A cementing well bottom multi-parameter measurement system and measurement method

Abstract

This article provides a cementing well bottom multi-parameter measurement system and measurement method, including: a protection pup joint, a measuring mechanism, a ratchet claw sleeve and a rubber plug; a cavity is provided on the inner wall of the upper end of the protection pup joint, and the cavity accommodates the measuring mechanism; the measuring mechanism can float out of the wellhead through slurry displacement, and is used to measure and store multiple parameters of the cementing well bottom; the ratchet claw sleeve is sleeved and fits the inner wall of the protection pup joint, and is used to fix the measuring mechanism in the cavity; the rubber plug is lowered into the cementing well with the slurry displacement pressure, and is engaged with the ratchet claw sleeve when it reaches the ratchet claw sleeve, driving the ratchet claw sleeve to move toward the lower end of the protection pup joint, so that the measuring mechanism is separated from the cavity and floats toward the wellhead, so that the real cementing well bottom measurement parameters can be directly obtained.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas drilling and cementing engineering, in particular to a cementing well bottom multi-parameter measurement system and a measurement method. Background Art

[0002] At present, in cementing operations, the determination of bottom hole parameters is based on the inversion and calculation of drilling parameters. Although the downhole temperature and pressure and other parameters are effectively measured and known in the drilling project, cementing operations are different from drilling operations. The specific heat capacity of cement slurry is quite different from that of drilling fluid. Various flow states during the injection process will affect key parameters such as bottom hole temperature and pressure to a certain extent. The sensitivity of cementing cement slurry performance to temperature and pressure and the inaccuracy of drilling parameter inversion often affect the cementing quality to a large extent. In severe cases, it may even cause cementing accidents and complications.

[0003] Therefore, in the existing cementing construction work, the method of determining the cementing bottom hole parameters by inversion and calculation is not accurate. Summary of the invention

[0004] In view of the above problems in the prior art, the purpose of this article is to provide a cementing bottom hole multi-parameter measurement system and measurement method to solve the problem of inaccurate determination of cementing bottom hole parameters by inversion and calculation in the prior art.

[0005] In order to solve the above technical problems, the specific technical solutions of this article are as follows:

[0006] On the one hand, this article provides a cementing bottom hole multi-parameter measurement system, including: a protection short section, a measurement mechanism, a ratchet claw sleeve and a rubber plug;

[0007] The inner wall of the upper end of the protection short section is provided with a cavity, and the cavity accommodates the measuring mechanism;

[0008] The measuring mechanism can float out of the wellhead by replacing the slurry, and is used to measure and store multiple parameters at the bottom of the cementing well;

[0009] The thorn-shaped claw sleeve is sleeved and fits against the inner wall of the protective short section, and is used to fix the measuring mechanism in the cavity;

[0010] The rubber plug is lowered into the cementing well with the displacement pressure, and engages with the ratchet claw sleeve when reaching the ratchet claw sleeve, driving the ratchet claw sleeve to move toward the lower end of the protection short section, so that the measuring mechanism is separated from the cavity and floats toward the wellhead.

[0011] As an embodiment of the present invention, the protection short section includes an upper connecting short section and a lower connecting short section;

[0012] The inner wall of the upper connecting short section is provided with a cavity;

[0013] The upper end outer wall of the lower connecting short section is sleeve-connected with the lower end inner wall of the upper connecting short section;

[0014] The inner wall of the upper connecting short section is communicated with the inner wall of the lower connecting short section to form a channel for the ratchet claw sleeve to move.

[0015] As an embodiment of the present invention, it further includes a first sealing ring, wherein the first sealing ring is sleeved on the upper end of the lower connecting short section;

[0016] The upper end outer wall of the lower connecting short section is sleeve-connected with the lower end inner wall of the upper connecting short section through the first sealing ring.

