Test platform for evaluating scale of logging instrument through ultrasonic well cementation

Abstract

The invention relates to the field of oil well logging, and discloses a test platform for evaluating the scale of a logging instrument through ultrasonic well cementation, an ultrasonic test bed is assembled in a measuring groove of a simulation environment platform, and a simulation environment unit is arranged in the simulation environment platform, so that the environment simulation conditions of different stratum materials and different media can be conveniently provided and restored; meanwhile, the upper end of the measuring tank is open, so that an ultrasonic transducer test bed can be conveniently placed. A plurality of transducer units are arranged in the ultrasonic test bench, the ultrasonic test bench is arranged in the sleeve in an inverted mode, the two ends of the ultrasonic test bench are clamped and fixed to the sleeve through clamps, and the vertical height of the ultrasonic test bench in the sleeve can be controlled by adjusting the thickness and the number of the clamps. The height reflects the distance between the transducer and the casing wall, the transducer units are arranged in the direction of the simulation environment unit, the actual oil well condition can be simulated at different positions and angles, the field experiment process of an oil field is replaced, and time and labor cost are saved.

Description

Technical Field

[0001] The present invention relates to the field of oil logging, and particularly to a test platform for calibrating an ultrasonic cementing evaluation logging instrument. Background Art

[0002] Acoustic logging is a logging method based on the acoustic characteristics of media such as rocks to study geological profiles and judge cementing quality. It is widely used in the fields of oil exploration and formation detection. It is an applied science and technology that closely combines basic theory, instrument development, data processing, and data interpretation, and has become an indispensable tool in aspects such as oil and gas exploration, reserve evaluation, well completion, and oil and gas production. Acoustic logging technology emerged in the early 1950s and has experienced decades of development. It has become an important field of geophysical logging discipline and is one of the modern logging methods with the fastest development and the widest application. Acoustic logging is an important means for oil and gas exploration and development.

[0003] In the field of oil engineering technology services, measuring the wall thickness and corrosion condition of steel casings, and evaluating the consolidation quality of cement behind the casings are important service items, among which acoustic waves are the most common measurement means. There are many types of acoustic wave excitation and reception devices. Common ones are piezoelectric ceramic transducers and magnetostrictive transducers. The shapes include spherical, tubular, plate-shaped, and also arrays composed of multiple transducers. The sound field shapes excited by transducers of different shapes are different, and different transducers are selected according to actual needs. In the above-mentioned acoustic logging field, a widely used ultrasonic transducer is a plate-shaped transducer, which relies on the vibration in the thickness direction of the plate to radiate a pencil-shaped sound field with good directivity.

[0004] By using complex signal processing means to process the received acoustic wave signals, information such as the thickness, corrosion, and cement consolidation quality of the steel casing can be obtained. However, before that, it is necessary to first figure out the influence of several external factors on the acoustic wave signals. These external factors include: acoustic wave incident angle, the distance between the ultrasonic transducer and the object to be measured (commonly a steel casing), the distance between the transmitting transducer and the receiving transducer, the distance between the receiving transducers, and cement density, etc. All these external factors will directly affect the finally obtained waveform of the acoustic wave. By continuously changing these external conditions, the internal law of acoustic wave propagation can be discovered, which is useful for instrument design and carrying out engineering technology services.

[0005] However, in the current acoustic wave excitation and reception devices, it is impossible to simulate the actual oil well conditions in different formation materials, different media, different positions, and angles, with high time and labor costs and low accuracy of the measured data. Summary of the Invention

[0006] In order to overcome the defects existing in the above-mentioned prior art, the purpose of the present invention is to provide a test platform for calibrating an ultrasonic cementing evaluation logging instrument, so as to solve the technical problems in the prior art that the excitation and reception devices of traditional acoustic waves cannot simulate the actual oil well conditions in different formation materials, different media, different positions and angles, with high time and labor costs and low accuracy of the measured data.

