Gas well dosing device and dosing method

Abstract

The invention discloses a gas well dosing device and method, and belongs to the technical field of shale gas exploitation, and the gas well dosing device comprises a box body and a pressurization assembly. A containing cavity is formed in the box body, the box body comprises a discharging port and at least two feeding ports, the feeding ports are formed in the top side of the box body and communicate with the containing cavity, and the discharging port is formed in the bottom side of the box body and communicates with the containing cavity; a control valve is arranged at the discharge port and can control the discharge port to be opened or closed; the pressurizing assembly is arranged on the box body and communicates with the containing cavity, and the pressurizing assembly can inject gas into the containing cavity to increase the pressure in the box body. The gas well dosing method is applied to the gas well dosing device, and the gas well dosing process is achieved. During use, gas is injected into the containing cavity through the pressurizing assembly to increase the pressure in the box body, and under the action of the gravity of water flow and the air pressure, the solid corrosion inhibitor and water flow into a shaft of a gas well through the discharging port, so that corrosion protection on the whole shaft is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of shale gas exploitation, and in particular to a gas well dosing device and a dosing method. Background Art

[0002] Shale gas is an important unconventional natural gas resource, and its exploitation is of great significance to energy supply. However, there are a series of technical problems in the exploitation of shale gas, one of which is the accumulation of liquid and solid impurities in the well, which leads to corrosion of well equipment and degradation of its performance.

[0003] In order to solve the above problems, shale gas wells must be treated by adding chemicals regularly. The chemicals added to conventional gas wells are liquid corrosion inhibitors to remove impurities and maintain equipment in the well. However, in order to maintain the concentration of liquid corrosion inhibitor in the wellbore above a specific value, it is necessary to continuously add liquid corrosion inhibitors, resulting in high investment costs and great safety and environmental risks. Since the diffusion range of liquid corrosion inhibitors in the wellbore after addition is limited, it is impossible to effectively protect the entire wellbore, and the anti-corrosion effect is poor. The current solution is to add small-particle solid corrosion inhibitors. Solid corrosion inhibitors have the advantages of long single-addition action time and full wellbore protection. When added, the solid corrosion inhibitor is mixed with water, and the solid corrosion inhibitor is driven by the water flow to settle to the target position of the wellbore, and is slowly dissolved and released to protect the entire wellbore from corrosion.

[0004] Since the storage of natural gas in shale rocks results in high pressure at the wellhead, traditional dosing devices are usually unable to withstand the high pressure at the wellhead, making it difficult to add liquid corrosion inhibitors and solid corrosion inhibitors. Summary of the invention

[0005] The purpose of the present invention is to provide a gas well dosing device to solve the technical problem in the prior art that the wellhead pressure of the gas well is too high, which makes it difficult to add chemicals.

[0006] As conceived above, the technical solution adopted by the present invention is:

[0007] A gas well dosing device, comprising:

[0008] A box body, a containing cavity is formed inside the box body, the box body comprises a discharge port and at least two feed ports, the feed port is arranged on the top side of the box body and communicates with the containing cavity, the discharge port is arranged on the bottom side of the box body and communicates with the containing cavity; the discharge port is provided with a control valve, and the control valve can control the discharge port to be opened or closed;

[0009] A pressurizing component is arranged on the box body and communicated with the accommodating cavity. The pressurizing component can inject gas into the accommodating cavity to increase the pressure in the box body.

[0010] It also includes a guide component, which is arranged in the accommodating cavity and is configured to guide the materials added from the feed port to mix and flow toward the discharge port.

[0011] Wherein, the guide assembly includes a guide plate, which is located below the feed port, and the middle part of the guide plate is recessed downward to form two guide slopes, and the junction of the two guide slopes forms a guide channel, which is connected to the discharge port.

[0012] Wherein, along the direction approaching the discharge port, the guide channel gradually slopes downward.

[0013] Wherein, the included angle between the guiding inclined surface and the bottom surface of the accommodating cavity is greater than or equal to 10 degrees and less than or equal to 60 degrees.

[0014] The discharge port is circular, the guide channel is arc-shaped, the edge of the guide channel abuts against the lower edge of the discharge port, and the radius of the guide channel is equal to the radius of the discharge port.

[0015] Wherein, it also includes a pressure relief component, which is arranged on the box body and connected to the accommodating chamber. When the gas pressure in the accommodating chamber is greater than or equal to a first pressure value, the pressure relief component opens.

[0016] Among them, it also includes a moving component, the box is arranged on the moving component, and the moving component can drive the box to move on the ground.

