A device and method for dynamically determining the amount of scale buildup in a wellbore

Abstract

The application provides a wellbore scaling amount dynamic determination device and method, wherein the wellbore scaling amount dynamic determination device comprises a reaction kettle system, a rotating scaling system, a sample preparation system and a measuring system; the reaction kettle system is divided into a top cover, a kettle body and a bottom cover, and through holes are arranged on the top cover and the bottom cover to connect with other components; the rotating scaling system comprises a motor and a hollow deposition rod, the hollow deposition rod is fixed on the top cover by a strong magnetic metal block, and the motor drives the hollow deposition rod to rotate; the sample preparation system comprises a high-pressure displacement pump and an intermediate container, the sample preparation system is connected with the reaction kettle system, and after experimental fluid is configured in the intermediate container, the experimental fluid is pumped into the kettle body of the reaction kettle by the high-pressure displacement pump; and the measuring device is connected with the sample preparation system through a pipeline to detect the gas-liquid ratio of the experimental fluid. The application has the advantages that the scaling amount can be tested under different conditions; the rotating scaling system is driven by the electromagnetic principle, the sealing property of the reaction kettle is ensured, and dynamic experiments can be carried out.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction, and more specifically, to a device and method for dynamically measuring the amount of scale buildup in wellbores. Background Technology

[0002] Currently, there are four types of experimental devices for measuring scale formation: 1. Simple atmospheric pressure device: Under normal temperature and pressure conditions, experimental materials such as metal plates, stainless steel balls, and quartz plates are placed in a beaker containing formation water, and the scale formation amount and rate are calculated by weighing. However, this device can only be used under normal temperature and pressure, which differs significantly from actual production conditions. 2. Fluid phase analysis device: Given the concentration of various ions in the formation water, this device, in conjunction with an ion chromatograph, calculates the scale formation amount by utilizing the difference in scale-forming ion concentration from multiple ion tests at different temperatures and pressures. This device can only simulate formation temperature and pressure and cannot simulate real wellbore flow conditions; it is a static experimental device. 3. Thin-tube dynamic scaling device: This device calculates the scale thickness by using the pressure difference across the thin tube according to the pipe pressure drop formula. Thin-tube dynamic scaling devices can only obtain scaling thickness, not scaling amount, and the scaling thickness is an assumed average uniform thickness, which cannot reflect the true scaling thickness. Fourth, dynamic experimental devices for the influence of flow on scaling: These devices measure scaling amount through the linkage of image recognition software and a turbidity probe. However, these devices can only be operated under normal pressure conditions, and the accuracy of scaling amount measurement depends on the accuracy of the image software algorithm, thus having a certain degree of error. In summary, existing scaling amount measurement devices are similar in principle, but they only consider a single scaling factor.

[0003] Chinese patent application CN108843314A, entitled "Experimental Apparatus and Method for Scaling Risk Assessment of Water and Gas Wellbore," discloses a method for calculating the amount of scaling in water and gas wellbore. The experimental apparatus in this patent consists of a wellbore simulation insulation system and an experimental fluid injection and collection system. In the wellbore simulation insulation system, the metal pipe simulating the wellbore is composed of multiple short metal pipe sections. When calculating the amount of scaling, it is necessary to calculate and combine the scaling amounts of each of these short metal pipe sections separately, which can easily lead to errors. Summary of the Invention

[0004] The purpose of this invention is to address at least one of the aforementioned deficiencies in the prior art. For example, the purpose of this invention is to provide a device and method for dynamically measuring wellbore scaling that can simulate formation temperature, pressure, and actual wellbore flow conditions.

[0005] To achieve the above objectives, one aspect of the present invention provides a dynamic measuring device for wellbore scaling, comprising a reaction vessel system, a rotating scaling system, a sample preparation system, and a measuring system. The reaction vessel system includes a first valve, a reaction vessel, a temperature control box, and a back pressure control and filtration unit. The reaction vessel includes a top cover, a bottom cover, and a vessel body. The vessel body is a vertically arranged hollow cylinder. The top cover and bottom cover are fixedly and sealed to the upper and lower ends of the vessel body, respectively. The top cover and bottom cover are respectively provided with a first through hole and a second through hole. The first valve is connected to the first through hole via a first pipeline to supply experimental fluid to the interior of the vessel body. The back pressure control and filtration unit is connected to the second through hole via a second pipeline to control the back pressure of the reaction vessel and collect inorganic scale from the discharged experimental fluid. The reaction vessel is housed in the temperature control box, which can control the temperature inside the reaction vessel.

[0006] The rotating scaling system includes a motor, a support frame, a first strong magnetic metal block, a second strong magnetic metal block, a metal-sealed bearing, and a hollow deposition rod. The support frame fixes the motor to the top of the top cover with the motor's output shaft pointing vertically downward. The first strong magnetic metal block is fixedly mounted on the motor's output shaft. The metal-sealed bearing, the second strong magnetic metal block, and the hollow deposition rod are all located inside the vessel body. The second strong magnetic metal block is rotatably connected to the lower end of the top cover via the metal-sealed bearing. The upper end of the hollow deposition rod is fixedly connected to the lower end of the second strong magnetic metal block.

[0007] The sample preparation system is connected to the reaction vessel system, and the sample preparation system is capable of supplying experimental fluid with predetermined pressure, flow rate and gas-liquid ratio to the reaction vessel;

[0008] The measurement system is connected to the sample preparation system to measure the gas-liquid ratio of the experimental fluid.

