Method of determining the per strata reserve quality of an oil well

摘要

The present invention relates to a method of evaluating the hydraulic potential of a porous stratum defined between two depths z_low and z_high, the method consisting in generating periodic modulation in the rate of flow from the well, in lowering down the well and in activating for a few periods at the depth z_low a measuring PLT sonde, in extracting from the resulting measurements the amplitude DeltaQ_low of the sinusoidal component of the flow rate modulation relating to one of the imposed periods T, the amplitude DeltaP_low of the sinusoidal component of the pressure modulation relating to the same period T, and the phase delay of the pressure sinewave relative to the flow rate sinewave phi_low, in determining the response $R_{\mathrm{low}}=\frac{\mathrm{Delta}{P}_{\mathrm{low}}}{\mathrm{Delta}{Q}_{\mathrm{low}}}{e}^{-{\mathrm{iphi}}_{\mathrm{low}}}$ in raising the sonde to depth z_high, and in determining the complex response $R_{\mathrm{high}}=\frac{\mathrm{Delta}{P}_{\mathrm{high}}}{\mathrm{Delta}{Q}_{\mathrm{low}}}{e}^{-i{\mathrm{phi}}_{\mathrm{high}}}$ in calculating the complex response $R_{\mathrm{stratum}}=\frac{R_{\mathrm{high}}.R_{\mathrm{low}}}{R_{\mathrm{low}}-R_{\mathrm{high}}}$ in postulating a physical model for the stratum by numerically inverting the mathematical formula giving the theoretical complex response, in determining the hydraulic characteristics of the stratum defined by the measured response R_stratum, in calculating the well productivity index IP_stratum relating to the stratum in question, and in deducing therefrom the mean deposit pressure P_D in the stratum using the formula: $P_D=P_{\mathrm{DH}}+\frac{Q_{\mathrm{stratum}}}{\mathrm{IP}}.$