[0017] Wherein, the moving assembly includes a support plate and moving wheels, the box body is arranged on the support plate, and the moving wheels are arranged at the bottom of the support plate.

[0018] A gas well dosing method, using the above-mentioned gas well dosing device, comprises:

[0019] Step 1: Connect the discharge port to the wellbore of the gas well;

[0020] Step 2: Add the solid corrosion inhibitor into the containing chamber through the feed port. After the solid corrosion inhibitor is added, add water into the containing chamber through the feed port, and close all the feed ports.

[0021] Step 3: Start the pressurizing component and inject gas into the accommodating cavity through the pressurizing component to increase the pressure in the box;

[0022] Step 4: After the pressure in the box is greater than the pressure in the gas well, open the control valve to allow the solid corrosion inhibitor and water to flow into the wellbore of the gas well through the outlet.

[0023] Beneficial effects of the present invention:

[0024] The gas well dosing device proposed in the present invention is, when in use, connected with the discharge port and the wellbore of the gas well; solid corrosion inhibitor and water are added into the box body through the feed port; then the pressurizing component is started, and gas is injected into the accommodating cavity through the pressurizing component to increase the pressure in the box body; after the pressure in the box body is greater than the pressure in the gas well, the control valve is opened, and under the action of the gravity of the water flow and the air pressure, the solid corrosion inhibitor and water flow into the wellbore of the gas well through the discharge port, so as to realize corrosion protection for the entire wellbore, thereby avoiding the technical problem of difficulty in adding the agent due to excessive wellhead pressure of the wellbore. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of a gas well dosing device provided in an embodiment of the present invention;

[0026] Figure 2 is a structural cross-sectional view of a gas well dosing device provided by an embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of the structure of the guide assembly provided in an embodiment of the present invention.

[0028] In the figure:

[0029] 10. Box body; 11. Accommodating chamber; 12. Feed inlet; 13. Discharge outlet; 14. Sealing cover; 141. Holding handle; 15. Control valve;

[0030] 20. Pressurizing assembly; 21. Air pump; 22. Air intake pipe;

[0031] 30. guide assembly; 31. guide plate; 32. guide channel;

[0032] 40. Pressure relief assembly;

[0033] 50. Moving assembly; 51. Support plate; 52. Moving wheel; 53. Push handle; 54. Locking part. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0035] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0037] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0038] The embodiment of the present invention provides a gas well dosing device, which enables a chemical to flow smoothly into a gas well by pressurizing the chemical, so as to achieve corrosion protection for the gas well.

[0039] See also Figure 1 and Figure 2 An embodiment of the present invention provides a gas well dosing device, including a casing 10 and a pressurizing assembly 20, wherein a containing chamber 11 is formed inside the casing 10, the casing 10 includes a discharge port 13 and at least two feed ports 12, the feed port 12 is arranged on the top side of the casing 10 and communicated with the containing chamber 11, the discharge port 13 is arranged on the bottom side of the casing 10 and communicated with the containing chamber 11; the discharge port 13 is provided with a control valve 15, the control valve 15 can control the discharge port 13 to be opened or closed; the pressurizing assembly 20 is arranged on the casing 10 and communicated with the containing chamber 11, the pressurizing assembly 20 can inject gas into the containing chamber 11 to increase the pressure inside the casing 10.

[0040] When in use, the discharge port 13 is connected to the wellbore of the gas well; solid corrosion inhibitor and water are added into the box body 10 through the feed port 12; then the pressurizing component 20 is started, and gas is injected into the accommodating chamber 11 through the pressurizing component 20 to increase the pressure in the box body 10; after the pressure in the box body 10 is greater than the pressure in the gas well, the control valve 15 is opened, and under the action of the gravity of the water flow and the air pressure, the solid corrosion inhibitor and water flow into the wellbore of the gas well through the discharge port 13 to achieve corrosion protection for the entire wellbore, thereby avoiding the technical problem of difficulty in adding the agent due to excessive wellhead pressure in the wellbore.

[0041] It is worth noting that due to the storage of natural gas in the gas well, high pressure is formed at the wellhead. In order to prevent the high pressure at the wellhead from affecting the dosing process, before adding the drug, the control valve 15 is first closed to put the discharge port 13 in a closed state, thereby facilitating the delivery of the agent into the box 10.

