Experimental device and method for simulating well shut-in water hammer pressure

Abstract

The invention discloses an experimental device and method for simulating well closing water hammer pressure. The experimental device comprises a first drill rod, the upper end of the first drill rod is connected with a lifting hook set, the lower end of the first drill rod is connected with a well mouth four-way joint, the lower end of the well mouth four-way joint is connected with a flashboard blowout preventer, and the lower end of the flashboard blowout preventer is connected with a shaft; the first drill rod is connected with the second drill rod. The bottom of the shaft is connected with the stratum simulation device. One end of the drilling fluid injection module is connected with a first drill rod, the other end is connected with a drilling fluid recovery pool, one end of the drilling fluid return module is connected with a wellhead four-way joint, the other end is connected with the drilling fluid recovery pool, and the gas injection module is connected with the stratum simulation device. According to the experimental device, a more real experimental environment is provided for well closing water hammer pressure testing, the well closing water hammer pressure can be effectively tested under different working conditions through the experimental method, and accurate water hammer pressure data can be rapidly obtained.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas development drilling and completion engineering, and in particular to an experimental device and method for simulating shut-in water hammer pressure. Background Art

[0002] With the continuous growth of global energy demand, especially the rising consumption demand for oil and natural gas, the output of traditional shallow oil and gas fields has gradually decreased, and the development of deep oil and gas fields has become a key way to supplement energy supply. The development of deep oil and gas resources can effectively improve the stability of energy supply and reduce dependence on imported energy. Deep and ultra-deep geological conditions are more complex and unstable. Encountering sudden changes in faults, rock formations, or changes in pressure in groundwater layers will lead to instability of the well wall or leakage of oil and gas layers, thereby causing overflow or even blowout. After a blowout occurs, emergency measures can be taken to close the wellhead to prevent continuous oil and gas spraying and causing greater disasters. During the well closing process, the wellhead blowout preventer is subject to a certain amount of water hammer pressure. Affected by the upward rush of gas invading the annulus, the magnitude of the water hammer pressure will vary. If the water hammer pressure is too large, it may even cause the wellhead blowout preventer group to fail, ultimately leading to uncontrolled blowout and oil and gas leakage. It may also cause a series of catastrophic consequences such as fire, explosion, and environmental pollution, and even threaten the life safety of operators, causing huge economic losses.

[0003] At present, although there are some theoretical models and numerical simulation methods to describe the water hammer phenomenon, most models still have simplified assumptions and fail to fully consider various complex factors, such as non-uniform flow, fluid viscosity, and the impact of temperature changes on pressure waves. In the actual drilling process, the generation of water hammer pressure is often affected by the combined action of multiple factors. For example, the flow characteristics of the drilling fluid (such as viscosity, density, temperature), the design and operating status of the drill bit, etc. will affect the water hammer pressure. These simplifications make it difficult for existing models to fully and accurately predict the occurrence and impact of water hammer pressure in the actual drilling process. At present, there is no suitable experimental device and experimental method for shut-in water hammer pressure. Summary of the invention

[0004] In order to solve the problem that the prior art lacks suitable experimental equipment and experimental methods for shut-in water hammer pressure, and further accurately predicts the occurrence and impact of water hammer pressure during actual drilling, the present invention proposes an experimental equipment and method for simulating shut-in water hammer pressure to solve the above problem.

[0005] The present application discloses an experimental device for simulating shut-in water hammer pressure, comprising a drilling fluid injection module, a drilling fluid return module, a gas injection module, a first drill pipe, a second drill pipe, a wellbore, a formation simulation device and a paperless recorder, wherein the first drill pipe is connected to a hook group at the upper end, and is connected to a wellhead spool at the lower end, a gate blowout preventer is connected to the lower end of the wellhead spool, and the gate blowout preventer is connected to the wellbore at the lower end, the second drill pipe is arranged inside the wellbore, the first drill pipe is connected to the second drill pipe, and the bottom of the wellbore is connected to the formation simulation device; One end of the drilling fluid injection module is connected to the first drill pipe, and the other end is connected to the drilling fluid recovery tank. One end of the drilling fluid return module is connected to the wellhead four-way, and the other end is connected to the drilling fluid recovery tank. The gas injection module is connected to the formation simulation device.

[0006] Preferably, the drilling fluid injection module includes a self-priming booster pump, one end of which is connected to a drilling fluid recovery tank, and the other end is connected to a first drill pipe bypass through a drilling fluid injection pipeline, and the drilling fluid injection pipeline is provided with a first positive and negative pressure sensor, a first electric valve and a first pipeline electromagnetic flowmeter.

