Acoustic logging fluctuation acoustic method

Abstract

The invention discloses an acoustic logging fluctuation acoustic method. The acoustic logging fluctuation acoustic method comprises the steps that an acoustic logging instrument is placed in to-be-logged liquid; the transmitting probe excites vibration, and the array receiving probe receives the acoustic logging waveform in the well and processes the acoustic logging waveform in the well to obtain a wave number-frequency distribution curve of coupling waves including stratum longitudinal, transverse and pseudo sharp waves. A cased well or open hole well model is established, and the two-dimensional spectrum of sound waves in liquid in the well and distribution of the amplitude extreme value of the two-dimensional spectrum are obtained; logging application is carried out according to the two-dimensional spectrum of the sound waves in the liquid in the well; a stratigraphic shear wave time difference processing method is adopted; a stratum longitudinal wave time difference processing method; radial distribution of stratum longitudinal wave time difference; radial distribution of stratum transverse wave time difference; radial distribution of pseudo sharp wave time difference; the three regions of the wave number correspond to the detection regions of the corresponding mode waves; three regions of the frequency correspond to detection regions of corresponding mode waves; and the cut-off frequency and the maximum detection depth of the mode wave. The method is suitable for monopole, dipole and orthogonal dipole acoustic measurement open hole wells and cased wells.

Description

technical field [0001] The invention belongs to the technical field of special instruments for measurement of stratum acoustic time difference and velocity parameters and lithology evaluation in petroleum engineering and various ground engineering constructions, and in particular relates to a method of using boreholes for acoustic logging to detect stratum acoustic parameters around wells. More specifically, it relates to a wave acoustics method for sonic logging. Background technique [0002] In the process of oil exploration, ground exploration and underground space development, it is very important to drill holes and perform acoustic logging in the holes to obtain the longitudinal and shear wave velocity parameters of the formation, which can be used to evaluate the lithology of the formation and calculate the porosity As well as evaluating and detecting underground mined-out areas, designing fracturing construction schemes, and so on. There are many types of acoustic lo...

AI Technical Summary

Problems solved by technology

The errors established on this basis, such as detection depth and detection area, have seriously affected people's understanding of the information measured by acoustic logging, causing serious deviations in understanding, which not only restricts the development of instruments, but also in practical engineering applications. There are also many problems in the process, such as: the problem of cementing quality inspection

Many key exploratory wells cost a lot, but in the end, due to errors in cementing quality inspections, misjudgments of the formations to be explored were made, and the oil layers obtained could not be verified in the end, resulting in exploration errors and huge losses caused by oil spills on the seabed.

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