[0042] When adding the medicine, since the solid corrosion inhibitor and water need to be added separately into the box 10, at least two feed ports 12 are required for respectively adding. In some embodiments, three or four feed ports 12 can be provided according to the required proportion of solid corrosion inhibitor and water. In this embodiment, two feed ports 12 are provided, and the two feed ports are respectively a medicine adding port and a water adding port. When in use, the water pipe can be connected to the water adding port to facilitate adding water into the box 10. In order to prevent impurities from entering the box 10 and affecting the effect of the medicine, a sealing cover 14 is detachably provided on the medicine adding port, and a gripping handle 141 is provided on the sealing cover 14. When adding medicine, the operator removes the sealing cover 14 by gripping the handle 141, and adds medicine to the box 10 through the medicine adding port; after the addition of medicine is completed, the operator seals the medicine adding port through the sealing cover 14 to prevent impurities from entering the box 10.

[0043] Regarding the pressurizing component 20, in this embodiment, an air pump 21 is selected as the pressurizing component 20. In order to facilitate disassembly and assembly, the air pump 21 is arranged on the top of the box body 10, and an air inlet pipe 22 is arranged on the air pump 21, and the air inlet pipe 22 is connected to the accommodating chamber 11. When in use, the air pump 21 inputs gas into the accommodating chamber 11 through the air inlet pipe 22, thereby increasing the pressure in the accommodating chamber 11. It can be understood that the air pump 21 is a common mechanical device in the mechanical field, and its specific structure and principle are not described in detail here.

[0044] For the convenience of observation, generally speaking, a first pressure gauge is provided in the wellhead, and a second pressure gauge is provided in the accommodating chamber 11. Herein, it is defined that the value measured by the first pressure gauge is the wellhead pressure value, and the value measured by the second pressure gauge is the pressure value of the box 10. When in use, the operator starts the air pump 21, compresses the air in the outside atmosphere through the air pump 21, and inputs it into the accommodating chamber 11 through the air inlet pipe 22, so that the air pressure in the accommodating chamber 11 is large, and observes the readings of the two pressure gauges at the same time. When the pressure value of the box 10 is greater than the wellhead pressure value, it indicates that the pressure in the box 10 is greater than the pressure at the wellhead. At this time, the air pump 21 can be turned off, the air supply to the accommodating chamber 11 is stopped, and the control valve 15 is opened. Since the pressure in the box 10 is greater than the pressure at the wellhead, under the action of the gravity of the water flow and the air pressure, the solid corrosion inhibitor and water can easily flow into the wellbore of the gas well through the discharge port 13 to achieve a protective effect.

[0045] In order to facilitate the effective flow of the added reagent to the discharge port 13, the gas well dosing device further includes a guide assembly 30, which is disposed in the accommodating chamber 11 and is configured to guide the materials added from the feed port 12 to mix and flow to the discharge port 13. The guide assembly 30 may be a pipe, a groove, etc., and it is only necessary to ensure that the reagents in the feed port 12 can be mixed and guided to the discharge port 13, thereby avoiding excessive reagents remaining on the inner wall of the accommodating chamber 11 and affecting the corrosion inhibition effect.

[0046] See also Figure 2 and Figure 3 The guide assembly 30 includes a guide plate 31, which is located below the feed port 12. The middle of the guide plate 31 is recessed downward to form two guide slopes. The intersection of the two guide slopes forms a guide channel 32, which is connected to the discharge port 13. The guide plate 31 has a larger contact area, which can guide more medicines and improve the delivery rate of the medicines. The middle recess and guide slope of the guide plate 31 can help guide the medicines to the discharge port 13, thereby achieving accurate guidance and positioning, and improving the delivery efficiency of the medicines.

[0047] In order to obtain a better guiding effect, in this embodiment, the discharge port 13 is circular, the guiding channel 32 is arc-shaped, the edge of the guiding channel 32 abuts against the lower edge of the discharge port 13, and the radius of the guiding channel 32 is equal to the radius of the discharge port 13. This allows the guiding channel 32 to completely fit with the discharge port 13, facilitates the outflow of the agent from the discharge port 13, improves the guiding efficiency, and prevents the solid corrosion inhibitor from being blocked.

[0048] Furthermore, the guide channel 32 gradually tilts downward in the direction close to the discharge port 13, thereby increasing the flow rate of the reagent, reducing the reagent residue on the guide plate 31, and improving the drainage efficiency; at the same time, the solid corrosion inhibitor is easy to flow and not prone to clogging.

[0049] The four sides of the guide plate 31 are connected to the inner wall of the accommodating chamber 11, the end of the guide plate 31 is at a higher position, the middle of the guide plate 31 is at a lower position and is flush with the lower edge of the discharge port 13, and the two sides of the guide plate 31 gradually tilt downward from the end to the middle to facilitate the flow of the medicine into the guide channel 32 located in the middle.

