An oil production wellhead for a fracturing self-flowing well

Abstract

The present invention relates to an oil production wellhead for a fracturing self-flowing well, characterized in that it comprises a first four-way valve, a first control valve, a first throttle valve, a second four-way valve, a third control valve, and a second throttle valve; the first interface of the first four-way valve is connected to the first control valve, which is connected to the first throttle valve; the second interface of the first four-way valve is connected to the fourth interface of the second four-way valve; the third interface of the second four-way valve is connected to the third control valve, which is connected to the second throttle valve. The present invention installs a throttle valve with adjustable flow rate on the oil pipe and the annulus passage of the artesian wellhead, and adjusts the flow rate of the liquid automatically overflowing from the artesian well through the throttle valve to ensure that the rate of automatically flowing out the petroleum mixture and the rate of water in the formation penetrating into the oil layer form a balanced state, thereby achieving the maximum stable and high oil production of the oil production wellhead within a certain range over a long period of time.

Description

Technical Field

[0001] The invention belongs to the technical field of simple oil production wellhead equipment, and in particular relates to an oil production wellhead for a fracturing self-flowing well. Background Art

[0002] At present, fracturing operations play an important role in the development and transformation of oil and gas field reservoirs. Its main working principle is: using a high-pressure and large-displacement pump, and utilizing the principle of liquid pressure transmission, the fracturing fluid is injected into the formation at high pressure, and the pressure in the wellbore is gradually increased, thereby building up high pressure at the bottom of the well. When this pressure is greater than the ground stress near the well wall and the tensile strength of the formation rock, cracks are generated in the formation near the bottom of the well: the fracturing fluid is continued to be injected (the liquid is generally accompanied by fracturing sand of about 60 mesh), the cracks extend forward and are filled with proppant, thereby forming sand-filled cracks with certain geometric dimensions and high conductivity in the formation near the bottom of the well, achieving the purpose of increasing oil production and injection.

[0003] In actual production, shallow oil wells are often constructed with simple wellheads. At the production site, multiple simple wells (called satellite wells) are often drilled within a certain radius for oil production. Oilfield fracturing fluid injection, also known as water-based fracturing fluid, is a key method used during oilfield development to replenish formation energy and increase oil recovery. During oilfield development, water is injected into the reservoir through specialized injection wells to maintain or restore the reservoir's stored reservoir pressure energy potential.

[0004] In a satellite well site, injection wells are typically located near the center of the area enclosed by all satellite wells. These wells inject water into the same layers of the satellite wells that require water injection. Prior to water injection, the wellheads of the satellite wells requiring water injection must be sealed, and production can resume after the water injection is complete. Satellite wells can be divided into artesian and pumping types. Pumping wells require pumping equipment for oil production, while artesian wells do not require pumping equipment. Based on existing technical theory, to achieve maximum stable and high oil production at each satellite wellhead over a longer period of time, the oil layer pressure potential stored in the reservoir must be kept stable within a certain range to ensure that the automatically flowing petroleum mixture and the water with a certain pressure potential energy in the formation gradually infiltrate the oil layer, forming a state of equilibrium. This requires regulating the flow rate of the liquid automatically overflowing from the artesian wells. Summary of the Invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides an oil production wellhead for a fracturing self-flowing well. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] The present invention provides an oil production wellhead for a fracturing self-flowing well, comprising a first four-way valve, a first control valve, a second control valve, a first throttle valve, a second four-way valve, a third control valve, a second throttle valve, a second stop valve, a tubing hanger, a tubing double male nipple, a casing flange, a casing double male nipple, and a second plug;

[0007] The first interface of the first four-way valve is connected to the first control valve, and the first control valve is connected to the first throttle valve; the second interface of the first four-way valve is connected to the fourth interface of the second four-way valve; and the third interface of the first four-way valve is connected to the second control valve.

[0008] The fourth interface of the first cross-connection is sealedly connected to the first end of the casing flange, and the second end of the casing flange is connected to the casing double male nipple.

[0009] One end of the tubing hanger is sealed and fixedly connected to the inner wall of the second interface of the first cross-piece, and the other end is sealed and fixedly connected to the double male short section of the tubing thread.

[0010] The first interface of the second four-way valve is threadedly sealed and connected to the second stop valve, and the second interface of the second four-way valve is threadedly sealed and connected to the second plug; the third interface of the second four-way valve is connected to the third control valve, and the third control valve is connected to the second throttle valve.

