Well cementing slurry density measurement device and method

Abstract

A well cementing slurry density measurement device and method. The device comprises: a body (1) having an internal accommodating space; a first diaphragm (2), which is fixedly arranged on the body (1) and forms a sealed accommodating cavity with the internal accommodating space of the body (1), the first diaphragm (2) being configured to deform when immersed in a liquid to be measured; a second diaphragm (4), of which a fixed end is fixedly arranged on the body (1) and divides the accommodating cavity into a conduction cavity (31) and a measurement cavity (32), the conduction cavity (31) and the measurement cavity (32) being in communication with each other, both the conduction cavity (31) and the measurement cavity (32) being filled with oil, and a moving end of the second diaphragm (4) being displaced when the first diaphragm (2) deforms; and a pressure sensor (5), which is arranged in the measurement cavity (32) by means of a mounting bracket (6), and comes into contact with the moving end of the second diaphragm (4) so as to measure a pressure value when the moving end of the second diaphragm (4) is displaced, the pressure value being used for characterizing the phase density of said liquid. The device can acquire density in real time at an operation site, and has high measurement accuracy, a simple structure, and a long service life.

Description

A cement slurry density detection device and method

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202410986686.X, filed July 23, 2024, the contents of which are incorporated by reference herein. TECHNICAL FIELD

[0003] The present application relates to the technical field of density detection, in particular to a cement slurry density detection device, a cement slurry density detection method, an electronic device and a readable storage medium. BACKGROUND

[0004] In the process of oil drilling cementing, various cement slurries with different properties are needed to quickly solidify the wellbore to prevent well wall collapse and achieve the purpose of balancing formation pressure and preventing blowout accidents.

[0005] In recent years, with the continuous increase of drilling depth, different substances and chemical agents need to be added to the cement slurry used for cementing, especially some substances containing solid particles and filaments, which have brought many difficulties to the detection of cement slurry. As the density of the currently used cement slurry is increasing, the characteristics of fast drying and early strength can cause the membrane of the cement slurry density detection instrument to stick, resulting in membrane blockage, winding and other phenomena, which directly leads to the failure of cement slurry density detection, and even leaves well leakage, sticking and other accident hazards, losing the role of guiding subsequent operation production. Therefore, the most common way of cement slurry density detection at the cementing site is still manual operation, and the workers take samples on site in front of the cement truck (cement slurry pool), take the samples back to the laboratory, and then manually analyze each item, and finally provide a test report. Due to the many human factors in the detection process, and the lack of real-time detection capability, it cannot meet the needs of cementing. SUMMARY

[0006] The purpose of the embodiments of the present application is to provide a cement slurry density detection device and method to solve the above problems of membrane sticking, blockage and winding of the cement slurry density detection instrument due to the increasing density of the cement slurry and the characteristics of fast drying and early strength, and the manual sampling and analysis of each item, the many human factors in the detection process, the lack of real-time detection capability, and the inability to meet the needs of cementing.

[0007] To achieve the above purpose, in a first aspect, the embodiments of the present application provide a cement slurry density detection device, which comprises:

[0008] a body having an internal accommodation space;

[0009] A first diaphragm is fixedly arranged on the body to form a closed containing cavity with the internal containing space of the body, and is used to deform under the extrusion of the liquid to be measured when the body is immersed in the liquid to be measured;

[0010] A second diaphragm is fixedly arranged on the body with a fixed end to divide the containing cavity into a conducting cavity and a detection cavity, the conducting cavity and the detection cavity are in communication with each other, and the conducting cavity and the detection cavity are both filled with oil, and when the first diaphragm deforms, the oil is pressed to move to push the moving end of the second diaphragm to displace;

[0011] A pressure sensor is arranged in the detection cavity through a mounting bracket and is in contact with the moving end of the second diaphragm, the moving end of the second diaphragm is pressed when it displaces, the pressure sensor is used to detect the pressure value applied when the moving end of the second diaphragm displaces, and the pressure value is used to represent the density of the liquid to be measured.

