Multi-sector data correction method and system for gamma imaging while drilling

A multi-sector data correction method for gamma imaging while drilling, comprising:

• S1:
• placing a gamma imaging tool into a wellbore in a formation, wherein the gamma imaging tool comprises a gamma sensor with azimuth blanking and an acquisition circuit signally connected to the gamma sensor and a processor;
• S2:
• dividing a circumference of the wellbore into a plurality of gamma imaging sectors, and dividing each gamma imaging sector into a plurality of counting zones, each counting zone corresponds to one tool face of the gamma imaging tool;
• S3:
• counting a number of valid counting pulses for each counting zone at a predetermined time interval during measurement while drilling using the gamma sensor, which comprises:
• S31:
• rotating the gamma imaging tool;
• S32:
• transmitting a valid counting signal to the acquisition circuit upon receiving a valid counting pulse at the gamma sensor, and,
• S33:
• recording, by the processor, a current tool face of the gamma imaging tool and a serial number of the counting zone corresponding to the current tool face;
• S4:
• constructing a plurality of measurement vectors featuring measurement results of all the plurality of gamma imaging sectors based on a value of recording times of each counting zone;
• S5:
• establishing a correction matrix with a conditional number less than a set value, said correction matrix being used to correct measurement data;
• and
• S6:
• calculating a gamma intensity of each measured sector with the plurality of measurement vectors and the correction matrix as constructed to correct measurement data of each measured sector for each predetermined time interval.