Flushing efficiency evaluation device for well cementation and use method

Abstract

The invention relates to the technical field of well cementation, in particular to a flushing efficiency evaluation device for well cementation and a using method, the flushing efficiency evaluation device for well cementation comprises a testing cylinder, an inner cylinder and an outer cylinder, the testing cylinder is fixedly installed on the upper side of a base, and the outer cylinder and the inner cylinder are sequentially installed on the inner side of the testing cylinder from outside to inside. The device is reasonable and compact in structure, the inner cylinder and the outer cylinder are arranged, the casing wall and the well wall are simulated, pollution treatment is conducted on an interface through oil-based drilling fluid, the pollution process of underground oil-based drilling fluid on the casing wall and the well wall is simulated, and flushing fluid is injected from the second cavity, enters the first cavity through the communicating hole and then returns out of the top of the first cavity; the process that the interface is flushed by flushing fluid in the actual construction process is simulated, the accuracy of evaluation is guaranteed, the pump speed is calculated through the pump injection displacement of construction design in the actual construction process, the flushing efficiency can be evaluated according to the pump speed, simulation evaluation is closer to the flushing environment of site construction, evaluation data are obtained more accurately, and the well cementation quality is improved.

Description

Technical Field

[0001] This invention relates to the field of cementing technology, and is a cementing flushing efficiency evaluation device and its usage method. Background Technology

[0002] Flushing efficiency evaluation devices are essential tools for evaluating the flushing effect of flushing fluids in the laboratory before cementing operations. With the increasing development of ultra-deep wells and horizontal wells, the application of oil-based drilling fluids is becoming more widespread. The application of oil-based drilling fluids causes the casing wall and wellbore wall to adhere to the oil-based drilling fluid, changing the interface from hydrophilic to oleophilic, thus affecting the bonding quality between the cement slurry and the primary and secondary interfaces. By injecting flushing fluid before cementing, the interface is flushed, realizing the change from oleophilic to hydrophilic, thereby improving the bonding quality between the cement slurry and the primary and secondary interfaces and improving cementing quality. Traditional six-speed rotary viscometers have a large error in evaluating flushing efficiency and cannot accurately simulate the flushing process of flushing fluid entering the well, leaving certain safety hazards for subsequent cementing operations.

[0003] Chinese patent document CN108240185A discloses an evaluation device for cementing flushing efficiency, comprising: a simulated wellbore mud cake forming component, a simulated wellbore mud cake flushing component, a heating water tank, a water pump, a mass flow meter, and a pressurization device; the simulated wellbore mud cake forming component includes: a first support, a first heating sleeve, a first simulated wellbore, a wellbore filter top cover, a wellbore filter bottom cover, and a core / steel column; the first heating sleeve is disposed on the first support, and the first simulated wellbore is disposed on the first heating sleeve. Inside the simulated wellbore, the top and bottom ends are connected to the upper and lower filter covers of the wellbore, respectively; the upper filter cover is provided with an air inlet; the core / steel column is located inside the simulated wellbore and connected to the lower filter cover; the first heating sleeve is used to set the first temperature value of the outer surface of the core / steel column when forming mud cake; the pressurizing device is connected to the air inlet; the pressurizing device is used to set the first pressure value of the outer surface of the core / steel column when forming mud cake. This cementing flushing efficiency evaluation device only utilizes the principle of equal shear rates between the actual wellbore and the simulated wellbore for flushing simulation testing, which cannot fully reflect the actual action process of the flushing fluid downhole, and cannot accurately evaluate the flushing efficiency or guide on-site construction. Summary of the Invention

[0004] This invention provides a cementing flushing efficiency evaluation device and its usage method, which overcomes the shortcomings of the prior art and can effectively solve the problem that existing cementing flushing efficiency evaluation devices cannot accurately evaluate flushing efficiency and guide on-site construction.

