Integrated testing method for filtration and displacement efficiency of horizontal well

By installing columnar rock displacement holders and annular rock displacement holders on the simulation test cylinder, and combining them with ultrasonic transducers to monitor the filter cake thickness, a realistic simulation and efficient testing of the downhole environment is achieved. This solves the problems of inaccurate simulation and complex operation in existing technologies, and improves the reliability of test results and work efficiency.

CN114575825BActive Publication Date: 2026-02-24SINOPEK PETROLEUM IZHINIRING TECH SERVIS KO LTD +1
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Patent Information

Application Number
CN202210330322.7
Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2022-03-30
Publication Date
2026-02-24
Estimated Expiration
2042-03-30

AI Technical Summary

Technical Problem

Existing displacement efficiency evaluation devices cannot fully simulate real formation conditions, especially for vertical and horizontal well sections, resulting in large errors between test results and downhole operations. Furthermore, traditional filter cake holders are complex to operate, easily damage the filter cake, and reduce work efficiency.

Method used

An integrated testing method for horizontal well filter loss and displacement efficiency was designed. By installing a columnar displacement holder and annular displacement holder on a simulated test cylinder, the filter loss and scouring environment of the downhole casing annulus was simulated. An auxiliary lifting mechanism was used to simplify the operation, and an ultrasonic transducer was used to monitor the filter cake thickness to achieve integrated testing.

Benefits of technology

It achieves a realistic simulation of the downhole environment, improves the reliability of test results and work efficiency, reduces labor intensity, and can directly evaluate filter loss and displacement efficiency without repeatedly disassembling and assembling the clamp, thus protecting the integrity of the filter cake.

✦ Generated by Eureka AI based on patent content.

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Abstract

The present application relates to a kind of horizontal well filtration and displacement efficiency integrated testing method, steps are as follows: column rock and ring rock displacement holder are installed in simulation test cylinder vertical section;Multiple annular cores and columnar cores are respectively installed on corresponding filter loss holder to carry out filter loss test;Select one annular core to do filter loss performance analysis, another is installed in ring rock displacement holder;Select one columnar core to do filter loss performance analysis, another columnar core is installed in columnar displacement holder;Start mud pump, test liquid is pumped out by mud pump, and is sent to the lower end entrance of simulation test cylinder, in turn flows through column rock displacement holder and ring rock displacement holder, and then is discharged from the upper end outlet of simulation test cylinder;When the filtrate amount of ring rock displacement holder reaches the set value, mud pump stops;Annular and columnar cores are removed, and displacement efficiency is analyzed.The test method can simulate the filtration and flushing environment of downhole casing annulus, and the test result is more real and reliable.
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Description

Technical Field

[0001] This invention relates to the field of tools for drilling, completion and cementing engineering of oil and gas wells, and particularly to an integrated testing method for horizontal well filtration loss and displacement efficiency. Background Technology

[0002] Drilling fluid is used as the working fluid in the drilling process. Drilling fluids are classified into oil-based drilling fluids and water-based drilling fluids, among others. The circulation of drilling fluid serves several purposes: cooling the drill bit, cleaning the bottom of the hole, removing cuttings, lubricating the drill string, protecting the borehole wall from collapse, balancing formation pressure, and transmitting the power needed to break the rock at the bottom of the hole to the drilling rig. Water in the drilling fluid entering the formation through the pores in the wellbore is called water loss. Simultaneously, clay particles in the drilling fluid are trapped and deposited on the wellbore wall, forming a layer of solid particles called mud cake.

[0003] After the wellbore is drilled to the predetermined depth, the casing is run into the well, and cement slurry is injected into the annular space between the wellbore and the casing. This construction operation is called cementing. Cementing mainly includes stages such as running the casing, injecting cement slurry, waiting for it to set, and testing and evaluation. Before injecting cement slurry, displacement fluid is used to flush away the loose mud cake, oil slurry, and oil film on the well wall and casing wall to improve the bonding performance between the first and second interfaces and the cement slurry.

[0004] To ensure cementing quality, various surface evaluation tests are crucial, including simulating the downhole environment and evaluating the filtration performance of the drilling fluid. Filtration tests are typically performed on both columnar and annular cores, allowing free water from the drilling fluid to permeate through the cores under pressure differential, with mud cake deposited on their surface. The filtration loss is then measured by weight. Next, the flushing efficiency under different flushing agents and flow rates is evaluated, simulating the scouring effect of pre-cementing flushing fluid on oil-based mud cake. This provides a research platform and technical basis for optimizing cementing flushing fluids and construction parameters.

[0005] Existing displacement efficiency evaluation devices mostly adopt a reaction vessel structure, which only performs flushing evaluation and simulation of the well wall. They cannot fully simulate real formation conditions, nor can they simulate vertical and horizontal well sections separately, resulting in a large error between the test results and the effects during downhole construction.

[0006] More importantly, the prerequisite for conducting a displacement test is to first carry out a filtration test in a real simulated formation environment to form a filter cake on the surface of the annular and columnar cores. Then, the cores must be transferred intact to the cleaning simulation test device for a flushing test. During the transfer and installation process, the filter cake must not be damaged.

[0007] Traditional core filter holders involve installing the core column inside a rubber sleeve and applying annular pressure, allowing drilling fluid to filter out the core through the core end face. Currently, these holders are overly complex. Circumferential sealing of the core requires applying a certain annular sealing pressure through a rubber sleeve, which in turn requires a sleeve tensioner to seal against the holder's cavity. The holder's plug also needs a corresponding plug and core pressure cap to achieve a final high-pressure seal. When disassembling the core, the rear plug and core pressure cap of the core filter holder must be removed, along with the upper plug and flange of the vertical cylinder section. The filtered core is then removed using specialized tools, weighed to measure the filtration loss, and then installed on a displacement fluid flushing device to evaluate the displacement efficiency. The operation is quite complex and cumbersome. At the same time, the clamping device will damage the mud cake on the surface of the core while removing the core using special tools. If the operation is not done properly, the mud cake will fall off, causing the entire filtration process to fail.

[0008] Traditional annular core loss holders are only suitable for routine core displacement experiments and cannot simulate the actual loss state during drilling. The conventional approach is to remove the filtered annular core column from the holder and place it on a weighing scale to measure the loss. Only by weighing can the loss be fed back and the thickness of the mud cake be determined. If the thickness does not reach the predetermined value, the holder must be reassembled and the loss test must be performed again. Repeated disassembly and reassembly of the holder increases the workload, reduces work efficiency, and can easily damage the filter cake. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide an integrated testing method for horizontal well filtration loss and displacement efficiency, which can realistically simulate the filtration loss and scouring environment of the downhole casing annulus, and the test results are more realistic and reliable.

[0010] To solve the above technical problems, the present invention provides an integrated testing method for horizontal well filter loss and displacement efficiency, comprising the following steps:

[0011] S1. Install the columnar rock displacement holder and the annular rock displacement holder in the vertical section of the simulation test tube, and connect the horizontal section inlet of the simulation test tube to the mud pump;

[0012] S2. Install multiple annular cores on their respective annular core filter holders and conduct filter loss tests until the filter cake on the inner wall of the annular core reaches the set thickness.

[0013] S3. Install multiple columnar cores on their respective columnar core filter holders and conduct filter loss tests until the filter cake on the inner wall of the columnar cores reaches the set thickness.

[0014] S4. Select one annular core for filtration performance analysis, and select another annular core to install in the annular displacement holder;

[0015] S5. Select one columnar core for filtration performance analysis, and select another columnar core to install in the columnar displacement holder;

[0016] S6. Start the mud pump. The test solution in the sample preparation tank is pumped out by the mud pump and sent to the lower inlet of the simulation test tube. After flowing through the columnar displacement holder and the ring rock displacement holder in sequence, it is discharged from the upper outlet of the simulation test tube and enters the test solution collection tank.

[0017] S7. When the amount of filtrate flowing out of the atoll displacement holder reaches the set value, the mud pump stops;

[0018] S8. Take out the annular core and columnar core and analyze the displacement efficiency.

