Some Theory And Method For Induced Polarization Logging Tools

For some logging strata, such as water-saturated strata, complex strata, the deep and ultra-deep strata, this thesis which base on the electrochemical theory and the analysis of induced polarization (IP) logging to achieve the information obtaining and calculations of multi-parameter, including the cation exchange capacity, the formation water salinity, the formation rock porosity, the pore radius distribution information, and etc.. And by electrical networks and the electrode array method, the information of impedance distribution can be obtained in laboratory condition, so the formation water saturation distribution information can also be calculated. The following aspects are the main research contents of this thesis.On the basis of the guiding ideology which "rock conduction mechanism is the essence of the solution ionic conduction process," the thesis obtain a model to describe the relationship amout the cation exchange capacity, formation water salinity, and formation potential in two equilibrium states, so a feasible way that obtain online the cation exchange capacity and formation water salinity be provide. In addition, the thesis obtain the mathematical relationship between saturation polarization ratio and rock porosity, base on the analysis for the rock pores polarization and depolarization process that explain that the relaxation process contain the information of pores structure. And the experiment result show the rationality of obtaining porosity by this method.However, the porosity is still not very good and detailed description parameter for the information of pore structure and size, Based on electrochemical theory, the percentage of different pore size can be obtain by inversion. The parameters can be used to the research of the formation permeability, with parameters of others logging tools.In addition, the thesis use the electrode array and electrical network simulation methods to describe and reconstruct the impedance of inhomogeneous medium by inversion. The simulation experiment result show that the method for obtaining impedance distribution information is a new way to reasearch the calculation of water saturation distribution.At last, the thesis gives design scheme of the international’s first downhole induced polarization logging tool. The preliminary logging experimental results show that the design is correct, and design specifications to meet basically expectations.