Experimental Simulation Device and Method for Sand Washing of Horizontal Well Sections with Coiled Tubing

Abstract

This invention provides a simulation device and method for sand flushing wells in horizontal well sections using coiled tubing, relating to the field of oil and gas extraction technology. The simulation device includes: a gravel transport module comprising a first horizontal tubing body with an injection port and a sand outlet; a jet simulation module comprising a jet nozzle movably disposed within the first horizontal tubing body and coiled tubing connected to the jet nozzle; and a well-washing fluid pumping module comprising a delivery pipeline connected to the coiled tubing and the sand outlet. This invention's simulation device can simulate the sand flushing process of horizontal wells under real-world conditions, thereby quantifying the actual effectiveness of sand flushing wells and providing better accuracy of experimental results.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, and in particular to a simulation device and method for sand flushing wells in horizontal well sections with coiled tubing. Background Technology

[0002] Horizontal well technology has proven effective in enhancing production in conventional oil reservoirs and developing unconventional oil reservoirs, and its application has expanded rapidly in recent years. However, due to the unique structure of horizontal wells, sand production is a more serious problem than in vertical wells. If the sand and gravel accumulated in a horizontal well are not removed in time, they can easily accumulate to form a sand bed. As the sand bed rises, it can block the annulus passages within the horizontal well, causing problems such as sand burial of the oil layer, sand blockage of the tubing, and erosion of downhole equipment.

[0003] During operation, horizontal wells can be flushed with coiled tubing to remove accumulated sand and gravel. However, existing flushing experimental setups are primarily used to study the flushing effect on vertical wells and cannot be directly applied to horizontal wells. Therefore, existing flushing experimental setups cannot quantify the impact of factors such as the movement of the coiled tubing within the horizontal well and the eccentricity of the coiled tubing placement on the flushing effect. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the technical problem to be solved by the embodiments of the present invention is to provide a simulation device and method for sand flushing wells in a horizontal well section with continuous tubing, for studying the influence of different factors on the sand flushing effect of horizontal wells.

[0005] The above-mentioned objective of this invention can be achieved by the following technical solution: This invention provides a simulation device for sand flushing wells in a horizontal well section with coiled tubing, comprising:

[0006] A gravel transport module, comprising a first horizontal pipe body, wherein the first horizontal pipe body is provided with a liquid injection port and a sand outlet;

[0007] A jet simulation module, comprising a jet nozzle movably disposed within the first horizontal pipe body and a continuous oil pipe connected to the jet nozzle;

[0008] The well-washing fluid pumping module includes a fluid delivery pipeline that is connected to the continuous tubing and the sand outlet.

[0009] In a preferred embodiment of the present invention, the horizontal well section coiled tubing sand washing well experimental simulation device further includes a gas supply module. The gas supply module includes a second horizontal pipe body, a gas transmission pipeline, and an air compressor. The second horizontal pipe body is sleeved on at least a portion of the first horizontal pipe body. Both ends of the second horizontal pipe body are sealed to the first horizontal pipe body. The second horizontal pipe body and the first horizontal pipe body are clamped to form a gas cavity. The first horizontal pipe body is provided with a gas hole structure communicating with the gas cavity. The air compressor is connected to the gas cavity through the gas transmission pipeline.

[0010] In a preferred embodiment of the present invention, an eccentric block is inserted at one end of the first horizontal pipe body, and the continuous oil pipe is movably inserted through the first horizontal pipe body via the eccentric block, and an inter-pipe sealing ring is provided between the continuous oil pipe and the first horizontal pipe body.

[0011] In a preferred embodiment of the present invention, the eccentric block includes an eccentric base and an arc-shaped groove disposed on the eccentric base. The axis of the arc-shaped groove is staggered and parallel to the axis of the first horizontal pipe, and the continuous oil pipe is slidably disposed in the arc-shaped groove.

[0012] In a preferred embodiment of the present invention, the other end of the first horizontal pipe is provided with an openable sealing cap, the inter-pipe sealing ring and the sealing cap are clamped to form a sand flushing well test section, the injection port is located near the sealing cap, and the sand outlet is located near the inter-pipe sealing ring.

[0013] In a preferred embodiment of the present invention, along the direction from the sand outlet to the continuous oil pipe, the fluid delivery pipeline is sequentially provided with a first control valve, a sedimentation tank, a fluid supply tank, a mud pump, and a first check valve.