[0012] Optionally, the body comprises:

[0013] A support body, which is a semi-open structure and has an internally recessed containing space;

[0014] An upper sealing cover is detachably arranged at the top end of the support body, and the first diaphragm and the second diaphragm are both arranged on the upper sealing cover.

[0015] Optionally, the upper sealing cover is connected with the support body through threads;

[0016] A sealing ring is arranged between the upper sealing cover and the support body.

[0017] Optionally, an oil return hole is formed in the upper sealing cover to communicate the conducting cavity and the detection cavity.

[0018] Optionally, the mounting bracket comprises:

[0019] A support rod is fixedly arranged on the support body, a top end of the support rod is rotatably provided with a supporting plate, and the pressure sensor is arranged on the supporting plate.

[0020] Optionally, the device further comprises:

[0021] A limiting rod is arranged on the support body, the limiting rod is provided with a spring, and a top end of the spring is in contact with the supporting plate.

[0022] Optionally, an oil injection hole is formed in the body, the oil injection hole is in communication with the detection cavity, and is used to inject oil into the detection cavity;

[0023] A sealing cover is detachably arranged on the oil injection hole.

[0024] Optionally, the body further comprises:

[0025] A lower sealing cover is detachably arranged at the bottom end of the support body by screw thread, and a mounting cavity is formed between the lower sealing cover and the support body, and a sealing ring is arranged between the lower sealing cover and the support body.

[0026] A processor is arranged in the mounting cavity and connected with the pressure sensor, and is used for obtaining the density of the liquid to be measured based on the pressure value.

[0027] In a second aspect, the embodiments of the present application further provide a cement slurry density detection method, which is applied to the cement slurry density detection device and comprises the following steps.

[0028] A plurality of pressure values are obtained by the cement slurry density detection device at different regions and different depths of the liquid to be measured.

[0029] The plurality of pressure values are subjected to data screening to obtain screened pressure values.

[0030] The density of the liquid to be measured is calculated by using the screened pressure values.

[0031] Optionally, the step of screening the plurality of pressure values to obtain the screened pressure values comprises the following steps.

[0032] The pressure values with a variance less than or equal to a set threshold value are taken as the screened pressure values.

[0033] Optionally, the step of calculating the density of the liquid to be measured by using the screened pressure values comprises the following steps.

[0034] The density of the liquid to be measured is calculated by using the following calculation formula:

[0035] Wherein, ρ is the density of the liquid to be measured; N i is the screened pressure value; α and β are fitting coefficients; i is an initial measurement count, and n is an effective measurement number.

[0036] In a third aspect, the embodiments of the present application further provide an electronic device, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the cement slurry density detection method when executing the computer program.

[0037] In a fourth aspect, the embodiments of the present application further provide a readable storage medium, and instructions are stored on the readable storage medium, and the instructions are used for causing a machine to execute the cement slurry density detection method.

[0038] The first diaphragm will deform when immersed in the to-be-tested liquid, and the moving end of the second diaphragm will generate corresponding displacement when the first diaphragm deforms, and then the pressure sensor detects the corresponding pressure value generated by the displacement of the second diaphragm, so that the density of the to-be-tested liquid is obtained based on the pressure value, the density of the operation site can be collected in real time, the detection precision is high, the device structure is simple, and the service life is long.

[0039] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0041] Fig. 1 is a structural schematic view of a first well cementing slurry density detection device provided by the present application;

[0042] Fig. 2 is a structural schematic view of a second well cementing slurry density detection device provided by the present application;

[0043] Fig. 3 is a structural schematic view of a third well cementing slurry density detection device provided by the present application;

[0044] Fig. 4 is a schematic view of the installation position of the second diaphragm provided by the present application;

[0045] Fig. 5 is a flow chart of a well cementing slurry density detection method provided by the present application.

