Oil-water identification method based on conductivity dispersion characteristics of undisturbed formation

An oil-water identification method based on RPFE characteristics of an undisturbed formation, comprising the following steps:

• step 1):
• acquiring a real part conductivity curve and an imaginary part conductivity curve of the undisturbed formation of an array induction logging sub-array 7 and a formation porosity curve;
• step 2):
• mapping an electrical spectrum curve of the array induction logging sub-array 7 based on real part and imaginary part conductivity curve data of the array induction logging sub-array 7;
• for real part and imaginary part conductivity data of the array induction logging sub-array 7 with different frequencies obtained in the step 1), mapping a real part and an imaginary part spectrum of the array induction logging sub-array 7 by using a logging mapping software;
• step 3):
• calculating the PFE of the array induction logging sub-array 7 according to the real part conductivity curve data of the array induction logging sub-array 7;
• for the real part conductivity curve data of the array induction logging sub-array 7 with the different frequencies obtained in the step 1), calculating and obtaining the RPFE according to the following formula:
• RPFE
• ⁢
• =
• σ
• l
• -
• σ
• h
• σ
• l
• wherein RPFE denotes the PFE calculated from the real part conductivity data, and σl and σh are taken from the real part conductivity curve data of the array induction logging sub-array 7 with 10 kHz and 150 kHz, respectively;
• step 4):
• constructing a two-dimensional oil-water identification chart according to the RPFE of the array induction logging sub-array 7 and a product of a resistivity after borehole correction of the array induction logging sub-array 7 and a formation porosity.