METHOD FOR IMPROVING INFLOW OF OIL OF CRITICAL ZONE TREATMENT Russian patent published in 1996 - IPC

FIELD: oil production. SUBSTANCE: laboratory filtering study for drawing curves of porous medium relative phase permeability vs water saturation is carried out. Seam oil and water dynamic viscosity is measured. Well product flooding vs critical zone water saturation (Leveret function) is formed and determined are critical zone water saturation in flooding corresponding to maximum achieved well discharge qmaxdch

and relative well productivity Qmax% with water saturation found from formula , where , K_prod(S_t); K_prod(S_bw) are relative well productivity at 1 m depth with water saturation of critical zone equal to S_t and S_bw respectively; S_t is current water saturation of porous medium; S_bw is saturation of porous medium with bound water; , M_oil/M_w is seam oil water dynamic viscosity respectively, MPaxs; K_w(S)_t is relative water phase permeability of the porous medium with water saturation S_t,Q; F(S_t) is Leveret function; critical zone water saturation in flooding corresponding to the current well discharge qtlq and similar well productivity Qt% at current water saturation; general degree of current well discharge reduction about maximum achieved one , degree of well discharge reduction at the expense of pollutants of the critical zone , and forecasting oil discharge decrement at the expense of critical zone treatment is defined from formula as follows: Δqforecastoil= qtoil•Q_p-qtoil, where qtoil is current oil well discharge prior to critical zone treatment. EFFECT: higher productivity. 2 dwg