[0011] In one embodiment of the present invention, the oil production wellhead for the fracturing self-flowing well further includes a first stop valve and a third stop valve. The first stop valve is arranged on the first throttle valve, and the third stop valve is arranged on the second throttle valve.

[0012] In one embodiment of the present invention, the oil production wellhead for the fracturing self-flowing well further includes a first pressure gauge and a second pressure gauge, the first pressure gauge is connected to the first shut-off valve, and the second pressure gauge is connected to the third shut-off valve.

[0013] In one embodiment of the present invention, the first control valve, the second control valve and the third control valve are all manual flat valves or manual wedge gate valves.

[0014] In one embodiment of the present invention, the first throttle valve and the second throttle valve are both manual throttle needle valves used for flow regulation of artesian wells.

[0015] In one embodiment of the present invention, the oil production wellhead for a fracturing self-flowing well also includes a connecting flange and a first plug; wherein, the connecting flange is connected to the second control valve, the first plug is sealed to the connecting flange, and the passage where the second control valve is located is connected to the annulus between the oil pipe and the casing, and the passage serves as a test passage for the wellhead status.

[0016] In one embodiment of the present invention, the connecting flange is a threaded flange or a clamp flange.

[0017] In one embodiment of the present invention, the first four-way valve and the second four-way valve are connected to the corresponding control valves by flange connection or clamp connection.

[0018] In one embodiment of the present invention, the control valve and the throttle valve are connected by flange connection or clamp connection.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The fracturing self-flowing well production wellhead of the present invention is provided with a flow-adjustable throttle valve installed on each of the oil pipe and annulus passage of the artesian wellhead. The throttle valve is used to adjust the flow rate of the liquid automatically overflowing from the artesian wellhead to ensure that the rate of automatic outflow of the petroleum mixture and the rate of water infiltration into the oil layer form a balance, thereby achieving maximum stable and high oil production from the production wellhead within a certain range over a long period of time. At the same time, by rationally setting the installation method and combination of the valves, the performance and safety of the production wellhead are met, the convenience of installation of the production wellhead is improved, and the sealing performance of the wellhead is further enhanced.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of a flange-connected fracturing and flowing wellhead provided by an embodiment of the present invention;

[0023] Figure 2 It is a structural schematic diagram of an oil production wellhead for a fracturing self-flowing well connected by a clamp provided in an embodiment of the present invention.

[0024] Icons: 1-first four-way valve; 2-first control valve; 3-second control valve; 4-first throttle valve; 401-first throttle valve core; 402-first throttle valve seat; 5-second four-way valve; 6-third control valve; 7-second throttle valve; 701-second throttle valve core; 702-second throttle valve seat; 8-first stop valve; 9-second stop valve; 10-third stop valve; 11-first pressure gauge; 12-second pressure gauge; 13-tubing hanger; 14-tubing double male short joint; 15-casing flange; 16-casing double male short joint; 17-conversion flange; 18-connecting flange; 19-first plug; 20-second plug. DETAILED DESCRIPTION

[0025] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following is a detailed description of an oil production wellhead for a fracturing self-flowing well proposed in accordance with the present invention in conjunction with the accompanying drawings and specific embodiments.

[0026] The aforementioned and other technical contents, features, and effects of the present invention are clearly presented in the following detailed description of the specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a deeper and more specific understanding of the technical means and effects adopted by the present invention to achieve the intended purpose can be obtained. However, the accompanying drawings are provided for reference and illustration purposes only and are not intended to limit the technical solutions of the present invention.

[0027] Example 1

[0028] Figure 1 The diagram is a structural diagram of a flange-connected oil production wellhead for a fracturing self-flowing well provided by an embodiment of the present invention.

[0029] As shown in the figure, this embodiment provides an oil production wellhead for a fracturing self-flowing well, including a first four-way valve 1, a first control valve 2, a second control valve 3, a first throttle valve 4, a second four-way valve 5, a third control valve 6, a second throttle valve 7, a second stop valve 9, a tubing hanger 13, a tubing double male short joint 14, a casing flange 15, a casing double male short joint 16 and a second plug 20.

[0030] The first port of the first four-way valve 1 is connected to the first control valve 2, which is connected to the first throttle valve 4. The second port of the first four-way valve 1 is connected to the fourth port of the second four-way valve 5. The third port of the first four-way valve 1 is connected to the second control valve 3.

