While-drilling natural gamma curve prediction method based on time sequence algorithm

Abstract

The method is applied to the technical field of wireless logging while drilling parameter prediction. The invention discloses a while-drilling natural gamma curve prediction method based on a time sequence algorithm, and the method comprises the following steps: collecting a drilled borehole natural gamma curve, building a while-drilling natural gamma curve ARIMA model on a time sequence, and thenpredicting a natural gamma curve at a drill bit. Verification results of actual drilling data show that the method predicts that the natural gamma curve conforms to the actual situation, the actual situation of the stratum encountered by the drill bit can be reflected before the natural gamma curve is measured while drilling, and the problem of measurement zero length does not exist.

Description

technical field [0001] The invention belongs to the technical field of wireless logging-while-drilling parameter prediction, in particular to a method for predicting natural gamma-ray curves while drilling based on a time series algorithm. Background technique [0002] In recent years, when the geological conditions are complicated or when drilling is steered in thin pay zones, the distance between the downhole geological parameters and the drill bit is critical. Due to the difficulty and high cost of near-bit measurement while drilling technology, there is a large gap with foreign technologies, and near-bit LWD is still not possible. In geosteering drilling, the sensor of the LWD wireless while-drilling tool is 8-20m away from the drill bit, and the data at the measurement point cannot correctly reflect the actual formation parameter information at the position of the drill bit. Intelligently measure the natural gamma ray within the range of 8-20m away from the drill bit p...

AI Technical Summary

Problems solved by technology

Due to the difficulty and high cost of near-bit measurement while drilling technology, there is a large gap with foreign technologies, and near-bit LWD is still not possible

In geosteering drilling, the sensor of the LWD wireless while-drilling tool is 8-20m away from the drill bit, and the data at the measurement point cannot correctly reflect the actual formation parameter information at the position of the drill bit. Intelligently measure the natural gamma ray within the range of 8-20m away from the drill bit parameters, the formation characteristics at the drill bit cannot be obtained, and the actual situation of entering the reservoir cannot be judged, which brings certain difficulties to judging whether it is in the reservoir

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