[0019] As an improvement of the present invention, S9. The columnar rock displacement holder and the annular rock displacement holder are installed in the horizontal section of the simulation test cylinder, and then S2 to S8 are repeated.

[0020] As a further improvement of the present invention, in S6, a rinsing solution is first placed in the sample preparation vessel to simulate physical rinsing, and then one or more chemical reagents are placed in the sample preparation vessel to simulate chemical rinsing.

[0021] As a further improvement to the present invention, the specific steps of S1 are as follows:

[0022] S1.1 First, fix the arc-shaped section of the cylinder, pre-install the upper conical guide at the upper end of the vertical section of the casing, and pre-install the lower conical guide at the inlet of the horizontal section of the casing;

[0023] S1.2 Place the arc-shaped section of the casing at the center of the arc-shaped section of the cylinder, then screw the vertical section of the casing onto the upper end of the arc-shaped section of the casing, and screw the horizontal section of the casing onto the lower end of the arc-shaped section of the casing.

[0024] S1.3 The cylinder clamping section is fitted onto the outer periphery of the vertical section of the casing and connected by a flange. Two columnar rock displacement clamps are symmetrically provided on the outer periphery of the middle section of the cylinder clamping section, and a ring rock displacement clamp is installed on the upper part of the cylinder clamping section.

[0025] S1.4 The cylindrical guide section is fitted onto the outer periphery of the horizontal section of the casing and connected by a flange;

[0026] S1.5 The upper tapered joint and the bent elbow are fixedly connected above the ring rock displacement clamp, and the lower tapered joint is fixedly connected to the outer port of the cylinder guide section through the flange.

[0027] As a further improvement to the present invention, the specific steps of S9 are as follows:

[0028] S9.1 First, fix the arc-shaped section of the cylinder, pre-install the upper conical guide at the upper end of the vertical section of the casing, and pre-install the lower conical guide at the inlet of the horizontal section of the casing;

[0029] S9.2 Place the arc-shaped section of the casing at the center of the arc-shaped section of the cylinder, then screw the vertical section of the casing onto the upper end of the arc-shaped section of the casing, and screw the horizontal section of the casing onto the lower end of the arc-shaped section of the casing.

[0030] S9.3 The cylinder clamping section is fitted onto the outer periphery of the horizontal section of the casing and connected by a flange. Two pillar rock displacement clamps are symmetrically provided on the outer periphery of the middle section of the cylinder clamping section. A ring rock displacement clamp is installed upstream of the pillar rock displacement clamp.

[0031] S9.4 The cylindrical guide section is fitted onto the outer periphery of the vertical section of the casing and connected by a flange;

[0032] S9.5 The upper conical joint and the bent elbow are fixedly connected to the upper end of the cylinder guide section, and the lower conical joint is fixedly connected to the outside of the ring rock displacement clamp through the flange.

[0033] As a further improvement of the present invention, positioning plates are respectively clamped between the connecting flanges of the cylinder clamping section, the cylinder arc section and the cylinder guide section, and the inner edges of the positioning plates are respectively stuck on the outer wall of the simulated sleeve. Multiple flow grooves are evenly distributed on the circumference of the annular space of each positioning plate.

[0034] As a further improvement of the present invention, a safety protection device, an online flow meter and an inlet pressure sensor are sequentially installed on the pipe between the outlet of the mud pump and the inlet of the lower conical joint; an online density meter is installed on the side wall of the upper conical joint; and an outlet pressure sensor is installed on the outlet pipe of the bent elbow; the filtrate outlet of the annular rock displacement clamp is connected to the filtrate loss feedback control system.

[0035] The outlet pipe of the bent elbow is also connected to the outlet of the cleaning pump, and the outlet pipe of the mud pump is also connected to the cleaning fluid collection tank.

[0036] As a further improvement of the present invention, the horizontal section of the simulated test tube is fixed above the horizontal frame by a retaining ring, the vertical frame is located behind the vertical section of the simulated test tube, the lower end of the vertical frame is fixedly connected to one end of the horizontal frame, and a gripper fixing frame extending forward is fixed on the vertical frame, the gripper fixing frame is clamped on the outer periphery of the vertical section of the simulated test tube;

[0037] Two horizontal guide rails are fixed to the upper part of the vertical frame. The horizontal guide rails support a vertical support plate through horizontal sliders. The front end face of the vertical support plate is fixed with a vertical guide rail. A cylinder bracket is fixed above the vertical guide rail. A lifting cylinder is fixed on the cylinder bracket. The piston rod of the lifting cylinder extends downward and is connected to an L-shaped connecting plate. The horizontal plate of the L-shaped connecting plate is fixedly connected to the upper end of the upper conical joint. The vertical plate of the L-shaped connecting plate is supported on the vertical guide rail through a vertical slider.

[0038] As a further improvement of the present invention, the annular rock filtration holder includes an annular rock filtration cylinder. The upper port of the annular rock filtration cylinder is covered with an upper annular rock filtration end cap, and the lower port of the annular rock filtration cylinder is covered with a lower annular rock filtration end cap. The upper end face of the lower annular rock filtration end cap is provided with an upwardly protruding annular ring. The annular ring is inserted into the lower port of the annular rock filtration cylinder, and an annular rock filtrate channel is left between the ring and the inner wall of the annular rock filtration cylinder. The lower annular rock filtration end cap is provided with a filtrate metering port and an annular rock filtrate metering port. The bottom of the filtrate channel is interconnected; the bottom of the annular core is supported on the top of the annular convex ring of the lower annular head, and the top of the annular core is supported below the upper annular head of the annular filter; a simulated drill pipe is provided along the axis of the annular core, the upper end of the simulated drill pipe is fixed to the center of the upper annular head of the annular filter, and the upper end of the center hole of the simulated drill pipe is connected to the annular drilling fluid injection port; a bottom guide is provided below the lower end of the simulated drill pipe to allow the drilling fluid to flow back outward and upward, and the bottom of the bottom guide abuts against the center of the bottom wall of the lower annular head of the annular filter.

[0039] As a further improvement of the present invention, the bottom hole guide has a centrally symmetrical structure. The annular guide cone at the center of the bottom hole guide is inserted into the lower port of the simulated drill pipe along the axis of the simulated drill pipe. The lower end of the annular guide cone is smoothly connected to the upward-opening annular return groove. The bottom of the annular return groove has a semi-circular arc cross section, and the outer wall of the annular return groove extends upward against the inner wall of the annular convex ring of the lower annular head.

[0040] As a further improvement of the present invention, two transducer connectors are symmetrically provided on the upper, middle and lower cross sections of the annular core. The inner cavity of each transducer connector is provided with an ultrasonic transducer for detecting the thickness of the mud cake. The inner end face of the ultrasonic transducer abuts against the outer wall of the annular core, and a high-pressure sealing plug is provided on the outer side of the ultrasonic transducer.

[0041] As a further improvement of the present invention, the columnar filtration clamp includes a columnar clamp cylinder, a columnar clamp upper cover is screwed onto the outer periphery of the upper end of the columnar clamp cylinder, a columnar clamp lower cover is screwed onto the outer periphery of the lower end of the columnar clamp cylinder, a columnar clamp lower head is provided in the lower part of the inner cavity of the columnar clamp cylinder, a downwardly extending columnar drilling fluid connector is provided at the bottom center of the columnar clamp lower head, the columnar drilling fluid connector extends downward from the center hole of the columnar clamp lower cover, and a through columnar drilling fluid injection hole is provided along the axis of the columnar clamp lower head; The columnar rock holder has symmetrically welded outward-extending columnar rock pipe joints in the middle of its cylindrical body. Columnar rock test joints are inserted into the inner cavities of the two columnar rock pipe joints. The outer steps on the inner side of the columnar rock test joints abut against the inner steps of the columnar rock pipe joints. The central protrusions on the outer sides of the two columnar rock test joints protrude from the central holes of the columnar rock pressure caps. The two columnar rock pressure caps are screwed onto the outer ports of the columnar rock pipe joints and press against the outer steps of the columnar rock test joints. Columnar rock cores are embedded in the countersunk holes on the inner end faces of the two columnar rock test joints. Columnar rock filtrate outflow holes are provided along the axis of the columnar rock test joints.