[0005] One of the technical solutions of the present invention is achieved through the following measures: a cementing flushing efficiency evaluation device, comprising a test cylinder, an inner cylinder and an outer cylinder, wherein the test cylinder is fixedly installed on the upper side of the base, and the outer cylinder and the inner cylinder are sequentially installed from the outside to the inside of the test cylinder, forming a first chamber between the inner side of the outer cylinder, the outer side of the inner cylinder and the inner wall of the test cylinder, and forming a second chamber between the inner side of the inner cylinder and the inner side of the test cylinder, wherein at least one outlet hole with its lower end communicating with the first chamber is provided at intervals on the upper end of the test cylinder, and an outlet valve is fixedly installed on the upper end of the test cylinder corresponding to each outlet hole position, wherein an inlet hole with its lower end communicating with the second chamber is provided on the upper end of the test cylinder, and an inlet valve is fixedly installed on the upper end of the test cylinder corresponding to the inlet hole position, wherein a connecting hole communicating with the first chamber and the second chamber is provided on the lower inner side of the test cylinder, wherein a drain hole with its upper end communicating with the second chamber is provided on the lower end of the test cylinder, and a drain valve is fixedly installed on the lower end of the test cylinder corresponding to the drain hole position.

[0006] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions: The aforementioned test cylinder may include an upper pressure cap, a lower pressure cap, and a cylinder body. The lower end of the upper pressure cap is detachably and fixedly installed together with the upper end of the cylinder body, and the lower end of the cylinder body is detachably and fixedly installed together with the upper end of the lower pressure cap. The lower end of the upper pressure cap is provided with a downward-opening annular first upper groove and a downward-opening annular second upper groove at intervals from the outside to the inside in the radial direction. The upper end of the lower pressure cap is provided with an upward-opening annular first lower groove and an upward-opening annular second lower groove at intervals. The upper and lower ends of the outer cylinder are respectively installed in the first upper groove and the first lower groove, and the upper and lower ends of the inner cylinder are respectively installed in the second upper groove and the second lower groove.

[0007] The upper end of the lower pressure cap corresponding to the inner side of the outer cylinder can be recessed downward to form a discharge groove. A support tube is fixedly installed in the discharge groove. The second lower slot is located at the upper end of the support tube. The connecting hole includes several notches distributed circumferentially at intervals at the upper end of the support tube. The lower end of each notch extends to the lower end of the support tube. The liquid discharge hole is located in the center of the discharge groove.

[0008] The aforementioned test cylinder may also include an insulation layer and a control module fixedly installed on the outside of the cylinder. An insulation layer is installed between the inner side of the cylinder and the outer side of the outer cylinder. A heating component is installed inside the insulation layer. A first temperature sensor, a second temperature sensor, and a third temperature sensor are provided from bottom to top in the insulation layer corresponding to the position between the heating component and the outer cylinder. The control module is connected to the heating component, the first temperature sensor, the second temperature sensor, and the third temperature sensor, respectively.

[0009] The above may also include a heating liquid tank, a delivery pump, and a storage tank. A first inlet pipeline is fixedly connected between the outlet of the heating liquid tank and the inlet of the delivery pump. A second inlet pipeline is fixedly connected between the outlet of the delivery pump and the inlet of the inlet valve. An outlet pipeline is fixedly connected between the outlet of the outlet valve and the inlet of the storage tank.

[0010] The second technical solution of the present invention is achieved through the following measures: a method for using a cementing flushing efficiency evaluation device, comprising the following steps: S1, make the outer cylinder and the inner cylinder made of the same material as the sleeve to be tested; S2, weigh the inner cylinder and the outer cylinder, and measure their masses as m respectively. 内0 m 外0 ; S3, assemble the cementing flushing efficiency evaluation device, close the drain valve, and open the inlet valve and all outlet valves; S4, inject the drilling fluid used in this operation into the test cylinder through the inlet valve until the drilling fluid fills the first and second chambers, and then close the outlet valve; S5, after applying pressure to the test cylinder through the liquid inlet valve, curing begins. The curing time is the same as the interval between the lower casing and the cement grout injection or is determined according to the site requirements. S6. After maintenance is completed, open the drain valve to drain the drilling fluid. S7, remove the inner cylinder and outer cylinder, and weigh the inner cylinder and outer cylinder respectively as m. 内1 m 外1 ; S8, put the outer and inner cylinders back in and reassemble the cementing flushing efficiency evaluation device; S9, after heating the prepared rinsing solution to the set temperature, inject it into the test cylinder through the inlet valve according to the set discharge rate and rinse the inner and outer cylinders; S10, after rinsing, remove the inner and outer cylinders, let them dry, and weigh the inner and outer cylinders respectively as m. 内2 m 外2 ; S11, calculate the flushing efficiency η of the inner cylinder according to the following formula. 内 : η 内 =(m 内1 -m 内2 ) / (m 内1 -m 内0 ); The flushing efficiency η of the outer cylinder is calculated using the following formula. 外 : η 外 =(m 外1 -m 外2 ) / (m 外1 -m 外0 ).