[0009] In one exemplary embodiment of one aspect of the present invention, the back pressure control and filtration unit may include a second valve, a high-pressure filter element, a back pressure controller, and a collection bottle, wherein the collection bottle is connected to the second through hole through a second pipeline, the second valve is disposed between the back pressure controller and the second through hole, the high-pressure filter element is disposed between the second valve and the collection bottle, and the back pressure controller is disposed between the high-pressure filter element and the collection bottle.

[0010] In one exemplary embodiment of one aspect of the present invention, the reactor system may further include an annular scale inhibitor plate disposed on the inner wall of the reactor to prevent the experimental fluid from scaling on the inner wall of the reactor.

[0011] In one exemplary embodiment of this invention, the top cover and bottom cover are fixedly and sealed to the vessel body via threads, and the top cover and bottom cover are also provided with loading and unloading holes for easy disassembly and installation.

[0012] In one exemplary embodiment of one aspect of the present invention, the sample preparation system may include a first sample preparation unit, a second sample preparation unit, a gas-liquid mixing pipeline, and a third valve. The first sample preparation unit and the second sample preparation unit are respectively connected to one end of the gas-liquid mixing pipeline, and the other end of the gas-liquid mixing pipeline is connected to the first pipeline. The third valve is disposed on the gas-liquid mixing pipeline.

[0013] In an exemplary embodiment of one aspect of the present invention, the first sample preparation unit may include a first high-pressure displacement pump, a first pressure gauge, a fourth valve, a first intermediate container, and a fifth valve, wherein the top and bottom of the first intermediate container may be respectively provided with a third through hole and a fourth through hole, the first high-pressure displacement pump is connected to the fourth through hole through a third pipeline, the fourth valve is disposed on the third pipeline, the first pressure gauge is disposed on the third pipeline and located between the first high-pressure displacement pump and the fourth valve, the third through hole is connected to a gas-liquid mixing pipeline through a fourth pipeline, and the fifth valve is disposed on the fourth pipeline;

[0014] The second sample preparation unit may include a second high-pressure displacement pump, a second pressure gauge, a sixth valve, a second intermediate container, and a seventh valve. The second intermediate container has a fifth through hole at its top and a sixth through hole at its bottom. The second high-pressure displacement pump is connected to the fifth through hole via a fifth pipeline. The sixth valve is located on the fifth pipeline. The second pressure gauge is located on the fifth pipeline and between the second high-pressure displacement pump and the sixth valve. The sixth through hole is connected to a gas-liquid mixing pipeline via a sixth pipeline. The seventh valve is located on the sixth pipeline.

[0015] In one exemplary embodiment of the present invention, the top and bottom of the top cover may be provided with grooves, and the first strong magnetic metal block and the second strong magnetic metal block are located inside the grooves.

[0016] In one exemplary embodiment of this invention, the measurement system may include a seventh pipeline, an eighth valve, an eighth pipeline, a gas meter, an analytical balance, and a capped collection bottle, wherein the capped collection bottle is placed on the analytical balance, one end of the seventh pipeline is connected to the gas-liquid mixing pipeline, and the other end extends into the capped collection bottle, the eighth valve is disposed on the seventh pipeline, and the gas meter is connected to the capped collection bottle through the eighth pipeline to measure the gas in the experimental fluid.

[0017] Another aspect of the present invention provides a method for dynamically measuring the amount of scale buildup in a wellbore, the method being implemented using a device for dynamically measuring the amount of scale buildup in a wellbore as described in any of the exemplary embodiments above, and the method comprising the steps of:

[0018] Turn on the sample preparation system to prepare the experimental fluid according to the actual on-site air-water ratio of the experimental sample, pressurize it to the experimental set pressure value and maintain it;

[0019] Evacuate the inside of the reactor, pump the experimental fluid into the reactor, and stop pumping the experimental fluid when the pressure in the reactor reaches the experimental set value.

[0020] Turn on the back pressure controller to apply back pressure to the reactor, making the back pressure equal to the experimental set pressure; turn on the temperature control box to make the temperature in the reactor equal to the experimental set temperature and maintain the temperature.

[0021] Start the rotating scaling system to make the hollow deposition rod rotate at the experimentally set speed, so that the inorganic salt scale in the experimental fluid in the reactor can be fully deposited on the hollow deposition rod;

[0022] Turn off the rotating scaling system and temperature control box, and reduce the back pressure to allow all the experimental fluid in the reactor to enter the collection bottle;

[0023] Remove the hollow deposition rod and high-pressure filter element, dry them, weigh them, and calculate the amount of scaling in the experimental fluid.

[0024] In another exemplary embodiment of the present invention, the method may further include using a detection system to detect whether the gas-water ratio of the experimental fluid configured by the sample preparation system is qualified; if qualified, the experiment is continued; if unqualified, the sample is prepared again.

[0025] In another exemplary embodiment of the present invention, the method may further include cleaning the reaction vessel, changing the experimental conditions, repeating the experiment, measuring the amount of scaling under different experimental conditions, and plotting the scaling amount change curve under different experimental conditions. The method of changing the experimental conditions includes changing at least one of the following: experimental temperature, experimental test pressure, motor speed, roughness of the hollow deposition rod, and gas-water ratio of the experimental fluid.

[0026] In another exemplary embodiment of the present invention, the amount of scaling can be calculated using Equation 1, which is:

[0027]

[0028] in, W s This refers to the amount of scale buildup, expressed in mg / L. m 1 denoted as the initial mass of the hollow deposition rod, in mg; m 2 The initial mass of the high-pressure filter element is mg. m 3 The mass of the hollow deposition rod after the experiment is in mg. m 4 The mass of the high-pressure filter element after the experiment is in mg.V Let L be the volume of the reactor.

[0029] In another exemplary embodiment of the present invention, the method further includes fitting experimental data to obtain an empirical formula for wellbore scaling amount that comprehensively considers factors such as temperature, pressure, fluid flow rate, surface roughness, and gas-water ratio.