[0007] Preferably, the drilling fluid return module includes a liquid-gas separator, one end of the liquid-gas separator is connected to the drilling fluid recovery tank, and the other end is connected to the wellhead four-way through the drilling fluid return pipeline, a second electric valve and a second pipeline electromagnetic flowmeter are arranged on the drilling fluid return pipeline, a gas outlet is arranged on the liquid-gas separator, a third electric valve is arranged between the liquid-gas separator and the drilling fluid recovery tank, and a liquid level monitor is arranged in the drilling fluid recovery tank.

[0008] Preferably, the gas injection module includes a high-pressure gas cylinder, which is connected to the formation simulation device through a gas injection pipeline. The gas injection pipeline is provided with a first-level pressure reducing valve, a gas one-way valve, a second-level pressure reducing valve, a turbine gas flowmeter and a second positive and negative pressure sensor.

[0009] Preferably, the gate blowout preventer includes a shell, the shell includes an upper hinge seat and a lower hinge seat, the upper hinge seat is provided with a first oil guide channel and a second oil guide channel, the lower hinge seat is provided with a third oil guide channel and a fourth oil guide channel, a first piston and a first oil cylinder are provided on the left side of the shell, a second piston and a second oil cylinder are provided on the right side of the shell, a first gate is connected to the right side of the first piston, and a second gate is connected to the left side of the second piston, the first piston isolates the first oil cylinder into a first shut-in oil chamber on the left and a first well-opening oil chamber on the right, the second piston isolates the second oil cylinder into a second well-opening oil chamber on the left and a second well-shut-in oil chamber on the right, the first oil guide channel is connected to the first shut-in oil chamber, the second oil guide channel is connected to the second shut-in oil chamber, the third oil guide channel is connected to the first well-opening oil chamber, and the fourth oil guide channel is connected to the second well-opening oil chamber.

[0010] Preferably, the wellhead spool, the gate blowout preventer, the second drill pipe, the first drill pipe and the wellbore are made of transparent materials, the wellhead spool is connected to a third positive and negative pressure sensor, a fourth positive and negative pressure sensor is provided at the connection between the wellbore and the gate blowout preventer, the wellbore consists of multiple sections, and a bubble monitor is provided on each section of the wellbore.

[0011] Preferably, the input end of the paperless recorder is connected to a gate blowout preventer, a first positive and negative pressure sensor, a second positive and negative pressure sensor, a third positive and negative pressure sensor, a fourth positive and negative pressure sensor, a first electric valve, a second electric valve, a third electric valve, a first pipeline electromagnetic flowmeter, a second pipeline electromagnetic flowmeter, a secondary pressure reducing valve, a turbine gas flowmeter, a liquid level monitor and a bubble monitor, and the output end of the paperless recorder is connected to a computer.

[0012] The present application also discloses an experimental method for simulating shut-in water hammer pressure. The experiment is conducted using the above experimental device for simulating shut-in water hammer pressure, and the method comprises the following steps: S1. The required density and viscosity of the drilling fluid are configured in the drilling fluid recovery pool 12, and the density of the drilling fluid is adjusted using anhydrous calcium chloride, and the viscosity of the drilling fluid is adjusted using sodium carboxymethyl cellulose particles; S2. Connect the experimental device, keep the self-priming booster pump 11 and the high-pressure gas cylinder 21 closed, open the first gate 606 and the second gate 607 of the gate blowout preventer 6, and keep the valves of the instruments on the drilling fluid injection pipeline 34 and the drilling fluid return pipeline 25 fully open; S3, turn on the paperless recorder 19 and all instruments connected to the paperless recorder 19, turn on the self-priming booster pump 11, check the sealing of the experimental device, if there is no leakage, adjust the pressure and displacement of the self-priming booster pump 11 to the set value; S4, observe the changes in the readings of each instrument on the paperless recorder 19, and after observing that the fourth positive and negative pressure sensor 7 and the second positive and negative pressure sensor 26 are stable, adjust the knob of the secondary pressure reducing valve 24 to the pressure reducing valve set value; S5, turning on the liquid level monitor 13, the liquid-gas separator 15 and the high-pressure gas cylinder 21; S6. After the liquid level monitor 13 sounds an alarm, the gate blowout preventer 6 is closed. After the gate is completely closed, the self-priming booster pump 11 is turned off; S7, after the paperless recorder 19 shows that the fourth positive and negative pressure sensor 7 remains stable, the shut-in water hammer pressure test is completed; S8, repeat S1-S7, set different drilling fluid displacements, and complete the shut-in water hammer pressure test of drilling fluid with different displacements; S9, changing the drilling fluid type in the drilling fluid recovery pool 12, repeating S1-S7, and completing the shut-in water hammer pressure test of different drilling fluid types.