[0011] The following are further optimizations and / or improvements to the second technical solution of the above invention: Specifically, step S4 involves injecting the drilling fluid used in this operation into the test cylinder through the inlet valve until the drilling fluid fills the first and second chambers, closing the outlet valve, setting the circulating heating temperature on the control module, and starting the heating component to operate.

[0012] Specifically, step S9 involves heating the prepared rinsing solution to a set temperature in a heating tank, then injecting it into the test cylinder through the inlet valve at a set discharge rate using a delivery pump to rinse the inner and outer cylinders.

[0013] The outer cylinder in step S1 above is made of artificial rock core material, or a rock core taken from the field, or the same material as the outer sleeve to be tested.

[0014] This invention features a reasonable and compact structure. By setting up an inner and outer cylinder, it simulates the casing wall and well wall. Oil-based drilling fluid is used to treat the interface contamination, simulating the contamination process of the casing wall and well wall by the downhole oil-based drilling fluid. A system is established where flushing fluid is injected from the second chamber, flows through a connecting hole to the first chamber, and then returns from the top of the first chamber, simulating the flushing process of the interface during actual construction. This ensures the accuracy of the evaluation. The pump speed is calculated based on the pump injection rate designed during actual construction, allowing for evaluation of flushing efficiency. This simulated evaluation more closely resembles the flushing environment of on-site construction, yielding more accurate evaluation data to guide on-site construction and improve cementing quality. Attached Figure Description

[0015] Appendix Figure 1 These are schematic diagrams of the main cross-sectional structure of embodiments one to six of the present invention.

[0016] Appendix Figure 2 For the appendix Figure 1 A schematic diagram of the upper and middle pressure cap from below.

[0017] Appendix Figure 3 For the appendix Figure 1 A top view of the lower pressure cap structure.

[0018] Appendix Figure 4 For the appendix Figure 1 The circuit connection block diagram.

[0019] The codes in the attached diagram are as follows: 1 for outer cylinder, 2 for inner cylinder, 3 for first chamber, 4 for second chamber, 5 for outlet valve, 6 for inlet valve, 7 for drain valve, 8 for upper pressure cap, 9 for lower pressure cap, 10 for cylinder body, 11 for first upper slot, 12 for second upper slot, 13 for first lower slot, 14 for second lower slot, 15 for discharge trough, 16 for support pipe, 17 for notch, 18 for insulation layer, 19 for control module, 20 for heating component, 21 for first thermometer, 22 for second thermometer, 23 for third thermometer, 24 for heating liquid tank, 25 for transfer pump, 26 for storage tank, 27 for first inlet pipeline, 28 for second inlet pipeline, and 29 for outlet pipeline. Detailed Implementation

[0020] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0021] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0022] The present invention will be further described below with reference to embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 As shown, the cementing flushing efficiency evaluation device includes a test cylinder, an inner cylinder 2, and an outer cylinder 1. The test cylinder is fixedly installed on the upper side of the base. The outer cylinder 1 and the inner cylinder 2 are installed sequentially from the outside to the inside of the test cylinder. A first chamber 3 is formed between the inner side of the outer cylinder 1, the outer side of the inner cylinder 2, and the inner wall of the test cylinder. A second chamber 4 is formed between the inner side of the inner cylinder 2 and the inner side of the test cylinder. At least one outlet hole with its lower end communicating with the first chamber 3 is provided at intervals at the upper end of the test cylinder. An outlet valve 5 is fixedly installed at the upper end of the test cylinder corresponding to each outlet hole position. An inlet hole with its lower end communicating with the second chamber 4 is provided at the upper end of the test cylinder. An inlet valve 6 is fixedly installed at the upper end of the test cylinder corresponding to the inlet hole position. A connecting hole connecting the first chamber 3 and the second chamber 4 is provided on the lower inner side of the test cylinder. A drain hole with its upper end communicating with the second chamber 4 is provided at the lower end of the test cylinder. A drain valve 7 is fixedly installed at the lower end of the test cylinder corresponding to the drain hole position.