[0014] In a preferred embodiment of the present invention, the sedimentation tank is provided with a filter screen structure, and the sedimentation tank is divided into a filterable area and a filtered area by the filter screen structure. The liquid supply tank is connected to the filtered area through the liquid delivery pipeline.

[0015] In a preferred embodiment of the present invention, a liquid flow meter and a first pressure gauge are further provided on the fluid delivery line located between the first one-way valve and the continuous oil pipe.

[0016] In a preferred embodiment of the present invention, both ends of the second horizontal tube are provided with end sealing rings, and both ends of the second horizontal tube are sealed to the first horizontal tube through the end sealing rings.

[0017] In a preferred embodiment of the present invention, an air tank and a second one-way valve are sequentially provided along the air compressor to the air chamber.

[0018] In a preferred embodiment of the present invention, a gas flow meter and a second pressure gauge are further provided on the gas delivery pipeline located between the second one-way valve and the gas chamber.

[0019] In a preferred embodiment of the present invention, a second control valve is provided on the injection port.

[0020] In a preferred embodiment of the present invention, both the first horizontal tube and the second horizontal tube are formed of transparent material.

[0021] This invention also provides an experimental method for using a horizontal well section coiled tubing sand washing well simulation device, comprising the following steps:

[0022] Install and inspect the experimental simulation device for sand flushing and well washing of horizontal well sections with coiled tubing.

[0023] A sand bed is laid in the horizontal well section coiled tubing sand washing well experimental simulation device. The experimental data is measured and recorded using the horizontal well section coiled tubing sand washing well experimental simulation device. The experimental data includes at least the original mass of the sand, the first eccentric position of the coiled tubing, the start and end position coordinates of the two ends of the sand bed, the height of the sand bed, the first preset value of the gas flow meter, the reading of the liquid flow meter, the reading of the first pressure gauge, the movement time of the jet nozzle, the final position coordinates of the jet nozzle, and the total weight of the returned sand.

[0024] Based on the experimental data, a formula for the influence of sand flushing on horizontal wells was established.

[0025] In a preferred embodiment of the present invention, a sand bed is laid in the horizontal well section coiled tubing sand washing well experimental simulation device, and the experimental data is measured and recorded using the horizontal well section coiled tubing sand washing well experimental simulation device, specifically including the following steps:

[0026] Immerse the gravel in the well washing fluid, drain the liquid from the gravel, and record the original mass of the gravel;

[0027] Open the sealing cap and move the jet nozzle to one end of the first horizontal tube;

[0028] The gravel is laid in the first horizontal pipe to form a sand bed, and the starting and ending position coordinates of the two ends of the sand bed and the height of the sand bed are recorded.

[0029] The continuous oil pipe is set at the first eccentric position in the first horizontal pipe body, and the jet nozzle is moved to the other end of the first horizontal pipe body through the continuous oil pipe to close the sealing cover.

[0030] Open the first control valve to the first opening degree, open the second control valve, start the air compressor, adjust the outlet pressure of the air compressor until the gas flow meter reading is the first preset gas volume value, and record the gas flow meter reading and the second pressure gauge reading;

[0031] Fill the first horizontal pipe body with the well-washing fluid from the injection port, and then close the second control valve;

[0032] Start the mud pump and switch it to the first pumping state to pump the well washing fluid into the delivery pipeline and remove air bubbles from the delivery pipeline.

[0033] Switch the first control valve to the second opening degree, switch the mud pump to the second pumping state, and record the reading of the liquid flow meter and the reading of the first pressure gauge;

[0034] The jet nozzle is moved from one end of the first horizontal pipe to one end of the first horizontal pipe at a first speed via the continuous oil pipe.

[0035] When the jet nozzle detaches from the sand bed, shut down the mud pump, the air compressor, and the first control valve, open the second control valve, and record the movement time of the jet nozzle and the final position coordinates of the jet nozzle;

[0036] The sand and gravel entering the settling tank are dried and the well fluid is weighed to obtain the total weight of the returned sand and gravel.

[0037] The technical solution of the present invention has the following significant beneficial effects:

[0038] The horizontal well section coiled tubing sand-washing experimental simulation device of this invention, when in use, accumulates gravel in the first horizontal tubing to form a sand bed, thereby simulating the blockage problem of horizontal wells. Through the injection port and sand outlet on the first horizontal tubing, washing fluid can be injected into the first horizontal tubing, thus simulating the process of washing fluid returning to the well chamber in a horizontal well. By cooperating with the coiled tubing and the jet nozzle, washing fluid can be injected into the first horizontal tubing, thereby simulating the washing process of a horizontal well. Furthermore, the coiled tubing is eccentrically positioned within the first horizontal tubing, which can be used to simulate the actual operating environment of coiled tubing in a horizontal well. This allows the horizontal well section coiled tubing sand-washing experimental simulation device to simulate the sand-washing process of horizontal wells under real-world conditions, facilitating the quantitative study of the influencing factors of sand-washing in horizontal wells and resulting in better accuracy of experimental results.