[0013] Preferably, the pressure setting value calculation method of the self-priming booster pump 11 is as follows:

[0014] in, is the pressure setting value of the self-priming booster pump, Pa; is atmospheric pressure, Pa; is the experimental drilling fluid density, kg / m 3 ; is the local gravitational acceleration, m / s 2 ; is the vertical height of the experimental wellbore, m; is the friction factor of the pipeline; is the total length of the experimental wellbore, m; is the inner radius of the experimental wellbore, m; is the outer radius of the experimental drill pipe, m; is the displacement setting value of the self-priming booster pump, m 3 / s; The displacement setting value of the self-priming booster pump is calculated as follows:

[0015] in, is the density of drilling fluid on site, kg / m 3 ; is the experimental drilling fluid viscosity, Pa·s; is the on-site drilling fluid viscosity, Pa·s; is the on-site drilling fluid displacement, m 3 / s; is the internal radius of the wellbore on site, m; is the outer radius of the drill pipe on site, m.

[0016] Preferably, the calculation method of the pressure reducing valve set pressure value is as follows:

[0017]

[0018]

[0019] in, Set the pressure value for the pressure reducing valve, Pa; is the bottom hole pressure during normal drilling, Pa; is the vertical depth of the formation, m; is the saturation of gas dissolved in drilling fluid, kg / m 3 ; is the depth of the gas reservoir drilled, m; is the gas viscosity of the gas intrusion, Pa·s; is the gas permeability, m 2 ; is the cross-sectional area of ​​the annulus at the drilling site, m 2 ; is the gas diffusion coefficient of gas invasion; is the annular drilling fluid velocity, m / s; To calculate the intermediate quantity.

[0020] Beneficial effects of the present invention: (1) The experimental device of the present invention fully considers the reproducibility of the real scene, especially in the construction of the upper wellhead spool and the gate blowout preventer simulation device, which perfectly restores the structure and function of the actual wellhead spool and the gate blowout preventer. By accurately simulating the actual operation process, the device can truly reproduce the closing process of the gate blowout preventer, ensuring that the blowout preventer operation in the test is highly consistent with the actual well closing process. This high degree of restoration makes the test results more reliable and provides a more realistic experimental environment for the performance verification of the blowout preventer.

[0021] (2) The experimental method of the present invention can effectively test the shut-in water hammer pressure under different working conditions and can cover a variety of different displacements and types of drilling fluids. This test method has significant advantages. First, it is easy to operate and implement during the experiment, and can quickly obtain accurate water hammer pressure data. It can comprehensively evaluate the potential impact of water hammer pressure on equipment and wellbore walls, thereby providing a scientific basis for the safety and efficiency of drilling operations.

[0022] (3) The present invention uses transparent acrylic materials to make the wellbore and drill pipe, which improves the intuitiveness and transparency of the experimental process. The changes in each link can be clearly observed, and the details and dynamics of the wellhead operation can be understood in real time, which greatly improves the operability and safety of the experiment. At the same time, the use of transparent materials not only enhances the effect of the experiment, but also facilitates the monitoring and adjustment of the internal operating status of the device.

[0023] (4) The experimental device of the present invention has a simple structure and does not require special processing materials and testing equipment. It can significantly reduce the relevant cost of setting up the experimental device while ensuring the accuracy and reliability of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of an experimental device for simulating shut-in water hammer pressure according to an embodiment of the present invention; Figure 2 A cross-sectional view of a gate blowout preventer according to an embodiment of the present invention; Figure 3 A partial enlarged view of the connection between the drill pipe and the wellhead spool according to an embodiment of the present invention; Figure 4A cross-sectional view of the connection between the drill pipe and the wellhead spool according to an embodiment of the present invention; Figure 5 It is a schematic diagram of the shut-in water hammer pressure test results according to an embodiment of the present invention.

[0025] The reference numerals are as follows: 1-hook assembly, 2-first positive and negative pressure sensor, 3-wellhead spool, 4-second electric valve, 5-third positive and negative pressure sensor, 6-gate blowout preventer, 7-fourth positive and negative pressure sensor, 8-second pipeline electromagnetic flowmeter, 9-first electric valve, 10-first pipeline electromagnetic flowmeter, 11-self-priming booster pump, 12-drilling fluid recovery tank, 13-liquid level monitor, 14-third electric valve, 15-liquid-gas separator, 16-gas outlet, 17-first bubble monitor, 18-first flange, 19-paperless recorder, 20-computer, 21-high-pressure gas cylinder, 22-first pressure reducing valve, 23-gas one-way valve, 24-secondary pressure reducing valve, 25-turbine gas flowmeter, 26-first Two positive and negative pressure sensors, 27-second flange, 28-second bubble monitor, 29-third bubble monitor, 30-third flange, 31-second drill pipe, 32-wellbore, 33-formation simulation device, 34-drilling fluid injection pipeline, 35-drilling fluid return pipeline, 36-gas phase injection pipeline, 37-first drill pipe, 601-first oil guide channel, 602-second oil guide channel, 603-third oil guide channel, 604-fourth oil guide channel, 605-shell, 606-first gate plate, 607-second gate plate, 608-first well opening oil chamber, 609-second well opening oil chamber, 610-first well closing oil chamber, 611-second well closing oil chamber, 612-first piston, 613-second piston. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples.