[0031] In an optional embodiment, the first four-way valve 1 and the second four-way valve 5 can also be connected through a conversion flange 17, both ends of the conversion flange 17 are flange surfaces, one end of which is connected to the second interface of the first four-way valve 1, and the other end of the conversion flange 17 is connected to the fourth interface of the second four-way valve 5.

[0032] In this embodiment, the fourth interface of the first cross-piece 1 is sealedly connected to the first end of the casing flange 15 , and the second end of the casing flange 15 is connected to the casing double male nipple 16 .

[0033] In this embodiment, one end of the tubing hanger 13 is sealed and fixedly connected to the inner wall of the second interface of the first spool 1 , and the other end is threaded and sealed and fixedly connected to the tubing double male nipple 14 .

[0034] In this embodiment, the first interface of the second four-way valve 5 is threadedly sealed and connected to the second stop valve 9, the second interface of the second four-way valve 5 is threadedly sealed and connected to the second plug 20, the third interface of the second four-way valve 5 is connected to the third control valve 6, and the third control valve 6 is connected to the second throttle valve 7.

[0035] In this embodiment, the first cross-connection 1 and the second cross-connection 5 are connected to the corresponding control valves by flange connection.

[0036] Furthermore, the first four-way valve 1 and the second four-way valve 5 are clamped with the corresponding control valves by metal gaskets between the flanges to achieve a sealed and fixed connection.

[0037] In this embodiment, the control valve and the throttle valve are connected by flange connection.

[0038] Furthermore, the control valve and the throttle valve are sealed and fixedly connected via a flange gasket.

[0039] In an optional embodiment, when the downhole pressure is insufficient to achieve gravity flow, the second interface of the second four-way 5 can be connected to the sucker rod and related equipment as a working path for active oil pumping, thereby meeting the need for simple modification of the oil wellhead.

[0040] In this embodiment, the oil production wellhead for the fracturing self-flowing well further includes a first stop valve 8 and a third stop valve 10 . The first stop valve 8 is arranged on the first throttle valve 4 , and the third stop valve 10 is arranged on the second throttle valve 7 .

[0041] In this embodiment, the oil production wellhead for the fracturing self-flowing well further includes a first pressure gauge 11 and a second pressure gauge 12 . The first pressure gauge 11 is connected to the first stop valve 8 , and the second pressure gauge 12 is connected to the third stop valve 10 .

[0042] The pressure gauge is used to monitor the pressure in the passageway and adjust the throttle valve according to the pressure reading, thereby adjusting the passageway flow rate. The first stop valve 8, the second stop valve 9, and the third stop valve 10 are all built-in pressure relief valves. The first stop valve 8 protects the first pressure gauge 11, and the third stop valve 10 protects the second pressure gauge 12, preventing accidental damage under high pressure. If the pressure gauge needs to be replaced, close the corresponding stop valve, loosen the pressure relief screw on the stop valve, and replace the pressure gauge.

[0043] In this embodiment, the second stop valve 9 is an oil quality sampling port, also called a sampling valve.

[0044] In this embodiment, the first control valve 2 , the second control valve 3 and the third control valve 6 are all manual flat valves or manual wedge gate valves.

[0045] In this embodiment, the first throttle valve 4 and the second throttle valve 7 are both manual throttle needle valves.

[0046] In one embodiment of the present invention, the throttle valve core is set with a taper, and the first throttle valve 4 and the second throttle valve 7 both move axially through their throttle valve cores, thereby adjusting the size of the gap between the throttle valve core and the throttle valve seat to achieve flow regulation of the artesian well.

[0047] For example, the second throttle valve core 701 is tapered and moves axially, and the flow rate of the artesian well is regulated by adjusting the size of the gap between the second throttle valve core 701 and the second throttle valve seat 702 .

[0048] In this embodiment, the oil production wellhead for the fracturing self-flowing well further includes a connecting flange 18 and a first plug 19 .

[0049] Among them, the connecting flange 18 is connected to the second control valve 3, the first plug 19 is sealed with the connecting flange 18, the passage where the second control valve 3 is located is connected to the annulus between the oil pipe and the casing, and the passage serves as a test passage for the wellhead state.

[0050] In this embodiment, the connecting flange 18 is a threaded flange.