[0039] This invention can simulate the sand flushing process by using coiled tubing, a jet nozzle, and a first horizontal tubing body. By recording the distance the sand bed moves and the total amount of sand returned per unit time, the effectiveness of sand flushing can be quantitatively determined. Furthermore, by using this horizontal section coiled tubing sand flushing experimental simulation device, the influence of various factors, including jet discharge rate, gas flow rate, coiled tubing eccentricity, coiled tubing pull-up speed, and coiled tubing lowering speed, on sand flushing can be further investigated. This horizontal section coiled tubing sand flushing experimental simulation device has the advantages of simple and reliable structure, convenient experimental operation, and low manufacturing cost. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0042] Figure 1 This is a schematic diagram of a structural simulation device for sand flushing and well washing experiments in a horizontal well section with coiled tubing.

[0043] The reference numerals in the above figures are as follows:

[0044] 100. Gravel transport module; 200. Jet simulation module; 300. Well washing fluid pumping module; 400. Gas supply module; 1. Liquid supply tank; 2. Mud pump; 3. Liquid delivery pipeline; 4. First check valve; 5. First pressure gauge; 6. Liquid flow meter; 7. Screw; 8. Eccentric block; 9. Coiled tubing; 10. Jet nozzle; 11. Air compressor; 12. Gas tank; 13. Second check valve; 14. Second pressure gauge; 15. Gas flow meter; 16. Second horizontal pipe body; 17. Injection port; 18. Second control valve; 19. Sealing cap; 20. First horizontal pipe body; 21. First control valve; 22. Sedimentation tank; 23. Sand outlet; 24. End sealing ring; 25. Filter structure; 26. Pipe sealing ring; 27. Gas delivery pipeline. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Implementation Method 1

[0047] Please refer to the following: Figure 1 As shown, an embodiment of the present invention provides a horizontal well section coiled tubing sand flushing well simulation device, which includes: a sand and gravel transport module 100, which includes a first horizontal pipe body 20, on which an injection port 17 and a sand outlet 23 are provided; a jet simulation module 200, which includes a jet nozzle 10 movably disposed in the first horizontal pipe body 20 and a coiled tubing 9 connected to the jet nozzle 10; and a well-washing fluid pumping module 300, which includes a fluid delivery pipeline 3, which is connected to the coiled tubing 9 and the sand outlet 23 respectively.

[0048] Overall, this horizontal well section coiled tubing sand-washing experimental simulation device, when in use, accumulates gravel within the first horizontal tubing 20 to form a sand bed, thereby simulating the blockage problem in horizontal wells. Through the injection port 17 and sand outlet 23 located on the first horizontal tubing 20, washing fluid can be injected into the first horizontal tubing 20, simulating the process of washing fluid returning to the well chamber. Through the cooperation of the coiled tubing 9 and the jet nozzle 10, washing fluid can be injected into the first horizontal tubing 20, simulating the washing process of a horizontal well. Furthermore, the eccentric placement of the coiled tubing 9 within the first horizontal tubing 20 can simulate the actual operating environment of the coiled tubing 9 in a horizontal well. This allows the horizontal well section coiled tubing sand-washing experimental simulation device to simulate the sand-washing process of horizontal wells under real-world conditions, facilitating the quantitative study of the influencing factors of sand-washing in horizontal wells and resulting in better experimental accuracy. Designers can determine the type of jet nozzle 10 according to experimental needs, such as a vortex-type jet nozzle; no specific limitations are imposed here.

[0049] In an embodiment of the present invention, the horizontal well section coiled tubing sand washing well experimental simulation device further includes a gas supply module 400. The gas supply module 400 includes a second horizontal pipe body 16, a gas transmission pipeline 27, and an air compressor 11. The second horizontal pipe body 16 is sleeved on at least a portion of the first horizontal pipe body 20. The two ends of the second horizontal pipe body 16 are sealed and connected to the first horizontal pipe body 20. The second horizontal pipe body 16 and the first horizontal pipe body 20 are clamped to form a gas cavity. The first horizontal pipe body 20 is provided with a gas hole structure (not shown) that communicates with the gas cavity. The air compressor 11 is connected to the gas cavity through the gas transmission pipeline 27.