[0027] An embodiment of the present invention discloses an experimental device for simulating shut-in water hammer pressure, the structure of which is as follows: Figure 1As shown, it includes a drilling fluid injection module A, a drilling fluid return module B, a gas injection module C, a first drill pipe 37, a second drill pipe 31, a wellbore 32, a formation simulation device 33 and a paperless recorder 19. The upper end of the first drill pipe 37 is connected to a hook group 1, the upper end of the hook group 1 is fixed to the load-bearing beam, and the lower end lifts the first drill pipe 37 through a wire rope. The lower end of the wellhead spool 3 is connected to a gate blowout preventer 6, and the lower end of the gate blowout preventer 6 is connected to the wellbore 32. The second drill pipe 31 is arranged inside the wellbore 32, and the bottom of the wellbore 32 is connected to the formation simulation device 33. One end of the drilling fluid injection module A is connected to the first drill pipe 37, and the other end is connected to the drilling fluid recovery tank 12. One end of the drilling fluid return module B is connected to the wellhead spool 3, and the other end is connected to the drilling fluid recovery tank 12. The gas injection module C is connected to the formation simulation device 33.

[0028] The main pipeline of the drilling fluid injection module A is made of explosion-proof metal hose, and the device joints are connected with 304 steel connectors, including a self-priming booster pump 11. One end of the self-priming booster pump 11 is connected to the drilling fluid recovery tank 12, and the other end is connected to the first drill pipe 37 bypass through a drilling fluid injection pipeline 34. The drilling fluid injection pipeline 34 is provided with a first positive and negative pressure sensor 2, a first electric valve 9 and a first pipeline electromagnetic flowmeter 10. In this embodiment, the drilling fluid injection pipeline 34 is 15 meters long. The main pipeline of the drilling fluid return module B is made of explosion-proof metal hose, and the device joints are connected with 304 steel connectors, including a liquid-gas separator 15. One end of the liquid-gas separator 15 is connected to a drilling fluid recovery tank 12 made of 304 steel, and the other end is connected to the wellhead spool 3 through a drilling fluid return pipeline 35. A second electric valve 4 and a second pipeline electromagnetic flowmeter 8 are provided on the drilling fluid return pipeline 35. A gas outlet 16 is provided on the liquid-gas separator 15. A third electric valve 14 is provided between the liquid-gas separator 15 and the drilling fluid recovery tank 12. A liquid level monitor 13 is provided in the drilling fluid recovery tank 12. The main pipeline of the gas injection module C is made of 304 steel, including a high-pressure gas cylinder 21, which is connected to the formation simulation device 33 through a gas injection pipeline 36. The gas injection pipeline 36 is provided with a first-level pressure reducing valve 22, a gas one-way valve 23, a second-level pressure reducing valve 24, a turbine gas flowmeter 25 and a second positive and negative pressure sensor 26.

[0029] The wellhead spool 3 is made of a transparent acrylic material, the left bypass is connected to the third positive and negative pressure sensor 5, the right bypass is connected to the drilling fluid return pipeline 35, and the lower end is connected to the gate blowout preventer 6 through a flange.

[0030] like Figure 2As shown, the ram blowout preventer 6 is made of a transparent acrylic material and includes a shell 605. The shell 605 includes an upper hinge seat and a lower hinge seat. The upper hinge seat is provided with a first oil guide channel 601 and a second oil guide channel 602. The lower hinge seat is provided with a third oil guide channel 603 and a fourth oil guide channel 604. The left side of the shell 605 is provided with a first piston 612 and a first oil cylinder. The right side of the shell 605 is provided with a second piston 613 and a second oil cylinder. The first ram 606 is connected to the right side of the first piston 612, and the left side of the second piston 613 is connected to the first ram 606. A second gate plate 607 is connected, the first piston 612 separates the first oil cylinder into a first well-closing oil chamber 610 on the left and a first well-opening oil chamber 608 on the right, the second piston 613 separates the second oil cylinder into a second well-opening oil chamber 609 on the left and a second well-closing oil chamber 611 on the right, the first oil guide channel 601 is connected to the first well-closing oil chamber 610, the second oil guide channel 602 is connected to the second well-closing oil chamber 611, the third oil guide channel 603 is connected to the first well-opening oil chamber 608, and the fourth oil guide channel 604 is connected to the second well-opening oil chamber 609.