[0046] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings: 1-body; 2-first diaphragm; 3-receiving cavity; 4-second diaphragm; 5-pressure sensor; 6-mounting bracket; 7-processor; 8-mounting rod; 11-supporting body; 12-upper sealing cover; 13-sealing ring; 14-lower sealing cover; 15-mounting cavity; 31-conducting cavity; 32-detection cavity; 61-supporting rod; 62-supporting plate; 63-limiting rod; 64-spring; 65-position adjusting nut; 81-ruler; 82-screw; 83-grip; 101-oil injection hole; 102-sealing cover; 121-oil return hole. DETAILED DESCRIPTION

[0047] The specific embodiments of the present application will be described in detail hereinafter with reference to the drawings. It should be understood that the specific embodiments described herein are merely illustrative and explanatory and are not intended to limit the present application.

[0048] In the embodiments of the present application, the orientation words such as "upper", "lower", "left", "right" used herein generally refer to the orientation or positional relationship shown in the drawings or the orientation or positional relationship commonly used when the product of the present application is used, unless otherwise specified.

[0049] The terms "first", "second", "third", etc. are only used for differentiation and description, and cannot be understood as indicating or implying relative importance.

[0050] The terms "parallel", "vertical", etc. do not mean that the components must be absolutely parallel or vertical, but can be slightly inclined. For example, "parallel" only means that its direction is relatively more parallel than "vertical", and does not mean that the structure must be completely parallel, but can be slightly inclined.

[0051] The terms "horizontal", "vertical", "overhanging", etc. do not mean that the components must be absolutely horizontal, vertical or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0052] In addition, the terms "approximately", "substantially", etc. are intended to indicate that the relevant content is not required to be absolutely accurate, but can have some deviation. For example, "approximately equal" does not only mean absolute equality, because in actual production and operation processes, it is difficult to achieve absolute "equality", and generally there is some deviation. Therefore, in addition to absolute equality, "approximately equal" also includes the above-mentioned case of having some deviation. For example, in other cases, unless otherwise specified, the terms "approximately", "substantially", etc. have similar meanings as described above.

[0053] In the description of the present application, it should also be noted that, unless otherwise specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0054] Fig. 1 is a structural schematic diagram of a first cement slurry density detection device provided by the present application; Fig. 2 is a structural schematic diagram of a second cement slurry density detection device provided by the present application; Fig. 3 is a structural schematic diagram of a third cement slurry density detection device provided by the present application; Fig. 4 is an installation position schematic diagram of a second diaphragm provided by the present application; and Fig. 5 is a flow chart of a cement slurry density detection method provided by the present application.

[0055] As shown in Figs. 1-3, the present embodiment provides a cement slurry density detection device, which comprises:

[0056] a body 1 having an internal accommodation space;

[0057] a first diaphragm 2 fixedly arranged on the body 1 to form a closed accommodation cavity 3 with the internal accommodation space of the body 1, the first diaphragm 2 being used to generate deformation when immersed in a liquid to be measured;

[0058] a second diaphragm 4, a fixed end of the second diaphragm 4 being fixedly arranged on the body 1 to divide the accommodation cavity 3 into a conduction cavity 31 and a detection cavity 32, the conduction cavity 31 and the detection cavity 32 being in communication with each other, and the conduction cavity 31 and the detection cavity 32 being both filled with oil liquid, a moving end of the second diaphragm 4 generating displacement when the first diaphragm 2 generates deformation;

[0059] a pressure sensor 5 arranged in the detection cavity 32 through a mounting bracket 6 and in contact with the moving end of the second diaphragm 4, the pressure sensor 5 being used to detect a pressure value generated by the moving end of the second diaphragm 4 when the moving end generates displacement, the pressure value being used to represent the density of the liquid to be measured.