[0050] By fitting a second horizontal tube 16 onto at least a portion of a first horizontal tube 20, and sealing both ends of the second horizontal tube 16 with the first horizontal tube 20, a gas chamber is formed. By pressurizing the gas chamber using an air compressor 11, the formation gas environment is simulated, allowing the first horizontal tube 20 to absorb the influence of the formation gas environment. This enables a more accurate simulation of the actual formation environment, resulting in more reliable experimental results in subsequent experiments.

[0051] The vent structure on the first horizontal pipe body 20 allows gas from the gas chamber to be forced into the first horizontal pipe body 20, simulating the formation gas environment and improving simulation accuracy. This facilitates a more accurate study of the sand flushing effect of horizontal wells. Specifically, the vent structure includes multiple vents located on the overlapping section of the first horizontal pipe body 20 and the second horizontal pipe body 16. Designers can determine the number, size, and location of the vents according to experimental needs; no specific limitations are imposed here.

[0052] In an embodiment of the present invention, an eccentric block 8 is inserted into one end of the first horizontal pipe body 20, and the continuous oil pipe 9 is movably inserted into the first horizontal pipe body 20 through the eccentric block 8. An inter-pipe sealing ring 26 is provided between the continuous oil pipe 9 and the first horizontal pipe body 20.

[0053] In practical use, when the coiled tubing 9 is installed in a horizontal well within the formation, visual installation is not possible, and the coiled tubing 9 has a certain weight, which can easily lead to eccentricity between the coiled tubing 9 and the axis of the horizontal well. During sand flushing, the eccentrically positioned coiled tubing 9 in the horizontal well needs to drive the jet nozzle 10 to move along the horizontal well. Therefore, in order to more accurately simulate the operating environment of the coiled tubing 9 in a horizontal well in an actual formation, an eccentric block 8 is used to eccentrically install the coiled tubing 9 inside the first horizontal pipe body 20, thereby more accurately simulating the sand flushing operation process of the coiled tubing 9 in a real environment.

[0054] Specifically, the eccentric block 8 includes an eccentric base and an arc-shaped groove disposed on the eccentric base. The axis of the arc-shaped groove is staggered and parallel to the axis of the first horizontal pipe 20, and the continuous oil pipe 9 is slidably disposed in the arc-shaped groove.

[0055] Specifically, the eccentric base is a semi-cylinder, which is fixed inside the first horizontal tube 20 by screws 7. The eccentric base has a certain length, thus ensuring the movement stability of the coiled tubing 9. An arc-shaped groove is provided on the rectangular end face of the eccentric base, and the coiled tubing 9 is slidably embedded in the arc-shaped groove. The arc-shaped groove can limit the radial displacement of the coiled tubing 9 and improve the axial sliding stability of the coiled tubing 9, so that the coiled tubing 9 can slide eccentrically within the first horizontal tube 20, simulating the lifting and lowering speed of the coiled tubing 9 during construction.

[0056] In other embodiments, the designer may adjust the structure of the eccentric base according to the installation requirements of the coiled tubing 9, without making specific restrictions here.

[0057] In an embodiment of the present invention, the other end of the first horizontal pipe body 20 is provided with an openable sealing cap 19, and the inter-pipe sealing ring 26 and the sealing cap 19 are clamped to form a sand flushing well washing test section. The injection port 17 is located near the sealing cap 19, and the sand outlet 23 is located near the inter-pipe sealing ring 26.

[0058] By providing a sealing cap 19 at the other end of the first horizontal tube 20, the sand and gravel can be easily piled up inside the first horizontal tube 20 to form a sand bed, which improves the ease of use.

[0059] By positioning the injection port 17 close to the sealing cap 19 and the sand outlet 23 close to the inter-pipe sealing ring 26, a well-washing fluid return flow channel is formed between the injection port 17, the first horizontal pipe body 20, and the sand outlet 23, which can simulate the flow process of the well-washing fluid in the underground environment of a horizontal well.

[0060] In an embodiment of the present invention, along the direction from the sand outlet 23 to the continuous oil pipe 9, the fluid delivery pipeline 3 is sequentially provided with a first control valve 21, a sedimentation tank 22, a fluid supply tank 1, a mud pump 2, and a first check valve 4.