[0031] When shutting in the well, the hydraulic oil of the gate blowout preventer 6 enters the first shut-in oil chamber 610 and the second shut-in oil chamber 611 on both sides through the first oil guide channel 601 and the second oil guide channel 602 on the upper hinge seat, respectively, and pushes the first piston 612, the first gate plate 606, the second piston 613, and the second gate plate 607 to move rapidly toward the center of the wellbore to shut in the well. When opening the well, the hydraulic oil enters the first well opening oil chamber 608 and the second well opening oil chamber 609 on both sides through the third oil guide channel 603 and the fourth oil guide channel 604 on the lower hinge seat, respectively, and pushes the first piston 612, the first gate plate 606, the second piston 613, and the second gate plate 607 to move rapidly away from the center of the wellbore, and the first gate plate 606 and the second gate plate 607 retract into the gate chamber. The upper end of the gate blowout preventer 6 is connected to the wellhead spool 3 through a flange, and the lower end is connected to the wellbore 32 through a flange, which is used to simulate the opening and closing of the gate blowout preventer 6 in the real drilling process.

[0032] The formation simulation device 33 includes a shell cavity and a simulated rock layer disposed therein, the simulated rock layer is made by 3D printing, and has holes and seams randomly distributed therein to simulate the real rock structure. The formation simulation device 33 is connected to the lower end of the wellbore 32 through the second flange 27 .

[0033] The shaft 32 is made of transparent acrylic material, with a total length of 20 meters. It consists of multiple shaft sections. Two adjacent shaft sections are connected by flanges and gaskets to ensure the sealing of the shaft. Each shaft section is equipped with a bubble monitor, which is connected to the shaft through a flange to monitor the shape of bubbles. Figure 1As shown, in this embodiment, the wellbore 32 is composed of three sections, and two adjacent wellbore sections are connected by a first flange 18 and a third flange 30, respectively. A first bubble monitor 17, a second bubble monitor 28 and a third bubble monitor 29 are respectively provided on each wellbore section, and a fourth positive and negative pressure sensor 7 is provided at the connection between the wellbore 32 and the gate blowout preventer 6.

[0034] like Figure 3 and Figure 4 As shown, the first drill rod 37 and the second drill rod 31 are made of transparent acrylic material, and the two sections of the drill rod are connected by threads. The first drill rod 37 is welded to the wellhead spool 3 as a whole to ensure the air tightness of the device. The first drill rod 37 is connected to the drilling fluid injection pipeline 34 through a bypass, and the lower end of the second drill rod 31 is connected to a simulated drill bit.

[0035] The input end of the paperless recorder 19 is connected to the gate blowout preventer 6, the first positive and negative pressure sensor 2, the second positive and negative pressure sensor 26, the third positive and negative pressure sensor 5, the fourth positive and negative pressure sensor 7, the first electric valve 9, the second electric valve 4, the third electric valve 14, the first pipeline electromagnetic flowmeter 10, the second pipeline electromagnetic flowmeter 8, the secondary pressure reducing valve 24, the turbine gas flowmeter 25, the liquid level monitor 13, the first bubble monitor 17, the second bubble monitor 28 and the third bubble monitor 29, and the output end of the paperless recorder 19 is connected to the computer 20.

[0036] Another embodiment of the present application discloses an experimental method for simulating shut-in water hammer pressure. The above-mentioned experimental device for simulating shut-in water hammer pressure is used to perform an experiment, comprising the following steps: S1. The required density and viscosity of the drilling fluid are configured in the drilling fluid recovery pool 12, and the density of the drilling fluid is adjusted using anhydrous calcium chloride, and the viscosity of the drilling fluid is adjusted using sodium carboxymethyl cellulose particles.

[0037] Drilling fluid density adjustment:

[0038] in, is the mass of anhydrous calcium chloride required, kg; is the experimental drilling fluid density, kg / m 3 ; is the volume of clean water, m 3 ; For the quality of clean water.

[0039] Preparation of drilling fluid viscosity:

[0040] is the required drilling fluid viscosity, mPa·s; is the constant of the rotational viscometer itself; is the torque of the rotational viscometer, N·m; is the rotation speed of the rotational viscometer, rpm.

[0041] S2. Connect the experimental device, keep the self-priming booster pump 11 and the high-pressure gas cylinder 21 closed, open the first gate 606 and the second gate 607 of the gate blowout preventer 6, keep the valves of the instruments on the drilling fluid injection pipeline 34 and the drilling fluid return pipeline 25 fully open, keep the valves of the instruments on other pipelines closed, and add the drilling fluid set in the experiment into the drilling fluid recovery pool 12.

