Underwater chemical agent injection metering method based on multi- viscosity fitting

Abstract

The application discloses a kind of underwater chemical agent injection metering methods based on multiple viscosity fitting, first, calibrate multiple different viscosity media, obtain the flow of each viscosity medium and differential pressure;So respectively fitted to obtain the outflow coefficient of each viscosity medium;Again, any viscosity medium participating in calibration is used as reference medium, and the remaining other media are used as calibration medium, and the relationship between the outflow coefficient and viscosity of the reference medium and the calibration medium is fitted, so that the general formula of the outflow coefficient of different viscosity media and the general flow calculation formula of different viscosity media are obtained.The significant effect of the application is that the outflow coefficient derivation process can be greatly simplified, the tedious calibration operation for multiple viscosity media can be avoided, time can be greatly saved, and cost can be reduced.The outflow coefficient has good adaptability and high matching degree, and a real flow value can be obtained, so the metering precision is high.

Description

Technical Field

[0001] This invention relates to the field of petroleum engineering, and more specifically to a method for controlling the injection of chemicals into subsea production tree networks. Background Technology

[0002] To ensure the normal operation of underwater oil pipelines and improve their service life and production efficiency, various chemicals need to be periodically introduced into the pipelines through underwater injection equipment. Regarding underwater injection equipment, the applicant's earlier Chinese patent application (application number: 202110934610.9) described the structure of an underwater chemical injection device, whose orifice plate and flow channel groove can reduce the pressure of the high-pressure chemical flow. However, subsequent practical experience has revealed the following problems:

[0003] Because underwater chemical injection equipment is a non-standard structure, traditional empirical values ​​for flow measurement are no longer applicable, and directly using empirical parameters will result in measurement inaccuracies. At the same time, underwater chemical injection equipment manages a wide variety of chemicals with different viscosities, flow characteristics, and discharge coefficients. It is impossible to use fixed coefficients to measure flow, and the workload of marking all types is huge and not very feasible. Summary of the Invention

[0004] To solve the above technical problems, this invention obtains a universal formula for different viscosity-related parameters through a small number of calibrations, thereby adapting to the flow measurement of reagents of various viscosities. The main technical solutions adopted are as follows:

[0005] A method for underwater chemical agent injection metering based on multi-viscosity fitting includes a device body, the device body comprising an agent inlet connector, a pressure reducing component, a needle valve assembly, and an agent outlet connector connected sequentially through flow channels, characterized by the following steps:

[0006] Step 1: Inject various media of different viscosities into the device body for calibration to obtain a calibration array. The calibration array includes several corresponding flow rates Q and differential pressure DP before and after the medium flows through the pressure reducing component.

[0007] Fit the flow rate-differential pressure relationship for each viscosity medium according to formula ①;

[0008]

[0009] Where: K is a fixed parameter; C is the outflow coefficient;

[0010] The effluent coefficients for various viscosities were obtained by fitting the data.

[0011] Step 2: Use any viscosity medium involved in the calibration as the reference medium, and its discharge coefficient is the reference discharge coefficient C. W The viscosity is the reference viscosity μ.W ;

[0012] The remaining media are calibration media, and their discharge coefficients are the calibration discharge coefficients C. X The viscosity is the nominal viscosity μ. X ;

[0013] C is fitted according to the following formula ② X / C W With μ W / μ X relation;

[0014] C X / C W =A*ln(μ W / μ X )+B, Formula ②;

[0015] Where: A and B are the fitting parameters for the outflow coefficient, obtained by fitting;

[0016] The calibration outflow coefficient C is obtained. X The calculation formula;

[0017] Step 3: Substitute formula ② into formula ① to obtain the general flow rate calculation formula for media of different viscosities:

[0018] Attached Figure Description

[0019] Figure 1 A schematic diagram of an underwater chemical injection device;

[0020] Figure 2 This is a schematic diagram of the structure of the wellhead connector 100;

[0021] Figure 3 This is a planar connection diagram of the wellhead connector 100, power unit 200, power transfer unit 300, drive unit 400, and fluid regulation unit 500.

[0022] Figure 4 for Figure 3 The left view;

[0023] Figure 5 for Figure 4 AA' section view;

[0024] Figure 6 for Figure 4 BB' sectional view;

[0025] Figure 7 for Figure 4 CC' section view;

[0026] Figure 8This is a three-dimensional structural diagram of the threaded sleeve 53;

[0027] Figure 9 This is a schematic cross-sectional view of the pressure reducing seat 22;

[0028] Figure 10 This is a schematic diagram of the cross-sectional structure of valve seat 51;

[0029] Figure 11 A cross-sectional structural diagram of the electronic compartment 600 and the ROV connection 700;

[0030] Figure 12 C X / C W -μ W / μ X Line graph. Detailed Implementation

[0031] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0032] A method for underwater chemical agent injection metering based on multi-viscosity fitting includes a device body, which comprises an agent inlet connector 1, a pressure reducing component 2, a needle valve assembly 5, and an agent outlet connector 3 connected sequentially through flow channels. The method is performed according to the following steps:

[0033] Step 1: Inject a fluid of any viscosity (such as water) into the device body as a reference medium, and use it as the reference viscosity μ. W Fit its baseline outflow coefficient C W ;

[0034] The fitting process is as follows: The reference medium is injected into the device body, and the flow rate Q and the differential pressure DP before and after the reference medium flows through the pressure reducing component 2 are obtained in real time; Q and DP correspond to each other to form a calibration array;

[0035] Fit the flow rate-differential pressure relationship for each viscosity medium according to formula ①;

[0036]

[0037] Where: K is a fixed parameter; C is the outflow coefficient;

[0038] The reference viscosity μ was obtained by fitting. W The corresponding baseline outflow coefficient C W

[0039] Step 2: Inject at least one other calibration medium of varying viscosity into the device body and fit the calibration viscosity μ. X The corresponding calibration outflow coefficient C X ;

[0040] The fitting process is the same as above.