[0030] In another exemplary embodiment of the present invention, the experimental set temperature can be room temperature to 200°C, the experimental set pressure can be 0.1 to 100 MPa, and the gas-to-water ratio of the experimental fluid can be 1000 to 20000 m³ / s. 3 / m 3 .

[0031] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0032] (1) Install an annular scale inhibitor plate inside the reactor to prevent inorganic salt scale from depositing on the inner wall and bottom of the reactor;

[0033] (2) Using the principle of electromagnetic stirring, dynamic experimental conditions are created. An external stepper motor drives the rotation of a strong magnet, so that the hollow deposition rod can rotate almost without resistance together with the metal sealed bearing, thereby shearing and stirring the experimental fluid to simulate the fluid flow in the well. Attached Figure Description

[0034] The above and other objects and / or features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0035] Figure 1 A schematic diagram of the structure of a dynamic wellbore scaling measurement device according to an exemplary embodiment of the present invention is shown.

[0036] Figure 2 It shows Figure 1 Schematic diagram of the top cover structure;

[0037] Figure 3 It shows Figure 2 Top view;

[0038] Figure 4 It shows Figure 2 The left view;

[0039] Figure 5 A schematic diagram of a hollow deposition rod structure according to an exemplary embodiment of the present invention is shown;

[0040] Figure 6 It shows Figure 5 Top view;

[0041] Figure 7A schematic diagram of an annular scale inhibitor plate structure of an exemplary embodiment of the present invention is shown;

[0042] Figure 8 It shows Figure 7 Top view;

[0043] Figure 9 A scaling amount curve of an exemplary embodiment of the present invention is shown.

[0044] Explanation of key figure labels:

[0045] 1-First valve, 2-Loading / unloading hole, 3-Motor, 4-First strong magnetic metal block, 5-Support frame, 6-Top cover, 7-Rubber pad, 8-Metal sealed bearing, 9-Second strong magnetic metal block, 10-Hollow sedimentation rod, 11-Temperature sensor, 12-Annular scale inhibitor plate, 13-Vase body, 14-Temperature control box, 15-Bottom cover, 16-Second valve, 17-High-pressure filter element, 18-High-pressure flange, 19-Back pressure controller, 20-Collection bottle, 21-Gas meter, 22-Analytical balance, 23-Collection bottle with cover, 24-Tenth valve, 25-Sixth valve, 26-Second pressure gauge, 27-Second high-pressure displacement pump, 28-Fourth Valves, 29-First high-pressure displacement pump, 30-First pressure gauge, 31-Ninth valve, 32-First intermediate container, 33-Fifth valve, 34-Second intermediate container, 35-Seventh valve, 36-First tee, 37-Third valve, 38-Eighth valve, 39-Second tee, 40-First pipeline, 41-Second pipeline, 42-Third pipeline, 43-Fourth pipeline, 44-Fifth pipeline, 45-Sixth pipeline, 46-Seventh pipeline, 47-Eighth pipeline, 48-Gas-liquid mixing pipeline, 49-First through hole, 50-Second through hole, 51-Third through hole, 52-Fourth through hole, 53-Fifth through hole, 54-Sixth through hole. Detailed Implementation

[0046] The following description, in conjunction with exemplary embodiments, will detail the device and method for dynamically measuring scale in wellbore according to the present invention.

[0047] It should be noted that "first," "second," "third," "fourth," "fifth," "sixth," "seventh," and "eighth" are merely for ease of description and distinction, and should not be interpreted as indicating or implying relative importance. "Above," "below," "inside," and "outside" are merely for ease of description and to establish relative orientation or positional relationships, and do not indicate or imply that the component referred to must have that specific orientation or position.

[0048] In a first exemplary embodiment of the present invention, the device for dynamically measuring the amount of scale in a wellbore may include a reaction vessel system, a rotating scaling system, a sample preparation system, and a measurement system.

[0049] The reaction vessel system includes a first valve, a reaction vessel, a temperature control box, and a back pressure control and filtration unit. The reaction vessel comprises a top cover, a bottom cover, and a vessel body. The vessel body is a vertically oriented hollow cylinder, with the top and bottom covers forming a fixed, sealed connection to the upper and lower ends of the vessel body. A first through-hole and a second through-hole are respectively provided on the top and bottom covers. The first valve is connected to the first through-hole via a first pipeline to supply experimental fluid to the interior of the vessel body. The back pressure control and filtration unit is connected to the second through-hole via a second pipeline to control the back pressure of the reaction vessel and collect inorganic salt scale from the discharged experimental fluid. The entire reaction vessel is housed within the temperature control box, which controls the internal temperature of the reaction vessel.

[0050] In this embodiment, the rotating scaling system includes a motor, a support frame, a first strong magnetic metal block, a second strong magnetic metal block, a metal-sealed bearing, and a hollow deposition rod. The support frame is used to fix the motor, which is vertically positioned with its output shaft facing downwards. The first strong magnetic metal block is fixedly mounted on the motor's output shaft. The metal-sealed bearing, the second strong magnetic metal block, and the hollow deposition rod are all disposed inside the reactor body. The second strong magnetic metal block is rotatably connected to the lower end of the top cover via the metal-sealed bearing, and the upper end of the hollow deposition rod is fixedly connected to the lower end of the second strong magnetic metal block.

[0051] In this embodiment, the sample preparation system is connected to the reaction vessel system, and the sample preparation system is capable of supplying experimental fluid with a predetermined pressure, flow rate, and gas-liquid ratio to the reaction vessel. The measurement system is connected to the sample preparation system to measure the gas-liquid ratio of the experimental fluid.