[0042] S3. Turn on the paperless recorder 19 and all instruments connected to the paperless recorder 19, turn on the self-priming booster pump 11, check the sealing of the experimental device, and if there is no leakage, adjust the pressure and displacement of the self-priming booster pump 11 to the set value.

[0043] The pressure setting value of the self-priming booster pump 11 is calculated as follows:

[0044] in, is the pressure setting value of the self-priming booster pump, Pa; is atmospheric pressure, Pa; is the local gravitational acceleration, m / s 2 ; is the vertical height of the experimental wellbore, m; is the friction factor of the pipeline; is the total length of the experimental wellbore, m; is the inner radius of the experimental wellbore, m; is the outer radius of the experimental drill pipe, m; is the displacement setting value of the self-priming booster pump, m 3 / s.

[0045] The displacement setting value of the self-priming booster pump is calculated as follows:

[0046] in, is the density of drilling fluid on site, kg / m 3 ; is the experimental drilling fluid viscosity, Pa·s; is the on-site drilling fluid viscosity, Pa·s; is the on-site drilling fluid displacement, m 3 / s; is the internal radius of the wellbore on site, m; is the outer radius of the drill pipe on site, m.

[0047] S4. Observe the changes in the readings of the instruments on the paperless recorder 19. After observing that the fourth positive and negative pressure sensor 7 and the second positive and negative pressure sensor 26 are stable, adjust the knob of the secondary pressure reducing valve 24 to the pressure reducing valve set value.

[0048] The calculation method of the pressure reducing valve set pressure value is as follows:

[0049]

[0050]

[0051] in, Set the pressure value for the pressure reducing valve, Pa; is the bottom hole pressure during normal drilling, Pa; is the vertical depth of the formation, m; is the saturation of gas dissolved in drilling fluid, kg / m 3 ; is the depth of the gas reservoir drilled, m; is the gas viscosity of the gas intrusion, Pa·s; is the gas permeability, m 2 ; is the cross-sectional area of ​​the annulus at the drilling site, m 2 ; is the gas diffusion coefficient of gas invasion; is the annular drilling fluid velocity, m / s; To calculate the intermediate quantity.

[0052] S5. Turn on the liquid level monitor 13, the liquid-gas separator 15 and the high-pressure gas cylinder 21.

[0053] S6. After the liquid level monitor 13 sounds an alarm, the gate blowout preventer 6 is closed. After the gate is completely closed, the self-priming booster pump 11 is turned off.

[0054] The calculation method of the alarm setting value of the liquid level monitor 13 is:

[0055] in, is the alarm setting value of the liquid level monitor, m; is the alarm volume of the drilling fluid recovery pool, m 3 ; is the length of the drilling fluid recovery pool, m; is the width of drilling fluid recovery pool, m.

[0056] S7, after the paperless recorder 19 shows that the fourth positive and negative pressure sensor 7 remains stable, the shut-in water hammer pressure test is completed. Figure 5As shown, Figure 5 It is a shut-in water hammer pressure curve. The horizontal axis in the figure represents the shut-in time, and the vertical axis represents the reading of the fourth positive and negative pressure sensor 7 corresponding to the shut-in time. The point corresponding to each time on the figure is the water hammer pressure at the corresponding moment. The figure shows the change of the shut-in water hammer pressure with the change of the shut-in time.

[0057] S8, repeat S1-S7, set different drilling fluid displacements, and complete the shut-in water hammer pressure test of drilling fluid with different displacements.

[0058] S9, changing the drilling fluid type in the drilling fluid recovery pool 12, repeating S1-S7, and completing the shut-in water hammer pressure test of different drilling fluid types.

[0059] In terms of experimental equipment, this application fully considers the development characteristics of deep formation pores and fractures, making the motion characteristics of gas-liquid two-phase flow after gas invasion in the experiment more realistic, ensuring that the experimental results have high practical significance and pertinence, and providing solid experimental data support for subsequent theoretical analysis and technical application. During the experimental test, the closing process of the gate blowout preventer 6 is highly consistent with the actual operation. The well closing operation is achieved by adjusting the gate in the gate blowout preventer 6, and the simulation of the process is highly consistent with the actual wellhead closure situation. Not only can the time and pressure of well closing be accurately controlled, but also the adjustment of various parameters in the experiment can be ensured to be consistent with the complex situation in the actual drilling operation. The calculation method of the pressure and gas invasion amount of gas invading the wellbore is converted according to the actual situation, so that the experimental test is highly consistent with the actual operation on site. In terms of parameter adjustment, this application has high flexibility in adjusting the experimental parameters, can test the well closing water hammer pressure under various conditions according to different drilling fluid displacement and fluid properties, can simulate the pressure changes and liquid properties that may be encountered in different drilling operations, and provide researchers with a highly adaptable and adjustable experimental platform. In terms of material costs, by using simple and easily accessible raw materials and equipment in the design and construction of the experimental device, efficient and low-cost experimental testing was successfully achieved. Compared with traditional experimental devices, it avoids the dependence on special processing materials and high-cost testing equipment, and fully considers the economy and operability in practical applications. By reasonably selecting basic materials and conventional equipment, not only the construction cost of the experimental device is significantly reduced, but also the efficiency and reliability of the experimental process are ensured, so that researchers can conduct experiments at a lower cost while ensuring the scientificity and accuracy of the experimental results.