[0017] As an embodiment of this article, the measuring mechanism includes a fixed core, a buoyancy device, a sealing shell and a sensor;

[0018] The fixed core sleeve is arranged inside the top of the sealing shell, and a buoyancy device is arranged at the bottom of the sealing shell;

[0019] The sensor is sleeved on the top of the fixed core and is used to measure and store multiple parameters of the cementing well bottom.

[0020] As an embodiment of this article, a second sealing ring is provided on the outer side of the sensor;

[0021] The sensor is sleeved on the top of the fixed core through the second sealing ring.

[0022] As an embodiment of this article, the measuring mechanism further includes a power supply processing device, wherein the power supply processing device includes a power supply system, a data storage device and a central processing unit;

[0023] The power supply system, the data storage device and the central processing unit are arranged inside the fixed core in sequence from bottom to top.

[0024] As an embodiment of this article, the buoyancy device includes one or more of an air bag, a floating hoop, foam, and a lightweight plastic.

[0025] As an embodiment of this invention, the rubber plug includes a skirt and a fixed core;

[0026] The skirt wing is sleeved on the outside of the fixed core, and the bottom of the fixed core is interference-fitted with the ratchet-shaped claw sleeve.

[0027] As an embodiment of this invention, a groove is provided at the upper end of the skirt;

[0028] The edge of the groove diverges outwards, and the extension direction of the edge of the groove forms a certain angle with the vertical axis of the fixed core

[0029] On the other hand, this article also provides a measurement method, which is applicable to any of the cementing bottom hole multi-parameter measurement systems described above, comprising:

[0030] Place the measuring mechanism in the cavity of the protection nipple;

[0031] The ratchet claw sleeve is sleeved on a position in the protection short section opposite to the measuring mechanism;

[0032] Transport the protection sub to the bottom of the cementing well and obtain the cementing well bottom parameters;

[0033] The rubber plug is transported to the bottom of the cementing well by using slurry displacement, and the rubber plug passes through the upper end of the protection short joint and has an interference fit with the ratchet claw sleeve. The ratchet claw sleeve moves with the rubber plug to the lower end of the protection short joint, thereby causing the measuring mechanism to detach from the cavity and float to the cementing wellhead.

[0034] By adopting the above technical solution, after the measuring system is placed at the bottom of the cementing well, the measuring mechanism measures the measuring parameters of the bottom of the cementing well. Since the measuring mechanism is fixed in the cavity by the ratchet claw sleeve in the initial state, when the rubber plug engages with the ratchet claw sleeve due to the displacement pressure, the ratchet claw sleeve is driven to move toward the lower end of the protection short section, so that the measuring mechanism is separated from the cavity and floats toward the wellhead through the upper end of the protection short section, the user can obtain the measuring mechanism at the cementing wellhead, and then directly obtain the real measuring parameters of the bottom of the cementing well.

[0035] In order to make the above and other purposes, features and advantages of this article more obvious and easy to understand, the following specifically cites preferred embodiments and describes them in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of this article or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of this article. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A schematic diagram of a multi-parameter measurement system for cementing bottom of a well according to an embodiment of the present invention is shown;

[0038] Figure 2 A preferred schematic diagram of a multi-parameter measurement system for cementing bottom of a well according to an embodiment of this invention is shown;

[0039] Figure 3 A schematic diagram of the measuring mechanism of the embodiment of this invention is shown;

[0040] Figure 4 A schematic diagram of a rubber plug according to an embodiment of the present invention is shown;

[0041] Figure 5 A schematic diagram of a measurement method according to an embodiment of this invention is shown.