[0007] The present invention is realized through the following technical solutions:

[0008] A test platform for calibrating an ultrasonic cementing evaluation logging instrument includes a simulation environment platform and an ultrasonic test bench. The simulation environment platform is provided with a simulation environment unit. A measuring groove is provided on the simulation environment platform. A casing is sleeved in the measuring groove. Casing plugs are provided at both ends of the casing. A liquid medium is injected into the casing. The ultrasonic test bench is provided with a number of transducer units. The ultrasonic test bench is inverted and arranged in the casing. The two ends of the ultrasonic test bench are clamped and fixed on the casing through clamps. The number of transducer units are respectively arranged towards the simulation environment unit.

[0009] Preferably, the simulation environment unit includes a granite measuring table, a sandstone measuring table and a limestone measuring table. The granite measuring table, the sandstone measuring table and the limestone measuring table are all in a cuboid structure. The measuring groove runs through the granite measuring table, the sandstone measuring table and the limestone measuring table.

[0010] Preferably, cement is filled between the casing and the measuring groove to form a cement sheath.

[0011] Preferably, the liquid medium includes water or drilling fluid.

[0012] Preferably, the ultrasonic test bench includes a base. Side plates are provided on both sides of the base. A number of transducer units are respectively arranged in the base. Sliding grooves are provided on the side plates. The two ends of the number of transducer units are respectively slidably connected in the sliding grooves of the side plates on both sides of the base. And the two ends of the number of transducer units are fixed in the sliding grooves of the side plates through first locking screws. A first scale line is provided at the top of the side plate for reading the interval distance between the number of transducer units.

[0013] Furthermore, the number of transducer units includes a vertical transducer assembly, a first inclined transducer assembly, a second inclined transducer assembly and a third inclined transducer assembly. The vertical transducer assembly constitutes a vertically self-exciting and self-receiving transducer system. The first inclined transducer assembly, the second inclined transducer assembly and the third inclined transducer assembly, wherein the structures of the first inclined transducer assembly, the second inclined transducer assembly and the third inclined transducer assembly are the same. The transducer of the first inclined transducer assembly is used for transmitting, and the transducers of the second inclined transducer assembly and the third inclined transducer assembly are used for receiving.

[0014] Furthermore, the first inclined transducer assembly includes a transmitting transducer, a transducer housing, and a rotating bracket. The transmitting transducer is assembled inside the transducer housing. Both sides of the transducer housing are fixedly arranged with the two ends of the rotating bracket through a second locking screw and a third locking screw respectively. The two ends of the rotating bracket are respectively slidably connected in the sliding grooves of the side plates. The rotating bracket is provided with a positioning step structure which is in close contact with the top of the side plate.

[0015] Furthermore, the rotating bracket is provided with a waist-shaped hole. The third locking screw is fixed in the waist-shaped hole and is used to limit the range of the rotation angle of the transducer housing. The rotating bracket is provided with a second scale line outside the waist-shaped hole, and a pointer line is provided on the transducer housing corresponding to the second scale line, which is used to set or read out the specific value of the incident angle between the cylindrical axis of the transmitting transducer and the vertical direction of the ultrasonic test bench at this time.

[0016] Furthermore, there are two annular grooves inside the transducer housing. Shock-absorbing rings made of elastic materials are installed in the grooves, and shock-absorbing pads made of elastic materials are installed at the upper and lower ends inside the transducer housing. The transducer housing and the transmitting transducer are isolated by the shock-absorbing rings and shock-absorbing pads.

[0017] Furthermore, the vertical transducer assembly includes a vertical transmitting transducer, a vertical transducer housing, and a fixing bracket. The vertical transmitting transducer is assembled inside the vertical transducer housing. Both sides of the vertical transducer housing are fixed to the two ends of the fixing bracket respectively. The two ends of the fixing bracket are slidably connected in the sliding grooves of the side plates.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] The present invention provides a test platform for calibrating an ultrasonic cementing evaluation logging instrument. By assembling the ultrasonic test bench in the measurement groove of the simulation environment platform, where a simulation environment unit is provided inside the simulation environment platform, it is convenient to provide an environmental simulation situation for restoring different formation materials and different media. At the same time, the upper end of the measurement groove is open, which is convenient for placing the ultrasonic transducer test bench. The ultrasonic test bench is provided with several transducer units. The ultrasonic test bench is inverted and arranged inside the casing. The two ends of the ultrasonic test bench are clamped and fixed on the casing through clamps. By adjusting the thickness and quantity of the clamps, the vertical height of the ultrasonic test bench in the casing can be controlled, and this height reflects the distance between the transducer and the casing wall. The several transducer units are respectively arranged towards the direction of the simulation environment unit, and can simulate the actual oil well situation at different positions and angles, replacing the oil field on-site experiment process, saving time and labor costs, and improving the instrument R & D efficiency.

