Invasion correction method and system for resistivity logging
Disclosed is an invasion correction method and system for resistivity logging. The method includes the steps of: analyzing mud filtrate invasion features based on an actual resistivity logging curve; determining an invasion mechanism, and performing forward modeling on a resistivity logging response; performing inversion by a random forest method to form a correction chart; and outputting a formation resistivity to finally form the invasion correction method and system for resistivity logging. In the present disclosure, double lateral correction under an invasion condition is accomplished, while a chart method and an inversion method are combined, ensuring the accuracy and operating rate of correction.
1 . An invasion correction system for resistivity logging, comprising:
a feature analysis module, configured to analyze mud filtrate invasion features based on an actual resistivity logging curve;
a resistivity forward modeling module, configured to determine an invasion mechanism, and perform forward modeling on a resistivity logging response;
a correction chart construction module, configured to perform inversion by a random forest method to form a correction chart, and calculate a correction coefficient to obtain an accurate corrected resistivity;
a parameter control module, configured to output a formation resistivity and perform parameter control under a complex borehole condition;
an instance verification module, configured to perform inspection on an actual gas test result; and
an arbitrary borehole condition correction module, configured to perform parameter control, and control, when the difference between correction values of two adjacent points is less than an adaptive range, data errors of a diameter expansion point and upper and lower sampling points within the adaptive range, to increase an applicable range of the chart and perform arbitrary borehole condition correction.