[0042] Description of the accompanying symbols:

[0043] 1. Protect the short section;

[0044] 11. Connect the short section on top;

[0045] 12. Connect the short section below;

[0046] 2. Measurement mechanism;

[0047] 21. Fixed core;

[0048] 211. Power supply system;

[0049] 212. Data storage device;

[0050] 213. Central Processing Unit;

[0051] 22. Sealing shell;

[0052] 221. Buoyancy device;

[0053] 23. Sensor;

[0054] 3. Thorn-shaped claw set;

[0055] 4. Rubber plug;

[0056] 5. The first sealing ring;

[0057] 6. Second sealing ring;

[0058] 7. Skirt wings;

[0059] 8. Fix the core. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of this article to clearly and completely describe the technical solutions in the embodiments of this article. Obviously, the described embodiments are only part of the embodiments of this article, not all of the embodiments. Based on the embodiments of this article, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this article.

[0061] It should be noted that the terms "first", "second", etc. in the specification and claims of this article and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of this article described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, device, product or equipment that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0062] like Figure 1 The schematic diagram of a multi-parameter measurement system for cementing bottom shown includes: a protection pup joint 1, a measurement mechanism 2, a thorn claw sleeve 3 and a rubber plug 4;

[0063] The inner wall of the upper end of the protection short section 1 is provided with a cavity, and the cavity accommodates the measuring mechanism 2;

[0064] The measuring mechanism 2 can float out of the wellhead by replacing the slurry, and is used to measure and store multiple parameters of the cementing well bottom;

[0065] The ratchet claw sleeve 3 is sleeved and fits against the inner wall of the protection short section 1, and is used to fix the measuring mechanism 2 in the cavity;

[0066] The rubber plug 4 is lowered into the cementing well with the displacement pressure, and engages with the ratchet claw sleeve 3 when reaching the ratchet claw sleeve 3, driving the ratchet claw sleeve 3 to move toward the lower end of the protection short section 1, so that the measuring mechanism 2 is separated from the cavity and floats toward the wellhead.

[0067] Through the above system, after the measurement system is placed at the bottom of the cementing well, the measurement mechanism 2 can measure the measurement parameters of the cementing well bottom. Since the measurement mechanism 2 is fixed in the cavity by the ratchet claw sleeve 3 in the initial state, when the rubber plug 4 engages with the ratchet claw sleeve 3 with the displacement pressure, the ratchet claw sleeve 3 is driven to move toward the lower end of the protection short section 1, so that the measurement mechanism 2 is separated from the cavity and floats toward the wellhead through the upper end of the protection short section 1, the user can obtain the measurement mechanism 2 at the cementing wellhead, and then directly obtain the real measurement parameters of the cementing well bottom.

[0068] like Figure 2 A preferred schematic diagram of a multi-parameter measurement system for cementing well bottom is shown. In order to ensure that the measuring mechanism 2 can be conveniently installed in the cavity of the protection pup joint 1, the protection pup joint 1 in this article may include two parts. As an embodiment of this article, the protection pup joint 1 includes an upper connecting pup joint 11 and a lower connecting pup joint 12;

[0069] The inner wall of the upper connecting short section 11 is provided with a cavity;

[0070] The upper end outer wall of the lower connecting short section 12 is sleeve-connected with the lower end inner wall of the upper connecting short section 11;

[0071] The inner wall of the upper connecting short section 11 is communicated with the inner wall of the lower connecting short section 12 to form a passage for the ratchet claw sleeve 3 to move.

[0072] In this way, the measuring mechanism 2 can be placed in the cavity of the upper short section 11, and then the thorn-shaped claw sleeve 3 is sleeved and fits against the inner wall of the short section, so that the measuring mechanism 2 can be fixed, and then the lower short section and the upper short section are docked and sleeved, so that the lower short section 12 and the upper short section 11 are spliced ​​together.

[0073] Since the cementing bottom pressure is relatively high, in order to prevent the upper connecting nipple 11 and the lower connecting nipple 12 from being pulled apart by pressure, the present invention further includes a first sealing ring 5, which is sleeved on the upper end of the lower connecting nipple 12;

[0074] The upper outer wall of the lower connecting short section 12 is sleeve-connected with the lower inner wall of the upper connecting short section 11 through the first sealing ring 5 .