[0020] Furthermore, the simulation environment unit includes a granite measurement table, a sandstone measurement table, and a limestone measurement table. The granite measurement table, the sandstone measurement table, and the limestone measurement table are all in a cuboid structure. The measurement grooves are arranged through the granite measurement table, the sandstone measurement table, and the limestone measurement table. Cement is filled between the casing and the measurement grooves to form a cement ring. The liquid medium includes water or drilling fluid, and data of the ultrasonic transducer in different formation materials, different media, different positions, and different angles can be obtained in the laboratory, providing a theoretical basis for the development of acoustic logging instruments.

[0021] Furthermore, the ultrasonic test bench includes a base. Side plates are provided on both sides of the base. A number of transducer units are respectively arranged inside the base. Sliding grooves are formed on the side plates. The two ends of the number of transducer units are respectively slidably connected to the sliding grooves of the side plates on both sides of the base, facilitating the movement of the number of transducer units in the sliding grooves. And the two ends of the number of transducer units are fixed in the sliding grooves of the side plates by first locking screws; a first scale line is provided on the top of the side plate, and the interval distance between the vertical transducer assembly and the inclined transducer assembly can be conveniently read or set through the scale line.

[0022] Furthermore, the vertical transducer assembly constitutes a vertically self-emitting and self-receiving vertical transducer system for studying vertically incident sound waves. The first inclined transducer assembly, the second inclined transducer assembly, and the third inclined transducer assembly constitute a single-shot multi-receiving system with inclined emission and inclined reception for studying obliquely incident sound waves.

[0023] Furthermore, the first inclined transducer assembly includes a transmitting transducer, a transducer housing, and a rotating bracket. The transmitting transducer is assembled inside the transducer housing. Both sides of the transducer housing are respectively fixedly arranged with the two ends of the rotating bracket through second locking screws and third locking screws; the two ends of the rotating bracket are respectively slidably connected to the sliding grooves of the side plates; a positioning step structure is provided on the rotating bracket, and the positioning step structure is in close contact with the top of the side plate to ensure the horizontal position consistency of the vertical transducer assembly, the first inclined transducer assembly, the second inclined transducer assembly, and the third inclined transducer.

[0024] Furthermore, the vertical transducer assembly includes a vertical transmitting transducer, a vertical transducer housing, and a fixing bracket; the vertical transmitting transducer is assembled inside the vertical transducer housing. Both sides of the vertical transducer housing are respectively fixed to the two ends of the fixing bracket. The two ends of the fixing bracket are slidably connected to the sliding grooves of the side plates, ensuring that the cylindrical axis direction of the self-emitting and self-receiving transducer is always perpendicular to the horizontal direction of the ultrasonic test bench, that is, the incident angle is perpendicular to the casing wall. Description of the Drawings

[0025] Figure 1 It is a three-dimensional view of the test platform for ultrasonic cementing evaluation logging instrument calibration in the present invention;

[0026] Figure 2 It is a side sectional view of the test platform for calibrating the ultrasonic cementing evaluation logging tool in the present invention;

[0027] Figure 3 It is a perspective view of the ultrasonic test bench in the present invention;

[0028] Figure 4 It is a perspective view of the inclined ultrasonic transducer assembly in the present invention;

[0029] Figure 5 It is a perspective view of the inclined ultrasonic transducer assembly in the present invention;

[0030] Figure 6 It is a side sectional view of the inclined ultrasonic transducer assembly in the present invention;

[0031] Figure 7 It is a perspective view of the vertical ultrasonic transducer assembly in the present invention.

