Ground stress multifrequency reverse demonstration method of dipole trans verse wave well logging

Abstract

The invention is used in the field of oil field logging technology, mainly resolving the defect of existent earth stress detection technology which has not any one non-destructive examination method. Said invention is characterized by that it includes the following steps: making cross dipole array acoustic log data undergo the process of angle rotation treatment, then obtaining two main time sequences, on said basis extracting flexural wave dispersion curves of two principal directions, utilizing data of n frequency points on the flexural wave dispersion curves of two principal polarization directions to create n equalities according to two formulae, in which said formulae can be obtained by inversion of well mode wave acoustic elastic equation, in which n is greater than or equal to 6, and atilizing resolution of sain n equalities so as to can obtain maximum main stress SH and minimum main stress Sh of formation.

Description

Technical field: [0001] The invention relates to a method for detecting geostress in oil-water wells in the field of oil field logging, in particular to a method for detecting geostress using dipole acoustic logging data. Background technique: [0002] Casing damage in oil and water wells is a major petroleum engineering problem that commonly exists in various oil fields at home and abroad. The casing is damaged and loses production capacity due to abnormal external force, which not only directly affects the production of the well, but also causes huge economic losses, and the casing damaged well will also cause imperfect regional injection-production systems, accelerate production decline, etc., and indirect losses are even greater. The investment in overhaul of casing damaged wells is also large, so predicting and preventing casing damage has become a common concern in the fields of petroleum engineering and well logging. The research results in recent years have given a ...

AI Technical Summary

Problems solved by technology

This method is based on fracturing, and the stress measurement around the wellbore is also carried out under the condition of destroying the wellbore. Because the tensile strength T of the rock is difficult to measure, it is difficult to obtain an accurate stress value.

It can be seen from the above description that both the borehole caving method and the hydraulic fracturing method are based on the destruction of the wellbore. Therefore, there is currently no non-destructive testing method that can be used for the in-situ stress detection of the actual wellbore.

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