[0075] In this way, it can be ensured that after the upper connecting sub 11 and the lower connecting sub 12 are spliced, they will not separate when subjected to cementing bottom hole pressure, thereby ensuring that the measuring mechanism 2 can be firmly fixed in the cavity to measure the cementing bottom hole pressure.

[0076] like Figure 3 The schematic diagram of the measuring mechanism shown in the figure is an embodiment of the present invention, wherein the measuring mechanism 2 comprises a fixed core 21, a buoyancy device 221, a sealing shell 22 and a sensor 23;

[0077] The fixed core 21 is sleeved inside the top of the sealing shell 22, and a buoyancy device 221 is provided at the bottom of the sealing shell 22;

[0078] The sensor 23 is sleeved on the top of the fixed core 21 and is used to measure and store multiple parameters of the cementing well bottom.

[0079] The sensor 23 is sleeved with a second sealing ring 6 on the outside;

[0080] The sensor 23 is sleeved on the top of the fixed core 21 through the second sealing ring 6.

[0081] The measuring mechanism 2 further comprises a power supply processing device, which comprises a power supply system 211, a data storage device 212 and a central processing unit 213;

[0082] The sensor 23 in this article is capable of measuring parameters such as temperature and pressure at the bottom of the cementing well. The measured parameters are processed by the central processor 213 into digital signals that can be recognized by the storage device and stored in the data storage device 212.

[0083] The power supply system 211 , the data storage device 212 and the central processing unit 213 are sequentially arranged inside the fixed core 21 from bottom to top.

[0084] Specific as Figure 3 The power supply system 211, data storage device 212 and central processing unit 213 are all accommodated at the bottom of the sealed shell 22. The data storage device 212 is provided on the upper side of the power supply system, and the central processing unit is provided on the upper side of the data storage device 212. The power supply system 211 supplies power to the data storage device 212, the central processing unit 213 and the sensor 23 respectively.

[0085] The central processor 213 is used to convert the data signal obtained by the sensor 23, and after the central processor 213 completes the data signal conversion, it transfers it to the data storage device 212, and the data storage device 212 is used to store the data persistently.

[0086] Herein, the buoyancy device 221 includes an air bag, a floating hoop, foam or lightweight plastic.

[0087] like Figure 4 The schematic diagram of the rubber plug shown is an embodiment of the present invention, wherein the rubber plug 4 includes a skirt 7 and a fixed core 8;

[0088] The skirt wing 7 is sleeved on the outside of the fixed core 21 , and the bottom of the fixed core 21 is interference fit with the ratchet claw sleeve 3 .

[0089] The upper end of the skirt 7 is provided with a groove;

[0090] The edge of the groove diverges outwards, and the extension direction of the edge of the groove forms a certain angle with the vertical axis of the fixed core 8 .

[0091] When the bottom protruding position of the fixed core contacts the ratchet claw sleeve 3, due to the interference fit, the ratchet claw sleeve 3 can be moved toward the lower connecting short section 12 to make the measuring mechanism 2 escape from the cavity.

[0092] Through the above system, the bottom hole temperature and pressure data are measured by the measuring mechanism 2, and the data are temporarily stored in the data storage device 212. After waiting for the cementing construction to be completed, the measuring mechanism 2 is separated from the cavity by the rubber plug 4, and the measuring mechanism 2 floats out of the wellhead under the buoyancy of the buoyancy device 221. The user uses a computer to read the measurement parameters such as temperature, pressure or radiation in the data storage device 212. Since the central processing unit 213 can decode and store the data measured by the sensor 23 in real time, the real-time nature of the data is guaranteed, which solves the problem that the bottom hole parameters cannot be directly measured in real time during cementing operations.