[0032] In the figure: 1 - Granite measuring table; 2 - Sandstone measuring table; 3 - Limestone measuring table; 4 - Cement sheath; 5 - Casing; 6 - Casing plug; 7 - Ultrasonic test bench; 8 - Fixture; 31 - Vertical transducer assembly; 32 - First inclined transducer assembly; 33 - Second inclined transducer assembly; 34 - Third inclined transducer assembly; 35 - Side plate; 36 - First locking screw; 37 - Base; 38 - First scale line; 41 - Transmitting transducer; 42 - Transducer housing; 43 - Rotating bracket; 44 - Second locking screw; 45 - Third locking screw; 46 - Waist-shaped hole; 47 - Second scale line; 48 - Pointer; 49 - Positioning step structure; 50 - Shock-absorbing ring; 51 - Shock-absorbing pad. 71 - Vertical transmitting transducer; 72 - Vertical transducer housing; 73 - Fixed bracket. Detailed implementation manners

[0033] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0034] The present invention will be further described in detail below with reference to the accompanying drawings:

[0035] The object of the present invention is to provide a test platform for calibrating an ultrasonic cementing evaluation logging instrument, so as to solve the technical problems in the prior art that the excitation and reception devices of traditional sound waves cannot simulate the actual oil well conditions in different formation materials, different media, different positions and angles, with high time and labor costs and low accuracy of the measured data.

[0036] See Figure 1 and Figure 2 In an embodiment of the present invention, a test platform for calibrating an ultrasonic cementing evaluation logging instrument is provided, including a simulation environment platform and an ultrasonic test bench 7. A simulation environment unit is provided inside the simulation environment platform, and a measurement groove is provided on the simulation environment platform. A casing 5 is sleeved inside the measurement groove, and casing plugs 6 are provided at both ends of the casing 5. A liquid medium is injected into the casing 5. A plurality of transducer units are provided inside the ultrasonic test bench 7, and the ultrasonic test bench 7 is inverted and arranged inside the casing 5. The two ends of the ultrasonic test bench 7 are clamped and fixed on the casing 5 through clamps 8, and a plurality of transducer units are respectively arranged towards the simulation environment unit.

[0037] Specifically, the simulation environment unit includes a granite measurement table 1, a sandstone measurement table 2, and a limestone measurement table 3. The granite measurement table 1, the sandstone measurement table 2, and the limestone measurement table 3 are all in a cuboid structure, and the measurement groove penetrates through the granite measurement table 1, the sandstone measurement table 2, and the limestone measurement table 3.

[0038] Wherein, cement is filled between the casing 5 and the measurement groove to form a cement sheath 4.

[0039] Wherein, the liquid medium includes water or drilling fluid.

[0040] Specifically, as shown in Figure 3 , the ultrasonic test bench 7 includes a base 37, side plates 35 are provided on both sides of the base 37, and a plurality of transducer units are respectively arranged inside the base 37. Slide grooves are provided on the side plates 35, and both ends of a plurality of transducer units are respectively slidably connected in the slide grooves of the side plates 35 on both sides of the base 37, and both ends of a plurality of transducer units are fixed in the slide grooves of the side plates 35 through first locking screws 36; a first scale line 38 is provided on the top of the side plate 35 for reading the interval distance between a plurality of transducer units.

[0041] When the locking screw 36 is loosened, the vertical transducer assembly 31, the first inclined transducer assembly 32, the second inclined transducer assembly 33 and the third inclined transducer assembly 34 can slide freely in the horizontal direction between the two side plates 35. At the same time, the vertical transducer assembly 31, the first inclined transducer assembly 32, the second inclined transducer assembly 33 and the third inclined transducer assembly 34 have a positioning step structure 49, which is in close contact with the top of the side plate 35, ensuring the consistency of the horizontal positions of the vertical transducer assembly 31, the first inclined transducer assembly 32, the second inclined transducer assembly 33 and the third inclined transducer assembly 34. At the same time, very small scale lines 38 are drawn on the top of the side plate 35, and the interval distance between the vertical transducer assembly 31, the first inclined transducer assembly 32, the second inclined transducer assembly 33 and the third inclined transducer assembly 34 can be conveniently read or set through the scale lines 38.