[0041] The flow rate, differential pressure, and discharge coefficient of some media in the above fitting process are extracted and shown in Table 1.

[0042] Table 1. Statistical Table of Flow Rate, Differential Pressure, and Outflow Coefficient

[0043]

[0044] Step 3: Using medium 1 (water) in Table 1 as the reference medium, calculate C. X / C W With μ W / μ X And fit C according to the following formula ② X / C W With μ W / μ X Relationship;

[0045] C X / C W =A*ln(μ W / μ X )+B, Formula ②;

[0046] Where: A and B are the fitting parameters for the outflow coefficient, and several corresponding C X / C W With μ W / μ X After substituting into formula ②, the logarithmic relationship was used to fit the results, which are shown in Table 2.

[0047] Table 2, C X / C W μ W / μ X Statistical table of parameters A and B

[0048]

[0049] That is, in formula ②, C X / C W =0.174535*ln(μ W / μ X +0.968846;

[0050] This yields the calibration outflow coefficient C. X The calculation formula;

[0051] C X =(0.174535*ln(μ) W / μ X )+0.968846)*C W ;

[0052] The above formula provides a general expression for the discharge coefficient of media with different viscosities. In terms of the method itself, a general formula for calculating the discharge coefficient can be obtained through a small amount of initial calibration. The method is simple and effective, saving considerable time. In practice, those skilled in the art can refer to the discharge coefficient and viscosity of any medium in Table 1, or they can calibrate a benchmark discharge coefficient themselves and then look up the viscosity of the target medium to obtain its discharge coefficient. This avoids the need for comprehensive calibration for every type of medium with different viscosities, simplifying the process of obtaining the discharge coefficient.

[0053] To make C more intuitive X / C W With μ W / μ X The logarithmic relationship between them, plot C X / C W -μ W / μ X The curve, the result is as follows Figure 12 .from Figure 12 It can be seen that C X / C W With μ W / μ X There is a good logarithmic relationship between them. The general formula for the outflow coefficient fitted by formula ② can output a relatively accurate flow rate with high measurement accuracy.

[0054] Step 3: Substitute formula ② into formula ① to obtain the general flow rate calculation formula for media of different viscosities:

[0055]

[0056] like Figure 1-11 As shown, the equipment body also includes a treehouse connector 100, a power unit 200, a power transfer unit 300, a drive unit 400, a fluid regulation unit 500, an electronic compartment 600, and an ROV connection unit 700 connected in sequence.

[0057] The wellhead connector 100 includes a docking cylinder 101. The upstream end of the docking cylinder 101 is used to connect to the corresponding interface on the wellhead, and the downstream end of the docking cylinder 101 is connected to the power unit 200. The cylinder wall of the docking cylinder 101 has several water-permeable holes. At least three connecting lugs 102 are provided on the inner wall of the docking cylinder 101. The connecting lugs 102 are close to the power unit 200 and are fixed to it by bolts.

[0058] The power unit 200 includes a power unit housing 201, which is cylindrical. The power unit housing 201 and the docking cylinder 101 are arranged along the same center line. The interior of the power unit housing 201 is used to install internal components. The upstream end of the power unit housing 201 is connected to the end of the docking cylinder 101 through the connecting lug 102. The downstream end of the power unit housing 201 is connected to the power adapter 300.

[0059] The power adapter 300 includes a power adapter housing 301, which is cylindrical and is arranged along the same center line as the power unit housing 201. The interior of the power adapter housing 301 is used to install internal components.

[0060] The downstream end face of the power unit housing 201 is provided with a first embedding recess, and the upstream end face of the power adapter housing 301 is provided with a first embedding boss. The first embedding boss matches the first embedding recess and extends into the first embedding recess. The downstream end face of the power unit housing 201 and the upstream end face of the power adapter housing 301 are fitted together to form a stepped first sealing surface. A first axial sealing ring and a first radial sealing ring are provided at the first sealing surface. The first radial sealing ring is located on the mating surface of the first embedding boss and the first embedding recess and is used to seal the radial mating portion of the mating surface of the first embedding boss and the first embedding recess. The first axial sealing ring is located outside the first radial sealing ring and is used to axially seal the downstream end face of the power unit housing 201 and the upstream end face of the power adapter housing 301 outside the first radial sealing ring. The downstream end face of the power adapter housing 301 is connected to the drive unit 400.

[0061] The drive unit 400 includes a drive unit housing 401, which is cylindrical. The drive unit housing 401 and the power adapter housing 301 are arranged along the same center line. The interior of the drive unit housing 401 is used to install internal components.