[0060] Specifically, in the present embodiment, after the cement slurry density detection device is completely immersed in the liquid to be measured, a pressure load from the liquid to be measured acts on the first diaphragm 2, the first diaphragm 2 will generate deformation towards the side close to the second diaphragm 4, and will push the oil liquid to move under pressure to transmit the pressure to the surface of the second diaphragm 4. As shown in Fig. 4, the moving end of the second diaphragm 4 is in an open state, the oil liquid flows along the unfixed part of the second diaphragm 4, and pushes the moving end of the second diaphragm 4 to generate displacement. The part not fixed (the moving end) has a slightly larger corresponding displacement size due to no fixed restriction, and has a larger deformation sensitivity. The deformation is captured by the pressure sensor 5 close to the second diaphragm 4 to generate a pressure signal.

[0061] In one embodiment, as shown in Fig. 1, the body 1 comprises:

[0062] a support body 11 having a semi-open structure and an internally recessed accommodation space;

[0063] An upper sealing cover 12 is detachably arranged at the top end of the support body 11, and the first diaphragm 2 and the second diaphragm 4 are arranged on the upper sealing cover 12.

[0064] In an embodiment, as shown in FIG. 1, the upper sealing cover 12 is threadedly connected with the support body 11, and a sealing ring 13 is arranged between the upper sealing cover 12 and the support body 11.

[0065] Specifically, the upper sealing cover 12 is threadedly connected with the support body 11, which facilitates quick installation and disassembly, thereby facilitating maintenance of the internal structure. In addition, the sealing ring 13 is arranged between the upper sealing cover 12 and the support body 11 before installation, which can further ensure air tightness and prevent liquid leakage during measurement. Furthermore, through thread connection, the contact force between the second diaphragm 4 and the pressure sensor 5 can be adjusted by rotating the upper sealing cover 12, so that the second diaphragm 4 and the pressure sensor 5 are at an optimal distance.

[0066] Furthermore, external threads are arranged at the end of the support body 11, internal threads are arranged on the upper sealing cover 12, and the sealing ring 13 is arranged on the support body 11, and the upper sealing cover 12 is tightened, thereby realizing thread connection.

[0067] In an embodiment, as shown in FIG. 1, an oil return hole 121 is arranged on the upper sealing cover 12 to communicate the conduction cavity 31 and the detection cavity 32.

[0068] Specifically, the oil return hole 121 is arranged on the upper sealing cover 12, one end of the oil return hole 121 is located in the conduction cavity 31, and the other end is located in the detection cavity 32, thereby realizing communication of oil in the conduction cavity 31 and the detection cavity 32, and ensuring normal flow of the oil.

[0069] In an embodiment, as shown in FIG. 1, the mounting bracket 6 comprises:

[0070] A support rod 61 is fixedly arranged on the support body 11, and a top end of the support rod 61 is rotatably provided with a supporting plate 62, and the pressure sensor 5 is arranged on the supporting plate 62.

[0071] Specifically, the support rod 61 is vertically arranged on the support body 11, and the support rod 61 can adopt an inverted U-shaped support rod, and the supporting plate 62 is rotatably arranged through a bearing, which can ensure stability of the connection, and the pressure sensor 5 is arranged on the supporting plate 62, so that the pressure sensor 5 can produce a certain amount of rotational displacement along with the supporting plate 62. The supporting plate 62 adopts a mesh structure, which has certain structural strength and can reduce its own weight. The support rod 61 is fixed to the support body 11 through bolts.

[0072] In an embodiment, as shown in FIG. 1, the device further comprises:

[0073] A limiting rod 63 is arranged on the support body 11, and a spring 64 is arranged on the limiting rod 63, and the top end of the spring 64 is in contact with the supporting plate 62.

[0074] Specifically, since the pressure sensor 5 can move with the supporting plate 62, in order to limit the displacement of the pressure sensor 5 and ensure the accuracy of the measurement, a limiting rod 63 is arranged vertically below the supporting plate 62, and a spring 64 is arranged on the limiting rod 63, and the top end of the spring 64 is in contact with the supporting plate 62, so that the position of the pressure sensor 5 can be relatively fixed. The limiting rod 63 is fixed to the support body 11 by a bolt.