[0052] In this exemplary embodiment, the back pressure control and filtration unit may include a second valve, a high-pressure filter element, a back pressure controller, and a collection bottle. The collection bottle is connected to a second through-hole via a second pipeline. The second valve is disposed between the back pressure controller and the second through-hole. The high-pressure filter element is disposed between the second valve and the collection bottle. The back pressure controller is disposed between the high-pressure filter element and the collection bottle.

[0053] In this exemplary embodiment, the reactor system may further include an annular anti-scaling plate disposed on the inner wall of the reactor to prevent scale formation of the experimental fluid on the inner wall of the reactor. Alternatively, a coating may be applied to the inner wall of the reactor to prevent scale formation of the experimental fluid inside the reactor.

[0054] In this exemplary embodiment, the top cover and bottom cover are fixedly and sealed to the vessel body via threads. Furthermore, the top cover and bottom cover are provided with mounting and dismounting holes to facilitate disassembly and installation of the top cover and bottom cover to the vessel body.

[0055] In this exemplary embodiment, the sample preparation system may include a first sample preparation unit, a second sample preparation unit, a gas-liquid mixing pipeline, and a third valve. The first and second sample preparation units are each connected to one end of the gas-liquid mixing pipeline, the other end of the gas-liquid mixing pipeline is connected to the first pipeline, and the third valve is disposed on the gas-liquid mixing pipeline.

[0056] In this exemplary embodiment, the first sample preparation unit may further include a first high-pressure displacement pump, a first pressure gauge, a fourth valve, a first intermediate container, and a fifth valve. The first intermediate container may have a third through-hole and a fourth through-hole at its top and bottom, respectively. The first high-pressure displacement pump is connected to the fourth through-hole via a third pipeline. The fourth valve is disposed on the third pipeline, and the first pressure gauge is disposed on the third pipeline and located between the first high-pressure displacement pump and the fourth valve. The third through-hole is connected to a gas-liquid mixing pipeline via the fourth pipeline, and the fifth valve is disposed on the fourth pipeline. The second sample preparation unit may include a second high-pressure displacement pump, a second pressure gauge, a sixth valve, a second intermediate container, and a seventh valve. The second intermediate container may have a fifth through-hole and a sixth through-hole at its top and bottom, respectively. The second high-pressure displacement pump is connected to the fifth through-hole via a fifth pipeline, and the sixth valve is disposed on the fifth pipeline. The second pressure gauge is disposed on the fifth pipeline and located between the second high-pressure displacement pump and the sixth valve. The sixth through-hole is connected to a gas-liquid mixing pipeline via a sixth pipeline, and the seventh valve is disposed on the sixth pipeline.

[0057] In this exemplary embodiment, grooves can be provided at both the top and bottom of the top cover. The first strong magnetic metal block is located in the groove at the top of the top cover, and the second strong magnetic metal block is located inside the groove at the bottom of the top cover. Here, the purpose of providing grooves at the top and bottom of the top cover is to reduce the distance between the strong magnetic metal blocks and increase the magnetic force between the strong magnetic metal blocks, so that the drilling speed of the stepper motor is the same as the drilling speed of the hollow deposition rod. At the same time, the bottom groove can fix the metal bearing.

[0058] In this exemplary embodiment, the measurement system may include a seventh pipeline, an eighth valve, a gas meter, an analytical balance, and a capped collection bottle. The capped collection bottle is placed on the analytical balance. One end of the seventh pipeline is connected to the gas-liquid mixing pipeline, and the other end extends into the capped collection bottle. The eighth valve is located on the seventh pipeline. The gas meter is connected to the capped collection bottle via the eighth pipeline to measure the gas in the experimental fluid.

[0059] Figure 1 A schematic diagram of the structure of a dynamic wellbore scaling measurement device according to an exemplary embodiment of the present invention is shown. Figure 2 It shows Figure 1 Schematic diagram of the top cover structure; Figure 3 It shows Figure 2 Top view; Figure 4 It shows Figure 2The left view; Figure 5 A schematic diagram of a hollow deposition rod structure according to an exemplary embodiment of the present invention is shown; Figure 6 It shows Figure 5 Top view; Figure 7 A schematic diagram of an annular scale inhibitor plate structure of an exemplary embodiment of the present invention is shown; Figure 8 It shows Figure 7 Top view; Figure 9 A scaling amount curve of an exemplary embodiment of the present invention is shown.

[0060] In a second exemplary embodiment of the present invention, as Figure 1 As shown, the dynamic measurement device for wellbore scaling includes a reaction vessel system, a rotating scaling system, a sample preparation system, and a measurement system.

[0061] The reactor system may include a reactor, a temperature control box 14, a first valve 1, and a back pressure control and filtration unit. The reactor is vertically installed inside the temperature control box, which controls the internal temperature of the reactor, i.e., the temperature of the experimental fluid.

[0062] The reactor includes a top cover 6, a vessel body 13, and a bottom cover 15. For example... Figure 1 , Figure 2 , Figure 4 As shown, the top cover 6 is provided with a mounting hole 2, which facilitates the disassembly and installation of the top cover from the vessel body. Correspondingly, as... Figure 1 As shown, the bottom cover can also be provided with a mounting hole to facilitate the disassembly and installation of the bottom cover and the vessel body. Furthermore, as... Figure 2 and Figure 3 As shown, the top cover also has a through hole 49, corresponding to, as Figure 1 As shown, a second through hole 50 is also provided on the bottom cover. The first through hole and the second through hole are respectively connected to the first pipeline 40 and the second pipeline 41. The first valve 1 is provided on the first pipeline 40, and the experimental fluid is delivered into the reactor through the first pipeline by controlling the first pipeline.