[0042] As a further improvement of the present invention, the upper part of the inner cavity of the columnar rock clamping device cylinder is provided with an upper end cap, and the top center of the upper end cap is provided with an upwardly extending columnar rock upper end cap center column. The columnar rock upper end cap center column extends upward from the center hole of the upper end cap of the columnar rock clamping device. The core rod is inserted into the inner cavity of the columnar rock clamping device cylinder along the center hole of the upper end cap, and a diffuser is installed at the lower end of the core rod. The diffuser and the columnar rock core are located on the same horizontal plane. The upper end of the core rod is driven by a magnetic coupler, and the core rod is supported in the stepped hole of the upper end cap of the columnar rock clamping device by a bearing.

[0043] Compared with existing technologies, this invention achieves the following beneficial effects: 1. This invention not only simulates the wellbore but also the casing, and not only simulates the displacement efficiency of the vertical wellbore and casing but also the displacement efficiency of the horizontal wellbore and casing. The most characteristic downhole environments can be simulated, and switching between them is convenient. An auxiliary lifting mechanism is also provided, which can automatically raise, lower, and move the disassembled components, assisting operators in disassembly, reducing labor intensity, and improving work efficiency.

[0044] 2. The annular filter loss holder is designed with simulated drill pipe and drilling fluid flow channels, which can simulate the state of drill pipe and drilling fluid backflow from the bottom of the well during the drilling process; this facilitates the accurate evaluation of the relationship between filter loss and drilling fluid flow rate and pressure; by connecting to an online metering device through the filter metering port, the filter loss can be directly controlled by feedback, and the expected target can be achieved in a single filter loss test, without the need for repeated disassembly and assembly of the holder and repeated weighing of the core column; through an ultrasonic transducer, the filter cake thickness of multiple sections can be monitored, and the filter cake formation process can be monitored; it can realize the evaluation of the relationship between injection flow rate and injection pressure and filter loss, and evaluate the filter cake formation process.

[0045] 3. The columnar core filter cake holder, through its integrated design, eliminates the rubber sleeve and its auxiliary mechanisms compared to traditional holders, reducing the need for annular pressure loading pumps. The core is installed in a quickly detachable sealed cavity, improving the ease of disassembly. Traditional filter cake holders mostly simulate the seepage situation after drilling fluid invades the formation; this columnar core filter cake holder uses a mandrel and disperser to agitate the drilling fluid, simulating the situation where drilling fluid penetrates the formation under centrifugal force during formation drilling. Furthermore, the columnar core is installed along the diameter of the cylinder, with the inner end face being the drilling fluid immersion end, better simulating the flow of drilling fluid in the formation. A magnetic coupler drives the mandrel and disperser, eliminating the need for dynamic sealing on the outer circumference of the mandrel, improving the pressure resistance of the device and facilitating the simulation of higher formation pressures. In particular, the columnar core test connector after the filter cake test can be directly pulled out and transferred along with its built-in columnar core to the columnar core replacement holder for installation; the filter cake remains undamaged throughout the entire process. Attached Figure Description

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The drawings are provided for reference and illustration only and are not intended to limit the present invention.

[0047] Figure 1 This is a flowchart of Embodiment 1 of the cleaning simulation testing device used in this invention;

[0048] Figure 2 This is a front view of the cleaning simulation testing device used in this invention;

[0049] Figure 3 for Figure 2 The left view;

[0050] Figure 4 This is a flowchart of Embodiment 2 of the cleaning simulation testing device used in this invention;

[0051] Figure 5 This is a front view of Embodiment 1 of the ring rock filter clamp used in this invention;

[0052] Figure 6 This is a cross-sectional view of Embodiment 2 of the ring rock filter clamp used in this invention;

[0053] Figure 7 This is a front view of the columnar rock filter clamp used in this invention;

[0054] Figure 8 for Figure 7 Sectional view along the middle AA.

[0055] In the diagram: 1a. Horizontal frame; 1b. Vertical frame; 2. Bending elbow; 3. Upper conical joint; 4a. Cylinder clamping section; 4b. Cylinder arc section; 4c. Cylinder guide section; 5. Lower conical joint; 6. Upper conical guide; 7a. Vertical section of casing; 7b. Arc section of casing; 7c. Horizontal section of casing; 8. Lower conical guide; 9. Pillar rock displacement clamp; 10. Ring rock displacement clamp; 11. Horizontal guide rail; 12. Horizontal slider; 13. Vertical support plate; 14. Vertical guide. 15. Rail; 16. Cylinder bracket; 17. Lifting cylinder; 18. L-shaped connecting plate; 19. Vertical slider; 20. Positioning piece; 21. Snap ring; 22. Clamping device fixing frame; 23. Sample preparation tank; 24. Mud pump; 25. Safety protection device; 26. Online flow meter; 27. Online density meter; 28. Filtration feedback control system; 29. ​​Test liquid collection tank; 30. Cleaning pump; 21. Cleaning liquid collection tank; P1. Inlet pressure sensor; P2. Outlet pressure sensor.

[0056] Annular Filtration Holder: 31. Upper Annular Filtration Head; 31a. Floating Sealing Ring; 31b. Upper Annular Sealing Ring; 31c. Spring; 31d. Upper Annular Head Sealing Ring; 32. Annular Filtration Cylinder; 32a. Annular Filtration Channel; 32b. Annular Cleaning Fluid Inlet; 32c. Positioning Inner Convex Ring; 33. Lower Annular Filtration Head; 33a. Lower Annular Head Annular Convex Ring; 33b. Lower Annular Sealing Ring; 33c. 33d. Filtrate metering port; 33e. Atomic drilling fluid drain port; 34. Atomic bottom end cap sealing ring; 35. Annular core; 36. Simulated drill pipe; 37. Atomic drilling fluid injection port; 38. Bottom hole guide; 39. Atomic guide cone; 40. Annular return groove; 31. Transducer connector; 32. High-pressure sealing plug; 33a. Plug center boss; 34. Lead wire hole; 45. Locking cap; 46. Ultrasonic transducer.

[0057] Columnar rock filter holder: 41. Drive motor; 42. Upper support plate; 43. Double-ended stud; 44. Lower support plate; 45a. Magnetic coupling seat; 45b. Coupling outer rotor; 45c. Coupling inner rotor; 46. Columnar rock holder upper cover; 47. Columnar rock holder cylinder; 48. Columnar rock holder upper end cap; 48a. Columnar rock upper end cap center column; 48b. Columnar rock upper end cap sealing ring; 49. Columnar rock sealing plug; 50. Upper bearing; 51. Lower bearing; 52. Bearing pressure. 53. Core rod; 54. Disperser; 55. Columnar core pipe connector; 56. Columnar core test connector; 56a. Columnar core filtrate outlet hole; 56b. Columnar core connector outer sealing ring; 56c. Columnar core connector inner sealing ring; 57. Columnar core cap; 58. Columnar core; 59. Columnar core holder lower end cap; 59a. Columnar core drilling fluid connector; 59b. Columnar core drilling fluid injection hole; 59c. Columnar core lower end cap sealing ring; 60. Columnar core holder lower cover; 61. Columnar core filtrate lower support seat. Detailed Implementation

[0058] like Figure 1 As shown, the cleaning simulation test device used in this invention includes annular rock filtration clamp, columnar rock filtration clamp, and cleaning simulation test device. The cleaning simulation test device includes multiple sample preparation tanks 22, a mud pump 23, a simulation test cylinder, and a test liquid collection tank 28. The outlet of each sample preparation tank 22 is connected to the inlet of the mud pump 23 through a preparation tank outlet valve. A safety protection device 24, an online flow meter 25, and an inlet pressure sensor P1 are installed sequentially on the outlet pipe of the mud pump 23. Then, it is connected to the lower conical joint inlet of the simulation test cylinder. The simulation test cylinder is L-shaped and fixed on the frame. The upper end of the simulation test cylinder is connected to an upper conical joint. An online density meter 26 is installed on the side wall of the upper conical joint. The outlet of the upper conical joint is connected to a bent elbow. The outlet of the bent elbow is connected to multiple test liquid collection tanks 28 through the test cylinder outlet pipe.