[0075] In another embodiment, as shown in FIG. 2, the limiting rod 63 is arranged as a threaded rod, and a position adjusting nut 65 is arranged on the limiting rod 63, and the position adjusting nut 65 is provided with an internal thread, so that the position of the position adjusting nut 65 on the limiting rod 63 can be adjusted by rotating, and the spring 64 is arranged on the limiting rod 63, and the bottom end of the spring 64 is fixed to the position adjusting nut 65, so that the extension length of the top end of the spring 64 can be adjusted by rotating the position adjusting nut 65, and the contact force and distance between the top end of the spring 64 and the supporting plate 62 can be adjusted.

[0076] In an embodiment, as shown in FIG. 1, an oil injection hole 101 is arranged on the body 1, and the oil injection hole 101 is in communication with the detection cavity 32, and is used for injecting oil into the detection cavity 32.

[0077] The oil injection hole 101 is detachably provided with a sealing cover 102.

[0078] Specifically, the oil injection hole 101 is arranged on the body 1, and the oil injection hole 101 can be used for injecting and discharging oil, and when it is not necessary to inject and discharge oil, the sealing cover 102 is used for sealing to avoid leakage. More specifically, the sealing cover 102 can be used in a threaded connection manner to plug the oil injection hole 101.

[0079] In an embodiment, as shown in FIG. 2, the body 1 further comprises:

[0080] A lower sealing cover 14 is detachably arranged at the bottom end of the support body 11 by a thread, and a mounting cavity 15 is formed between the lower sealing cover 14 and the support body 11, and a sealing ring 13 is arranged between the lower sealing cover 14 and the support body 11.

[0081] The device further comprises:

[0082] A processor 7 is arranged in the installation cavity 15 and connected with the pressure sensor 5, and is used to obtain the density of the liquid to be measured based on the pressure value.

[0083] Specifically, the body 1, the upper sealing cover 12 and the lower sealing cover 14 are all provided with a cylindrical structure. The lower sealing cover 14 is connected to the bottom end of the support body 11 in a threaded connection manner, so as to form an installation cavity 15, which can be used to install the processor 7, thereby protecting the installation cavity 15. Through threaded connection, it is convenient and fast to install and disassemble, so as to facilitate the maintenance of the internal structure; in addition, a sealing ring 13 is arranged between the lower sealing cover 14 and the support body 11 before installation, which can further ensure the air tightness and avoid liquid leakage during measurement. Further, external threads are arranged at the end of the support body 11, internal threads are arranged on the lower sealing cover 14, and the sealing ring 13 is arranged on the support body 11, and the lower sealing cover 14 is tightened, so as to realize threaded connection.

[0084] In another embodiment, since the cement slurry density detection device needs to be completely immersed in the liquid to be measured during measurement, and in order to ensure the accuracy of the measured density, the values at multiple different positions and depths in the liquid to be measured are measured to obtain the final density value, therefore, as shown in FIG. 3, an installation rod 8 is detachably arranged on the body 1, and a scale 81 is arranged on the installation rod 8. Specifically, a mounting hole is arranged on the body 1, and a mounting hole is also arranged at the corresponding position of the installation rod 8, and the connection between the installation rod and the body 1 is realized by screwing a screw 82 through the two mounting holes. A handle 83 is arranged at the other end of the installation rod 8, the cement slurry density detection device is completely immersed in the liquid to be measured through the installation rod 8, and the depth of the cement slurry density detection device can be directly read through the scale 81 on the installation rod 8, so that the depth of the cement slurry density detection device in the liquid to be measured can be directly displayed and adjusted.

