Calibration method and device of acoustic variable density logging instrument

A calibration device and logging tool technology, applied in construction and other directions, can solve the problems of wrong evaluation of cementing quality, difficult and consistent response, affecting the amplitude of received signal acoustic waves, etc., so as to improve the quality of cementing evaluation, facilitate on-site operations, and improve accuracy sexual effect

CN105888647AActive Publication Date: 2016-08-24YANGTZE UNIVERSITY
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2016-08-24

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Abstract

The invention provides a probe consistency calibration method of an acoustic variable density logging instrument according to the attenuation rate related calibration principle. A calibration device is designed; through the probe consistency calibration device of the acoustic variable density logging instrument, all acoustic variable density logging instruments can be calibrated in a workshop to obtain the calibration coefficient of each acoustic variable density instrument; and the acoustic amplitude responses are unified to the same scale, thus the problem of acoustic amplitude scale caused in the logging site without a free casing is solved, the influence on the casing size, well fluid and pipe column is eliminated, the site operation is greatly facilitated, and the well cementation assessment quality is improved.
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Description

technical field

[0001] The invention relates to the field of oil drilling, in particular to a method and device for calibrating an acoustic wave variable density logging instrument. Background technique

[0002] In the field of oil drilling and production, cementing is one of the important links in drilling engineering. The quality of cementing is one of the key technologies to ensure the life of oil and gas wells, improve recovery and rationally develop oil and gas resources. At present, the measurement by the acoustic wave variable density logging tool is an important means of cementing quality evaluation. The sound system of the acoustic variable density logging tool is composed of a transmitting probe and two receiving probes. The source distances are 3ft (near probe) and 5ft (far probe). The amplitude of the first wave of the tube wave is used to evaluate the cement bond between the casing and the cement sheath (the first interface). The 5ft probe receives the full wa...

Examples

Embodiment Construction

[0045] In order to make the above objects, features and advantages of the present invention more comprehensible, specific implementations of the present invention will be described in detail below in conjunction with the accompanying drawings.

[0046] The consistency calibration principle of the acoustic wave variable density logging tool adopted in the present invention is: the acoustic system of the logging tool and the transmitter of the calibration instrument form an acoustic system with a symmetrical structure, as follows figure 1 As shown, the transmitter of the logging tool is the transmitting probe of the acoustic variable density instrument, and the transmitter of the calibration instrument is the transmitting probe of the consistency calibration device. Under the control of the surface acquisition system, the acoustic wave signal with a frequency of 20KHz is excited according to the timing of the acquisition system. When the logging tool emits sound waves, the data c...