Method for determining pore structure and in-place permeability utilizing induced polarization spectrum of rock

Abstract

This invention relates to a method for determine the zone permeability and pore structures by use of rock induced polarization and it solves the problem of single parameter and complicated influence factors in current induced polarization method. Its characteristics are the following: first to supply electricity to control units through constant-current source to generate polarization field in rock core then to cut off electricity. The polarization field fading with time and through measuring fading electric potential to obtain the induced polarization fading spectrum, and to obtain relaxing time spectrum by multiple exponential decline match of fading spectrum. And it can quantitatively descript zone capillary pressure and pore space structure. And it can calculate permeability by combining pore space materials with relaxing time geometrical mean and is characterized by high permeability accuracy and on-spot accessing.

Description

Technical field: [0001] The invention belongs to the induced polarization potential logging interpretation of different lithology formations used in the field of petroleum geophysical well logging, in particular to a method for determining pore structure, capillary pressure curve and formation permeability by using rock induced polarization spectrum. Background technique: [0002] Induced polarization logging has been developed for decades. People have been using the induced polarization potential and polarizability of rocks to qualitatively determine parameters such as formation water salinity and shale content. Establish a relationship with the polarizability and the permeability of the formation, but the effect has not been good. Since the induced polarization potential of rock is related to the structure of the electric double layer on the particle surface, the arrangement direction of the electric double layer in the excited electric field affects the induced polarizati...

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Problems solved by technology

[0006] In order to overcome the insufficiency of in-situ permeability and pore structure being difficult to obtain accurately and quantitatively, the single parameter of the induced polarization logging method, and the resulting impact on oil field development, the present invention provides a method for determining the formation permeability by using the rock induced polarization spectrum. , capillary pressure curve and pore structure method, use the induced polarization logging method to directly determine the formation permeability, capillary pressure curve and pore structure and other parameters, and calculate the permeability according to the given model. This method has high measurement accuracy and detection The advantages of deep depth, large signal amplitude, high signal-to-noise ratio, low logging cost, and on-site measurement are possible, so induced polarization spectroscopy logging technology has very good application prospects

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