[0059] An outlet pressure sensor P2 is installed on the outlet pipe of the test cylinder. The inlet pressure sensor P1 and the outlet pressure sensor P2 are used to detect the pressure at the inlet and outlet of the system and provide feedback to the control system to control the mud pump 23. At the same time, they can be linked online with the safety protection device 24 to realize functions such as automatic stop of injection and alarm in case of overpressure.

[0060] The online flow meter 25 is used to achieve remote linkage with the mud pump 23. It controls the volume injection volume through feedback. During operation, the injection is automatically controlled by the set volume, which does not require conversion based on the frequency converter.

[0061] The mud pump 23 is used to quantitatively inject the prepared sample into the annulus of the simulated test tube. It adopts a frequency conversion feedback controller to realize remote online control. The injection flow rate is fed back and controlled by the online flow meter 25. The mud pump 23 can meet the injection of different samples such as drilling fluid, displacement fluid and cement slurry.

[0062] The simulation test cylinder includes a cylinder clamping section 4a, a cylinder arc-shaped section 4b, and a cylinder guide section 4c. The cylinder clamping section is equipped with an annular displacement clamp 10 and a columnar displacement clamp 9. The annular displacement clamp 10 includes an outer cylinder containing an annular core 34. The annular core 34 is taken to the annular filtration clamp, and the filtrate outlet of the annular displacement clamp 10 is connected to the filtration feedback control system 27. The columnar core 58 of the columnar displacement clamp 9 is taken to the columnar filtration clamp.

[0063] The online density meter 26 is used to monitor the density change of the fluid after passing through the simulated test tube. The filtration loss feedback control system 27 is installed at the filtrate outlet of the annular displacement holder 10. It controls the injection pressure and injection flow rate of the mud pump 23 through the feedback of the filtrate volume, thereby controlling the filtration loss of the wellbore mud cake, oil slurry and oil film.

[0064] like Figure 2 , Figure 3 As shown, the two ends of the shell of the arc-shaped section 4b of the cylinder are connected to the shell flanges of the clamping section 4a or the flow guiding section 4c of the cylinder via flanges. A simulated sleeve is provided along the axis of the simulated test cylinder. The simulated sleeve includes a vertical section 7a, an arc-shaped section 7b, and a horizontal section 7c. The two ends of the arc-shaped section 7b are respectively provided with female threads that are screwed into the male threads of the vertical section 7a and the horizontal section 7c of the sleeve. The upper end of the clamping section 4a of the cylinder is connected to an upper conical joint 3, and the upper port of the upper conical joint 3 is connected to a bent elbow 2. The inlet of the flow guiding section 4c of the cylinder is connected to a lower conical joint 5. The upper end of the vertical section 7a and the inlet of the horizontal section 7c of the sleeve are respectively provided with top-closed conical guides. The cone apex of the conical guides is inserted into the inner cavity of the large end of the corresponding conical joint and is coaxial.

[0065] The frame includes a horizontal frame 1a and a vertical frame 1b. The cylinder guide section 4c extends along the horizontal frame 1a and is fixed above the horizontal frame 1a by a retaining ring 20. The vertical frame 1b is located behind the cylinder clamping section 4a. The lower end of the vertical frame 1b is fixedly connected to one end of the horizontal frame 1a. A forward-extending clamping bracket 21 is fixed on the vertical frame 1b. The clamping bracket 21 is locked around the outer periphery of the cylinder clamping section 4a.

[0066] Each pair of flanges in the simulated test casing holds a positioning plate 19, the inner edge of which is secured to the outer wall of the simulated casing. Multiple flow grooves or flow holes are evenly distributed on the circumference of each positioning plate 19 within the annulus. Each positioning plate 19 simulates the function of a downhole centralizer, ensuring the simulated casing is centered without affecting fluid flow.

[0067] When the annular rock displacement clamp 10 is located at the upper part of the vertical section, it is difficult to disassemble and assemble the bending elbow 2 and the upper conical joint 3 due to the relatively high position. In addition, the vertical well section has more tests and more frequent disassembly and assembly. Therefore, this device is equipped with an auxiliary lifting mechanism to reduce the labor intensity of the test personnel.

[0068] Two horizontal guide rails 11 are fixed to the upper part of the vertical frame 1b. The horizontal guide rails 11 support the vertical support plate 13 through the horizontal slider 12. The front end face of the vertical support plate 13 is fixed with a vertical guide rail 14. A cylinder bracket 15 is fixed above the vertical guide rail 14. A lifting cylinder 16 is fixed on the cylinder bracket 15. The piston rod of the lifting cylinder 16 extends downward and is connected to the L-shaped connecting plate 17. The horizontal plate of the L-shaped connecting plate 17 is fixedly connected to the upper end of the upper conical joint 3. The vertical plate of the L-shaped connecting plate 17 is supported on the vertical guide rail 14 through the vertical slider 18.

[0069] The ring rock displacement clamp 10 includes a clamp outer cylinder with a built-in annular rock core 34. The upper and lower ends of the clamp outer cylinder are clamped between the simulated test cylinder flange. The upper and lower ends of the annular rock core 34 are sealed with the corresponding flange through annular sealing rings. The bottom of the annular gap between the annular rock core 34 and the clamp outer cylinder is provided with a filtrate outlet.

[0070] When installing the annular core 34, remove the lower flange bolts of the upper conical joint 3, retract the piston rod of the lifting cylinder 16, and lift the upper conical joint 3 and the bent elbow 2 upwards via the L-shaped connecting plate 17. The vertical slider 18 slides along the vertical guide rail 14 to ensure no tilting occurs. Then push the vertical support plate 13 to the right. The vertical support plate 13 slides along the horizontal guide rail 11 via the horizontal slider 12, moving the upper conical joint 3 away from above the annular core displacement holder 10. Then remove the outer cylinder of the annular core displacement holder 10, install the annular core 34, and then fit the outer cylinder onto the outer circumference of the annular core 34.

[0071] When restoring the upper conical joint 3, push the vertical support plate 13 to the left so that the upper conical joint 3 is above the ring rock displacement clamp 10. Then, extend the piston rod of the lifting cylinder 16, and lower the upper conical joint 3 and the bent elbow 2 with the L-shaped connecting plate 17 until the flange of the upper conical joint 3 falls on the ring rock displacement clamp 10, and then connect it with bolts.

[0072] In traditional displacement tests, the fluid flows along the entire cross-section of the casing. The difference between the full surface area of ​​the wellbore and the annular area, where the casing occupies a large portion of the cross-section, is significant. With the same mud pump displacement, the flow velocity at each cross-section varies considerably. Furthermore, the flow patterns of full-area flow and annular cross-section flow differ greatly. In full-area flow, the velocity is fastest along the axis and slowest near the inner wall of the casing. In a real wellbore, the central region is occupied by the casing, and the fluid can only flow in the annular space between the outer wall of the casing and the inner wall of the casing. The velocity is slowest near the inner wall of the casing and also slowest near the outer wall of the casing. The radial center between the inner wall of the casing and the outer wall of the casing has the highest velocity.

[0073] During the displacement test, the displacement fluid enters through the inlet of the lower conical connector 5. The lower conical guide 8 directs the displacement fluid into the annular cavity for flushing simulation, completely simulating the actual flow state in the wellbore. This flushes the mud cake on the inner surface of the columnar core 58 and the annular core. After displacement at the set flow rate and pressure, the columnar core displacement holder 9 and the annular core displacement holder 10 are disassembled, and the mud cake weight is weighed for comparison. This invention realistically simulates the state of a wellbore with casing, and the test results are closer to the actual downhole condition.