[0050] Specifically, the angle between the guiding inclined surface and the bottom surface of the accommodating cavity 11 is greater than or equal to 10 degrees and less than or equal to 60 degrees, so that the agent on the guide plate 31 flows evenly and obtains a better guiding effect. This prevents the angle from being too small, causing the agent to flow slowly and affecting the drainage effect; or the angle from being too large, resulting in an excessively high flow rate, and the solid corrosion inhibitor is easily accumulated at the discharge port 13 to cause blockage.

[0051] In some cases, if the discharge port 13 is blocked, the medicine in the box 10 cannot flow out, which will gradually increase the pressure in the accommodating chamber 11. In order to avoid the box 10 bursting due to excessive pressure, causing damage to the device and endangering the safety of the staff, the gas well dosing device proposed in this embodiment also includes a pressure relief component 40, which is arranged on the box 10 and connected to the accommodating chamber 11. When the gas pressure in the accommodating chamber 11 is greater than or equal to the first pressure value, the pressure relief component 40 is opened to discharge the gas in the accommodating chamber 11 to reduce the pressure in the accommodating chamber 11. It can be understood that, in general, the gas pressure in the wellhead is relatively stable and not easy to fluctuate greatly. Therefore, the wellhead pressure value is used as a reference standard, and the first pressure value set is much greater than the wellhead pressure value, and at the same time greater than the pressure value of the box 10 under normal construction conditions, so that the pressure in the box 10 can be relieved when the pressure is too high, which plays a safety effect to ensure the safety of personnel, and will not interfere with the normal pressurization process of the box 10.

[0052] In order to facilitate the transfer and transportation of the box 10, the gas well dosing device also includes a moving assembly 50, the box 10 is arranged on the moving assembly 50, and the moving assembly 50 can drive the box 10 to move on the ground, so as to facilitate the transportation of the box 10 to the construction position. In some embodiments, the moving assembly 50 can be a crane, a slide rail, etc. In this embodiment, the moving assembly 50 includes a support plate 51 and a moving wheel 52, the box 10 is arranged on the support plate 51, and the moving wheel 52 is arranged at the bottom of the support plate 51, which has the advantages of low cost and easy disassembly and assembly. In this embodiment, the moving wheel 52 is a universal wheel, so it has a high degree of freedom and is convenient for transporting the box 10. In order to facilitate the transportation of the operator, a push handle 53 is provided on the support plate 51, which is convenient for holding and pushing the support plate 51 to move. In addition, in order to prevent the moving wheel 52 from slipping during the construction process and affecting the construction process, a locking portion 54 is provided on the moving wheel 52. After the box 10 is moved to the construction position, the moving wheel 52 is locked by the locking portion 54, thereby improving stability.

[0053] The embodiment of the present invention further provides a gas well dosing method, which uses the gas well dosing device to dosing the gas well, including:

[0054] Step 1: Connect the discharge port 13 to the wellbore of the gas well; and close the control valve 15 to ensure that the discharge port 13 is in a closed state, then connect the water pipe to the water inlet, and open the sealing cover 14.

[0055] It is understandable that before connecting the discharge port 13 to the wellbore of the gas well, the operator moves the box 10 to the construction position by pushing the moving assembly 50, and after the box 10 is placed, the discharge port 13 is connected to the wellbore of the gas well. The discharge port 13 is connected to the wellbore of the gas well through a casing.

[0056] Step 2: Add the solid corrosion inhibitor into the containing chamber 11 through the feed port 12 . After the solid corrosion inhibitor is added, add water into the containing chamber 11 through the feed port 12 , and close all the feed ports 12 .

[0057] In this step, the solid corrosion inhibitor is firstly added into the accommodating chamber 11 through the dosing port. After the solid corrosion inhibitor is added, the water pipe is opened to supply water to the accommodating chamber 11 through the water inlet. After the water volume reaches the required standard, the water pipe is closed, and the dosing port and the water inlet are closed. After the solid corrosion inhibitor and water enter the accommodating chamber 11, they flow from top to bottom into the guide channel 32 through the guide slope on the guide plate 31, and then flow to the discharge port 13 after being mixed in the guide channel 32.

[0058] Step 3: Start the pressurizing component 20 to inject gas into the accommodating chamber 11 through the pressurizing component 20 to increase the pressure in the box body 10 .