[0060] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An experimental device for simulating shut-in water hammer pressure, characterized in that: The invention comprises a drilling fluid injection module, a drilling fluid return module, a gas injection module, a first drill pipe (37), a second drill pipe (31), a wellbore (32), a formation simulation device (33) and a paperless recorder (19); the first drill pipe (37) has an upper end connected to a hook assembly (1), a lower end connected to a wellhead spool (3), a lower end of the wellhead spool (3) connected to a gate blowout preventer (6), a lower end of the gate blowout preventer (6) connected to the wellbore (32), the second drill pipe (31) is arranged inside the wellbore (32), the first drill pipe (37) is connected to the second drill pipe (31), and the bottom of the wellbore (32) is connected to the formation simulation device (33); One end of the drilling fluid injection module is connected to the first drill pipe (37), and the other end is connected to the drilling fluid recovery pool (12); one end of the drilling fluid return module is connected to the wellhead spool (3), and the other end is connected to the drilling fluid recovery pool (12); and the gas injection module is connected to the formation simulation device (33).

2. The experimental device for simulating shut-in water hammer pressure according to claim 1, characterized in that: The drilling fluid injection module comprises a self-priming booster pump (11), one end of the self-priming booster pump (11) being connected to a drilling fluid recovery tank (12), and the other end of the self-priming booster pump (11) being connected to a first drill pipe (37) bypass via a drilling fluid injection pipeline (34), and a first positive and negative pressure sensor (2), a first electric valve (9) and a first pipeline electromagnetic flowmeter (10) being provided on the drilling fluid injection pipeline (34).

3. The experimental device for simulating shut-in water hammer pressure according to claim 2, characterized in that: The drilling fluid return module comprises a liquid-gas separator (15), one end of the liquid-gas separator (15) is connected to a drilling fluid recovery tank (12), and the other end is connected to a wellhead spool (3) via a drilling fluid return pipeline (35), a second electric valve (4) and a second pipeline electromagnetic flowmeter (8) are provided on the drilling fluid return pipeline (35), a gas outlet (16) is provided on the liquid-gas separator (15), a third electric valve (14) is provided between the liquid-gas separator (15) and the drilling fluid recovery tank (12), and a liquid level monitor (13) is provided in the drilling fluid recovery tank (12).

4. The experimental device for simulating shut-in water hammer pressure according to claim 3, characterized in that: The gas injection module comprises a high-pressure gas cylinder (21), the high-pressure gas cylinder (21) being connected to a formation simulation device (33) via a gas phase injection pipeline (36), and the gas phase injection pipeline (36) being provided with a primary pressure reducing valve (22), a gas non-return valve (23), a secondary pressure reducing valve (24), a turbine gas flow meter (25) and a second positive and negative pressure sensor (26).

5. The experimental device for simulating shut-in water hammer pressure according to claim 4, characterized in that: The ram blowout preventer (6) comprises a housing (605), the housing (605) comprising an upper hinge seat and a lower hinge seat, the upper hinge seat being provided with a first oil guide hole (601) and a second oil guide hole (602), the lower hinge seat being provided with a third oil guide hole (603) and a fourth oil guide hole (604), a first piston (612) and a first oil cylinder being provided on the left side of the housing (605), a second piston (613) and a second oil cylinder being provided on the right side of the housing (605), a first ram (606) being connected to the right side of the first piston (612), and a second ram (606) being connected to the left side of the second piston (613) (607), the first piston (612) separates the first oil cylinder into a first well-closing oil chamber (610) on the left and a first well-opening oil chamber (608) on the right, the second piston (613) separates the second oil cylinder into a second well-opening oil chamber (609) on the left and a second well-closing oil chamber (611) on the right, the first oil guide channel (601) is connected to the first well-closing oil chamber (610), the second oil guide channel (602) is connected to the second well-closing oil chamber (611), the third oil guide channel (603) is connected to the first well-opening oil chamber (608), and the fourth oil guide channel (604) is connected to the second well-opening oil chamber (609).