[0023] During use, by setting up inner cylinder 2 and outer cylinder 1, the casing wall and well wall are simulated. Oil-based drilling fluid is used to treat the interface, simulating the contamination process of downhole oil-based drilling fluid on the casing wall and well wall. A flushing fluid is injected from the second chamber 4, passes through the connecting hole to the first chamber 3, and then returns from the top of the first chamber 3, simulating the flushing process of the interface during actual construction. This ensures the accuracy of the evaluation. The pump speed is calculated based on the pump injection rate designed during actual construction. The flushing efficiency can be evaluated based on the pump speed, making the simulation evaluation closer to the flushing environment of the actual construction, obtaining more accurate evaluation data, guiding on-site construction, and improving cementing quality.

[0024] The above-mentioned cementing flushing efficiency evaluation device can be further optimized and / or improved according to actual needs: Example 2: As an optimization of the above examples, as shown in the appendix. Figure 1 , 2 As shown in Figure 3, the test cylinder includes an upper pressure cover 8, a lower pressure cover 9, and a cylinder body 10. The lower end of the upper pressure cover 8 is detachably and fixedly installed together with the upper end of the cylinder body 10. The lower end of the cylinder body 10 is detachably and fixedly installed together with the upper end of the lower pressure cover 9. The lower end of the upper pressure cover 8 is provided with a downward-opening annular first upper groove 11 and a downward-opening annular second upper groove 12 at intervals from the outside to the inside in the radial direction. The upper end of the lower pressure cover 9 is provided with an upward-opening annular first lower groove 13 and an upward-opening annular second lower groove 14 at intervals. The upper and lower ends of the outer cylinder 1 are respectively installed in the first upper groove 11 and the first lower groove 13, and the upper and lower ends of the inner cylinder 2 are respectively installed in the second upper groove 12 and the second lower groove 14.

[0025] During use, this design facilitates the disassembly of the inner cylinder 2 and the outer cylinder 1, allowing for the weighing of the inner cylinder 2 and the outer cylinder 1 before and after rinsing, thus enabling rapid measurement of rinsing efficiency. The upper and lower slots allow for quick installation of the inner cylinder 2 and the outer cylinder 1, preventing deformation and detachment of the inner cylinder 2 and the outer cylinder 1 during experiments, thereby improving the stability of the inner cylinder 2 and the outer cylinder 1 within the cylinder body 10.

[0026] Example 3: As an optimization of the above examples, as shown in the appendix. Figure 1 , 3 As shown, the upper end of the lower pressure cap 9 corresponding to the inner side of the outer cylinder 1 is recessed downward to form a discharge groove 15. A support tube 16 is fixedly installed in the discharge groove 15. The second lower slot 14 is provided at the upper end of the support tube 16. The connecting hole includes several notches 17 distributed circumferentially at intervals at the upper end of the support tube 16. The lower end of each notch 17 extends to the lower end of the support tube 16. The liquid discharge hole is located in the center of the discharge groove 15.

[0027] During use, by setting up the discharge tank 15 and the notch 17, the liquid can flow in the first chamber 3 and the second chamber 4. The cleaned liquid can quickly flow into the discharge tank 15 and be quickly discharged through the notch 17 and the drain port, shortening the liquid discharge time and improving the measurement time of flushing efficiency, thus improving work efficiency. In addition, the inner cylinder 2 and the outer cylinder 1 can be set at the same height, which is convenient for maintenance after drilling fluid is injected.

[0028] Example 4: As an optimization of the above examples, as shown in the appendix. Figure 1 , 4 As shown, the test cylinder also includes an insulation layer 18 and a control module 19 fixedly installed on the outside of the cylinder body 10. An insulation layer 18 is installed between the inner side of the cylinder body 10 and the outer side of the outer cylinder 1. A heating component 20 is installed inside the insulation layer 18. A first thermometer 21, a second thermometer 22 and a third thermometer 23 are provided in the insulation layer 18 from bottom to top at the position corresponding to the position between the heating component 20 and the outer cylinder 1. The control module 19 is connected to the heating component 20, the first thermometer 21, the second thermometer 22 and the third thermometer 23 respectively.

