Rheological peculiarities of fluids flow in microcracked channels
Keywords:Microcrack opening, Non-Newtonian fluids, boundary layer, Jamin effect, limiting yield stress, structural viscosity.
It has been determined that the cause of the non-linear effect manifestation during Newtonian fluids flows as well as strengthening of the anomalous phenomena of non-Newtonian fluids in microcapillary cracks is value of crack opening.
Non-Newtonian properties are manifested in the system of crack-fluid during viscous fluids flow into cracks with h hcr opening, non-Newtonian properties are increased for anomalous fluids but these effects are absent at h > hcr. These effects occur in the crack-fluid system only at h hcr. It has been determined experimen-tally that after fluids seepage from the crack, the above-mentioned effects are absent.
The obtained microcracked effect for homogene-ous fluid purified from air or gas is an analog of Jamin effect and it is called as microcracked fluid effect. This effect can increase still further Jamin effect at two-three phase systems of fluids flow in microcrack. The critical values of the crack opening have been determined wherein the above-mentioned changes in the fluids properties are practically disappeared.
The stimulation methods and bottom-hole zone due to powerful energy fields of oil-and-gas fields with fractured rocks should promote increasing the cracks opening of the oil-and-gas fields of the viscous and anomalous oils.