[0074] The integrated testing method for horizontal well fluid loss and displacement efficiency includes the following steps:

[0075] S1. Install the columnar rock displacement clamp 9 and the annular rock displacement clamp 10 in the vertical section of the simulation test tube, and connect the horizontal section inlet of the simulation test tube to the mud pump 23.

[0076] S2. Install multiple annular cores 34 on their respective annular core filter holders and conduct filter loss tests until the filter cake on the inner wall of the annular core reaches the set thickness.

[0077] S3. Install multiple columnar cores 58 on their respective columnar core filter holders and conduct filter loss tests until the filter cake on the inner wall of the columnar cores reaches the set thickness.

[0078] S4. Select one annular core for filtration performance analysis, and select another annular core to install in the annular displacement holder 10;

[0079] S5. Select one columnar core for filtration performance analysis, and select another columnar core to install in the columnar displacement holder;

[0080] S6. Start the mud pump 23. The test liquid in the sample preparation tank 22 is drawn out by the mud pump 23 and sent to the lower inlet of the simulated test tube. After flowing through the columnar displacement holder 9 and the ring rock displacement holder 10 in sequence, it is discharged from the upper outlet of the simulated test tube and enters the test liquid collection tank.

[0081] S7. When the amount of filtrate flowing out from the atoll displacement holder 10 reaches the set value, the mud pump 23 stops;

[0082] S8. Take out the annular core 34 and the columnar core 58 and analyze the displacement efficiency.

[0083] The specific steps of S1 are as follows:

[0084] S1.1 First fix the arc-shaped section 4b of the cylinder, pre-install the upper conical guide 6 at the upper end of the vertical section 7a of the casing, and pre-install the lower conical guide 8 at the inlet of the horizontal section 7c of the casing.

[0085] S1.2 Place the arc-shaped section 7b of the sleeve at the center of the arc-shaped section 4b of the cylinder, then screw the vertical section 7a of the sleeve onto the upper end of the arc-shaped section 7b, and screw the horizontal section 7c of the sleeve onto the lower end of the arc-shaped section 7b.

[0086] S1.3 The cylinder clamping section 4a is fitted onto the outer periphery of the vertical section 7a of the casing and connected by a flange. Two column rock displacement clamps 9 are symmetrically provided on the outer periphery of the middle section of the cylinder clamping section 4a. A ring rock displacement clamp 10 is installed on the upper part of the cylinder clamping section 4a.

[0087] S1.4 The cylindrical guide section 4c is fitted onto the outer periphery of the horizontal section 7c of the sleeve and connected by a flange;

[0088] S1.5 The upper tapered joint 3 and the bent elbow 2 are fixedly connected above the ring rock displacement clamp 10, and the lower tapered joint 5 is fixedly connected to the outer port of the cylinder guide section 4c through the flange.

[0089] In S6, flushing fluid is first placed in sample preparation tank 22 to simulate physical flushing. Flushing fluid is placed in a sample preparation tank 22 and pumped by mud pump 23 and sent to the interface of lower conical joint 5 to simulate the turbulent flushing and hydraulic mechanical action of flushing fluid to flush the well wall and remove the loose mud cake and oil stains from the well wall.

[0090] One or more chemical reagents are then added to sample preparation tank 22 to simulate chemical scouring, aiming to effectively remove loose mud cake and oil stains from the well wall, improve the well wall, and enhance the water wetting environment. Different chemical reagents can be tested in different sample preparation tanks 22 for comparative analysis, facilitating the rapid identification of the optimal solution. Both of these different scouring simulations are used to improve the bonding strength of the first and second interfaces.

[0091] like Figure 4 As shown, the horizontal well section will be tested next. In S9, the column displacement holder 9 and the annular displacement holder 10 will be installed in the horizontal section of the simulation test tube, and then S2 to S8 will be repeated.

[0092] The specific steps for S9 are as follows:

[0093] S9.1 First fix the arc-shaped section 4b of the cylinder, pre-install the upper conical guide 6 at the upper end of the vertical section 7a of the casing, and pre-install the lower conical guide 8 at the inlet of the horizontal section 7c of the casing.

[0094] S9.2 Place the arc-shaped section 7b of the sleeve at the center of the arc-shaped section 4b of the cylinder, then screw the vertical section 7a of the sleeve onto the upper end of the arc-shaped section 7b, and screw the horizontal section 7c of the sleeve onto the lower end of the arc-shaped section 7b.

[0095] S9.3 The cylinder clamping section 4a is fitted onto the outer periphery of the horizontal section 7c of the casing and connected by a flange. Two pillar rock displacement clamps 9 are symmetrically provided on the outer periphery of the middle section of the cylinder clamping section 4a. A ring rock displacement clamp 10 is installed upstream of the pillar rock displacement clamp 9.

[0096] S9.4 The cylindrical guide section 4c is fitted onto the outer periphery of the vertical section 7a of the sleeve and connected by a flange;

[0097] S9.5 The upper conical joint 3 and the bent elbow 2 are fixedly connected to the upper end of the cylinder guide section 4c, and the lower conical joint 5 is fixedly connected to the outside of the ring rock displacement clamp 10 through the flange.

[0098] The annular displacement holder 10 is located near the lower conical joint 5, which facilitates the disassembly and replacement of the annular core 34. The columnar displacement holder 9 and the annular displacement holder 10 are placed on the horizontal section for testing, which is beneficial to directly obtain the real displacement data of the horizontal section in the horizontal well, and provides an accurate basis for accurately guiding the operation of the horizontal well.

[0099] The outlet pipe of the test cylinder is also connected to the outlet of the cleaning pump 29, and the outlet pipe of the cleaning pump 29 is also connected to the inlet of the sample preparation tank 22 via a valve. The outlet pipe of the mud pump is also connected to the cleaning liquid collection tank 30. After the test, the cleaning pump 29 injects clean water into the outlet pipe of the test cylinder to clean the inner cavity of the simulated test cylinder, and the washing water enters the cleaning liquid collection tank 30.

[0100] By switching the valves, the cleaning pump 29 can also inject clean water into each sample preparation tank 22 and clean the connecting pipe of the mud pump 23. The cleaning water still enters the cleaning liquid collection tank 30.

[0101] like Figure 5As shown, the annular rock filter holder of this invention includes an annular rock filter cylinder 32. The upper port of the annular rock filter cylinder 32 is covered with an upper annular rock filter head 31, and the lower port is covered with a lower annular rock filter head 33. The upper and lower ends of the annular rock filter cylinder 32 are respectively provided with cylinder flanges. The two cylinder flanges are connected to the flanges of the upper and lower annular rock filter heads 31 and 33 respectively by high-strength screws to ensure precise positioning between them. The upper annular rock filter head 31 is sealed to the upper port of the annular rock filter cylinder 32 through an upper annular rock filter head sealing ring 31d, and the lower annular rock filter head 33 is sealed to the lower port of the annular rock filter cylinder 32 through a lower annular rock filter head sealing ring 33e.

[0102] The upper end face of the annular filtration lower end cap 33 is provided with an upwardly protruding annular convex ring 33a. The annular convex ring 33a is inserted into the lower port of the annular filtration cylinder 32, and an annular filtrate channel 32a is left between it and the inner wall of the annular filtration cylinder 32. The annular filtration lower end cap 33 is provided with a filtrate metering port 33c, which communicates with the bottom of the annular filtrate channel 32a. The bottom of the annular filtration lower end cap 33 is provided with an annular drilling fluid drain port 33d, which communicates with the inner cavity space of the annular convex ring 33a.

[0103] The bottom of the annular core 34 is supported on the top of the annular convex ring 33a of the lower end cap of the annular rock. The outer wall of the bottom of the annular core 34 is flush with the outer circumference of the annular convex ring 33a of the lower end cap of the annular rock. The top of the annular convex ring 33a of the lower end cap of the annular rock is fitted with an annular sealing ring 33b, which seals the bottom of the annular core 34. The upper end of the annular filter cylinder 32 is provided with a positioning inner convex ring 32c extending in the axial direction. The upper outer wall of the annular core 34 abuts against the inner wall of the positioning inner convex ring 32c, thus achieving coaxial positioning of the annular core 34.