[0063] The vessel body is a hollow cylinder with smooth inner walls. For example... Figure 1 As shown, the annular scale inhibitor plate 12 is fixedly installed on the inner wall surface of the reactor to keep the inner wall of the reactor smooth and prevent the formation of inorganic salt scale on the inner wall surface and the bottom of the reactor. Figure 7 and 8 As shown, the annular scale inhibitor plate 12 has through holes at corresponding positions on the inner wall of the reactor, corresponding to the second through holes, connecting to the second pipeline. Here, the annular scale inhibitor plate can be made of a smooth inorganic non-metallic material, which will not adsorb scale-forming ions, so that the crystal nuclei of inorganic salt scale cannot be generated on the reactor wall and bottom, but only on the hollow deposition rod.

[0064] In this embodiment, as Figure 1 As shown, the back pressure control and filtration unit includes a second valve 16, a high-pressure filter element 17, a back pressure controller 19, and a collection bottle 20. Specifically, the back pressure control and filtration unit is connected to a second through hole on the bottom cover via a second pipeline 41. The collection bottle is located at the end of the second pipeline. The back pressure controller is located between the high-pressure filter element and the collection bottle. The second valve is located between the high-pressure filter element and the second through hole. Furthermore, the front and rear ends of the high-pressure filter element are connected to the second pipeline via a high-pressure flange 18.

[0065] In this embodiment, as Figure 1 As shown, the rotating scaling system includes a motor 3, a support frame 5, a first strong magnetic metal block 4, a second strong magnetic metal block 9, a metal-sealed bearing 8, and a hollow deposition rod 10. The support frame is fixedly mounted on the upper surface of the top cover, and the motor 3 is mounted on the support frame with its output end facing downwards. The first strong magnetic metal block is fixedly connected to the output shaft of the motor. Here, the motor can be a stepper motor. Further, a groove is formed at the upper end of the top cover, and the support frame is fixed above the groove. The first strong magnetic metal block is located in the groove at the upper end of the top cover. The metal-sealed bearing and the second strong magnetic metal block are located in the groove at the lower end of the top cover, and the hollow deposition rod is coaxially arranged with the motor. Specifically, the metal-sealed bearing is fixedly connected to the lower end of the top cover. The upper end of the second strong magnetic metal block is sealed and fixedly connected to the metal bearing. Figure 5 and Figure 6 As shown, the hollow deposition rod 10 is a hollow cylinder with its upper end fixedly connected to the lower end of the second strong magnetic metal block. The hollow deposition rod is coaxially arranged with the motor. During the operation of the rotary scaling system, the motor drives the first strong magnetic metal block to rotate. The first strong magnetic metal block drives the second strong magnetic metal block to rotate. The second strong magnetic metal block drives the rotating shaft of the hollow deposition rod to rotate. The stirring block of the hollow deposition rod stirs and shears the experimental fluid in the reactor to simulate the fluid flow in a well. In particular, the hollow deposition rod is lightweight, and the surface roughness can be determined by the selected material. In addition, when the rotary scaling device lacks a motor and cannot generate flow conditions, the hollow deposition rod can be rotated manually by rotating the first metal block. Alternatively, the reactor can be placed on a rotating support, and the reactor can be manually tilted up and down to make the experimental fluid flow up and down, thus achieving the purpose of dynamic experimentation.

[0066] Furthermore, such as Figure 1 As shown, the rotating scaling system may further include a rubber pad 7 and a temperature sensor 11. The rubber pad is positioned between the top cover and the metal-sealed bearing to reduce vibration. The temperature sensor is fixedly mounted on the reactor body to measure the internal temperature of the reactor.

[0067] In this embodiment, as Figure 1As shown, the sample preparation system is connected to the reactor system to supply experimental fluid to the reactor. The sample preparation system includes a first sample preparation unit, a second sample preparation unit, a gas-liquid mixing pipeline 48, and a third valve 37. The sample preparation system is used to supply experimental fluid with a predetermined pressure, flow rate, and gas-liquid ratio to the reactor. The third valve is located on the gas-liquid mixing pipeline to control its opening and closing. The first and second sample preparation units are each connected to one end of the gas-liquid mixing pipeline, and the other end of the gas-liquid mixing pipeline is connected to the first pipeline. Here, the first and second sample preparation units can be connected to the gas-liquid mixing pipeline via a first tee 36.

[0068] Furthermore, such as Figure 1 As shown, the first sample preparation unit includes a first high-pressure displacement pump 29, a first pressure gauge 30, a fourth valve 28, a first intermediate container 32, and a fifth valve 33. A third through-hole 51 is provided at the top of the first intermediate container, and correspondingly, a fourth through-hole 52 is provided at the bottom of the first intermediate container. The third through-hole is connected to a gas-liquid mixing pipeline via a fourth pipe 43, and the fifth valve 33 is provided on the fourth pipe. The fourth through-hole is connected to the first high-pressure displacement pump via the third pipe 42, and the fourth valve is located between the fourth through-hole and the first high-pressure displacement pump. The first pressure gauge 30 is located between the first high-pressure displacement pump and the fourth valve. Furthermore, a ninth valve 31 may also be provided between the fourth through-hole and the fourth valve. Here, during the use of the first high-pressure displacement pump, because its piston movement range is limited, in high-pressure experiments, there may be situations where a single pressurization cannot reach the experimental pressure. In this case, it is necessary to close the ninth valve and the fourth valve to allow the piston of the first high-pressure displacement pump to reset, and the pressure of the first high-pressure displacement pump to zero. During the secondary pressurization process, in order to avoid a decrease in pressure in the first intermediate container 32, the fourth valve needs to be opened first to make the pressure in the third pipeline 42 equal to that in the first intermediate container 32, and then the ninth valve is opened to pressurize the first intermediate container 32 to reach the experimental pressure.