[0042] Among them, several transducer units include a vertical transducer assembly 31, a first inclined transducer assembly 32, a second inclined transducer assembly 33 and a third inclined transducer assembly 34; the vertical transducer assembly 31 constitutes a vertically self-emitting and self-receiving transducer system; the first inclined transducer assembly 32, the second inclined transducer assembly 33 and the third inclined transducer assembly 34, where the structures of the first inclined transducer assembly 32, the second inclined transducer assembly 33 and the third inclined transducer assembly 34 are the same, the transducer of the first inclined transducer assembly 32 is used for transmitting, and the transducers of the second inclined transducer assembly 33 and the third inclined transducer assembly 34 are used for receiving.

[0043] Among them, according to Figure 4 , Figure 5 and Figure 6 shown, the first inclined transducer assembly 32 includes a transmitting transducer 41, a transducer housing 42 and a rotating bracket 43. The transmitting transducer 41 is assembled in the transducer housing 42, and both sides of the transducer housing 42 are fixedly arranged with the two ends of the rotating bracket 43 through a second locking screw 44 and a third locking screw 45 respectively; both ends of the rotating bracket 43 are slidably connected in the chute of the side plate 35; a positioning step structure 49 is provided on the rotating bracket 43, and the positioning step structure 49 is in close contact with the top of the side plate 35. The positioning step structure 49 forms a certain angle with the vertical direction of the rotating bracket 43, and this angle depends on the incident angle of the obliquely incident sound wave emitted by the transmitting transducer, which is set to 65 degrees here.

[0044] Among them, a waist-shaped hole 46 is provided on the rotating bracket 43, and the third locking screw 45 is fixed in the waist-shaped hole 46 to limit the range of the rotation angle of the transducer housing 42, so that the angle between the cylindrical axis of the transmitting transducer 41 and the vertical direction of the ultrasonic test bench 7 can be adjusted in the range of 10 degrees to 40 degrees, that is, the incident angle of the transmitting transducer 41 can vary between 10 degrees and 40 degrees, and this angle range is set to 30 degrees in the present invention; the rotating bracket 43 is provided with a second scale line 47 on the outer side of the waist-shaped hole 46, and a pointer line 48 is provided on the transducer housing 42 corresponding to the second scale line 47, which is used to set or read the specific value of the incident angle between the cylindrical axis of the transmitting transducer 41 and the vertical direction of the ultrasonic test bench 7 at this time.

[0045] Among them, there are two annular grooves inside the transducer housing 42, and shock-absorbing rings 50 made of elastic material are installed in the grooves. Shock-absorbing pads 51 made of elastic material are installed at the upper and lower ends of the transducer housing 42. The transducer housing 42 and the transmitting transducer 41 are isolated by the shock-absorbing rings 50 and the shock-absorbing pads 51 to reduce the impact of external vibrations on the transmitting transducer 41.

[0046] Among them, according to Figure 7 As shown, the vertical transducer assembly 31 includes a vertical transmitting transducer 71, a vertical transducer housing 72 and a fixed bracket 73; the vertical transmitting transducer 71 is assembled in the vertical transducer housing 72, and the two sides of the vertical transducer housing 72 are respectively fixed to the two ends of the fixed bracket 73, and the two ends of the fixed bracket 73 are slidably connected in the slide groove of the side plate 35.

[0047] In the present invention, the granite measuring platform 1, the sandstone measuring platform 2 and the limestone measuring platform 3 are rectangular parallelepiped, and the cross section of the measuring slot opened on them is a partially circular cavity. This structure cooperates with the medium in the slot to simulate the real environmental conditions of the casing wellbore. The ultrasonic test platform 7 is suspended in the casing 5 by the test platform uprighting frame, so that the ultrasonic test platform 7 is located at the center of the casing 5.

