent is evaluated by the resistance coefficient, residual resistance factor, and relative change of permeability, which is mainly used to evaluate the sealing performance of profile control agent.
Similarly, from Table 4 and Figures 7 and 8, it can be seen that when the core permeability is high (>1000 mD), the resistance coefficient, residual resistance factor, and relative change of permeability in the process of injecting are greater with asphalt particle concentration increased.
Resistance factor and residual resistance factor were the important indicators that characterize abilities of liquid fluidity control and the permeability descent.
where [F.sub.R] was resistance factor, FRR was residual resistance factor, [DELTA][P.sub.wi] was stable pressure of precious water flooding (MPa), [DELTA][P.sub.p] was stable pressure of GO dispersion flooding (MPa), [DELTA][P.sub.wa] was stable pressure of subsequent water flooding (MPa).
Compared with other polymer solutions the MGS-CPS compositions are characterized by low polymer and cross linking agent content, but they provide for a high residual resistance factor
. This helps to reduce treatment costs without a loss of the process efficiency.