[0051] During the specific operation process, the double male short joint 14 of the oil pipe and the casing form an annular space passage running through the first four-way valve 1, the first control valve 2 and the first throttle valve 4 are sealed and connected to form a first annular space bypass passage, and the second control valve 3 forms a second annular space sealed bypass passage, wherein the second annular space sealed bypass passage serves as a test passage, and the second control valve 3 is normally closed; the double male short joint 14 of the oil pipe and the second four-way valve 5 are sealed and connected to form an oil pipe passage, and the third control valve 6 and the second throttle valve 7 are connected to form an oil pipe sealed bypass passage; when the artesian well is working, due to the water injection operation, the pressure potential energy of the downhole oil overcomes the gravity potential energy to achieve gravity flow, the first control valve 2 and the third control valve 6 are normally open, the oil flowing by gravity in the first annular space bypass passage flows through the first throttle valve 4, the pressure in the passage is measured by the first pressure gauge 11, and the flow rate of the outflowing oil is adjusted by the first throttle valve 4. The oil flowing freely in the oil pipe bypass passage passes through the second throttle valve 7. The pressure in the passage is measured by the second pressure gauge 12, and the flow rate of the outflowing oil is adjusted by the second throttle valve 7. Calculation is performed to ensure that the flow rate of the oil flowing out of the first annular bypass passage and the oil pipe bypass passage is in balance with the rate of water infiltration into the oil layer.

[0052] Example 2

[0053] Figure 2 It is a structural schematic diagram of an oil production wellhead for a fracturing self-flowing well connected by a clamp provided in an embodiment of the present invention.

[0054] As shown in the figure, this embodiment provides an oil production wellhead for a fracturing self-flowing well, including a first four-way valve 1, a first control valve 2, a second control valve 3, a first throttle valve 4, a second four-way valve 5, a third control valve 6, a second throttle valve 7, a second stop valve 9, a tubing hanger 13, a tubing double male short joint 14, a casing flange 15, a casing double male short joint 16 and a second plug 20.

[0055] The first port of the first four-way valve 1 is connected to the first control valve 2, which is connected to the first throttle valve 4. The second port of the first four-way valve 1 is connected to the fourth port of the second four-way valve 5. The third port of the first four-way valve 1 is connected to the second control valve 3.

[0056] In an optional embodiment, the first four-way valve 1 and the second four-way valve 5 can also be connected through a conversion flange 17, one end of the conversion flange 17 is a flange surface, connected to the second interface of the first four-way valve 1, and the other end of the conversion flange 17 is a sleeve, connected to the fourth interface of the second four-way valve 5.

[0057] In this embodiment, the fourth interface of the first cross-piece 1 is sealedly connected to the first end of the casing flange 15 , and the second end of the casing flange 15 is connected to the casing double male nipple 16 .

[0058] In this embodiment, one end of the tubing hanger 13 is sealed and fixedly connected to the inner wall of the second interface of the first spool 1 , and the other end is threaded and sealed and fixedly connected to the tubing double male nipple 14 .

[0059] In this embodiment, the first interface of the second four-way valve 5 is threadedly sealed and connected to the second stop valve 9, the second interface of the second four-way valve 5 is threadedly sealed and connected to the second plug 20, the third interface of the second four-way valve 5 is connected to the third control valve 6, and the third control valve 6 is connected to the second throttle valve 7.

[0060] In this embodiment, the first four-way valve 1 and the second four-way valve 5 are connected to the corresponding control valves by clamp connection.

[0061] In this embodiment, the control valve and the throttle valve are connected by a clamp connection.

[0062] In an optional embodiment, when the downhole pressure is insufficient to achieve gravity flow, the second interface of the second four-way 5 can be connected to the sucker rod and related equipment as a working path for active oil pumping, thereby meeting the need for simple modification of the oil wellhead.

[0063] In this embodiment, the oil production wellhead for the fracturing self-flowing well further includes a first stop valve 8 and a third stop valve 10 . The first stop valve 8 is arranged on the first throttle valve 4 , and the third stop valve 10 is arranged on the second throttle valve 7 .

[0064] In this embodiment, the oil production wellhead for the fracturing self-flowing well further includes a first pressure gauge 11 and a second pressure gauge 12 . The first pressure gauge 11 is connected to the first stop valve 8 , and the second pressure gauge 12 is connected to the third stop valve 10 .

