SU894644A2 - Device for testing and calibrating acoustic well logging apparatus - Google Patents

Description

The invention relates to field geophysics, namely to acoustic research methods, and is intended to monitor and calibrate acoustic logging tools.

According to the main auth. No. 739450, a device is known for monitoring and calibrating acoustic logging borehole devices, comprising a hollow reference tube, a part of which is made with holes in its walls, the shape and order of placement of the holes are set depending on the required test ranges of the instruments, taking into account the diameter of the pipe and Instrument base measurement ij.

Before conducting downhole measurements, a reference pipe is installed at the wellhead, an acoustic logging tool is placed in the reference pipe, and by observing the wave patterns in different parts of the pipe, instrument performance is calibrated and the measured parameters are calibrated.

However, such use of a standardization pipe is possible only in cases where the wellbore is filled up to the mouth of the drilling mud. Meanwhile, the position of the hydrostatic fluid level in the wellbore, determined by the magnitude of the reservoir pressure, is often at a considerable distance to the mouth. In addition, when using standardized tubes at the base or in laboratory conditions to test

10 and acoustic logging equipment settings, the sizing tube must be placed in another tube, which acts as a casing, so that working fluid is kept in the sizing tube, which has 15 to one versts in the walls. All this reduces the reliability, efficiency and the possibility of using the known device in various conditions.

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The purpose of the invention is to increase the reliability and enhance the functionality of using the known device.

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Claims (2)

This goal is achieved by the fact that in the proposed device, which includes a hollow reference pipe with holes in the pipe walls, the holes contain plugs made of a material with low acoustic rigidity, for example, rubber. FIG. 1 shows an E1O device for monitoring and calibrating downhole acoustic logging tools; in fig. 2 - control kr va (KK); FIG. 3 — wave patterns (BC); in fig. 4 shows a modification of the design of round holes on the walls of the calibration pipe; in fig. 5 illustrates the use of a device for monitoring and calibrating borehole acoustic logging instruments in working hours in wells with a low hydrostatic level of the fluid in the barrel. The device (FIG. 1) includes a floor of the standardized pipe 1 with a removable cover 2 from one of the ends of the pipe 1. A part of the pipe contains holes in the walls 3. The holes 3 in the walls of the pipe are round (figure 4) and arranged so that the remaining parts of the walls form helical lines on the surface of the pipe (figure 4). The holes 3 in the walls of the pipe 1 contain plugs 4 made of rubber. The device works as follows (figure 5). Before work is carried out in wells in which the level 5 of the wellbore fluid 6 is located at a significant distance (H,; p) from the wellhead, the reference flow tube 1 is closed from the lower end by the lid 2 and installed at the wellhead as shown in FIG. . After this, the reference pipe is filled with the borehole fluid. The acoustic logging device 7 is placed with it. The device checks and performs the corresponding adjustment of the instrument performance and calibrates the measured parameters according to the instrument readings 7 in different parts of the standard tube 1. At the same time, control curves (CK) of the measured parameters are recorded (Fig. 2) and the wave signals are observed and photographed pictures (VK) (fig.Z). After that, the lid 2 is opened, the device 7 is lowered to a predetermined depth and optional borehole measurements are performed. After completing the borehole measurements, the device 7 is again placed in the pipe 1, the lid 2 is closed, the pipe 1 is filled with the borehole liquid 6 and all the testing operations are repeated and Calibration instrument acoustic logging. The fixed QC and RK (Figures 2 and 3) are documentary evidence of the correct operation of the device, the stability of its operation over time (by comparing registered QC and VK before and after borehole saiviepoB), compliance with the device’s operating characteristics and matching specified registration scales. control parameters (reference) values. The use of the device for monitoring and calibration of acoustic logging tools provides, in comparison with the known advantages: kraschaets consumption of materials and simplified construction of the device and, therefore, it is reduced the weight and cost by eliminating the need to use additional housings for holding the liquid in etalonirovochnoy pipe having openings v.stenkah; furthermore widen the possibility of using the device. It is possible to use the proposed device in wells with a low hydrostatic fluid level in the wellbore, i.e. for l p the total length of the device, m; distance from wellhead to fluid level, m; distance from the mouth to the middle of the reservoir with a low reservoir pressure, m; the specific gravity of the well, fluid in the wellbore, the magnitude of the reservoir pressure, seaport. It is possible to use the device (when installing removable covers at both ends of the calibration pipe) to check the accuracy of acoustic logging tools in directional wells, setting different angles of the calibration pipe with the device placed on it for testing, and also significantly improve working conditions during maintenance. the proposed device in field conditions. Claim 1. Device for monitoring and calibration of downhole acoustic logging devices according to author. No. 739450, distinguished by the fact that, in order to increase reliability and expand its use, the holes in the walls of the standard tube contain plugs made of a material with low acoustic rigidity. 2. The device according to claim 1, about t l and the fact that the plugs are made of rubber. Sources of information, rintye taken into account during the examination 1. USSR author's certificate 739450, cl. G 01 V 1/40, E 21 B 47/00 (prototype). Flash: .1 Fig: 5 FIG I Sara & csxsy Hi W PI