[0085] The cement slurry density detection device disclosed in the scheme can realize accurate detection of the cement slurry density by detecting the pressure value in real time through the pressure sensor 5, and can obtain accurate cement slurry density parameters by adopting the double-layer semi-closed diaphragm structure composed of the first diaphragm 2 and the second diaphragm 4, thereby greatly improving the accuracy of the on-site cement slurry density detection. In addition, manual sampling is not required during the detection process, which avoids the inaccuracy of manual operation, reduces the labor intensity, solves the defect that the existing equipment is prone to failure, and can directly detect the cement slurry density on site, synchronously transmit, automatically process and analyze, has high detection efficiency, accurate data, and the detection result has more value for guiding production.

[0086] The embodiment of the present application also provides a cement slurry density detection method applied to the cement slurry density detection device, as shown in Figure 5, the method comprises the following steps:

[0087] Step one, obtaining a plurality of pressure values, the plurality of pressure values are obtained by the cement slurry density detection device at different regions and different depths of the liquid to be measured;

[0088] Specifically, during the measurement process, the cement slurry density detection device needs to be completely immersed in the liquid to be measured, and in order to ensure the accuracy of the measured density, the cement slurry density detection device is used to measure the values at a plurality of different positions and different depths in the liquid to be measured, so as to calculate the final density value.

[0089] Step two, data screening is performed on the plurality of pressure values to obtain screened pressure values;

[0090] Specifically, the variance of the plurality of pressure values is calculated, and the pressure values with a variance greater than a set threshold value are removed, and the pressure values with a variance less than or equal to the set threshold value are taken as the screened pressure values.

[0091] Step three, the density of the liquid to be measured is calculated by using the screened pressure values.

[0092] Specifically, the following calculation formula is used to calculate the density of the liquid to be measured:

[0093] Wherein, p is the density of the liquid to be measured; N i is the screened pressure value; alpha and beta are fitting coefficients, and alpha is related to the altitude, and beta is related to the type of the liquid to be measured; i is the initial measurement count, and n is the effective measurement number.

[0094] The embodiment of the present application also provides an electronic device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to realize the cement slurry density detection method.

[0095] The embodiment of the present application also provides a readable storage medium, and instructions are stored on the readable storage medium, the instructions are used to make the machine execute the cement slurry density detection method.

[0096] The above describes the optional embodiments of the embodiments of the present application in detail in combination with the drawings, but the embodiments of the present application are not limited to the specific details in the above embodiments, and various simple modifications can be made to the technical solutions of the embodiments of the present application within the technical concept of the embodiments of the present application, and these simple modifications all belong to the protection scope of the embodiments of the present application.

[0097] Those skilled in the art can understand that all or part of the steps of the method in the above-mentioned embodiments can be completed by instructing the relevant hardware by a program, and the program is stored in a storage medium, and the program includes a plurality of instructions for enabling a single-chip microcomputer, a chip or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The foregoing storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk and various storage media capable of storing program codes.

[0098] The optional embodiments of the present application are described in detail above in combination with the drawings, but the embodiments of the present application are not limited to the specific details in the above-mentioned embodiments, and various simple modifications can be made to the technical solutions of the embodiments of the present application within the technical concept range of the embodiments of the present application, and the simple modifications all belong to the protection range of the embodiments of the present application. In addition, it should be noted that each specific technical feature described in the above-mentioned specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the embodiments of the present application will not be described again for various possible combinations

[0099] In addition, various different embodiments of the embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the embodiments of the present application, and it should be considered as the disclosed content of the embodiments of the present application.