[0061] Specifically, the first control valve 21 is a butterfly valve. During use, when the injection port 17 injects the washing fluid into the first horizontal pipe body 20, the washing fluid carrying sand and gravel is discharged back from the sand outlet 23 to the settling tank 22. This discharged washing fluid settles in the settling tank 22. By measuring the amount of sand and gravel discharged in the settling tank 22, the sand flushing and well washing effect of the first horizontal pipe body 20 can be quantitatively studied.

[0062] Furthermore, the washing fluid in the sedimentation tank 22 can continue to flow into the supply tank 1 after filtration. The washing fluid in the supply tank 1 is then pumped to the coiled tubing 9 by the mud pump 2 and sprayed into the first horizontal pipe body 20 through the jet nozzle 10, thereby performing sand flushing and well washing operations on the sand bed accumulated in the first horizontal pipe body 20.

[0063] The first one-way valve 4 installed on the infusion pipeline 3 can prevent backflow of the well washing fluid, thereby ensuring the pressure environment inside the infusion pipeline 3, avoiding the backflow of sand and gravel in the first horizontal pipe body 20 into the supply pool 1, and improving the measurement accuracy of the backflow of sand and gravel.

[0064] In an embodiment of the present invention, a filter structure 25 is provided in the sedimentation tank 22, and the sedimentation tank 22 is divided into a filterable area and a filtered area by the filter structure 25. The liquid supply tank 1 is connected to the filtered area through the liquid delivery pipeline 3.

[0065] The filter screen structure 25 installed in the sedimentation tank 22 can filter the washing fluid discharged through the sand outlet 23, thereby removing sand and gravel from the washing fluid. The filtered washing fluid then enters the filtered area from the filtration zone and flows into the supply tank 1 for recycling. The designer can determine the specific mesh size of the filter screen structure 25 according to the filtration requirements of the sand and gravel, and no specific restrictions are made here.

[0066] In an embodiment of the present invention, a liquid flow meter 6 and a first pressure gauge 5 are also provided on the fluid delivery pipeline 3 located between the first one-way valve 4 and the continuous tubing 9. The liquid flow meter 6 and the first pressure gauge 5 can record the pumping flow rate and pumping pressure of the well washing fluid in the fluid delivery pipeline 3, thereby facilitating quantitative research on the sand flushing and well washing effect.

[0067] In an embodiment of the present invention, both ends of the second horizontal tube 16 are provided with end sealing rings 24, and both ends of the second horizontal tube 16 are sealed to the first horizontal tube 20 through the end sealing rings 24.

[0068] The end sealing rings 24 seal both ends of the second horizontal tube 16 with the outer wall of the first horizontal tube 20, thereby forming an air cavity. The designer can determine the material and type of the end sealing rings 24 according to the application requirements, and no specific restrictions are imposed here.

[0069] In an embodiment of the present invention, an air tank 12 and a second one-way valve 13 are sequentially provided on the air supply pipeline 27 along the air compressor 11 to the air chamber.

[0070] By installing a gas tank 12 on the gas pipeline 27, the gas tank 12 can act as a gas buffer, reducing gas pressure fluctuations in the gas pipeline 27 and improving the stability of gas delivery.

[0071] The second one-way valve 13 can prevent the gas in the gas chamber and the well washing fluid in the first horizontal pipe 20 from being discharged back into the gas tank 12 and the air compressor 11, thus improving the safety of use.

[0072] In an embodiment of the present invention, a gas flow meter 15 and a second pressure gauge 14 are also provided on the gas supply pipeline 27 located between the second one-way valve 13 and the gas chamber.

[0073] The gas flow rate and pressure can be obtained by the gas flow meter 15 and the second pressure gauge 14 installed on the gas pipeline 27. By recording the gas flow rate and pressure, it is easy to quantitatively study the effect of gas on the sand flushing and well washing effect of horizontal wells.

[0074] In an embodiment of the present invention, a second control valve 18 is provided on the injection port 17. The second control valve 18 can control the opening and closing of the injection port 17, thereby facilitating the control of the flow rate of the well-washing fluid entering the first horizontal pipe body 20. Specifically, the second control valve 18 can be configured as a ball valve.

[0075] In an embodiment of the present invention, both the first horizontal tube 20 and the second horizontal tube 16 are formed of transparent material. Specifically, both the first horizontal tube 20 and the second horizontal tube 16 are formed of plexiglass. By making the first horizontal tube 20 and the second horizontal tube 16 transparent, viewing windows are formed on the first horizontal tube 20 and the second horizontal tube 16. These viewing windows can be used to observe the sand flushing process inside the first horizontal tube 20, facilitating a better observation and study of the influence of different factors on the sand flushing effect.

