A method for identifying early overflow layers while drilling during oil and gas drilling

Abstract

The invention discloses a method for identifying early overflow layers while drilling in the process of oil and gas drilling, comprising the following steps: S1, selecting the real-time overflow monitoring parameters of mud logging while drilling that can be obtained in advance and can reflect the early stage of overflow; S2, respectively Use trend algorithm and data standardization method to process the selected overflow monitoring parameters; S3. Input the processed overflow monitoring data into the trained factor analysis model for overflow layer identification, and use the numerical value of the overflow while drilling data Qualitative evaluation in the form of the overflow layer identification curve; S4, calculate the dynamic difference and trend feature quantity of the total pool volume data corresponding to the late well depth, and extract the trend of the data. If the calculated dynamic difference of the total pool volume and If the trend characteristic quantity exceeds the set threshold, it is judged that the result of S3 is an overflow layer; S5, repeat steps S2 to S4 until all parameters are processed. The invention can detect and accurately predict the depth of the overflow layer in advance.

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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