[0069] The second sample preparation unit includes a second high-pressure displacement pump 27, a second pressure gauge 26, a sixth valve 25, a second intermediate container 34, and a seventh valve 35. For example... Figure 1As shown, the top of the second intermediate container 34 is provided with a sixth through hole 54, and correspondingly, the bottom of the second intermediate container is provided with a fifth through hole 53. Further, the sixth through hole 54 is connected to the gas-liquid mixing pipeline 48 through a sixth pipeline 45, and a seventh valve is provided on the sixth pipeline. The fifth through hole 53 is connected to the second high-pressure displacement pump 27 through the fifth pipeline 44, and the sixth valve is located between the fifth through hole and the second high-pressure displacement pump. A second pressure gauge is located between the second high-pressure displacement pump and the sixth valve. In addition, a tenth valve 24 is also provided between the fifth through hole and the sixth valve. Here, in the high-pressure experiment, if a single pressurization fails to reach the experimental pressure, the tenth and sixth valves need to be closed to allow the piston of the second high-pressure displacement pump to reset, bringing the pressure of the second high-pressure displacement pump to zero. During the second pressurization process, to prevent a pressure drop in the second intermediate container 34, the fourth valve needs to be opened first to make the pressure in the fifth pipeline 44 equal to that in the second intermediate container 34, and then the ninth valve is opened to pressurize until the pressure in the second intermediate container 34 reaches the experimental pressure.

[0070] In this embodiment, as Figure 1 As shown, the measurement system includes a seventh pipeline 46, an eighth valve 38, an eighth pipeline 47, a gas meter 21, an analytical balance 22, and a capped collection bottle 23. The seventh pipeline is connected to the gas-liquid mixing pipeline, i.e., to the sample preparation system. Here, the seventh pipeline and the gas-liquid mixing pipeline are connected via a second tee 39. The eighth valve is located on the seventh pipeline, and the other end of the seventh pipeline is connected to the capped collection bottle, with the seventh pipeline extending into the capped collection bottle. An analytical balance is installed at the lower end of the capped collection bottle to weigh the amount of liquid in the experimental fluid. The eighth pipeline connects the capped collection bottle to the gas meter. Specifically, one end of the eighth pipeline extends slightly into the capped collection bottle. The gas meter measures the gas content in the experimental fluid.

[0071] In a third exemplary embodiment of the present invention, the dynamic method for measuring wellbore scaling is implemented using any one of the dynamic measuring devices for wellbore scaling described in the first or second exemplary embodiments. Specifically, the measuring steps include:

[0072] The experimental fluid was prepared according to the actual gas and water conditions on site using the sample preparation system, and the experimental fluid was pressurized to the predetermined pressure and kept at a constant pressure.

[0073] The inside of the reactor is evacuated to a vacuum. Here, the vacuum is achieved by connecting an external vacuum pump.

[0074] The experimental fluid in the sample preparation system is pumped into the reactor at constant pressure. When the experimental set pressure Pi reaches the predetermined value, the sample transfer is stopped.

[0075] The back pressure controller applies back pressure Ph inside the reactor, making the back pressure Ph equal to the experimental set pressure Pi; the temperature control box is turned on, and the experimental set temperature Ti is adjusted to the predetermined temperature and maintained at a constant temperature.

[0076] Start the rotating scaling system and adjust the hollow deposition rod to rotate at a predetermined speed v, so that the inorganic salt scale in the experimental fluid in the reactor is fully deposited on the hollow deposition rod.

[0077] Shut down the temperature control box and the rotating scaling system, reduce the back pressure Ph, and drain all the experimental fluid from the reactor into the collection bottle. Remove the hollow deposition rod and high-pressure filter element, dry and weigh them, and calculate the amount of scaling.

[0078] In this embodiment, the first intermediate container stores oil or gas, and the second intermediate container stores formation water. The experimental fluid is prepared in the first intermediate container, and the sample is transferred to the reaction vessel by a first sample preparation unit. Specifically, the formation water includes formation water from water-producing oil and gas wells that is at risk of scaling.

[0079] In this embodiment, after the experimental fluid is prepared, the corresponding valves of the first preparation unit and the measurement system are opened to discharge a small portion of the experimental fluid into the measurement system. The gas volume of the experimental fluid is measured using an analytical balance and a gas meter, and the gas-to-water ratio of the experimental fluid is calculated. The gas-to-water ratio of the experimental fluid is compared with the on-site gas-to-water ratio. If the difference is large, the experimental fluid is re-prepared; if the difference is small, the next step is performed.

[0080] In this embodiment, an external vacuum pump is used to evacuate the inside of the reactor to a vacuum.

[0081] In this embodiment, the experimental steps further include cleaning the reaction vessel, changing the experimental conditions, and repeating the above experimental steps to obtain the scaling amount variation curves under different experimental conditions. The changed experimental conditions include one or more of the following: experimental set temperature Ti, experimental set pressure Pi, motor speed v, roughness μ of the hollow deposition rod, and gas-water ratio of the experimental fluid. Furthermore, the amount of scaling in the wellbore can also be affected by gas composition, such as CO2, but the gas composition is relatively constant in a specific single well, so it is not considered.

[0082] In this embodiment, the formula for calculating the amount of scaling is:

[0083]

[0084] in, Ws This refers to the amount of scale buildup, expressed in mg / L. m 1 denoted as the initial mass of the hollow deposition rod, in mg; m 2 The initial mass of the high-pressure filter element is mg.m 3 The mass of the hollow deposition rod after the experiment is in mg. m 4 The mass of the high-pressure filter element after the experiment is in mg. V Let L be the volume of the reactor.

