A downhole flow control device for a gas well of the Tesla valve type

Abstract

The application discloses a Tesla valve type gas well downhole flow control device, relates to fluid control technology for realizing water control and production increase in a gas field development process, and aims to solve the technical problems of poor fluid flowability of gas and water, poor gas-water two-phase separation effect and poor gas well water invasion inhibition effect in the prior art. The device comprises a Tesla valve type downhole flow control valve cover and a Tesla valve type downhole flow control valve body. The first inlet, the phase state sorting cavity, the tail Tesla valve type flow channel, the lateral Tesla valve type flow channel, the O-shaped cavity and the outlet of the Tesla valve type downhole flow control valve body are communicated. The flow channel widths of the first inlet, the tail Tesla valve type flow channel and the lateral Tesla valve type flow channel are all smaller than the flow channel width of the phase state sorting cavity, and the tail end of the phase state sorting cavity is communicated with the tail Tesla valve type flow channel through a reduced diameter structure. The control device can effectively enhance the separation efficiency of gas-water two-phase fluid, generate higher flow resistance to the water phase, and thus inhibit water invasion.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil and gas field development, and relates to a fluid control technology for realizing water control and production increase in the development process of a gas field, in particular to a Tesla valve type downhole flow control device for a gas well. BACKGROUND

[0002] In the development process of a gas reservoir, with the prolongation of the production time and the continuous decline of the reservoir pressure, the probability of water invasion increases significantly. This water invasion not only causes a sharp decline in the productivity of the gas well and a substantial reduction in the recovery rate, but also causes reservoir damage that is often difficult to recover, even irreversible. It is worth noting that in a heterogeneous reservoir, due to the existence of high-permeability layers or fracture development zones, water invasion usually breaks through these dominant channels first, resulting in a serious imbalance in the production profile between high and low permeability layers. However, the existing conventional drainage gas recovery technology has obvious limitations in dealing with this problem. On the one hand, it cannot implement precise management for specific water-producing layers or water-producing sections, but can only perform liquid drainage operations on the entire wellbore. On the other hand, this method cannot effectively prevent the negative impact of the water-producing layer section on other gas-producing layer sections, resulting in a significant reduction in the treatment effect.

[0003] The application with the application number CN202410312751.0 discloses a control device suitable for downhole segmented water control and gas recovery in a gas well, which comprises: a water control and gas recovery control device, including a bearing base pipe, a fixed installation groove, a Tesla valve type water control device, a smooth gas drag reduction groove, and a bearing base pipe outlet; the Tesla valve type water control device includes a Tesla valve type water control device flow passage bearing body, a Tesla valve type water control device flow passage bearing body flow inlet, a Tesla valve type water control device flow passage bearing body flow channel, a Tesla valve type water control device flow passage bearing body flow outlet, and a Tesla valve type water control device outer packaging body; the bearing base pipe is a hollow pipe with a certain thickness, the outer surface of the bearing base pipe is provided with a fixed installation groove, the groove surface of the fixed installation groove is flat, and the bearing base pipe outlet is provided; the fixed installation groove is used to fix the Tesla valve type water control device, and the position in contact with one side surface of the fixed installation groove is provided with a smooth gas drag reduction groove.

[0004] In the control device, when only gas flows through the water control gas production control device, the flow resistance generated by the gas in the flow passage of the Tesla valve type water control device is very small; when a small amount of water begins to appear in the formation, the gas and water two-phase fluid enters the flow passage of the Tesla valve type water control device, and due to the characteristics of the Tesla valve type water control device, a small amount of water is mixed with the gas in the flow passage of the Tesla valve type water control device and is carried out by the gas flow, and is finally carried to the ground; due to the characteristics of the Tesla valve type water control device, the reverse flow resistance of the Tesla valve is greater than the forward flow resistance, and the flow resistance generated by the water in the flow passage is much greater than the resistance generated by the gas, and the greater the water production, the higher the resistance value, so when a large amount of water appears in the formation, the high flow resistance value generated by the water in the flow passage of the Tesla valve type water control device makes it more difficult for the water to pass through and enter the tubing, and the other unaffected gas production layers can continue to produce.