[0104] The top of the annular core 34 is supported below the annular filter upper end cap 31. A floating sealing ring 31a is embedded in the lower end face of the annular filter upper end cap 31, and an annular upper sealing ring 31b is embedded in the lower end face of the floating sealing ring 31a to achieve a seal with the top of the annular core 34. The upper part of the floating sealing ring 31a is supported in the groove of the annular filter upper end cap 31 by a spring 31c.

[0105] First, the lower end cap 33 of the annular filter is fixedly connected to the annular filter cylinder 32. Then, the bottom guide 36 is placed at the bottom of the inner cavity of the lower end cap 33. Next, the annular core 34 is placed on the annular convex ring 33a of the lower end cap. Then, the simulated drill pipe 35 is inserted from bottom to top into the center hole of the upper end cap 31 of the annular filter and fixed. Then, the upper end cap 31 of the annular filter is pressed onto the upper port of the annular filter cylinder 32 and connected to each other with high-strength screws. With the help of the elasticity of the floating sealing ring 31a, the annular core 34 can be clamped and sealed, which can compensate for the axial dimension error of the annular core 34. The simulated drill pipe 35 and the bottom guide 36 are coaxial with the annular filter cylinder 32.

[0106] A simulated drill pipe 35 is provided along the axis of the annular core 34. The upper end of the simulated drill pipe 35 is fixed to the center of the annular filter upper end cap 31, and the upper end of the center hole of the simulated drill pipe 35 is connected to the annular drilling fluid injection port 35a. Below the lower end of the simulated drill pipe 35, a bottom guide 36 is provided to make the drilling fluid flow outward and upward. The bottom of the bottom guide 36 abuts against the center of the bottom wall of the annular filter lower end cap 33.

[0107] The bottom-hole guide 36 has a centrally symmetrical structure. The annular guide cone 36a at the center of the bottom-hole guide 36 is inserted into the lower port of the simulated drill pipe 35 along the axis of the simulated drill pipe 35. The lower end of the annular guide cone 36a is smoothly connected to the upward-opening annular return groove 36b. The bottom of the annular return groove 36b has a semi-circular arc cross section, and the outer wall of the annular return groove 36b extends upward against the inner wall of the annular convex ring 33a of the lower end cap of the annular rock.

[0108] The middle section of the ring rock filtration cylinder 32 is symmetrically provided with two ring rock cleaning fluid injection ports 32b that are connected to the ring rock filtrate channel 32a.

[0109] A screw plug is screwed into the annular drilling fluid drain port 33d to seal it. High-pressure drilling fluid enters the center hole of the simulated drill pipe from the annular drilling fluid injection port 35a at the top of the simulated drill pipe 35. After being discharged from the lower end of the simulated drill pipe 35, it flows downward along the annular guide cone 36a into the inner side of the annular return channel 36b. After turning through the semi-circular guide channel, it flows back upward into the annulus around the outer periphery of the drill pipe. Under the action of pressure difference, free water passes through the annular core 34 and enters the annular filtrate channel 32a, where it collects and forms a filter cake on the inner wall of the annular core 34. The filtrate in the annular filtrate channel 32a flows out from the filtrate metering port 33c of the annular filtrate lower end cap 33. The filtrate loss is controlled online by an external filtrate feedback controller. Cleaning water can be injected into the annular filtrate channel 32a through the annular cleaning fluid injection port 32b.

[0110] like Figure 6As shown, two transducer connectors 37 are symmetrically arranged on the same cross section of the annular core 32. The inner cavity of the transducer connector 37 is equipped with an ultrasonic transducer 40 for detecting the thickness of the mud cake. The inner end face of the ultrasonic transducer 40 abuts against the outer wall of the annular core 34, and a high-pressure sealing plug 38 is provided on the outer side of the ultrasonic transducer 40.

[0111] The high-pressure sealing plug 38 has a sealing ring around its circumference that seals with the inner wall of the transducer connector 37. The outer end of the high-pressure sealing plug 38 has a central boss 38a that extends from the central hole of the locking cap 39. The locking cap 39 is screwed onto the threaded outer port of the transducer connector 37. A through lead hole 38b is provided along the axis of the high-pressure sealing plug 38 to facilitate the lead wire of the ultrasonic transducer 40 to be led out.

[0112] A pair of ultrasonic transducers 40 can be installed on each of the upper, middle, and lower cross sections of the ring-shaped filter cylinder 32 to monitor the mud cake at each section. The ultrasonic transducers 40 can be selected as HS-GS100K type ultrasonic detection shear wave transducers.

[0113] After the ultrasonic transducer 40 is pressed against the outer wall of the annular core 34 by the high-pressure sealing plug 38, the locking cap 39 is screwed on to press and position the step of the high-pressure sealing plug 38. The ultrasonic transducer 40 monitors the filter cake formation process through P-waves and S-waves, and can determine whether the filter cake thickness has reached the set value without disassembly. This allows for rapid evaluation of the relationship between injection flow rate and injection pressure and filtration loss, greatly improving experimental efficiency and significantly reducing the workload of experimental personnel.

[0114] After the annular core filtration test is completed, the annular core 34 can be removed by removing the annular core filtration head 31 and the annular core filtration cylinder 32 and then transferred to the cylinder of the annular core displacement holder 10 for displacement test.

[0115] like Figure 7 , Figure 8 As shown, the columnar rock filter holder of the present invention includes a columnar rock filter cylinder 47. A columnar rock filter upper cover 46 is screwed onto the outer periphery of the upper end of the columnar rock filter cylinder 47, and a columnar rock filter lower cover 60 is screwed onto the outer periphery of the lower end of the columnar rock filter cylinder 47. The bottom of the columnar rock filter lower cover 60 is supported on a columnar rock filter lower support base 61. A columnar rock filter lower end cap 59 is provided in the lower part of the inner cavity of the columnar rock filter cylinder 47. A columnar rock filter lower end cap sealing ring 59c is embedded on the outer periphery of the columnar rock filter lower end cap 59 to achieve a seal with the inner wall of the columnar rock filter cylinder 47. The bottom center of the lower end cap 59 of the column rock holder is provided with a downward extending column rock drilling fluid connector 59a. The column rock drilling fluid connector 59a extends downward from the center hole of the lower cover 60 of the column rock holder, and a through column rock drilling fluid injection hole 59b is provided along the axis of the lower end cap 59 of the column rock holder.

[0116] The upper part of the inner cavity of the column rock clamping device cylinder 47 is provided with a column rock clamping device upper end cap 48. The outer periphery of the column rock clamping device upper end cap 48 is embedded with a column rock clamping device upper end cap sealing ring 48b, which seals with the inner wall of the column rock clamping device cylinder 47. The top center of the column rock clamping device upper end cap 48 is provided with an upwardly extending column rock clamping device upper end cap center column 48a, which extends upward from the center hole of the column rock clamping device upper cover 46.

[0117] The cylindrical body 47 of the column rock holder is symmetrically welded with outwardly extending column rock pipe joints 55 in the middle circumference. Column rock test joints 56 are respectively inserted into the inner cavities of the two column rock pipe joints 55. When the outer step of the inner side of the column rock test joint abuts against the inner step of the column rock pipe joint, it is inserted into place and axial positioning is achieved. The central bosses on the outer sides of the two column rock test joints 56 protrude from the central holes of the column rock pressure caps 57. The two column rock pressure caps 57 are respectively screwed onto the outer circumference of the outer port of the column rock pipe joint 55 and pressed against the outer step of the central boss of the column rock test joint 56. Columnar rock cores 58 are respectively embedded in the countersunk holes on the inner end faces of the two column rock test joints 56. Column rock filtrate outflow holes 56a are respectively provided along the axis of the column rock test joints 56.