[0076] Implementation Method 2

[0077] An embodiment of the present invention provides an experimental method for using a horizontal well section coiled tubing sand washing well simulation device, comprising the following steps:

[0078] Step 1000: Install and inspect the horizontal well section coiled tubing sand flushing well simulation device.

[0079] Step 2000: Lay a sand bed in the horizontal well section coiled tubing sand washing well simulation device, and use the horizontal well section coiled tubing sand washing well simulation device to measure and record experimental data. The experimental data includes at least the original mass of the sand, the first eccentric position of the coiled tubing 9, the starting and ending position coordinates of the two ends of the sand bed, the height of the sand bed, the first preset gas volume value of the gas flow meter 15, the reading of the liquid flow meter 6, the reading of the first pressure gauge 5, the movement time of the jet nozzle 10, the final position coordinates of the jet nozzle 10, and the total weight of the returned sand.

[0080] Step 3000: Establish the formula for the influence of sand flushing on horizontal wells based on experimental data.

[0081] In an embodiment of the present invention, the installation and inspection of the horizontal well section coiled tubing sand flushing well washing experimental simulation device specifically includes the following steps:

[0082] Step 1001: Prepare the gravel transport module 100, the jet simulation module 200, the well washing fluid pumping module 300, and the gas supply module 400. Check whether each module is intact and confirm that each module is free of any problems and can work normally.

[0083] Step 1002: Arrange and connect the modules in an orderly manner according to the design, ensuring good connection between the modules, allowing the coiled tubing 9 to slide freely left and right within the first horizontal tubing body 20, and ensuring that the horizontal well section coiled tubing sand flushing well simulation device has no airtightness issues.

[0084] Step 1003: Open the sealing cover 19 and use the continuous oil pipe 9 to move the jet nozzle 10 out of the first horizontal pipe body 20.

[0085] Step 1004: Add an appropriate amount of well-washing fluid to the supply tank 1, and replenish the well-washing fluid in the supply tank 1 as needed. Turn on the mud pump 2 and gradually increase the outlet pressure to a suitable value. During this process, perform the following checks: whether the mud pump 2 can work normally; whether there is any liquid leakage in the delivery pipeline 3; whether the readings of the first pressure gauge 5 and the liquid flow meter 6 are normal; and whether the jet nozzle 10 can rotate normally to perform sand flushing operation after the mud pump 2 supplies fluid.

[0086] Step 1005: If any problems occur during the inspection, immediately shut down mud pump 2 and resolve the issues. Once it is confirmed that all modules are functioning normally, shut down mud pump 2.

[0087] Step 1006: Move the jet nozzle 10 into the first horizontal pipe body 20 via the continuous tubing 9, close the sealing cap 19, slightly open the first control valve 21 to allow a certain flow rate, start the air compressor 11 until it is stable, adjust the outlet pressure of the air compressor 11 to a lower value, fill the first horizontal pipe body 20 with well-washing fluid through the injection port 17 and maintain a certain rate of continuous injection, then gradually increase the outlet pressure of the air compressor 11 to the set value. During this process, perform the following checks: whether the air compressor 11 is working normally, whether there is any air leakage in the gas supply line 27; whether the readings of the second pressure gauge 14 and the gas flow meter 15 are normal; and whether air bubbles are generated normally in the first horizontal pipe body 20.

[0088] Step 1007: If any problems arise during the inspection, immediately shut down the air compressor 11 and resolve the issues. Once you have ensured that all parts are functioning properly, shut down the air compressor 11.

[0089] In an embodiment of the present invention, a sand bed is laid in a horizontal well section coiled tubing sand washing well experimental simulation device, and the experimental data is measured and recorded using the horizontal well section coiled tubing sand washing well experimental simulation device, specifically including the following steps:

[0090] Step 2001: Immerse the gravel in the well washing fluid, drain the liquid from the gravel, and record the original mass m of the gravel.

[0091] Step 2002: Open the sealing cover 19 and move the jet nozzle 10 to one end of the first horizontal tube 20.

[0092] Step 2003: Lay gravel inside the first horizontal pipe 20 to form a sand bed, and record the starting and ending position coordinates (L0, L2, L3) of the two ends of the sand bed. l ), and the height H of the sand bed.

[0093] Step 2004: Set the continuous oil pipe 9 at the first eccentric position inside the first horizontal pipe body 20, and drive the jet nozzle 10 to move to the other end of the first horizontal pipe body 20 through the continuous oil pipe 9, and close the sealing cover 19.