[0062] The upstream end face of the drive housing 401 is provided with a second embedding recess, and the downstream end face of the power adapter housing 301 is provided with a second embedding boss. The second embedding boss matches the second embedding recess and extends into the second embedding recess. The downstream end face of the power adapter housing 301 and the upstream end face of the drive housing 401 are fitted together to form a stepped second sealing surface. A second axial sealing ring and a second radial sealing ring are provided at the second sealing surface. The second radial sealing ring is located on the mating surface of the second embedding boss and the second embedding recess and is used to seal the radially mating portion of the mating surface of the second embedding boss and the second embedding recess. The second axial sealing ring is located outside the second radial sealing ring and is used to axially seal the downstream end face of the power adapter housing 301 outside the second radial sealing ring and the upstream end face of the drive housing 401. The downstream end face of the drive housing 401 is connected to the fluid regulating part 500.

[0063] The downstream end of the power unit housing 201, the upstream end of the drive unit housing 401, and the power adapter housing 301 are tightened by a plurality of first axial tension bolts. All the first axial tension bolts are arranged around the center line of the power adapter housing 301. The first axial tension bolts pass through the downstream end of the power unit housing 201, the upstream end of the drive unit housing 401, and the power adapter housing 301.

[0064] The fluid regulating unit 500 includes a regulating unit housing 501, which is cylindrical. The regulating unit housing 501 and the drive unit housing 401 are arranged along the same center line. The interior of the regulating unit housing 501 is used to install internal components.

[0065] The upstream end face of the adjusting housing 501 is provided with a third embedding boss, and the downstream end face of the driving housing 401 is provided with a third embedding recess. The third embedding boss matches the third embedding recess and extends into the third embedding recess. The downstream end face of the driving housing 401 and the upstream end face of the adjusting housing 501 are fitted together to form a stepped third sealing surface. A third axial sealing ring and a third radial sealing ring are provided on the third sealing surface. The third radial sealing ring is located on the mating surface of the third embedding boss and the third embedding recess and is used to seal the radial mating portion of the mating surface of the third embedding boss and the third embedding recess. The third axial sealing ring is located outside the third radial sealing ring and is used to axially seal the downstream end face of the driving housing 401 outside the third radial sealing ring and the upstream end face of the adjusting housing 501. The downstream end face of the adjusting housing 501 is connected to the electronic compartment 600.

[0066] The downstream end of the drive housing 401 and the upstream end of the adjustment housing 501 are tightened by a plurality of second axial tension bolts. All the second axial tension bolts are arranged around the center line of the drive housing 401 and / or the adjustment housing 501, and the second axial tension bolts pass through the downstream end of the drive housing 401 and the upstream end of the adjustment housing 501 at the same time.

[0067] A fourth embedding recess is provided on the downstream end face of the adjusting part housing 501, and a sealing partition 502 is embedded in the fourth embedding recess. The sealing partition 502 matches the fourth embedding recess. The downstream end face of the adjusting part housing 501 and the sealing partition 502 are tightened by several bolts. Several fourth radial sealing rings are provided between the radial contact surfaces of the adjusting part housing 501 and the sealing partition 502.

[0068] The power unit housing 201, power transfer housing 301, drive unit housing 401, and adjustment unit housing 501 are connected to form the equipment housing. The purpose of the separate equipment housing is to facilitate the subsequent installation and sealing of internal components. The internal spaces of the power unit housing 201, power transfer housing 301, drive unit housing 401, and adjustment unit housing 501 are axially connected and can form an internal component installation area. Internal components are provided in the internal component installation area, including a pressure reducing component 2 and a needle valve assembly 5.

[0069] A chemical input connector 1, a chemical output connector 3, and a tree plug x are installed on the upstream end face of the power unit housing 201. The chemical input connector 1, the chemical output connector 3, and the tree plug x are all commercially available products. All three are axially located on the upstream end face of the power unit housing 201, and their center lines are parallel to each other. Their product structure and installation structure will not be described in detail here.

[0070] The "upstream end" and "downstream end" mentioned in the above description are based on the connection sequence of the wellhead connector 100, power unit 200, power transfer unit 300, drive unit 400, fluid regulation unit 500, electronic compartment 600, and ROV connection unit 700 in the equipment. The wellhead connector 100 is defined as upstream, and the ROV connection unit 700 is defined as downstream.

[0071] A flow channel is provided in the solid part of the device housing (i.e., the part between the inner wall and the outer wall of the device housing), the inlet end of the flow channel is connected to the drug input connector 1, and the outlet end of the flow channel is connected to the drug output connector 3.

[0072] The drug inlet connector 1, the pressure reducing component 2, the needle valve assembly 5, and the drug outlet connector 3 are connected in sequence through the flow channel;

[0073] Specifically: The pressure-reducing component 2 includes a pressure-reducing sleeve 21 and a pressure-reducing seat 22. The pressure-reducing sleeve 21 is cylindrical. The pressure-reducing sleeve 21 can be an independent shell disposed within the adjusting part housing 501, or it can be integrally formed with the adjusting part housing 501, or it can be equal to the adjusting part housing 501. Taking the case where the pressure-reducing sleeve 21 is equal to the adjusting part housing 501 as an example:

[0074] The inner cavity of the adjusting housing 501 (pressure reducing sleeve 21) is cylindrical, and the pressure reducing seat 22 is cylindrical. The pressure reducing seat 22 is axially embedded inside the pressure reducing sleeve 21, and the pressure reducing seat 22 is located in the downstream section of the adjusting housing 501.