[0118] The core rod 53 is inserted into the inner cavity of the columnar rock holder cylinder 47 along the central hole of the upper end cap. The upper end of the core rod 53 is driven by a magnetic coupler. The magnetic coupler includes a coupled outer rotor 45b and a coupled inner rotor 45c that are paired and coupled to each other and are coaxial. The coupled outer rotor 45b is embedded in the inner cavity of the lower port of the magnetic coupling seat 45a. The coupled inner rotor 45c is located in the upper inner cavity of the central hole of the upper end cap and is fixedly connected to the upper end of the core rod 53. A columnar rock sealing plug 49 is screwed into the upper port of the central hole of the upper end cap. The lower part of the columnar rock sealing plug 49 is inserted into the central hole of the upper end cap and achieves static sealing through an O-ring.

[0119] The magnetic coupling seat 45a is driven by a drive motor 41. The flange of the drive motor 41 is fixed around the central hole of the upper support plate 42. The output shaft of the drive motor 41 is inserted downward into the upper central hole of the magnetic coupling seat 45a. The middle section of the magnetic coupling seat 45a and the coupling outer rotor 45b are fitted onto the upper outer periphery of the central column 48a of the columnar rock head. The inner diameter of the central hole of the upper support plate is larger than the outer diameter of the central column 48a of the columnar rock head to avoid interference. A set screw is screwed onto the upper part of the magnetic coupling seat 45a, and the inner end of the set screw abuts against the output shaft of the drive motor 41. The core rod 53 is driven to rotate by the magnetic coupler, so that the upper end of the core rod 53 does not need to be equipped with a dynamic seal, which improves the pressure resistance of the device.

[0120] The outer periphery of the upper support plate 42 is connected to the lower support plate 44 via a double-ended stud 43. The double-ended stud 43 has threaded sections at both ends. The bottom of the upper support plate 42 presses against the upper step of the double-ended stud 43, and the top of the lower support plate 44 supports the lower step of the double-ended stud 43, achieving precise positioning and ensuring parallelism. Nuts are screwed onto the threaded sections at both ends for tightening. The central threaded hole of the lower support plate 44 is screwed onto the central post 48a of the upper end cap of the column rock, and the bottom of the lower support plate 44 abuts against the shoulder of the central post 48a of the upper end cap of the column rock.

[0121] The upper part of the core rod 53 is supported in the upper stepped hole of the upper end cap 48 of the columnar rock holder by the upper bearing 50, and the middle part of the core rod 53 is supported in the lower stepped hole of the upper end cap 48 of the columnar rock holder by the lower bearing 51. A bearing cap 52 is fixed to the bottom center of the upper end cap 48 of the columnar rock holder by screws, and the top flange of the bearing cap 52 presses against the outer ring of the lower bearing 51. A diffuser 54 is installed at the lower end of the core rod 53, and the diffuser 54 is located on the same cross section as the columnar rock core 58.

[0122] The outer periphery of the column rock test joint 56 is fitted with an outer sealing ring 56b of the column rock joint and the inner wall of the column rock pipe joint 55 to achieve a seal. The inner wall of the countersunk hole of the column rock test joint 56 is fitted with an inner sealing ring 56c of the column rock joint and the column core 58 to achieve a seal.

[0123] A test columnar core connector 55 is screwed onto the lower end of the columnar core injection port 59b, and drilling fluid is injected into the inner cavity of the columnar core holder cylinder 47 through the columnar core injection port 59b. Simultaneously, the drive motor 41 drives the magnetic coupling seat 45a to rotate, which in turn drives the outer coupling rotor 45b to rotate. The outer coupling rotor 45b, through magnetic induction, drives the inner coupling rotor 45c to rotate, which in turn drives the core rod 53 to rotate. The core rod 53 then drives the disperser 54 at the lower end to rotate, simulating the rotation of the drill pipe during drilling. The disperser 54 is positioned at the same height as the columnar core 58. The rotation of the disperser 54 centrifugally throws the drilling fluid onto the surface of the columnar core 58. Under simulated formation pressure, the drilling fluid is filtered out through the surface layer of the columnar core 58. This simulates the depth of drilling fluid penetration into the formation during drilling and measures the mass of the mud cake formed on the surface of the columnar core 58. Under simulated formation pressure, drilling fluid is filtered out through columnar core 58 and collected from columnar filtrate outlet 56a, and then weighed.

[0124] By unscrewing the core cap 57, the core test connector 56 can be directly removed without the need for auxiliary tools, and the mud cake on the inner end face of the core will not be damaged, allowing for accurate calculation of the core's filtration loss.

[0125] After the columnar core filtration test is completed, unscrew the columnar core cap 57, pull out the columnar core test connector 56, and insert the columnar core test connector 56 into the columnar core tube connector of the columnar core displacement holder 9. The columnar core tube connector of the columnar core displacement holder 9 and the columnar core filtration holder are completely identical in structure and interchangeable. After the columnar core cap of the columnar core displacement holder 9 locks the columnar core test connector, the displacement test can be carried out. During the whole process, there is no need to contact the columnar core 58, and the filter cake on it will not be damaged.

[0126] The above description is merely a preferred embodiment of the present invention and does not limit the scope of patent protection of the present invention. Besides the above embodiments, the present invention may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention. Technical features of the present invention not described can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. An integrated testing method for horizontal well filter loss and displacement efficiency, characterized in that, The steps are as follows: S1. Install the columnar rock displacement holder and the annular rock displacement holder in the vertical section of the simulation test cylinder. The upper end of the vertical section of the simulation test cylinder is connected to an upper conical joint. The upper port of the upper conical joint is connected to a bent elbow. The outlet of the bent elbow is connected to multiple test liquid collection tanks through the outlet pipe of the test cylinder. The lower end of the vertical section of the simulation test cylinder is connected to the horizontal section through the arc section of the cylinder. The inlet of the horizontal section of the simulation test cylinder is connected to a lower conical joint. The inlet of the lower conical joint is connected to a mud pump. A simulated sleeve is provided along the axis of the simulated test tube. The simulated sleeve includes a vertical section, an arc-shaped section, and a horizontal section. The two ends of the arc-shaped section are connected to the vertical section and the horizontal section, respectively. The upper end of the vertical section and the inlet of the horizontal section are respectively provided with a top-closed conical guide. The cone apex of the conical guide is inserted into the inner cavity of the large end of the corresponding conical connector and is coaxial. S2. Install multiple annular cores on their respective annular core filter holders and conduct filter loss tests until the filter cake on the inner wall of the annular core reaches the set thickness. S3. Install multiple columnar cores on their respective columnar core filter holders and conduct filter loss tests until the filter cake on the inner wall of the columnar cores reaches the set thickness. S4. Select one annular core for filtration performance analysis, and select another annular core to install in the annular displacement holder; S5. Select one columnar core for filtration performance analysis, and select another columnar core to install in the columnar displacement holder; S6. Start the mud pump. The test solution in the sample preparation tank is pumped out by the mud pump and sent to the lower inlet of the simulation test tube. After flowing through the columnar displacement holder and the ring rock displacement holder in sequence, it is discharged from the upper outlet of the simulation test tube and enters the test solution collection tank. S7. When the amount of filtrate flowing out from the atoll displacement holder reaches the set value, the mud pump stops; S8. Take out the annular core and columnar core and analyze the displacement efficiency.

2. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 1, characterized in that, It also includes the following steps: S9. Install the column rock displacement holder and the ring rock displacement holder on the horizontal section of the simulation test cylinder, and then repeat S2 to S8.

3. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 1, characterized in that, In S6, a rinsing solution is first placed in the sample preparation vessel to simulate physical rinsing, and then one or more chemical reagents are placed in the sample preparation vessel to simulate chemical rinsing.

4. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 1, characterized in that, The specific steps of S1 are as follows: S1.1 First, fix the arc-shaped section of the cylinder, pre-install the upper conical guide at the upper end of the vertical section of the casing, and pre-install the lower conical guide at the inlet of the horizontal section of the casing; S1.2 Place the arc-shaped section of the casing at the center of the arc-shaped section of the cylinder, then screw the vertical section of the casing onto the upper end of the arc-shaped section of the casing, and screw the horizontal section of the casing onto the lower end of the arc-shaped section of the casing. S1.3 The cylinder clamping section is fitted onto the outer periphery of the vertical section of the casing and connected by a flange. Two columnar rock displacement clamps are symmetrically provided on the outer periphery of the middle section of the cylinder clamping section, and a ring rock displacement clamp is installed on the upper part of the cylinder clamping section. S1.4 The cylindrical guide section is fitted onto the outer periphery of the horizontal section of the casing and connected by a flange; S1.5 The upper tapered joint and the bent elbow are fixedly connected above the ring rock displacement clamp, and the lower tapered joint is fixedly connected to the outer port of the cylinder guide section through the flange.

5. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 2, characterized in that, The specific steps for S9 are as follows: S9.1 First, fix the arc-shaped section of the cylinder, pre-install the upper conical guide at the upper end of the vertical section of the casing, and pre-install the lower conical guide at the inlet of the horizontal section of the casing; S9.2 Place the arc-shaped section of the casing at the center of the arc-shaped section of the cylinder, then screw the vertical section of the casing onto the upper end of the arc-shaped section of the casing, and screw the horizontal section of the casing onto the lower end of the arc-shaped section of the casing. S9.3 The cylinder clamping section is fitted onto the outer periphery of the horizontal section of the casing and connected by a flange. Two pillar rock displacement clamps are symmetrically provided on the outer periphery of the middle section of the cylinder clamping section. A ring rock displacement clamp is installed upstream of the pillar rock displacement clamp. S9.4 The cylindrical guide section is fitted onto the outer periphery of the vertical section of the casing and connected by a flange; S9.5 The upper conical joint and the bent elbow are fixedly connected to the upper end of the cylinder guide section, and the lower conical joint is fixedly connected to the outside of the ring rock displacement clamp through the flange.

6. The integrated testing method for horizontal well filtration loss and displacement efficiency according to claim 4 or 5, wherein positioning plates are respectively clamped between the connecting flanges of the cylinder clamping section, the cylinder arc section and the cylinder guide section, the inner edges of the positioning plates are respectively stuck on the outer wall of the simulated casing, and multiple flow grooves are evenly distributed on the circumference of the annulus of each positioning plate.

7. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 4 or 5, characterized in that, A safety protection device, an online flow meter, and an inlet pressure sensor are sequentially installed on the pipe between the outlet of the mud pump and the inlet of the lower conical joint. An online density meter is installed on the side wall of the upper conical joint. An outlet pressure sensor is installed on the outlet pipe of the bent elbow. The filtrate outlet of the annular displacement clamp is connected to the filtrate loss feedback control system. The outlet pipe of the bent elbow is also connected to the outlet of the cleaning pump, and the outlet pipe of the mud pump is also connected to the cleaning fluid collection tank.

8. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 1, characterized in that, The horizontal section of the simulated test tube is fixed above the horizontal frame by a retaining ring. The vertical frame is located behind the vertical section of the simulated test tube. The lower end of the vertical frame is fixedly connected to one end of the horizontal frame. A gripper fixing frame that extends forward is fixed on the vertical frame. The gripper fixing frame is locked on the outer periphery of the vertical section of the simulated test tube. Two horizontal guide rails are fixed to the upper part of the vertical frame. The horizontal guide rails support a vertical support plate through horizontal sliders. The front end face of the vertical support plate is fixed with a vertical guide rail. A cylinder bracket is fixed above the vertical guide rail. A lifting cylinder is fixed on the cylinder bracket. The piston rod of the lifting cylinder extends downward and is connected to an L-shaped connecting plate. The horizontal plate of the L-shaped connecting plate is fixedly connected to the upper end of the upper conical joint. The vertical plate of the L-shaped connecting plate is supported on the vertical guide rail through a vertical slider.

9. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 1, characterized in that, The annular rock filtration holder includes an annular rock filtration cylinder. The upper port of the annular rock filtration cylinder is covered with an upper annular rock filtration head, and the lower port is covered with a lower annular rock filtration head. The upper end face of the lower annular rock filtration head has an upwardly protruding annular ring. The annular ring is inserted into the lower port of the annular rock filtration cylinder, leaving an annular rock filtrate channel between it and the inner wall of the annular rock filtration cylinder. The lower annular rock filtration head has a filtrate metering port and the bottom of the annular rock filtrate channel. The annular core is supported at the bottom of the annular lower end cap and the top of the annular core is supported at the bottom of the annular filter upper end cap. A simulated drill pipe is provided along the axis of the annular core. The upper end of the simulated drill pipe is fixed to the center of the annular filter upper end cap, and the upper end of the center hole of the simulated drill pipe is connected to the annular drilling fluid injection port. A bottom guide is provided below the lower end of the simulated drill pipe to allow the drilling fluid to flow back outward and upward. The bottom of the bottom guide abuts against the center of the bottom wall of the annular filter lower end cap.

10. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 9, characterized in that, The bottom hole guide has a centrally symmetrical structure. The annular guide cone at the center of the bottom hole guide is inserted into the lower port of the simulated drill pipe along the axis of the simulated drill pipe. The lower end of the annular guide cone is smoothly connected to the upward-opening annular return groove. The bottom of the annular return groove has a semi-circular arc cross section, and the outer wall of the annular return groove extends upward against the inner wall of the annular convex ring of the lower annular head.

11. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 9, characterized in that, Two transducer connectors are symmetrically arranged on each of the upper, middle and lower cross sections of the annular core. The inner cavity of each transducer connector is equipped with an ultrasonic transducer for detecting the thickness of the mud cake. The inner end face of the ultrasonic transducer abuts against the outer wall of the annular core, and a high-pressure sealing plug is provided on the outer side of the ultrasonic transducer.

12. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 1, characterized in that, The column rock filter holder includes a column rock holder cylinder. A top cover is screwed onto the upper circumference of the column rock holder cylinder, and a bottom cover is screwed onto the lower circumference of the column rock holder cylinder. A bottom end cap is provided in the lower part of the inner cavity of the column rock holder cylinder. A downwardly extending column rock drilling fluid connector is provided at the bottom center of the bottom end cap. The column rock drilling fluid connector extends downward from the center hole of the bottom end cap and has a through-hole for injecting column rock drilling fluid along the axis of the bottom end cap. The middle part of the cylinder is symmetrically welded with outwardly extending columnar rock pipe joints. Columnar rock test joints are respectively inserted into the inner cavities of the two columnar rock pipe joints. The outer step on the inner side of the columnar rock test joint abuts against the inner step of the columnar rock pipe joint. The central protrusions on the outer sides of the two columnar rock test joints pass through the central holes of the columnar rock pressure caps. The two columnar rock pressure caps are respectively screwed onto the outer ports of the columnar rock pipe joints and pressed against the outer steps of the columnar rock test joints. Columnar rock cores are respectively embedded in the countersunk holes on the inner end faces of the two columnar rock test joints. Columnar rock filtrate outflow holes are respectively provided along the axis of the columnar rock test joints.

13. The integrated testing method for horizontal well filter loss and displacement efficiency according to claim 12, characterized in that, The upper part of the inner cavity of the columnar rock clamping device cylinder is provided with an upper end cap. The top center of the upper end cap is provided with an upwardly extending columnar rock upper end cap center column. The columnar rock upper end cap center column extends upward from the center hole of the upper end cap of the columnar rock clamping device. The core rod is inserted into the inner cavity of the columnar rock clamping device cylinder along the center hole of the upper end cap, and a diffuser is installed at the lower end of the core rod. The diffuser and the columnar rock core are located on the same horizontal plane. The upper end of the core rod is driven by a magnetic coupler. The core rod is supported in the stepped hole of the upper end cap of the columnar rock clamping device by a bearing.

Citation Information

Patent Citations

  • Well cementation simulated flushing efficiency evaluation device

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  • Cementing flushing efficiency evaluation device and method

    CN108240185A

  • Evaluation device and method for flushing efficiency of cementing drilling fluid filter cake

    CN110617018A

  • Horizontal well filtration and cleaning simulation combined testing device

    CN114575824A