[0029] Based on the requirements, the control module 19 is a known temperature controller, and the first temperature sensor 21, the second temperature sensor 22, and the third temperature sensor 23 are all known temperature sensors. The heating component 20 is a known heating cable. During use, this setup allows the heating temperature to be set to the current cycle temperature after drilling fluid is added to the cylinder 10. Pressure is applied through the inlet valve 6 for pressurized curing. The curing time is the interval between casing installation and cement slurry injection, or determined according to site requirements. This ensures that the drilling fluid temperature and pressure inside the cylinder 10 are consistent with those inside the casing, achieving a simulation evaluation that more closely resembles the flushing environment of on-site construction, obtaining more accurate evaluation data, guiding on-site construction, and improving cementing quality.

[0030] Example 5: As an optimization of the above examples, as shown in the appendix. Figure 1 As shown, it also includes a heating liquid tank 24, a delivery pump 25, and a storage tank 26. A first inlet pipeline 27 is fixedly connected between the outlet of the heating liquid tank 24 and the inlet of the delivery pump 25. A second inlet pipeline 28 is fixedly connected between the outlet of the delivery pump 25 and the inlet of the inlet valve 6. An outlet pipeline 29 is fixedly connected between the outlet of the outlet valve 5 and the inlet of the storage tank 26.

[0031] As required, a discharge pipeline 29 is fixedly connected between the outlet of one of the discharge valves 5 and the inlet of the storage tank 26. During operation, this setup allows for the generation of flushing fluid in the heated tank 24 at the same temperature as the on-site construction environment. As required, the delivery pump 25 is a known flow pump, which controls the flow rate of the flushing fluid flowing into the inlet of the inlet valve 6. This enables a more accurate simulation of the flushing environment compared to the actual construction environment, providing more precise evaluation data to guide on-site construction and improve cementing quality.

[0032] Example 6: As an optimization of the above examples, as shown in the appendix Figures 1 to 4 As shown, the method of using this cementing flushing efficiency evaluation device includes the following steps: S1. Make an outer cylinder 1 and an inner cylinder 2 made of the same material as the casing to be tested. The outer cylinder 1 is made of artificial rock core material, or a rock core taken from the field, or the same material as the outer casing to be tested. S2, weigh the inner cylinder 2 and the outer cylinder 1, and measure their masses as m respectively. 内0 m 外0 ; S3, Assemble the cementing flushing efficiency evaluation device, close the drain valve 7, and open the inlet valve 6 and all outlet valves 5; S4, inject the drilling fluid used in this operation into the test cylinder 10 through the inlet valve 6 until the drilling fluid fills the first chamber 3 and the second chamber 4, close the outlet valve 5, set the circulating heating temperature on the control module 19 and make the heating component 20 start working. S5, after applying pressure to the test cylinder 10 through the liquid inlet valve 6, curing begins. The curing time is the same as the interval between the lower casing and the cement grout injection or is determined according to the site requirements. S6, After maintenance is completed, open the drain valve 7 to drain the drilling fluid. S7, remove the inner cylinder 2 and the outer cylinder 1, and weigh the inner cylinder 2 and the outer cylinder 1 respectively as m. 内1 m 外1 ; S8, put the outer cylinder 1 and inner cylinder 2 back in, and reassemble the cementing flushing efficiency evaluation device; S9, after the prepared rinsing solution is heated to the set temperature in the heating liquid tank 24, the delivery pump 25 injects the solution into the test cylinder 10 through the inlet valve 6 according to the set discharge rate and rinses the inner cylinder 2 and the outer cylinder 1. S10, After rinsing, remove the inner cylinder 2 and outer cylinder 1, let them dry, and weigh them to determine their masses as m and m, respectively. 内2 m 外2 ; S11, calculate the flushing efficiency η of the inner cylinder 2 according to the following formula. 内 : η 内 =(m内1 -m 内2 ) / (m 内1 -m 内0 ); The flushing efficiency η of the outer cylinder 1 is calculated according to the following formula. 外 : η 外 =(m 外1 -m 外2 ) / (m 外1 -m 外0 ).

[0033] When the outer cylinder 1 is made of artificial rock core material, and the inner cylinder 2 is made of the same material as the casing used in this operation, the masses m of the inner cylinder 2 and the outer cylinder 1 are weighed separately before evaluating the flushing efficiency. 内0 m 外0 Close the drain valve 7, open the outlet valve 5 and inlet valve 6, and inject the drilling fluid used in this operation into the cementing flushing efficiency evaluation device through the inlet valve 6 until the drilling fluid fills the first chamber 3 and the second chamber 4. Close the outlet valve 5, set the heating temperature to the circulation temperature of this operation, and apply pressure through the inlet valve 6 for pressurized curing. The curing time is the interval between casing installation and cement slurry injection or as determined according to site requirements. After curing, drain the drilling fluid through the drain valve 7, remove the contaminated inner cylinder 2 and outer cylinder 1, and weigh them respectively. 内1 m 外1 Then, put the outer cylinder 1 and inner cylinder 2 back in and assemble the cementing flushing efficiency evaluation device.