6. The experimental device for simulating shut-in water hammer pressure according to claim 5, characterized in that: The wellhead spool (3), the ram blowout preventer (6), the second drill pipe (31), the first drill pipe (37) and the wellbore (32) are made of transparent materials; the wellhead spool (3) is connected to a third positive and negative pressure sensor (5); a fourth positive and negative pressure sensor (7) is provided at the connection between the wellbore (32) and the ram blowout preventer (6); the wellbore (32) is composed of a plurality of sections, and a bubble monitor is provided on each section of the wellbore.

7. The experimental device for simulating shut-in water hammer pressure according to claim 6, characterized in that: The input end of the paperless recorder (19) is connected to a gate blowout preventer (6), a first positive and negative pressure sensor (2), a second positive and negative pressure sensor (26), a third positive and negative pressure sensor (5), a fourth positive and negative pressure sensor (7), a first electric valve (9), a second electric valve (4), a third electric valve (14), a first pipeline electromagnetic flowmeter (10), a second pipeline electromagnetic flowmeter (8), a secondary pressure reducing valve (24), a turbine gas flowmeter (25), a liquid level monitor (13) and a bubble monitor, and the output end of the paperless recorder (19) is connected to a computer (20).

8. An experimental method for simulating shut-in water hammer pressure, characterized in that: The experiment is carried out using the experimental device for simulating shut-in water hammer pressure according to any one of claims 1 to 7, comprising the following steps: S1. Preparing the required density and viscosity of the drilling fluid in the drilling fluid recovery tank (12), using anhydrous calcium chloride to adjust the density of the drilling fluid, and using sodium carboxymethyl cellulose particles to adjust the viscosity of the drilling fluid; S2. Connect the experimental device, keep the self-priming booster pump (11) and the high-pressure gas cylinder (21) closed, open the first gate (606) and the second gate (607) of the gate blowout preventer (6), and keep the valves of the instruments on the drilling fluid injection pipeline (34) and the drilling fluid return pipeline (25) fully open; S3, turn on the paperless recorder (19) and all instruments connected to the paperless recorder (19), turn on the self-priming booster pump (11), check the sealing of the experimental device, and if there is no leakage, adjust the pressure and displacement of the self-priming booster pump (11) to the set value; S4. Observe the changes in the readings of the instruments on the paperless recorder (19). After observing that the fourth positive and negative pressure sensor (7) and the second positive and negative pressure sensor (26) are stable, adjust the knob of the secondary pressure reducing valve (24) to the pressure reducing valve set value; S5, turning on the liquid level monitor (13), the liquid-gas separator (15) and the high-pressure gas cylinder (21); S6. After the liquid level monitor (13) sounds an alarm, the gate blowout preventer (6) is closed. After the gate is completely closed, the self-priming booster pump (11) is turned off. S7, after the paperless recorder (19) shows that the fourth positive and negative pressure sensors (7) remain stable, the shut-in water hammer pressure test is completed; S8, repeat S1-S7, set different drilling fluid displacements, and complete the shut-in water hammer pressure test of drilling fluid with different displacements; S9, changing the drilling fluid type in the drilling fluid recovery tank (12), repeating S1-S7, and completing the shut-in water hammer pressure test of different drilling fluid types.

9. The experimental method for simulating shut-in water hammer pressure according to claim 8, characterized in that: The method for calculating the pressure setting value of the self-priming booster pump (11) is as follows: in, is the pressure setting value of the self-priming booster pump, Pa; is atmospheric pressure, Pa; is the experimental drilling fluid density, kg / m 3 ; is the local gravitational acceleration, m / s 2 ; is the vertical height of the experimental wellbore, m; is the friction factor of the pipeline; is the total length of the experimental wellbore, m; is the inner radius of the experimental wellbore, m; is the outer radius of the experimental drill pipe, m; is the displacement setting value of the self-priming booster pump, m 3 / s; The displacement setting value of the self-priming booster pump is calculated as follows: in, is the density of drilling fluid on site, kg / m 3 ; is the experimental drilling fluid viscosity, Pa·s; is the on-site drilling fluid viscosity, Pa·s; is the on-site drilling fluid displacement, m 3 / s; is the internal radius of the wellbore on site, m; is the outer radius of the drill pipe on site, m.

10. The experimental method for simulating shut-in water hammer pressure according to claim 9, characterized in that: The calculation method of the pressure reducing valve set pressure value is as follows: in, Set the pressure value for the pressure reducing valve, Pa; is the bottom hole pressure during normal drilling, Pa; is the vertical depth of the formation, m; is the saturation of gas dissolved in drilling fluid, kg / m 3 ; is the depth of the gas reservoir drilled, m; is the gas viscosity of the gas intrusion, Pa·s; is the gas permeability, m 2 ; is the cross-sectional area of ​​the annulus at the drilling site, m 2 ; is the gas diffusion coefficient of gas invasion; is the annular drilling fluid velocity, m / s; To calculate the intermediate quantity.

Images