[0093] like Figure 5 A schematic diagram of a measurement method shown in FIG. 1 includes:

[0094] Step 501, placing the measuring mechanism in the cavity of the protection pup joint;

[0095] Step 502, sleeve the ratchet claw sleeve onto a position in the protection short section opposite to the measuring mechanism;

[0096] The measuring mechanism 2 is placed in the cavity of the upper connecting short section 11 of the protection short section 1, and then the ratchet claw sleeve 3 is sleeved and fitted on the inner wall of the protection short section 1 to fix the measuring mechanism 2 in the cavity. Then the lower connecting short section 12 of the protection short section 1 is spliced ​​with the upper connecting short section 11. At this time, the inner walls of the upper connecting short section 11 and the lower connecting short section 12 form a channel to accommodate the ratchet claw sleeve 3 to slide up and down. However, the outer diameter of the ratchet claw sleeve 3 in this article can be slightly larger than the inner diameter of the channel. Only under the action of gravity, the ratchet claw sleeve 3 cannot move freely in the channel to prevent the measuring mechanism 2 from falling off in the cavity.

[0097] The lower joint is connected to the male and female buckles of the casing string respectively (the casing string is a connector that extends into the bottom of the cementing well). The construction personnel install the measurement system at the bottom of the cementing well through the casing string. The measurement system as a whole is located above the floating collar.

[0098] Step 503: transport the protection sub to the bottom of the cementing well and obtain cementing well bottom parameters;

[0099] The sensor 23 of the measuring mechanism 2 obtains parameters such as the temperature and pressure at the bottom of the cementing well, and transmits the measured data to the central processing unit 213. The central processing unit 213 converts the obtained data signal and then transfers it to the data storage device 212. The power supply system 211 is responsible for the power supply of the sensor 23, the central processing unit 213 and the data storage device 212.

[0100] Step 504: Use slurry displacement to transport the rubber plug to the bottom of the cementing well. The rubber plug will pass through the upper end of the protection pup joint and have an interference fit with the ratchet claw sleeve. The ratchet claw sleeve moves with the rubber plug toward the lower end of the protection pup joint, thereby causing the measuring mechanism to leave the cavity and float to the cementing wellhead.

[0101] After the measurement is completed, the construction personnel carry out normal cementing operation. When replacing the slurry, the rubber plug 4 is used for slurry replacement. That is, after the rubber plug 4 is placed at the cementing wellhead, the replacement slurry is injected into the cementing well, and the rubber plug 4 extends into the bottom of the cementing well along with the replacement slurry.

[0102] The special rubber plug 4 has a specially designed skirt, which can be combined with the ratchet claw sleeve 3. When the special rubber plug 4 reaches the ratchet claw sleeve 3, the skirt drags the ratchet claw sleeve 3 to move downward (moving downward in the direction of the connecting short section 12), and the measuring mechanism 2 is not fixed in the cavity, and then detaches from the internal cavity of the connecting short section. Due to the effect of the airbag, the measuring mechanism 2 as a whole floats out of the wellhead under the buoyancy of the drilling fluid.

[0103] The rubber plug 4 continues to move downward under the displacement pressure and separates from the ratchet claw sleeve 3 until the aluminum core of the rubber plug 4 reaches the floating collar to complete the entire cementing process.

[0104] The measuring mechanism 2 that floats to the wellhead is salvaged, and the temperature and pressure data measured in the data storage device 212 are read by a computer to complete the measurement and analysis of multiple parameters at the bottom of the cementing well.

[0105] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this article.

[0106] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0107] In the several embodiments provided herein, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or can be electrical, mechanical or other forms of connection.

[0108] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of this article.

[0109] In addition, each functional unit in each embodiment of this invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional unit.

[0110] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this article is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of this article. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0111] Specific embodiments are used in this article to illustrate the principles and implementation methods of this article. The description of the above embodiments is only used to help understand the methods and core ideas of this article. At the same time, for general technicians in this field, according to the ideas of this article, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on this article.