[0034] Connect the inlet valve 6 of the evaluation device to the second inlet pipeline 28, and the outlet valve 5 to the outlet pipeline 29. Load the prepared flushing fluid into the heating tank 24, and set the temperature of the heating tank 24 according to the site parameters. Calculate the pump speed based on the actual pumping rate during construction, and set the discharge rate of the delivery pump 25 to evaluate the flushing efficiency. Establish a system where the flushing fluid enters the cementing flushing efficiency evaluation device through the inlet pipeline and inlet valve 6, passes through the second chamber 4 and the first chamber 3, and then is discharged from the outlet valve 5 and outlet pipeline 29 to the storage tank 26. This simulates the flushing interface process during actual construction, ensuring the accuracy of the evaluation. After the flushing evaluation is completed, remove the inner cylinder 2 and outer cylinder 1 and measure their masses (m). 内2 m 外2 The flushing efficiency is evaluated through calculation and visual observation of the flushing interface. The flushing efficiency calculation method is as follows: η 内 =(m 内1 -m 内2 ) / (m 内1 -m 内0 ), η 外 =(m 外1 -m 外2 ) / (m 外1 -m外0 This allows for simulation evaluations that more closely resemble the flushing environment of on-site construction, resulting in more accurate evaluation data to guide on-site construction and improve cementing quality.

[0035] When the outer cylinder 1 is made of rock core samples taken from the field, and the inner cylinder 2 is made of the same material as the casing used in this operation, the masses m of the inner cylinder 2 and the outer cylinder 1 are weighed separately before the flushing efficiency evaluation. 内0 m 外0 Close the drain valve 7, open the upper outlet valve 5 and the inlet valve 6, and inject the drilling fluid used in this operation into the cementing flushing efficiency evaluation device through the inlet valve 6 until the drilling fluid fills the first chamber 3 and the second chamber 4. Close the outlet valve 5, set the heating temperature to the circulation temperature of this operation, and apply pressure through the inlet valve 6 for pressurized curing. The curing time is the interval between casing installation and cement slurry injection or as determined according to site requirements. After curing, drain the drilling fluid through the drain valve 7, remove the contaminated inner cylinder 2 and outer cylinder 1, and weigh them respectively. 内1 m 外1 Then, put the outer cylinder 1 and inner cylinder 2 back in and assemble the cementing flushing efficiency evaluation device.

[0036] Connect the inlet valve 6 of the evaluation device to the second inlet pipeline 28, and the outlet valve 5 to the outlet pipeline 29. Load the prepared flushing fluid into the heating tank 24, and set the temperature of the heating tank 24 according to the site parameters. Calculate the pump speed based on the actual pumping flow rate during construction, and set the flow rate of the pump to evaluate the flushing efficiency. Establish a system where the flushing fluid enters the cementing flushing efficiency evaluation device through the inlet pipeline and inlet valve 6, passes through the second chamber 4 and the first chamber 3, and then is discharged from the outlet valve 5 and outlet pipeline 29 to the storage tank 26. This simulates the flushing interface process during actual construction, ensuring the accuracy of the evaluation. After the flushing evaluation is completed, remove the inner cylinder 2 and outer cylinder 1 and measure their masses (m). 内2 m 外2 The flushing efficiency is evaluated through calculation and visual observation of the flushing interface. The flushing efficiency calculation method is as follows: η 内 =(m 内1 -m 内2 ) / (m 内1 -m 内0 ), η 外 =(m 外1 -m 外2 ) / (m 外1 -m 外0 This allows for simulation evaluations that more closely resemble the flushing environment of on-site construction, resulting in more accurate evaluation data to guide on-site construction and improve cementing quality.

