Calculation method of water saturation of variable rock electrical coupling index

Abstract

The invention discloses a variable rock-electricity coupling index water saturation calculation method, comprising the following steps: a. establishing a new water saturation calculation model; b. establishing a saturation core database; c. information on the saturation core database Carry out excavation and establish the rock-electricity coupling index calculation chart; d. Process the newly input logging data to obtain the rock-electricity coupling index of the newly input logging data; e. Use the rock-electricity coupling index obtained in step d for step The calculation model in a, which calculates the water saturation of the new input log data. The present invention proposes the concept of rock-electric coupling index for the first time, finds a corresponding calculation method, and achieves the purpose of improving calculation accuracy.

Description

technical field [0001] The invention relates to a method for calculating water saturation of variable rock electrical coupling index, which is used for processing petroleum geological logging data. Background technique [0002] An important content in the processing of petroleum geological logging data is the calculation of water saturation. At present, there are more than 30 calculation models, all of which are derived from the Archie formula. For different regions and different geological bodies, the evolution of these calculation models is generally inseparable from the following three points: Odd formula for shale correction; ② Archie formula for salinity correction; ③ Archie formula for temperature correction. For example, "Logging Technology" in the 05th issue of 2007 disclosed the calculation method of water saturation index n value, and studied the calculation method of water saturation index n value of different samples under different experimental conditions. Acc...

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Problems solved by technology

[0003] However, the existing method still has the following disadvantages: every time a correction is made, a new item or a new undetermined parameter will be added to the Archie formula, and the result will narrow the adaptability of the calculation model

In addition, Archie’s formula itself has four pending parameters, all of which require core experimental data to calibrate, if more parameters to be determined are added, the stability of the calculation results of the calculation model will be deteriorated

Theoretical and experimental studies have shown that even with the same lithology, the Archie formula cementation index (m, dimensionless) and saturation index (n, dimensionless) are not fixed, while the current calculation of water saturation uses a fixed m, n value, which is the main reason why the calculation accuracy of Archie's formula is not high

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