[0075] At least three pressure-reducing channels 22a are provided in the solid area inside the pressure-reducing seat 22. The total number of pressure-reducing channels 22a is odd. The pressure-reducing channels 22a are threaded, and each pressure-reducing channel 22a has a different spiral diameter. The multiple pressure-reducing channels 22a are arranged along a common center line. The spiral diameter of the multiple pressure-reducing channels 22a increases radially from the inside to the outside. Each pressure-reducing channel 22a is a channel with a circular cross-section and has the same channel diameter. One end of each pressure-reducing channel 22a is a pressure-reducing channel inlet, and the other end is a pressure-reducing channel outlet. The pressure-reducing channel inlet of the outer layer and the pressure-reducing channel outlet of the adjacent inner layer are located at the same end of the pressure-reducing seat 22. The pressure-reducing channel outlet of the outer layer and the pressure-reducing channel inlet of the adjacent inner layer are located at the same end of the pressure-reducing seat 22. Two adjacent pressure-reducing channels 22a in the inner and outer layers are connected end to end in sequence.

[0076] The pressure-reducing seat 22 is provided with a pressure-reducing inlet and a pressure-reducing outlet. The pressure-reducing inlet communicates with the inlet of the outermost first pressure-reducing channel 22a, and the pressure-reducing outlet communicates with the outlet of the innermost last pressure-reducing channel 22a. In a more specific embodiment, the pressure-reducing inlet opens onto the cylindrical outer wall of the pressure-reducing seat 22, away from the downstream end of the adjusting housing 501 (and also away from the sealing partition 502). The pressure-reducing outlet opens onto one end face of the pressure-reducing seat 22, facing the downstream end of the adjusting housing 501 (and also towards the sealing partition 502). The pressure-reducing inlet and outlet are respectively close to both ends of the pressure-reducing seat 22. The inner wall of 1 is provided with an annular drug inlet cavity around the pressure reducing component inlet. The annular drug inlet cavity is connected to the pressure reducing component inlet. The flow channel is connected to the annular drug inlet cavity. A low-pressure drug center flow channel is provided on the pressure reducing seat 22 along its center line. A low-pressure drug outflow space is reserved between the pressure reducing seat 22 and the closed partition 502. The pressure reducing component inlet is connected to the low-pressure drug outflow space. The low-pressure drug outflow space is connected to the inlet of the low-pressure drug center flow channel. The outlet of the low-pressure drug center flow channel extends to the needle valve assembly 5.

[0077] A specific embodiment of a needle valve assembly 5 is as follows: the needle valve assembly 5 includes a valve seat 51, a valve needle 52, a screw sleeve 53, a sliding sleeve sleeve 54, a drive motor 57, and a drive screw 58;

[0078] The valve seat 51 is located in the upstream section of the regulating housing 501. The valve seat 51 is abutted against and axially pressed against the pressure reducing seat 22. The valve seat 51 includes a throttling seat 511 and a needle sleeve 512.

[0079] A throttling seat recess is provided on the end face of the pressure reducing seat 22 facing the needle valve assembly 5. The throttling seat 511 matches the throttling seat recess and is embedded in the throttling seat recess. A throttling seat cover plate recess is provided on the end face of the throttling seat 511 facing away from the pressure reducing seat 22. A throttling seat cover plate 513 is embedded in the throttling seat cover plate recess. The throttling seat cover plate 513 is connected and tightened to the throttling seat 511 by several bolts. A throttling seat ring mounting through hole is provided at the center of the throttling seat cover plate 513. The throttling seat ring mounting through hole is a circular hole. A throttling seat ring 514 is embedded in the throttling seat ring mounting through hole. The throttling seat ring 514 includes a throttling abutment and a throttling extension. The throttling abutment is disc-shaped and located at the throttling seat ring mounting through hole. The throttling extension is cylindrical and coaxially arranged with the throttling abutment. The outer diameter of the throttling extension is smaller than that of the throttling abutment. The end faces of the throttling extension and the throttling abutment opposite to the throttling seat 511 are fixedly connected. The free end face of the throttling extension is flush with the end face of the throttling seat cover plate 513. The throttling abutment and the throttling extension are integrally formed. An abutment retaining ring extends integrally into the inner wall of the throttling seat ring mounting through hole. The abutment retaining ring is away from the throttling seat 511. During the tightening process of the throttling seat cover plate 513 and the throttling seat 511 by several bolts, the abutment retaining ring squeezes the throttling abutment to make it axially press against the end face of the throttling seat 511.

[0080] A throttling orifice 51c extends through the centerline of the throttling seat 511 and the throttling seat ring 514. The inlet of the throttling orifice 51c forms a needle valve inlet, which is connected to and communicates with the outlet end of the low-pressure agent central flow channel.