[0037] When the outer cylinder 1 is made of the same material as the outer sleeve to be tested, and the inner cylinder 2 is made of the same material as the sleeve used in this test, the masses m of the inner cylinder 2 and the outer cylinder 1 are weighed separately before the flushing efficiency evaluation. 内0 m 外0 Close the drain valve 7, open the outlet valve 5 and inlet valve 6, and inject the drilling fluid used in this operation into the cementing flushing efficiency evaluation device through the inlet valve 6 until the drilling fluid fills the first chamber 3 and the second chamber 4. Close the outlet valve 5, set the heating temperature to the circulation temperature of this operation, and apply pressure through the inlet valve 6 for pressurized curing. The curing time is the interval between casing installation and cement slurry injection or as determined according to site requirements. After curing, drain the drilling fluid through the drain valve 7, remove the contaminated inner cylinder 2 and outer cylinder 1, and weigh them respectively. 内1 m 外1 Then, put the outer cylinder 1 and inner cylinder 2 back in and assemble the cementing flushing efficiency evaluation device.

[0038] Connect the inlet valve 6 to the second inlet pipeline 28, and the outlet valve 5 to the outlet pipeline 29. Load the prepared flushing fluid into the heating tank 24, and set the temperature of the heating tank 24 according to the site parameters. Calculate the pump speed based on the actual pumping flow rate during construction, and set the flow rate of the pump to evaluate the flushing efficiency. Establish a system where the flushing fluid enters the cementing flushing efficiency evaluation device through the inlet pipeline and inlet valve 6, passes through the second chamber 4 and the first chamber 3, and then is discharged from the outlet valve 5 and outlet pipeline 29 to the storage tank 26. This simulates the flushing interface process during actual construction, ensuring the accuracy of the evaluation. After the flushing evaluation is completed, remove the inner cylinder 2 and outer cylinder 1 and measure their masses (m). 内2 m 外2 The flushing efficiency is evaluated through calculation and visual observation of the flushing interface. The flushing efficiency calculation method is as follows: η 内 =(m 内1 -m 内2 ) / (m 内1 -m 内0 ), η 外 =(m 外1 -m 外2 ) / (m 外1 -m 外0 This allows for simulation evaluations that more closely resemble the flushing environment of on-site construction, resulting in more accurate evaluation data to guide on-site construction and improve cementing quality.

[0039] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A device for evaluating the flushing efficiency of cementing operations, characterized in that... The device includes a test cylinder, an inner cylinder, and an outer cylinder. The test cylinder is fixedly installed on the upper side of the base. The outer cylinder and the inner cylinder are installed sequentially from the outside to the inside of the test cylinder. A first chamber is formed between the inner side of the outer cylinder, the outer side of the inner cylinder, and the inner wall of the test cylinder. A second chamber is formed between the inner side of the inner cylinder and the inner side of the test cylinder. The upper end of the test cylinder is provided with at least one liquid outlet hole with its lower end communicating with the first chamber. A liquid outlet valve is fixedly installed on the upper end of the test cylinder corresponding to each liquid outlet hole position. The upper end of the test cylinder is provided with a liquid inlet hole with its lower end communicating with the second chamber. A liquid inlet valve is fixedly installed on the upper end of the test cylinder corresponding to the liquid inlet hole position. The lower inner side of the test cylinder is provided with a connecting hole connecting the first chamber and the second chamber. The lower end of the test cylinder is provided with a liquid discharge hole with its upper end communicating with the second chamber. A liquid discharge valve is fixedly installed on the lower end of the test cylinder corresponding to the liquid discharge hole position.

2. The cementing flushing efficiency evaluation device according to claim 1, characterized in that... The test cylinder includes an upper pressure cap, a lower pressure cap, and a cylinder body. The lower end of the upper pressure cap is detachably and fixedly installed together with the upper end of the cylinder body, and the lower end of the cylinder body is detachably and fixedly installed together with the upper end of the lower pressure cap. The lower end of the upper pressure cap is provided with a downward-opening annular first upper groove and a downward-opening annular second upper groove at intervals from the outside to the inside in the radial direction. The upper end of the lower pressure cap is provided with an upward-opening annular first lower groove and an upward-opening annular second lower groove at intervals. The upper and lower ends of the outer cylinder are respectively installed in the first upper groove and the first lower groove, and the upper and lower ends of the inner cylinder are respectively installed in the second upper groove and the second lower groove.