[0065] The pressure gauge is used to monitor the pressure in the passageway and adjust the throttle valve according to the pressure reading, thereby adjusting the passageway flow rate. The first stop valve 8, the second stop valve 9, and the third stop valve 10 are all built-in pressure relief valves. The first stop valve 8 protects the first pressure gauge 11, and the third stop valve 10 protects the second pressure gauge 12, preventing accidental damage under high pressure. If the pressure gauge needs to be replaced, close the corresponding stop valve, loosen the pressure relief screw on the stop valve, and replace the pressure gauge.

[0066] In this embodiment, the second stop valve 9 is an oil quality sampling port, also called a sampling valve.

[0067] In this embodiment, the first control valve 2 , the second control valve 3 and the third control valve 6 are all manual flat valves or manual wedge gate valves.

[0068] In this embodiment, the first throttle valve 4 and the second throttle valve 7 are both manual throttle needle valves.

[0069] In one embodiment of the present invention, the throttle valve core is set with a taper, and the first throttle valve 4 and the second throttle valve 7 both move axially through their throttle valve cores, thereby adjusting the size of the gap between the throttle valve core and the throttle valve seat to achieve flow regulation of the artesian well.

[0070] For example, the first throttle valve core 401 is tapered and moves axially, and the flow rate of the artesian well is regulated by adjusting the size of the gap between the first throttle valve core 401 and the first throttle valve seat 402 .

[0071] In this embodiment, the oil production wellhead for the fracturing self-flowing well further includes a connecting flange 18 and a first plug 19 .

[0072] Among them, the connecting flange 18 is connected to the second control valve 3, the first plug 19 is sealed with the connecting flange 18, the passage where the second control valve 3 is located is connected to the annulus between the oil pipe and the casing, and the passage serves as a wellhead status test passage.

[0073] In this embodiment, the connecting flange 18 is a clamp flange.

[0074] During the specific operation process, the double male short joint 14 of the oil pipe and the casing form an annular space passage running through the first four-way valve 1, the first control valve 2 and the first throttle valve 4 are sealed and connected to form a first annular space bypass passage, and the second control valve 3 forms a second annular space sealing bypass passage, wherein the second annular space sealing bypass passage serves as a test passage, and the second control valve 3 is normally closed; the double male short joint 14 of the oil pipe is connected to the second four-way valve 5 to form an oil pipe sealing passage, and the third control valve 6 and the second throttle valve 7 are connected to form an oil pipe sealing bypass passage; when the artesian well is working, due to the water injection operation, the pressure potential energy of the downhole oil overcomes the gravity potential energy to achieve gravity flow, the first control valve 2 and the third control valve 6 are normally open, the oil flowing by gravity in the first annular space bypass passage flows through the first throttle valve 4, the pressure in the passage is measured by the first pressure gauge 11, and the flow rate of the outflowing oil is adjusted by the first throttle valve 4. The oil flowing freely in the oil pipe bypass passage passes through the second throttle valve 7. The pressure in the passage is measured by the second pressure gauge 12, and the flow rate of the outflowing oil is adjusted by the second throttle valve 7. Calculation is performed to ensure that the flow rate of the oil flowing out of the first annular bypass passage and the oil pipe bypass passage is in balance with the rate of water infiltration into the oil layer.

[0075] The fracturing self-flowing well production wellhead of the embodiment of the present invention installs a flow-adjustable throttle valve on each of the oil pipe and annulus passage of the artesian wellhead. The throttle valve regulates the flow rate of the liquid automatically overflowing from the artesian wellhead to ensure that the rate of automatic outflow of the petroleum mixture and the rate of water infiltration into the oil layer form a balance, thereby achieving maximum stable and high oil production from a certain range of the production wellhead over a long period of time. At the same time, by rationally setting the installation method and combination of the valves, the performance and safety of the production wellhead are met, the convenience of the production wellhead installation is improved, and the sealing performance of the wellhead is further enhanced.

[0076] It should be noted that, in this document, relational terms such as first and second are used solely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not explicitly listed. Without further limitation, an element defined by the phrase "comprising a..." does not preclude the presence of additional identical elements in the article or device comprising the element. Terms such as "connected" or "connected" are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. References to orientations or positional relationships, such as "upper," "lower," "left," and "right," are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate description and simplify the description of the present invention. They do not indicate or imply that the device or element referred to must have, be constructed, or operate in a specific orientation, and are therefore not to be construed as limiting the present invention.