[0081] The needle sleeve 512 is cylindrical and coaxially fitted into the inner cavity of the adjusting part housing 501. Along its centerline, the needle sleeve 512 is sequentially provided with a transition hole 51b, a valve stem sliding hole, and a valve needle sealing hole 51a. All three holes are circular. The inner diameter of the transition hole 51b is larger than the diameter of the valve needle 52. The inner diameter of the valve needle sliding hole is larger than the diameter of the valve needle 52 but smaller than the inner diameter of the transition hole 51b. The inner diameter of the valve needle sealing hole 51a is larger than the diameter of the valve needle 52. The valve needle sealing hole 51a and the valve needle sealing hole 51a are axially connected in sequence and their center lines coincide. The valve needle sealing hole 51a faces away from the throttle seat 511, and the transition hole 51b faces the throttle seat 511. The transition hole 51b is connected to and connected to the outlet end of the throttle hole 51c. At least two radial drug outlet holes 51d are also provided on the throttle seat 511. The center line of the radial drug outlet hole 51d is perpendicular to the center line of the transition hole 51b. All the radial drug outlet holes 51d are evenly distributed around the transition hole 51b. The inner end of the radial drug outlet hole 51d is connected to the transition hole 51b. The outer end of the radial drug outlet 51d forms the needle valve outlet; an annular drug outlet cavity is provided around the center line of the outer wall of the throttling seat 511, the needle valve outlet communicates with the annular drug outlet cavity, the flow channel communicates with the annular drug outlet cavity, a valve needle sealing sleeve 55 is embedded in the valve needle sealing hole 51a, the valve needle sealing sleeve 55 includes a first valve needle sealing element 551 and a second valve needle sealing element 552, the valve needle sealing hole 51a is a two-stage stepped hole, the small hole section of the valve needle sealing hole 51a communicates with the valve needle sliding hole, and the first valve needle sealing element 551 is located in the valve needle sealing hole 51a. The bottom of the small hole section of valve needle seal 551 is provided with a sealing structure between the small hole section wall of valve needle sealing hole 51a and the second valve needle seal 552 is threadedly assembled with the large hole section of valve needle sealing hole 51a. The second valve needle seal 552 extends a pushing part towards the first valve needle seal 551. The pushing part extends into the small hole section of valve needle sealing hole 51a. The pushing part axially abuts against and presses the first valve needle seal 551. A sealing structure is provided between the pushing part and the small hole section wall of valve needle sealing hole 51a.

[0082] A valve needle through hole is provided at the center line of the first-stage valve needle seal 551 and the second-stage valve needle seal 552. The valve needle 52 is movably inserted into the valve needle through hole. A sliding sealing structure is provided between the outer wall of the valve needle 52 and the inner wall of the valve needle through hole. The center line of the valve needle 52 coincides with the center line of the valve needle through hole (or the valve needle sealing hole 51a). The head of the valve needle 52 extends into the transition hole 51b and is aligned with the throttling hole 51c.

[0083] The valve needle 52 includes a valve stem and a needle tip. The head of the valve stem is connected to the needle tip, the needle tip is aligned with the throttling orifice 51c, the outer wall of the needle tip matches the orifice wall of the throttling orifice 51c, and the tail of the valve stem extends into the drive housing 401.

[0084] A valve seat retaining ring 402 is sandwiched between the drive housing 401 and the adjustment housing 501. The valve seat retaining ring 402 is axially pressed against the needle sleeve 512 and a section of the valve needle seal 551. With the cooperation of the valve seat retaining ring 402, the needle sleeve 512 and the section of the valve needle seal 551, the internal spaces of the drive housing 401 and the adjustment housing 501 are relatively isolated.

[0085] In the above structure, the head of the valve needle 52 extends into the valve seat 51, and the head of the valve needle 52 is located between the needle valve inlet and the needle valve outlet to adjust the opening degree of the needle valve.

[0086] The drive motor 57 is located inside the power unit housing 201. The output shaft of the drive motor 57 faces the power transfer unit 300. The housing of the drive motor 57 is fixed to the downstream end face of the power unit housing 201 by bolts. The output shaft of the drive motor 57 extends into the power transfer housing 301 and is axially connected to the rotating seal. A drive rotor 59 is assembled inside the power transfer housing 301. The drive rotor 59 is rotatably assembled with the inner wall of the power transfer housing 301. The rotation center line of the drive rotor 59 coincides with the center line of the power transfer housing 301. A rotating seal (rotary seal) is provided between the drive rotor 59 and the inner wall of the power transfer housing 301. The drive rotor 59 and the rotating seal cooperate to seal the internal space of the power transfer housing 301, thereby isolating the internal space of the power unit housing 201 and the internal space of the drive unit housing 401 from each other.

[0087] The drive screw 58 and the screw sleeve 53 are both located inside the drive housing 401. The drive screw 58 and the screw sleeve 53 are coaxially threaded together. The center line of the drive screw 58 coincides with the center line of the drive housing 401. One end of the drive screw 58 is coaxially fixedly connected to the drive rotating seat 59.

[0088] The threaded sleeve 53 is slidably assembled inside the sliding sleeve sleeve 54. The sliding sleeve sleeve 54 can be an independent shell provided in the drive unit outer shell 401, or it can be a part of the drive unit outer shell 401, or it can be equal to the drive unit outer shell 401.

[0089] Taking the sliding sleeve 54 as an example, which is equivalent to the drive unit housing 401: the threaded sleeve 53 is cylindrical and is assembled in the internal space of the drive unit housing 401. To reduce the friction between the threaded sleeve 53 and the drive unit housing 401, the threaded sleeve 53 is clearance-fitted with the drive unit housing 401. To ensure the smooth sliding of the threaded sleeve 53 inside the drive unit housing 401, two annular limiting grooves 53a are provided on the outer wall of the threaded sleeve 53 around its center line. The two annular limiting grooves 53a are distributed along the axial direction of the threaded sleeve 53. Guide sliding rings 531 are respectively fitted in the two annular limiting grooves 53a, and the guide sliding rings 531 are slidably assembled with the inner wall of the sliding sleeve 54.