[0094] Step 2005: Open the first control valve 21 to the first opening degree, open the second control valve 18, start the air compressor 11, adjust the outlet pressure of the air compressor 11 until the reading of the gas flow meter 15 is the first preset gas volume value, and record the reading of the gas flow meter 15 as Q2 and the reading of the second pressure gauge 14 as P2.

[0095] Step 2006: Fill the first horizontal pipe body 20 with well washing fluid through injection port 17, and close the second control valve 18.

[0096] Step 2007: Start mud pump 2, switch mud pump 2 to the first pumping state, pump the well washing fluid into the delivery pipeline 3, and remove air bubbles in the delivery pipeline 3.

[0097] Step 2008: Switch the first control valve 21 to the second opening, switch the mud pump 2 to the second pumping state, and record the reading of the liquid flow meter 6 as Q1 and the reading of the first pressure gauge 5 as P1.

[0098] Step 2009: Drive the jet nozzle 10 from one end of the first horizontal pipe body 20 to one end of the first horizontal pipe body 20 at a first speed through the continuous oil pipe 9.

[0099] Step 2010: When the jet nozzle 10 detaches from the sand bed, shut off the mud pump 2, air compressor 11, and first control valve 21, open the second control valve 18, and record the motion time t of the jet nozzle 10 and the final position coordinate L of the jet nozzle 10. t .

[0100] Step 2011: The sand and gravel entering the settling tank 22 are controlled dry and the well washing fluid is weighed to obtain the total mass m of the returned sand and gravel. ′ .

[0101] Furthermore, the sliding speed of the coiled tubing 9 within the first horizontal tube body 20 can be changed multiple times, that is, the coiled tubing 9 can be controlled to slide at different speeds within the first horizontal tube body 20 to simulate the lifting and lowering speed of the coiled tubing 9 during construction, and the amount of sand flushing per unit time under different sliding speeds v can be measured as Q.

[0102] The above experimental steps can be used to investigate the effects of the lifting or lowering speed of the coiled tubing 9 within the first horizontal tubing 20 on the sand flushing effect of horizontal wells. Simultaneously, this experimental simulation device can also study the effects of factors such as jet displacement, gas flow rate, outer diameter of the coiled tubing 9, inner diameter of the wellbore, eccentricity of the coiled tubing 9, properties of the flushing fluid, properties of the gravel, initial sand bed height, jet nozzle parameters 10, and the movement speed of the coiled tubing 9 on the jet sand flushing effect; no specific limitations are imposed here.

[0103] To better obtain various experimental data, instruments such as stopwatches, measuring tapes, electronic scales, water-based markers, gravel, and well-washing fluid can be used to record various data during the experiment.

[0104] All articles and references disclosed herein, including patent applications and publications, are incorporated herein by reference for various purposes. The term “substantially constitutes…” used to describe a combination should include the identified element, component, part, or step, as well as other elements, components, parts, or steps that do not substantially affect the essential novelty of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, components, parts, or steps herein also contemplates embodiments substantially constituted by such elements, components, parts, or steps. The use of the term “may” herein is intended to indicate that any described attribute “may” include is optional. Multiple elements, components, parts, or steps can be provided by a single integrated element, component, part, or step. Alternatively, a single integrated element, component, part, or step can be divided into multiple separate elements, components, parts, or steps. The disclosure of “a” or “an” used to describe an element, component, part, or step does not imply exclusion of other elements, components, parts, or steps.