[0059] In this step, the air inlet pipe 22 of the air pump 21 is connected to the accommodating chamber 11, and the air pump 21 is turned on. The air in the external atmosphere is compressed by the air pump 21 and input into the accommodating chamber 11 through the air inlet pipe 22, so that the air pressure in the accommodating chamber 11 is high, and the readings of the first pressure gauge and the second pressure gauge are observed at the same time. When the pressure value of the box 10 is greater than the wellhead pressure value, the air pump 21 is turned off to stop supplying air to the accommodating chamber 11.

[0060] Step 4: After the pressure in the box 10 is greater than the pressure in the gas well, open the control valve 15 to allow the solid corrosion inhibitor and water to flow into the wellbore of the gas well through the discharge port 13. At this time, since the pressure in the box 10 is greater than the pressure at the wellhead, the solid corrosion inhibitor and water can easily flow into the wellbore of the gas well through the discharge port 13 under the action of the gravity of the water flow and the air pressure to achieve a protective effect.

[0061] After step 4, the method further includes step 5: when the pressure value in the box body 10 is less than or equal to the second pressure value, closing the control valve 15.

[0062] The above embodiments are only to illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications, which are 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. A gas well dosing device, It is characterized in that include: A box body (10), wherein a receiving chamber (11) is formed inside the box body (10), the box body (10) comprises a discharge port (13) and at least two feed ports (12), the feed port (12) being arranged on the top side of the box body (10) and communicating with the receiving chamber (11), the discharge port (13) being arranged on the bottom side of the box body (10) and communicating with the receiving chamber (11); the discharge port (13) is provided with a control valve (15), and the control valve (15) is capable of controlling the discharge port (13) to be opened or closed; A pressurizing component (20) is arranged on the box body (10) and is in communication with the accommodating chamber (11); the pressurizing component (20) is capable of injecting gas into the accommodating chamber (11) to increase the pressure in the box body (10).

2. The gas well dosing device according to claim 1, It is characterized in that It also includes a guide component (30), which is arranged in the accommodating cavity (11), and the guide component (30) is configured to guide the materials added from the feed port (12) to be mixed and flow toward the discharge port (13).

3. The gas well dosing device according to claim 2, It is characterized in that The guide assembly (30) comprises a guide plate (31), wherein the guide plate (31) is located below the feed port (12), wherein the middle portion of the guide plate (31) is recessed downward to form two guide inclined surfaces, wherein the junction of the two guide inclined surfaces forms a guide channel (32), and the guide channel (32) is connected to the discharge port (13).

4. The gas well dosing device according to claim 3, It is characterized in that In a direction approaching the discharge port (13), the guide channel (32) gradually slopes downward.

5. The gas well dosing device according to claim 3, It is characterized in that The included angle between the guiding inclined surface and the bottom surface of the accommodating cavity (11) is greater than or equal to 10 degrees and less than or equal to 60 degrees.

6. The gas well dosing device according to claim 3, It is characterized in that The discharge port (13) is circular, the guide channel (32) is arc-shaped, the edge of the guide channel (32) abuts against the lower edge of the discharge port (13), and the radius of the guide channel (32) is equal to the radius of the discharge port (13).

7. The gas well dosing device according to claim 1, It is characterized in that It also includes a pressure relief component (40), which is arranged on the box body (10) and connected to the accommodating chamber (11). When the gas pressure in the accommodating chamber (11) is greater than or equal to a first pressure value, the pressure relief component (40) opens.

8. The gas well dosing device according to any one of claims 1 to 7, It is characterized in that It also comprises a moving component (50), the box (10) is arranged on the moving component (50), and the moving component (50) can drive the box (10) to move on the ground.

9. The gas well dosing device according to claim 8, It is characterized in that The moving assembly (50) comprises a support plate (51) and moving wheels (52); the box body (10) is arranged on the support plate (51); and the moving wheels (52) are arranged at the bottom of the support plate (51).

10. A method for adding chemicals to a gas well. It is characterized in that The gas well dosing device used in any one of claims 1 to 9 comprises: Step 1: Connect the discharge port (13) to the wellbore of the gas well; Step 2: Add the solid corrosion inhibitor into the containing chamber (11) through the feed port (12). After the solid corrosion inhibitor is added, add water into the containing chamber (11) through the feed port (12), and close all the feed ports (12); Step 3: starting the pressurizing component (20) to inject gas into the accommodating chamber (11) through the pressurizing component (20) to increase the pressure in the box body (10); Step 4: After the pressure in the box (10) is greater than the pressure in the gas well, the control valve (15) is opened to allow the solid corrosion inhibitor and water to flow into the wellbore of the gas well through the discharge port (13).

Images