[0085] Furthermore, by combining the relevant temperature, pressure, fluid velocity, surface roughness of the hollow deposition rod, and gas-water ratio, an empirical formula for wellbore scaling amount is obtained.

[0086] An empirical formula for the amount of scale buildup in wellbore is obtained by comprehensively considering factors such as temperature, pressure, fluid velocity, surface roughness, and gas-water ratio.

[0087] In this embodiment, the experimental setting temperature is room temperature to 200°C, the experimental setting pressure is 0.1 to 100 MPa, and the gas-to-water ratio of the experimental fluid is 1000 to 20000 m³ / s. 3 / m 3 .

[0088] In this embodiment, the dynamic method for scale formation in wellbore also includes an operation step of the experimental apparatus, which includes:

[0089] The oil or gas in the first intermediate container is mixed with the formation water in the second intermediate container and pressurized to the experimentally set pressure. However, the invention is not limited to this; the oil or gas in the first intermediate container and the formation water in the second intermediate container can also be pumped simultaneously into a sealed container for mixing. For example, a mixing container can be installed on a gas-liquid mixing pipeline.

[0090] The experimental fluid in the second intermediate container was pressurized and transferred to the reaction vessel. The temperature control chamber and hollow deposition rod were started, and the scaling experiment was carried out at the set temperature and rotation speed.

[0091] All experimental fluid was drained from the reactor. The hollow deposition rod and high-pressure filter element were removed, dried, weighed, and the amount of scale was calculated.

[0092] like Figure 9 As shown, the amount of scale buildup in the wellbore was measured under three pressure conditions (13.87 MPa, 33.87 MPa, and 53.87 MPa) and two temperature conditions (108.15℃, 123.15℃, and 138.15℃). Figure 9 It is known that, at the same temperature, the lower the pressure, the higher the scale formation. At the same pressure, the higher the temperature, the higher the scale formation. The results indicate that this invention can accurately measure the amount of scale formation in wellbore under high pressure and high temperature conditions.

[0093] In summary, the advantages proposed by this invention include at least the following:

[0094] (1) The present invention provides an empirical formula for the amount of scale in a water-producing gas well that can accurately measure the scale under different temperatures, pressures, flow rates and surface roughnesses. By fitting the experimental data, an empirical formula for the amount of scale in the wellbore that comprehensively considers the factors of temperature, pressure, fluid flow rate, surface roughness and gas-water ratio is obtained. This also provides the present invention with an accurate measurement capability, which is more effective in guiding on-site production.

[0095] (2) The rotating scaling system designed based on the principle of electromagnetic stirrer in this invention can conduct dynamic experiments and also avoids the occurrence of sealing failure;

[0096] (3) The annular scale inhibitor plate of the present invention can effectively prevent inorganic salt scale from depositing on the reactor wall and bottom, thus ensuring the accuracy of scale measurement.

[0097] Although the device and method for dynamically measuring scale in wellbore of the present invention have been described above in conjunction with exemplary embodiments, those skilled in the art should understand that various modifications and changes can be made to the exemplary embodiments of the present invention without departing from the spirit and scope defined by the claims.

Claims

1. A device for dynamically measuring the amount of scale buildup in wellbore, characterized in that, The dynamic measuring device includes a reaction vessel system, a rotating scaling system, a sample preparation system, and a measuring system, wherein... The reactor system includes a first valve, a reactor, a temperature control box, and a back pressure control and filtration unit. The reactor includes a top cover, a bottom cover, and a reactor body. The reactor body is a vertically oriented hollow cylinder. The top and bottom covers are fixedly and sealed to the upper and lower ends of the reactor body, respectively. The top and bottom covers are respectively provided with a first through hole and a second through hole. The first valve is connected to the first through hole via a first pipe to supply experimental fluid to the reactor body. The back pressure control and filtration unit is connected to the second through hole via a second pipe to control the back pressure of the reactor and collect inorganic scale from the discharged experimental fluid. The reactor is housed in the temperature control box, which controls the internal temperature of the reactor. The reactor system also includes an annular scale inhibitor plate, which is installed on the inner wall of the reactor to prevent scale formation from the experimental fluid. The annular scale inhibitor plate is made of a smooth inorganic non-metallic material. The back pressure control and filtration unit includes a second valve, a high-pressure filter element, a back pressure controller, and a liquid collection bottle. The liquid collection bottle is connected to the second through hole through a second pipeline. The second valve is located between the back pressure controller and the second through hole. The high-pressure filter element is located between the second valve and the liquid collection bottle. The back pressure controller is located between the high-pressure filter element and the liquid collection bottle. The rotating scaling system includes a motor, a support frame, a first strong magnetic metal block, a second strong magnetic metal block, a metal-sealed bearing, and a hollow deposition rod. The support frame fixes the motor to the top of the top cover with the motor's output shaft pointing vertically downward. The first strong magnetic metal block is fixedly mounted on the motor's output shaft. The metal-sealed bearing, the second strong magnetic metal block, and the hollow deposition rod are all located inside the vessel body. The second strong magnetic metal block is rotatably connected to the lower end of the top cover via the metal-sealed bearing. The upper end of the hollow deposition rod is fixedly connected to the lower end of the second strong magnetic metal block. The sample preparation system is connected to the reaction vessel system and is capable of supplying experimental fluids with predetermined pressure, flow rate, and gas-liquid ratio to the reaction vessel. The sample preparation system includes a first sample preparation unit and a second sample preparation unit. The first sample preparation unit is equipped with a first intermediate container, which stores oil or gas. The second sample preparation unit is equipped with a second intermediate container, which stores formation water. The measurement system is connected to the sample preparation system to measure the gas-liquid ratio of the experimental fluid.