[0090] The guide sliding ring 531 can be made of plastic (e.g., PEEK) to reduce friction with the inner wall of the drive housing 401. To further reduce friction, a lubricant can be added. The two openings of the drive housing 401 are respectively sealed by the "drive rotary seat 59 / rotation seal" and the "valve seat retaining ring 402 / needle sleeve 512 / segment valve needle seal 551" to form a relatively sealed space, and the sliding lubricant is filled between the threaded sleeve 53 and the drive housing 401.

[0091] The axial length of the drive housing 401 is greater than the axial length of the threaded sleeve 53. Since the drive housing 401 is relatively sealed, the spaces at both ends of the threaded sleeve 53 need to be connected to ensure its normal sliding. The way the spaces at both ends of the threaded sleeve 53 are connected can be:

[0092] On the outer wall of the threaded sleeve 53, corresponding to each of the annular limiting grooves 53a, there is a strip-shaped pressure balancing groove 53b. The length direction of the pressure balancing groove 53b is perpendicular to the width direction of the annular limiting groove 53a, and the depth of the pressure balancing groove 53b is greater than the depth of the annular limiting groove 53a. The pressure balancing grooves 53b extend into the two side walls of the annular limiting groove 53a, connecting the spaces on both sides of the guide sliding ring 531. Since the threaded sleeve 53 and the drive housing 401 are in clearance fit, the spaces at both ends of the threaded sleeve 53 are connected through the pressure balancing groove 53b and the gap between the threaded sleeve 53 and the drive housing 401. This connection method also has the effect that during each sliding process of the threaded sleeve 53, lubricant is pushed through the gap between the threaded sleeve 53 and the drive housing 401, so as to fully lubricate both of them.

[0093] The threaded sleeve 53 has a drive threaded through hole at its center line. The drive screw 58 is threadedly connected to the drive threaded through hole. The solid part of the threaded sleeve 53 has at least one (or two) lubricant balance holes 53c. The lubricant balance holes 53c are arranged radially. The outer end of the lubricant balance hole 53c extends to the outer wall of the threaded sleeve 53. The inner end of the lubricant balance hole 53c communicates with the drive threaded through hole.

[0094] A lubricant injection blind hole 54a is provided on the outer wall of the drive unit housing 401. The bottom of the lubricant injection blind hole 54a has a lubricant through hole communicating with the inner cavity of the drive unit housing 401. A piston 541 is assembled in the lubricant injection blind hole 54a, and a piston limiting ring 542 is fixed at the outer end of the lubricant injection blind hole 54a. The lubricant injection blind hole 54a is used to inject lubricant into the interior of the drive unit housing 401. Before being submerged, the piston 541 is located at the outer end of the lubricant injection blind hole 54a. During the lubricant injection process, air may easily remain inside the drive unit housing 401. Therefore, as much lubricant as possible should be filled inside the piston 541. After the equipment is placed underwater, the piston 541 is automatically moved to the bottom of the lubricant injection blind hole 54a under the action of water pressure, thereby forcing the lubricant in the lubricant injection blind hole 54a into the inner cavity of the drive unit housing 401 and maintaining the internal and external pressure balance.

[0095] The tail of the valve needle 52 is axially fixedly connected to the threaded sleeve 53 and circumferentially rotatably connected. The threaded sleeve 53 slides within the drive housing 401, thereby driving the valve needle 52 to move axially.

[0096] The solid portion of the threaded sleeve 53 is also axially provided with a threaded sleeve guide rod. The threaded sleeve guide rod is eccentrically arranged, and its two ends are respectively fixed to the downstream end face of the power adapter housing 301 and the upstream end face of the adjustment housing 501. The center line of the threaded sleeve guide rod is parallel to the center line of the threaded sleeve 53. The threaded sleeve guide rod is slidably assembled with the threaded sleeve 53. When the drive screw 58 rotates, the threaded sleeve 53 slides axially due to the restriction of the threaded sleeve guide rod.

[0097] The device body also includes a first pressure sensor 61, a second pressure sensor 62, and a third pressure sensor;

[0098] The first pressure sensor 61 is connected to the flow channel at the upstream end of the pressure reducing component 2 to measure the upstream fluid pressure P1 before the drug flows through the pressure reducing component 2;

[0099] The second pressure sensor 62 is connected to the flow channel between the pressure reducing component 2 and the needle valve assembly 5 to measure the mid-section fluid pressure P2 after the drug flows through the pressure reducing component 2 and before the needle valve assembly 5;

[0100] The third pressure sensor is connected to the flow channel of the downstream section of the needle valve assembly 5 to measure the downstream fluid pressure P3 after the drug flows through the needle valve assembly 5.

[0101] The closed partition 502 is provided with a first pressure detection hole, a second pressure detection hole and a third pressure detection hole. The first pressure sensor 61 is sealed in the first pressure detection hole, the second pressure sensor 62 is sealed in the second pressure detection hole and the third pressure sensor is sealed in the third pressure detection hole.

[0102] The sealing isolation ring 231, the sealing isolation orifice plate 232, and the sealing isolation cylinder 233 are integrally formed.

[0103] The electronic compartment 600 includes an electronic compartment housing 601, which is connected to the downstream end of the adjustment part housing 501 by a number of bolts. A PCB module 602 is suspended inside the electronic compartment housing 601. At least two blind holes for supporting columns are provided on the closed partition 502 facing the PCB module 602. The center line of the blind holes for supporting columns is parallel to the center line of the adjustment part housing 501. The box support column 603 is threaded into the blind holes for supporting columns and extends into the electronic compartment housing 601. The PCB module 602 is fixedly connected to the box support column 603 by bolts.

