While-drilling identification method for early overflow layer in oil-gas drilling process

Abstract

The invention discloses a while-drilling identification method for an early overflow layer in an oil and gas drilling process. The while-drilling identification method comprises the following steps: S1, selecting while-drilling logging real-time overflow monitoring parameters which can be obtained in advance and can reflect the early overflow stage; S2, processing the selected overflow monitoringparameters by adopting a trend algorithm and a data standardization method respectively; S3, inputting the processed overflow monitoring data into a trained factor analysis model for overflow horizonrecognition, and carrying out qualitative evaluation on overflow while-drilling data in a numerical form to obtain an overflow horizon recognition curve; S4, calculating a dynamic difference value anda trend characteristic quantity of the total pool volume data corresponding to the late well depth, performing trend extraction on the data, and if the calculated total pool volume dynamic differencevalue and trend characteristic quantity exceed set thresholds, judging that a result in S3 is an overflow horizon; and S5, repeating the steps S2 to S4 until all parameters are processed. According to the invention, the overflow horizon depth can be discovered in advance and accurately forecasted.

Description

technical field [0001] The invention relates to the technical field of petroleum development, in particular to a method for identifying early overflow layers while drilling during oil and gas drilling. Background technique [0002] During the drilling process, when the internal pressure of the wellbore is lower than the pore pressure of the drilled formation, the formation fluid will invade the wellbore and form overflow. Severe overflow will lead to blowout. By analyzing the logging data while drilling, the overflow can be found in time to avoid blowout accidents and prevent damage to the country and the lives and property of the people. Therefore, it is of great significance to optimize the overflow identification method, optimize the overflow monitoring parameters, identify the overflow layer in advance, and improve the real-time and accuracy of monitoring. [0003] At present, at home and abroad, most of the overflow identification methods based on late parameters are u...

AI Technical Summary

Problems solved by technology

[0006] In view of the above problems, the present invention provides a method for identifying early overflow layers while drilling in the process of oil and gas drilling. Through the structural trend algorithm, the influence of the drilling base value is eliminated, and the real-time parameters of comprehensive mud logging and the trend characteristics of dc index data are accurately extracted. Through training The factor score coefficient matrix obtained by the factor analysis model can comprehensively identify the overflow layer, and the identification result can be given while drilling, the depth of the overflow layer can be detected early and accurately predicted, and the problem of poor real-time performance and reliability existing in the current overflow monitoring method can be solved. question

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