Claims

1. A cement slurry density detection device, characterized in that, The device comprises: a body (1) having an internal accommodation space; a first diaphragm (2) fixedly arranged on the body (1) to form a closed accommodation cavity (3) with the internal accommodation space of the body (1), the first diaphragm (2) being used to deform under the extrusion of a liquid to be tested when immersed in the liquid to be tested; a second diaphragm (4) having a fixed end fixedly arranged on the body (1) to divide the accommodation cavity (3) into a transmission cavity (31) and a detection cavity (32), the transmission cavity (31) and the detection cavity (32) being in communication with each other, and the transmission cavity (31) and the detection cavity (32) being filled with oil, the oil being pressed to move to push a moving end of the second diaphragm (4) to displace when the first diaphragm (2) deforms; a pressure sensor (5) arranged in the detection cavity (32) through a mounting bracket (6) and in contact with the moving end of the second diaphragm (4), the moving end of the second diaphragm (4) extruding the pressure sensor (5) to displace, the pressure sensor (5) being used to detect a pressure value applied when the moving end of the second diaphragm (4) displaces, the pressure value being used to represent the density of the liquid to be tested.

2. The set cement slurry density detection apparatus of claim 1, wherein, The body (1) comprises: a support body (11) having a semi-open structure and an internally recessed accommodation space; an upper sealing cover (12) detachably arranged at a top end of the support body (11), the first diaphragm (2) and the second diaphragm (4) being arranged on the upper sealing cover (12).

3. The set cement slurry density detection apparatus of claim 2, wherein, The upper sealing cover (12) is threadedly connected with the support body (11). A sealing ring (13) is arranged between the upper sealing cover (12) and the support body (11).

4. The set cement slurry density detection apparatus of claim 2, wherein, An oil return hole (121) is formed in the upper sealing cover (12) to communicate the transmission cavity (31) with the detection cavity (32).

5. The set cement slurry density detection apparatus of claim 2, wherein, The mounting bracket (6) comprises: a support rod (61) fixedly arranged on the support body (11), a top end of the support rod (61) being rotatably provided with a supporting plate (62), and the pressure sensor (5) being arranged on the supporting plate (62).

6. The set cement slurry density detection apparatus of claim 5, wherein, The device further comprises: a limiting rod (63) arranged on the support body (11), the limiting rod (63) being externally sleeved with a spring (64), and a top end of the spring (64) being in contact with the supporting plate (62).

7. The set cement slurry density detection apparatus of claim 1, wherein, An oil injection hole (101) is formed in the body (1) to communicate with the detection cavity (32) and inject oil into the detection cavity (32); a sealing cover (102) is detachably arranged on the oil injection hole (101).

8. The set cement slurry density detection apparatus of claim 2, wherein, The body (1) further comprises: a lower sealing cover (14) detachably arranged at a bottom end of the support body (11) through threads, a mounting cavity (15) being formed between the lower sealing cover (14) and the support body (11), and a sealing ring (13) being arranged between the lower sealing cover (14) and the support body (11); the device further comprises: A processor (7) is arranged in the installation cavity (15) and connected with the pressure sensor (5) to obtain the density of the liquid to be measured based on the pressure value.

9. A method for detecting the density of a cement slurry for cementing a well, applied to the device for detecting the density of a cement slurry for cementing a well according to any one of claims 1 to 8, characterized in that, The method comprises: obtaining a plurality of pressure values, the plurality of pressure values being obtained by the cement slurry density detection device at different regions and depths of the liquid to be measured; performing data screening on the plurality of pressure values to obtain screened pressure values; calculating the density of the liquid to be measured by using the screened pressure values.

10. The method of detecting the density of a cement slurry for well cementation according to claim 9, characterized in that, The screening on the plurality of pressure values to obtain the screened pressure values comprises: screening the pressure values with a variance less than or equal to a set threshold as the screened pressure values.

11. The method of detecting the density of a cement slurry for well cementation according to claim 9, characterized in that, The calculation of the density of the liquid to be measured by using the screened pressure values comprises: The following calculation formula is used to calculate the density of the liquid to be measured: where p is the density of the liquid to be measured; N i Pn is the post-screening pressure value; a and b are fitting coefficients; i is the initial measurement count, and n is the effective measurement count.

12. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to implement the cement slurry density detection method of any one of claims 9-11.

13. A readable storage medium having instructions stored thereon for causing a machine to execute the cement slurry density detection method of any one of claims 9-11.

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