[0104] At least two electrical connectors are provided on the enclosed partition 502, and at least two wiring harness holes are provided on the solid part of the equipment housing. The control wiring harness of the drive motor 57 is connected to the corresponding electrical connector through the wiring harness hole, and the wiring harness of the oil well plug x is connected to the corresponding electrical connector through the wiring harness hole.

[0105] The electrical connectors and the output terminals of the first, second, and third pressure sensors 61, 62, and 63 are connected to the PCB module 602 via wiring harnesses.

[0106] The ROV connection 700 includes an ROV connection housing 701 and an ROV drive handle 704. The connection housing 701 is fixedly connected to the electronic compartment housing 601. An ROV stud 702 is fixedly installed inside the ROV connection housing 701. The center line of the ROV stud 702 is parallel to the center line of the chemical input connector 1 / chemical output connector 3 / tree power plug x. An ROV sleeve 703 is threaded onto the ROV stud 702. The ROV drive handle 704 is fixedly connected to the ROV sleeve 703. The ROV sleeve 703 is rotatably assembled with and sealed to the connection housing 701.

[0107] A first alignment mark groove is provided at the connection between the power unit housing 201 and the power transfer housing 301. A second alignment mark groove is provided at the connection between the power transfer housing 301 and the drive unit housing 401. A third alignment mark groove is provided at the connection between the drive unit housing 401 and the adjustment housing 501. The first, second, and third alignment mark grooves can be located on the same axial straight line. A guide block is also provided on the outer wall of the power unit housing 201. The guide block is used to guide the connection process between the equipment and the tree.

[0108] The valve needle 52 is used to control the opening degree of the needle valve assembly 5. The opening degree of the needle valve assembly 5 can be calculated based on the position of the valve needle 52. The sensing end of the linear displacement sensor is fixedly connected to the screw sleeve 53. The sensing end of the rotational displacement sensor is connected to the output shaft of the drive motor 57. The rotational displacement sensor can also be integrated with the drive motor 57 (servo motor).

[0109] The linear displacement sensor and the rotational displacement sensor are used to detect the position of the valve needle, thereby calculating the opening degree of the needle valve.

[0110] Beneficial effects: The technical solution of this invention can greatly simplify the process of obtaining the discharge coefficient, avoid the tedious calibration operation for media of various viscosities, save time and reduce costs; the discharge coefficient has good adaptability and high matching degree, can obtain a flow value that is close to the truth, and has high measurement accuracy.

[0111] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention. Those skilled in the art, under the guidance of the present invention, can make various similar representations without departing from the spirit and claims of the present invention, and such modifications all fall within the protection scope of the present invention.

Claims

1. A method for metering underwater chemical agents based on multi-viscosity fitting, comprising a device body, the device body including an agent input connector (1), a pressure reducing component (2), a needle valve assembly (5), and an agent output connector (3) connected sequentially through a flow channel, characterized in that... Follow these steps: Step 1: Inject various media of different viscosities into the device body for calibration to obtain a calibration array. The calibration array includes several corresponding flow rates Q and differential pressure DP before and after the medium flows through the pressure reducing component (2). Fit the flow rate-differential pressure relationship for each viscosity medium according to formula ①; Formula ①; Where: K is a fixed parameter; C is the outflow coefficient; The effluent coefficients for each viscosity medium were obtained by fitting. Step 2: Use any viscosity medium involved in the calibration as the reference medium, and its discharge coefficient is the reference discharge coefficient C. W The viscosity is the reference viscosity μ. W ; The remaining media are calibration media, and their discharge coefficients are the calibration discharge coefficients C. X The viscosity is the nominal viscosity μ. X ; C is fitted according to the following formula ② X / C W With μ W / μ X relation; C X / C W =A*ln(μ W / μ X )+B, Formula ②; Where: A and B are the fitting parameters for the outflow coefficient, obtained by fitting; The calibration outflow coefficient C is obtained. X The calculation formula; Step 3: Substitute formula ② into formula ① to obtain the general flow rate calculation formula for media of different viscosities: Formula 3.

2. The underwater chemical agent injection metering method based on multi-viscosity fitting according to claim 1, characterized in that: The device body also includes a first pressure sensor (61) and a second pressure sensor (62). The first pressure sensor (61) is connected to the flow channel at the upstream end of the pressure reducing component (2) to measure the upstream fluid pressure P1 before the agent flows through the pressure reducing component (2); The second pressure sensor (62) is connected to the flow channel at the downstream end of the pressure reducing component (2) to measure the downstream fluid pressure P2 after the agent flows through the pressure reducing component (2); DP = P1 - P2.

3. The underwater chemical agent injection metering method based on multi-viscosity fitting according to claim 1, characterized in that: The pressure reducing component (2) includes a pressure reducing sleeve (21) and a pressure reducing seat (22), wherein the pressure reducing seat (22) is disposed inside the pressure reducing sleeve (21); At least two pressure-reducing channels (22a) are provided inside the pressure-reducing seat (22), the pressure-reducing channels (22a) are threaded, and the multiple pressure-reducing channels (22a) are connected end to end in sequence; The pressure reducing seat (22) is provided with a pressure reducing component inlet and a pressure reducing component outlet. The pressure reducing component inlet is connected to the inlet of the first pressure reducing channel (22a), and the pressure reducing component outlet is connected to the outlet of the last pressure reducing channel (22a).