[0077] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. An oil production wellhead for a fracturing self-flowing well, characterized in that: The invention comprises a first four-way valve (1), a first control valve (2), a second control valve (3), a first throttle valve (4), a second four-way valve (5), a third control valve (6), a second throttle valve (7), a second stop valve (9), a tubing hanger (13), a tubing double male short joint (14), a casing flange (15), a casing double male short joint (16) and a second plug (20); The first interface of the first four-way valve (1) is connected to the first control valve (2), and the first control valve (2) is connected to the first throttle valve (4); the second interface of the first four-way valve (1) is connected to the fourth interface of the second four-way valve (5); and the third interface of the first four-way valve (1) is connected to the second control valve (3). The fourth interface of the first four-way joint (1) is sealedly connected to the first end of the casing flange (15), and the second end of the casing flange (15) is connected to the casing double male nipple (16); One end of the tubing hanger (13) is sealed and fixedly connected to the inner wall of the second interface of the first four-way (1), and the other end is threadedly sealed and fixedly connected to the tubing double male nipple (14); The first interface of the second four-way valve (5) is threadedly sealed and connected to the second stop valve (9), and the second interface of the second four-way valve (5) is threadedly sealed and connected to the second plug (20); the third interface of the second four-way valve (5) is connected to the third control valve (6), and the third control valve (6) is connected to the second throttle valve (7); During operation, the tubing double male nipple (14) and the casing form an annular passage that passes through the first four-way valve (1); the first control valve (2) and the first throttle valve (4) are sealed and connected to form a first annular bypass passage; the second control valve (3) forms a second annular sealed bypass passage, wherein the second annular sealed bypass passage serves as a test passage, and the second control valve (3) is normally closed; the tubing double male nipple (14) and the second four-way valve (5) are sealed and connected to form an tubing passage; the third control valve (6) and the second throttle valve (7) are connected to form an tubing sealed bypass passage; in the artesian well operation During the injection operation, the downhole oil pressure potential energy overcomes the gravity potential energy to realize gravity flow, the first control valve (2) and the third control valve (6) are normally open, the oil flowing by gravity in the first annular bypass passage flows through the first throttle valve (4), and the flow rate of the outflowing oil is adjusted by the first throttle valve (4); the oil flowing by gravity in the oil pipe sealing bypass passage flows through the second throttle valve (7), and the flow rate of the outflowing oil is adjusted by the second throttle valve (7); by calculation, it is ensured that the flow rate of the oil flowing out of the first annular bypass passage and the oil pipe bypass passage forms a balance with the penetration rate of water in the formation into the oil layer.

2. The oil production wellhead for a fracturing self-flowing well according to claim 1, characterized in that: The oil production wellhead for the fracturing self-flowing well further includes a first stop valve (8) and a third stop valve (10); The first stop valve (8) is arranged on the first throttle valve (4), and the third stop valve (10) is arranged on the second throttle valve (7).

3. The oil production wellhead for a fracturing self-flowing well according to claim 2, characterized in that: The oil production wellhead for the fracturing self-flowing well further includes a first pressure gauge (11) and a second pressure gauge (12); The first pressure gauge (11) is connected to the first stop valve (8), and the second pressure gauge (12) is connected to the third stop valve (10).

4. The oil production wellhead for a fracturing self-flowing well according to claim 1, characterized in that: The first control valve (2), the second control valve (3) and the third control valve (6) are all manual flat valves or manual wedge gate valves.

5. The oil production wellhead for a fracturing self-flowing well according to claim 1, characterized in that: The first throttle valve (4) and the second throttle valve (7) are both manual throttle needle valves used for flow regulation in artesian wells.

6. The oil production wellhead for a fracturing self-flowing well according to claim 1, characterized in that: The oil production wellhead for the fracturing self-flowing well also includes a connecting flange (18) and a first plug (19); Wherein, the connecting flange (18) is connected to the second control valve (3); the first plug (19) is sealed and connected to the connecting flange (18); The passage where the second control valve (3) is located is connected to the annulus between the oil pipe and the casing, and the passage serves as a test passage for the wellhead state.

7. The oil production wellhead for a fracturing self-flowing well according to claim 6, characterized in that: The connecting flange (18) is a threaded flange or a clamp flange.

8. The oil production wellhead for a fracturing self-flowing well according to claim 1, characterized in that: The first four-way valve (1) and the second four-way valve (5) are connected to the corresponding control valve by flange connection or clamp connection.

9. The oil production wellhead for a fracturing self-flowing well according to claim 1, characterized in that: The connection method between the control valve and the throttle valve is flange connection or clamp connection.

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