[0105] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An experimental method for using a simulation device for sand flushing and well washing in a horizontal well section with coiled tubing, characterized in that, The horizontal well section coiled tubing sand washing well simulation device includes: A gravel transport module, comprising a first horizontal pipe body, the first horizontal pipe body being provided with a liquid injection port and a sand outlet; a second control valve being provided on the liquid injection port; A jet simulation module, comprising a jet nozzle movably disposed within the first horizontal pipe body and a continuous oil pipe connected to the jet nozzle; A well-washing fluid pumping module includes a fluid delivery pipeline connected to the coiled tubing and the sand outlet. Along the direction from the sand outlet to the coiled tubing, the fluid delivery pipeline is sequentially equipped with a first control valve, a sedimentation tank, a fluid supply tank, a mud pump, and a first check valve. A flow meter and a first pressure gauge are also provided on the fluid delivery pipeline located between the first check valve and the coiled tubing. A gas supply module includes a second horizontal pipe, a gas supply pipeline, and an air compressor. The second horizontal pipe is sleeved on at least a portion of a first horizontal pipe, with both ends of the second horizontal pipe sealed to the first horizontal pipe. The second and first horizontal pipes clamp together to form a gas cavity. The first horizontal pipe has a perforated structure communicating with the gas cavity. The air compressor is connected to the gas cavity through the gas supply pipeline. An eccentric block is inserted into one end of the first horizontal pipe, through which the continuous oil pipe can... The coiled tubing is installed within the first horizontal pipe body, and an inter-pipe sealing ring is provided between the coiled tubing and the first horizontal pipe body. An openable sealing cap is provided at the other end of the first horizontal pipe body. The inter-pipe sealing ring and the sealing cap clamp together to form a sand-washing test section. The injection port is located near the sealing cap, and the sand outlet is located near the inter-pipe sealing ring. Along the air compressor to the air chamber, an air tank and a second one-way valve are sequentially provided on the air delivery pipeline. A gas flow meter and a second pressure gauge are also provided on the air delivery pipeline located between the second one-way valve and the air chamber. The experimental method includes the following steps: Install and inspect the experimental simulation device for sand flushing and well washing of the horizontal well section coiled tubing. A sand bed was laid inside the horizontal section coiled tubing sand washing well simulation device, and experimental data were measured and recorded using the device. Immerse the gravel in the well washing fluid, drain the liquid from the gravel, and record the original mass of the gravel; Open the sealing cover and move the jet nozzle to one end of the first horizontal tube; The gravel is laid in the first horizontal pipe to form a sand bed, and the starting and ending position coordinates of the two ends of the sand bed and the height of the sand bed are recorded. The continuous oil pipe is set at the first eccentric position in the first horizontal pipe body, and the jet nozzle is moved to the other end of the first horizontal pipe body through the continuous oil pipe to close the sealing cover. Open the first control valve to the first opening degree, open the second control valve, start the air compressor, adjust the outlet pressure of the air compressor until the gas flow meter reading is the first preset gas volume value, and record the reading of the gas flow meter and the reading of the second pressure gauge; Fill the first horizontal pipe body with the well-washing fluid from the injection port, and close the second control valve; Start the mud pump, switch the mud pump to the first pumping state, pump the well washing fluid into the delivery pipeline, and remove the air bubbles in the delivery pipeline; Switch the first control valve to the second opening degree, switch the mud pump to the second pumping state, and record the reading of the liquid flow meter and the reading of the first pressure gauge; The jet nozzle is moved from one end of the first horizontal pipe to one end of the first horizontal pipe at a first speed via the continuous oil pipe. When the jet nozzle detaches from the sand bed, shut down the mud pump, the air compressor, and the first control valve, open the second control valve, and record the movement time of the jet nozzle and the final position coordinates of the jet nozzle; The sand and gravel entering the settling tank are drained and the well washing fluid is weighed to obtain the total weight of the returned sand and gravel. The experimental data includes at least the original mass of the gravel, the first eccentric position of the coiled tubing, the starting and ending position coordinates of the two ends of the sand bed, the height of the sand bed, the first preset gas volume value of the gas flow meter, the reading of the liquid flow meter, the reading of the first pressure gauge, the movement time of the jet nozzle, the final position coordinates of the jet nozzle, and the total weight of the returned gravel. Based on the experimental data, a formula for the influence of sand flushing on horizontal wells was established.

2. The experimental method for using the horizontal well section coiled tubing sand-washing well simulation device as described in claim 1, characterized in that, The eccentric block includes an eccentric base and an arc-shaped groove disposed on the eccentric base. The axis of the arc-shaped groove is staggered and parallel to the axis of the first horizontal pipe. The continuous tubing is slidably disposed within the arc-shaped groove.

3. The experimental method for using the horizontal well section coiled tubing sand-washing well simulation device as described in claim 1, characterized in that, The sedimentation tank is equipped with a filter screen structure, which divides the sedimentation tank into a filterable area and a filtered area. The liquid supply tank is connected to the filtered area through the liquid delivery pipeline.

4. The experimental method for using the horizontal well section coiled tubing sand-washing well simulation device as described in claim 1, characterized in that, Both ends of the second horizontal tube are provided with end sealing rings, and both ends of the second horizontal tube are sealed to the first horizontal tube through the end sealing rings.

5. The experimental method for using the horizontal well section coiled tubing sand-washing well simulation device as described in claim 1, characterized in that, Both the first horizontal tube and the second horizontal tube are formed from transparent material.

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