[0048] In the ultrasonic test bench 7, the vertical transducer assembly 31 constitutes a self-transmitting and self-receiving vertical transducer system for studying vertically incident sound waves. The first tilted transducer assembly 32, the second tilted transducer assembly 33 and the third tilted transducer assembly 34 constitute a single-transmitting and multiple-receiving system of tilted transmission and tilted reception for studying obliquely incident sound waves; wherein the first tilted transducer assembly 32 includes a transmitting transducer, and the second tilted transducer assembly 33 and the third tilted transducer assembly 34 include a receiving transducer; the device requires at least one transmitting transducer, but there can be multiple receiving transducers. The present invention is only illustrated with two receiving transducers, but it does not mean that there can only be two receiving transducers.

[0049] In the present invention, the second inclined transducer assembly 33 and the third inclined transducer assembly 34 have the same structure as the first inclined transducer assembly 32. The difference is that the first inclined transducer assembly 32 uses a transmitting transducer, while the second inclined transducer assembly 33 and the third inclined transducer assembly 34 use receiving transducers.

[0050] In summary, the present invention provides a test platform for calibrating an ultrasonic cementing evaluation logging instrument. By assembling the ultrasonic test bench in the measurement tank of the simulation environment platform, where a simulation environment unit is provided in the simulation environment platform to facilitate providing an environmental simulation that restores different formation materials and different media. At the same time, the upper end of the measurement tank is open, facilitating the placement of the ultrasonic transducer test bench. The ultrasonic test bench is provided with several transducer units and is inverted and arranged in the casing. The two ends of the ultrasonic test bench are clamped and fixed to the casing through clamps. By adjusting the thickness and quantity of the clamps, the vertical height of the ultrasonic test bench in the casing can be controlled, and this height reflects the distance between the transducer and the casing wall. The several transducer units are respectively arranged towards the direction of the simulation environment unit, which can simulate the actual oil well situation at different positions and angles, replacing the on-site experiment process in the oil field, saving time and labor costs, and improving the instrument R & D efficiency.

[0051] The measurement tank of the present invention is composed of granite, sandstone, limestone, cement sheath and casing. The measurement tank is filled with fluid media such as water or drilling fluid, and the two ends of the measurement tank are sealed with plugs. The measurement tank and the media in the tank simulate the real environmental conditions of the casing wellbore. At the same time, the upper end of the measurement tank is open, facilitating the placement of the ultrasonic transducer test bench. The ultrasonic transducer test bench can change its position in the casing through the clamps at both ends. This distance usually includes the distance between the ultrasonic transducer and the casing wall, i.e., the source distance. The ultrasonic transducer test bench includes a vertical self-emitting and self-receiving system and a single-shot multi-receiving system with inclined transmission and inclined reception. The former is mainly used for studying the vertically incident sound waves, and the latter is mainly used for studying the obliquely incident sound waves. The inclined ultrasonic transducer assembly and the vertical ultrasonic transducer assembly can be accurately moved in the horizontal direction of the ultrasonic transducer test bench, and scale lines are drawn on the transducer test bench, allowing the distance between the transducers to be set or observed. The inclined transducer assembly can achieve the angular variation between the ultrasonic transducer and the rotating bracket, and the incident angle and reception angle of the transmitting transducer and the receiving transducer can be controlled by adjusting this angle.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that modifications or equivalent replacements can still be made to the specific implementation manners of the present invention. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A test platform for calibrating an ultrasonic cementing evaluation logging instrument, characterized in that, it includes a simulation environment platform and an ultrasonic test bench (7). A simulation environment unit is provided inside the simulation environment platform. A measurement groove is provided on the simulation environment platform. A casing (5) is sleeved inside the measurement groove. Casing plugs (6) are provided at both ends of the casing (5). A liquid medium is injected into the casing (5). A number of transducer units are provided inside the ultrasonic test bench (7). The ultrasonic test bench (7) is inverted and arranged inside the casing (5). The two ends of the ultrasonic test bench (7) are clamped and fixed on the casing (5) through clamps (8). The number of transducer units are respectively arranged towards the simulation environment unit.

2. The test platform for calibrating an ultrasonic cementing evaluation logging instrument according to claim 1, characterized in that, the simulation environment unit includes a granite measurement table (1), a sandstone measurement table (2) and a limestone measurement table (3). The granite measurement table (1), the sandstone measurement table (2) and the limestone measurement table (3) are all in a cuboid structure. The measurement groove is arranged through the granite measurement table (1), the sandstone measurement table (2) and the limestone measurement table (3).

