Resolution Improvement Method of Azimuth Gamma Imaging Logging Based on Regularization Constraint
The azimuth gamma logging while drilling can be used for formation radioactive intensity analysis, geo-steering and reservoir interface identification, but it is greatly affected by statistical errors, resulting in low resolution of curves and imaging. Especially in the formations with low contrast, this effect is more pronounced. In order to improve the imaging resolution of the azimuth gamma logging while drilling, a regularization method for potential gamma data is proposed based on instrument response characteristics to obtain more accurate formation radioactivity intensity. Firstly, according to the detector response principle, the response sensitivity function of azimuth gamma logging is obtained by numerical simulation and experiment, and the accuracy of the sensitivity factor is verified. Then, the original azimuth gamma data is processed by constructing regularization formula and adjusting calculation parameters. The result shows that the focusing performance and contrast of azimuth gamma curve obtained by this method are improved, which avoids the overfitting problem caused by the linear solution method in the past.Moreover, the resolution of gamma imaging is significantly enhanced, and the recognition ability of thin layer is also improved. As a result, this method can provide more accurate and clear imaging results, thereby improving the geo-steering ability of the instrument and reservoir drilling rate.
azimuthal gamma logging while drillingimaging resolutionregularizationradioactivity intensityMonte Carlo simulation