Claims

1. A cementing bottom hole multi-parameter measurement system, characterized in that: include: Protect the short joint, measuring mechanism, thorn claw sleeve and rubber plug; The inner wall of the upper end of the protection short section is provided with a cavity, and the cavity accommodates the measuring mechanism; The measuring mechanism can float out of the wellhead by replacing the slurry, and is used to measure and store multiple parameters at the bottom of the cementing well; The thorn-shaped claw sleeve is sleeved and fits against the inner wall of the protective short section, and is used to fix the measuring mechanism in the cavity; The rubber plug is lowered into the cementing well with the displacement pressure, and engages with the ratchet claw sleeve when reaching the ratchet claw sleeve, driving the ratchet claw sleeve to move toward the lower end of the protection short section, so that the measuring mechanism is separated from the cavity and floats toward the wellhead.

2. The cementing bottom hole multi-parameter measurement system according to claim 1, characterized in that: The protection short section includes an upper connecting short section and a lower connecting short section; The inner wall of the upper connecting short section is provided with a cavity; The upper end outer wall of the lower connecting short section is sleeve-connected with the lower end inner wall of the upper connecting short section; The inner wall of the upper connecting short section is communicated with the inner wall of the lower connecting short section to form a channel for the ratchet claw sleeve to move.

3. The cementing bottom hole multi-parameter measurement system according to claim 2, characterized in that: It also includes a first sealing ring, which is sleeved on the upper end of the lower connecting short section; The upper end outer wall of the lower connecting short section is sleeve-connected with the lower end inner wall of the upper connecting short section through the first sealing ring.

4. The cementing bottom hole multi-parameter measurement system according to claim 1, characterized in that: The measuring mechanism comprises a fixed core, a buoyancy device, a sealing shell and a sensor; The fixed core sleeve is arranged inside the top of the sealing shell, and a buoyancy device is arranged at the bottom of the sealing shell; The sensor is sleeved on the top of the fixed core and is used to measure and store multiple parameters of the cementing well bottom.

5. The cementing bottom hole multi-parameter measurement system according to claim 4, characterized in that: A second sealing ring is sleeved on the outer side of the sensor; The sensor is sleeved on the top of the fixed core through the second sealing ring.

6. The cementing bottom hole multi-parameter measurement system according to claim 4, characterized in that: The measuring mechanism further comprises a power supply processing device, wherein the power supply processing device comprises a power supply system, a data storage device and a central processing unit; The power supply system, the data storage device and the central processing unit are arranged inside the fixed core in sequence from bottom to top.

7. The cementing bottom hole multi-parameter measurement system according to claim 4, characterized in that: The buoyancy device includes one or more of an air bag, a floating hoop, foam, and a lightweight plastic.

8. The cementing bottom hole multi-parameter measurement system according to claim 1, characterized in that: The rubber plug comprises a skirt and a fixed core; The skirt wing is sleeved on the outside of the fixed core, and the bottom of the fixed core is interference-fitted with the ratchet-shaped claw sleeve.

9. The cementing bottom hole multi-parameter measurement system according to claim 8, characterized in that: The upper end of the skirt is provided with a groove; The edge of the groove diverges outwards, and an extending direction of the edge of the groove forms a certain angle with a vertical axis of the fixed core.

10. A measurement method, characterized in that: The cementing bottom hole multi-parameter measurement system applicable to any one of claims 1 to 9 above comprises: Place the measuring mechanism in the cavity of the protection nipple; The ratchet claw sleeve is sleeved on a position in the protection short section opposite to the measuring mechanism; Transport the protection sub to the bottom of the cementing well and obtain the cementing well bottom parameters; The rubber plug is transported to the bottom of the cementing well by using slurry displacement, and the rubber plug passes through the upper end of the protection short joint and has an interference fit with the ratchet claw sleeve. The ratchet claw sleeve moves with the rubber plug to the lower end of the protection short joint, thereby causing the measuring mechanism to detach from the cavity and float to the cementing wellhead.

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