3. The test platform for calibrating an ultrasonic cementing evaluation logging instrument according to claim 1, characterized in that, cement is filled between the casing (5) and the measurement groove to form a cement sheath (4).

4. The test platform for calibrating an ultrasonic cementing evaluation logging instrument according to claim 1, characterized in that, the liquid medium includes water or drilling fluid.

5. The test platform for calibrating an ultrasonic cementing evaluation logging instrument according to claim 1, characterized in that, the ultrasonic test bench (7) includes a base (37). Side plates (35) are provided on both sides of the base (37). A number of transducer units are respectively arranged inside the base (37). Sliding grooves are provided on the side plates (35). The two ends of the number of transducer units are respectively slidably connected in the sliding grooves of the side plates (35) on both sides of the base (37). And the two ends of the number of transducer units are fixed in the sliding grooves of the side plates (35) through first locking screws (36). A first scale line (38) is provided at the top of the side plate (35) for reading the interval distance between the number of transducer units.

6. The test platform for calibrating an ultrasonic cementing evaluation logging instrument according to claim 5, characterized in that, A plurality of transducer units include a vertical transducer assembly (31), a first inclined transducer assembly (32), a second inclined transducer assembly (33), and a third inclined transducer assembly (34); the vertical transducer assembly (31) constitutes a self-emitting and self-receiving vertical transducer system; the first inclined transducer assembly (32), the second inclined transducer assembly (33), and the third inclined transducer assembly (34), wherein the structures of the first inclined transducer assembly (32), the second inclined transducer assembly (33), and the third inclined transducer assembly (34) are the same, the transducer of the first inclined transducer assembly (32) is for transmitting, and the transducers of the second inclined transducer assembly (33) and the third inclined transducer assembly (34) are for receiving.

7. A test platform for calibrating an ultrasonic cementing evaluation logging tool according to claim 6, characterized in that the first inclined transducer assembly (32) includes a transmitting transducer (41), a transducer housing (42), and a rotating bracket (43), the transmitting transducer (41) is assembled in the transducer housing (42), and both sides of the transducer housing (42) are fixedly arranged with the two ends of the rotating bracket (43) through a second locking screw (44) and a third locking screw (45); the two ends of the rotating bracket (43) are respectively slidably connected in the sliding grooves of the side plate (35); a positioning step structure (49) is provided on the rotating bracket (43), and the positioning step structure (49) is in close contact with the top of the side plate (35).

8. A test platform for calibrating an ultrasonic cementing evaluation logging tool according to claim 7, characterized in that a kidney-shaped hole (46) is provided on the rotating bracket (43), the third locking screw (45) is fixed in the kidney-shaped hole (46) for limiting the range of the rotation angle of the transducer housing (42); a second scale line (47) is provided on the rotating bracket (43) outside the kidney-shaped hole (46), and a pointer line (48) is provided on the transducer housing (42) corresponding to the second scale line (47) for setting or reading out the specific value of the incident angle between the cylindrical axis of the transmitting transducer (41) and the vertical direction of the ultrasonic test bench (7) at this time.

9. A test platform for calibrating an ultrasonic cementing evaluation logging tool according to claim 7, characterized in that there are two annular grooves inside the transducer housing (42), and shock-absorbing rings (50) made of elastic materials are installed in the grooves, and shock-absorbing pads (51) made of elastic materials are installed at the upper and lower ends inside the transducer housing (42), wherein the transducer housing (42) and the transmitting transducer (41) are isolated through the shock-absorbing rings (50) and the shock-absorbing pads (51).

10. A test platform for calibrating an ultrasonic cementing evaluation logging tool according to claim 7, characterized in that The vertical transducer assembly (31) includes a vertical transmitting transducer (71), a vertical transducer housing (72) and a fixing bracket (73); the vertical transmitting transducer (71) is assembled in the vertical transducer housing (72), both sides of the vertical transducer housing (72) are respectively fixed to both ends of the fixing bracket (73), and both ends of the fixing bracket (73) are slidably connected in the sliding grooves of the side plates (35).

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