2. The device for dynamically measuring scale in wellbore according to claim 1, characterized in that, The top cover and bottom cover are fixedly and sealed to the vessel body by threads, and the top cover and bottom cover are also provided with loading and unloading holes for easy disassembly and installation.

3. The dynamic measuring device for wellbore scaling according to claim 1, characterized in that, The sample preparation system further includes a gas-liquid mixing pipeline and a third valve. The first sample preparation unit and the second sample preparation unit are respectively connected to one end of the gas-liquid mixing pipeline, and the other end of the gas-liquid mixing pipeline is connected to the first pipeline. The third valve is installed on the gas-liquid mixing pipeline.

4. The dynamic measuring device for wellbore scaling according to claim 1, characterized in that, The first sample preparation unit further includes a first high-pressure displacement pump, a first pressure gauge, a fourth valve, and a fifth valve. The first intermediate container has a third through hole and a fourth through hole at its top and bottom, respectively. The first high-pressure displacement pump is connected to the fourth through hole through a third pipeline. The fourth valve is located on the third pipeline. The first pressure gauge is located on the third pipeline and between the first high-pressure displacement pump and the fourth valve. The third through hole is connected to a gas-liquid mixing pipeline through the fourth pipeline. The fifth valve is located on the fourth pipeline. The second sample preparation unit further includes a second high-pressure displacement pump, a second pressure gauge, a sixth valve, and a seventh valve. The second intermediate container has a fifth through hole at the top and a sixth through hole at the bottom. The second high-pressure displacement pump is connected to the fifth through hole through a fifth pipeline. The sixth valve is located on the fifth pipeline. The second pressure gauge is located on the fifth pipeline and between the second high-pressure displacement pump and the sixth valve. The sixth through hole is connected to the gas-liquid mixing pipeline through the sixth pipeline. The seventh valve is located on the sixth pipeline.

5. The dynamic measuring device for wellbore scaling according to claim 1, characterized in that, The top and bottom of the top cover are provided with grooves, and the first strong magnetic metal block and the second strong magnetic metal block are located inside the grooves.

6. The dynamic measuring device for wellbore scaling according to claim 3, characterized in that, The measurement system includes a seventh pipeline, an eighth valve, an eighth pipeline, a gas meter, an analytical balance, and a capped collection bottle. The capped collection bottle is placed on the analytical balance. One end of the seventh pipeline is connected to the gas-liquid mixing pipeline, and the other end extends into the capped collection bottle. The eighth valve is located on the seventh pipeline. The gas meter is connected to the capped collection bottle through the eighth pipeline to measure the gas in the experimental fluid.

7. A method for dynamically determining the amount of scale buildup in a wellbore, characterized in that, The measurement method is implemented using the dynamic wellbore scaling measurement device as described in any one of claims 1 to 6, and the measurement method includes the following steps: Turn on the sample preparation system to prepare the experimental fluid according to the actual on-site air-water ratio of the experimental sample, pressurize it to the experimental set pressure value and maintain it; Evacuate the inside of the reactor, pump the experimental fluid into the reactor, and stop pumping the experimental fluid when the pressure in the reactor reaches the experimental set value. Turn on the back pressure controller to apply back pressure to the reactor, making the back pressure equal to the experimental set pressure; turn on the temperature control box to make the temperature in the reactor equal to the experimental set temperature and maintain the temperature. Start the rotating scaling system to make the hollow deposition rod rotate at the experimentally set speed, so that the inorganic salt scale in the experimental fluid in the reactor can be fully deposited on the hollow deposition rod; Turn off the rotating scaling system and temperature control box, and reduce the back pressure to allow all the experimental fluid in the reactor to enter the collection bottle; Remove the hollow deposition rod and high-pressure filter element, dry them, weigh them, and calculate the amount of scaling in the experimental fluid. The amount of scaling is calculated using Equation 1, which is: in, W s This refers to the amount of scale buildup, expressed in mg / L. m 1 denoted as the initial mass of the hollow deposition rod, in mg; m 2 The initial mass of the high-pressure filter element is mg. m 3 The mass of the hollow deposition rod after the experiment is in mg. m 4 The mass of the high-pressure filter element after the experiment is in mg. V Let L be the volume of the reactor.

8. The method for dynamically determining the amount of scale buildup in a wellbore according to claim 7, characterized in that, The method also includes using a detection system to check whether the gas-water ratio of the experimental fluid prepared by the sample preparation system is qualified; if it is qualified, the experiment continues; if it is not qualified, the sample is prepared again.

9. The method for dynamically determining the amount of scale buildup in a wellbore according to claim 7, characterized in that, The method further includes cleaning the reaction vessel, changing the experimental conditions, repeating the experiment, measuring the amount of scaling under different experimental conditions, and plotting the scaling amount change curves under different experimental conditions. The changing experimental conditions include changing at least one of the following: experimental temperature, experimental test pressure, motor speed, roughness of the hollow deposition rod, and gas-water ratio of the experimental fluid.

10. The method for dynamically determining the amount of scale buildup in a wellbore according to claim 7, characterized in that, The method also includes fitting experimental data to obtain an empirical formula for wellbore scaling amount that comprehensively considers factors such as temperature, pressure, fluid flow rate, surface roughness, and gas-water ratio.

11. The method for dynamically determining the amount of scale buildup in a wellbore according to claim 7, characterized in that, The experimental setup included a temperature range of room temperature to 200°C, a pressure range of 0.1 to 100 MPa, and a gas-to-water ratio of 1000 to 2000 m³ / s. 3 / m 3 .

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