3. The cementing flushing efficiency evaluation device according to claim 2, characterized in that... The upper end of the lower pressure cap corresponding to the inner side of the outer cylinder is recessed downward to form a discharge groove. A support tube is fixedly installed in the discharge groove. The second lower slot is located at the upper end of the support tube. The connecting hole includes several notches distributed circumferentially at intervals at the upper end of the support tube. The lower end of each notch extends to the lower end of the support tube. The liquid discharge hole is located in the center of the discharge groove.

4. The cementing flushing efficiency evaluation device according to claim 2 or 3, characterized in that... The test cylinder also includes an insulation layer and a control module fixedly installed on the outside of the cylinder. An insulation layer is installed between the inner side of the cylinder and the outer side of the outer cylinder. A heating component is installed inside the insulation layer. A first temperature sensor, a second temperature sensor, and a third temperature sensor are spaced from bottom to top in the insulation layer corresponding to the position between the heating component and the outer cylinder. The control module is connected to the heating component, the first temperature sensor, the second temperature sensor, and the third temperature sensor, respectively.

5. The cementing flushing efficiency evaluation device according to claim 1, 2, or 3, characterized in that... It also includes a heating liquid tank, a delivery pump, and a storage tank. A first inlet pipeline is fixedly connected between the outlet of the heating liquid tank and the inlet of the delivery pump. A second inlet pipeline is fixedly connected between the outlet of the delivery pump and the inlet of the inlet valve. An outlet pipeline is fixedly connected between the outlet of the outlet valve and the inlet of the storage tank.

6. The cementing flushing efficiency evaluation device according to claim 4, characterized in that... It also includes a heating liquid tank, a delivery pump, and a storage tank. A first inlet pipeline is fixedly connected between the outlet of the heating liquid tank and the inlet of the delivery pump. A second inlet pipeline is fixedly connected between the outlet of the delivery pump and the inlet of the inlet valve. An outlet pipeline is fixedly connected between the outlet of the outlet valve and the inlet of the storage tank.

7. A method of using a cementing flushing efficiency evaluation device according to any one of claims 1 to 6, characterized in that... The steps include the following: S1, make the outer cylinder and the inner cylinder made of the same material as the sleeve to be tested; S2, weigh the inner cylinder and the outer cylinder, and measure their masses as m respectively. 内0 m 外0 ; S3, assemble the cementing flushing efficiency evaluation device, close the drain valve, and open the inlet valve and all outlet valves; S4, inject the drilling fluid used in this operation into the test cylinder through the inlet valve until the drilling fluid fills the first and second chambers, and then close the outlet valve; S5, after applying pressure to the test cylinder through the liquid inlet valve, curing begins. The curing time is the same as the interval between the lower casing and the cement grout injection or is determined according to the site requirements. S6. After maintenance is completed, open the drain valve to drain the drilling fluid. S7, remove the inner cylinder and outer cylinder, and weigh the inner cylinder and outer cylinder respectively as m. 内1 m 外1 ; S8, put the outer and inner cylinders back in and reassemble the cementing flushing efficiency evaluation device; S9, after heating the prepared rinsing solution to the set temperature, inject it into the test cylinder through the inlet valve according to the set discharge rate and rinse the inner and outer cylinders; S10, after rinsing, remove the inner and outer cylinders, let them dry, and weigh the inner and outer cylinders respectively as m. 内2 m 外2 ; S11, calculate the flushing efficiency η of the inner cylinder according to the following formula. 内 : η 内 =(m 内1 -m 内2 ) / (m 内1 -m 内0 ); The flushing efficiency η of the outer cylinder is calculated using the following formula. 外 : η 外 =(m 外1 -m 外2 ) / (m 外1 -m 外0 )。 8. The method of using the cementing flushing efficiency evaluation device according to claim 7, characterized in that, Step S4 specifically involves injecting the drilling fluid used in this operation into the test cylinder through the inlet valve until the drilling fluid fills the first and second chambers, closing the outlet valve, setting the circulating heating temperature on the control module, and starting the heating component to work.

9. The method of using the cementing flushing efficiency evaluation device according to claim 7 or 8, characterized in that, Step S9 specifically involves heating the prepared rinsing solution to a set temperature in a heating tank, and then injecting it into the test cylinder through the inlet valve at a set discharge rate to rinse the inner and outer cylinders.

10. The method of using the cementing flushing efficiency evaluation device according to claim 7 or 8, characterized in that, The outer cylinder in step S1 is made of artificial rock core material, or a rock core taken on site, or the same material as the outer sleeve to be tested.

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