4. The underwater chemical agent injection metering method based on multi-viscosity fitting according to claim 3, characterized in that: Multiple pressure-reducing channels (22a) are arranged along a common center line, and the thread diameter of the multiple pressure-reducing channels (22a) increases radially from the inside to the outside. Two adjacent pressure-reducing channels (22a) are connected end to end.

5. The underwater chemical agent injection metering method based on multi-viscosity fitting according to claim 4, characterized in that: The pressure reducing seat (22) is columnar. The pressure reducing component inlet is open on the outer wall of the pressure reducing seat (22), and the pressure reducing component outlet is open on one end face of the pressure reducing seat (22). The pressure reducing component inlet and the pressure reducing component outlet are respectively close to the two ends of the pressure reducing seat (22). An annular drug inlet cavity is provided around the pressure reducing seat (22), and the annular drug inlet cavity is connected to the pressure reducing component inlet.

6. The underwater chemical agent injection metering method based on multi-viscosity fitting according to claim 3, 4 or 5, characterized in that: All of the pressure-reducing channels (22a) have a circular cross-section, and the inner diameter of all the pressure-reducing channels (22a) is the same everywhere, where d is the inner diameter of the pressure-reducing channel (22a).

7. The underwater chemical agent injection metering method based on multi-viscosity fitting according to claim 1, 2, 3, 4 or 5, characterized in that: The needle valve assembly (5) includes a valve seat (51), a valve needle (52), a screw sleeve (53), and a sliding sleeve sleeve (54). The valve seat (51) is provided with a needle valve inlet and a needle valve outlet. The needle valve inlet is connected to the outlet of the pressure reducing component (2) through a flow channel, and the needle valve outlet is connected to the drug output connector (3) through a flow channel. The head of the valve needle (52) extends into the valve seat (51), and the head of the valve needle (52) is located between the needle valve inlet and the needle valve outlet. The threaded sleeve (53) is assembled inside the sliding sleeve sleeve (54). The threaded sleeve (53) and the sliding sleeve sleeve (54) are in clearance fit. Two annular limiting grooves (53a) are provided on the outer wall of the threaded sleeve (53) around its center line. The two annular limiting grooves (53a) are distributed along the axial direction of the threaded sleeve (53). Guide sliding rings (531) are respectively fitted in the two annular limiting grooves (53a). The guide sliding rings (531) are slidably assembled with the inner wall of the sliding sleeve sleeve (54). A strip-shaped pressure balance groove (53b) is provided on the outer wall of the threaded sleeve (53) corresponding to each of the annular limiting grooves (53a). The length direction of the pressure balance groove (53b) is perpendicular to the width direction of the annular limiting groove (53a). The depth of the pressure balance groove (53b) is greater than the depth of the annular limiting groove (53a). The pressure balance groove (53b) extends into the two side walls of the annular limiting groove (53a). The pressure balance groove (53b) connects the spaces on both sides of the guide sliding ring (531). The tail of the valve needle (52) is connected to the threaded sleeve (53), and the threaded sleeve (53) slides inside the sliding sleeve sleeve (54) to drive the valve needle (52) to move axially. The two ends of the sliding sleeve (54) are sealed, and the sliding sleeve (54) is filled with a sliding lubricant.

8. The underwater chemical agent injection metering method based on multi-viscosity fitting according to claim 7, characterized in that: The valve seat (51) is provided with a valve needle sealing hole (51a), a transition hole (51b), and a throttling hole (51c) connected in sequence. The center lines of the valve needle sealing hole (51a), the transition hole (51b), and the throttling hole (51c) coincide. At least two radial discharge holes (51d) are also provided on the valve seat (51). The center line of the radial discharge hole (51d) is perpendicular to the center line of the transition hole (51b). All the radial discharge holes (51d) are arranged around the transition hole (51b). The inner end of the radial discharge hole (51d) is connected to the transition hole (51b). A valve needle sealing sleeve (55) is embedded in the valve needle sealing hole (51a), and the valve needle (52) is movably inserted into the valve needle sealing sleeve (55). The center line of the valve needle (52) coincides with the center line of the valve needle sealing hole (51a), and the head of the valve needle (52) extends into the transition hole (51b) and is aligned with the throttling hole (51c). The outer end of the throttling orifice (51c) forms the needle valve inlet, and the outer end of the radial drug outlet orifice (51d) forms the needle valve outlet.

9. The underwater chemical agent injection metering method based on multi-viscosity fitting according to claim 7, characterized in that: The needle valve assembly (5) also includes a drive motor (57), the output shaft of which is connected to a drive screw (58), which is coaxially threaded with the screw sleeve (53).

10. The underwater chemical agent injection metering method based on multi-viscosity fitting according to claim 8, characterized in that: The valve needle sealing sleeve (55) includes a first valve needle seal (551) and a second valve needle seal (552). The valve needle sealing hole (51a) is a two-stage stepped hole. The small hole section of the valve needle sealing hole (51a) is connected to the transition hole (51b). The first valve needle seal (551) is located at the bottom of the small hole section of the valve needle sealing hole (51a). The second valve needle seal (552) is threadedly assembled with the large hole section of the valve needle sealing hole (51a). The second valve needle seal (552) extends a pushing part towards the first valve needle seal (551). The pushing part extends into the small hole section of the valve needle sealing hole (51a). The pushing part axially abuts against the first valve needle seal (551) and presses it tightly.

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