[0005] The control device can effectively block the water production layer in the gas well, prevent water from entering the wellbore, greatly delay the water breakthrough time of the gas well, and ensure the normal production of the gas in the other production layers and receive less hindrance, which greatly contributes to the improvement of the gas production and recovery rate of the entire gas well.

[0006] The control device directly sets the Tesla valve type water control device flow inlet for the gas and water to enter in the Tesla valve type water control device flow passage carrier, and directly sets the Tesla valve type water control device flow outlet after the Tesla valve type water control device flow passage. Since the inner diameters of the Tesla valve type water control device flow inlet, the Tesla valve type water control device flow passage and the Tesla valve type water control device flow outlet are the same, when the gas and water enter the Tesla valve type water control device flow passage carrier, the flow stability of the fluid is poor, the gas-water two-phase separation effect is limited, and the water invasion inhibition effect in the gas well is poor. SUMMARY

[0007] The purpose of the present application is to solve the technical problems of poor fluid flow, poor gas-water two-phase separation effect and poor water invasion inhibition effect in the Tesla valve type flow passage in the prior art, and to provide a Tesla valve type downhole flow control device for a gas well.

[0008] In order to achieve the above purpose, the present application specifically adopts the following technical scheme:

[0009] A Tesla valve type downhole flow control device for a gas well, comprising a Tesla valve type downhole flow control valve cover and a Tesla valve type downhole flow control valve body.

[0010] The Tesla valve type downhole flow control valve body is provided with a first inlet on the side surface and an outlet on the bottom surface, and is internally provided with a phase separation chamber, a tail Tesla valve type flow channel, a lateral Tesla valve type flow channel and an O-shaped cavity;

[0011] The first inlet is in communication with the first end of the phase separation chamber, the side surface of the phase separation chamber is in communication with the lateral Tesla valve type flow channel, the tail end of the phase separation chamber is in communication with the tail Tesla valve type flow channel, and the tail Tesla valve type flow channel and the lateral Tesla valve type flow channel are in communication with the outlet through the O-shaped cavity after being merged at the other end.

[0012] The flow channel width of the first inlet, the tail Tesla valve type flow channel and the lateral Tesla valve type flow channel is smaller than the flow channel width of the phase separation chamber, and the tail end of the phase separation chamber is in communication with the tail Tesla valve type flow channel through a reduced diameter structure.

[0013] Further, the tail Tesla valve type flow channel and the lateral Tesla valve type flow channel each include a merging flow channel and parallel straight flow channels and curved flow channels divided by Tesla valve type shunt guide vanes, the straight flow channels are Tesla valve type reverse side flow channels, the curved flow channels are Tesla valve type reverse straight flow channels and Tesla valve type curved flow channels arranged in sequence, the first end of the Tesla valve type reverse side flow channel and the first end of the Tesla valve type reverse straight flow channel are in communication with the tail end of the phase separation chamber, and the tail end of the Tesla valve type reverse side flow channel and the tail end of the Tesla valve type curved flow channel are in communication with the merging flow channel.

[0014] Further, the Tesla valve type downhole flow control valve body is further provided with a second inlet on the side surface, the phase separation chamber has two, and the tail Tesla valve type flow channel and the lateral Tesla valve type flow channel each have two groups; the first inlet and the second inlet, the two phase separation chambers, the first group of tail Tesla valve type flow channels and the second group of tail Tesla valve type flow channels, and the first group of lateral Tesla valve type flow channels and the second group of lateral Tesla valve type flow channels are each symmetric about the center axis of the O-shaped cavity.

[0015] The first group of tail Tesla valve type flow channels and the lateral Tesla valve type flow channels are in communication with the first inlet through one of the phase separation chambers, the second group of tail Tesla valve type flow channels and the lateral Tesla valve type flow channels are in communication with the second inlet through the other phase separation chamber, and the other ends of the two groups of tail Tesla valve type flow channels and the lateral Tesla valve type flow channels are in communication with the O-shaped cavity.

[0016] Further, the merging flow channel of the first group of tail Tesla valve type flow channels is collinear with the merging flow channel of the second group of lateral Tesla valve type flow channels and is tangent to the O-shaped cavity.

[0017] The merging flow channel of the second group of tail Tesla valve type flow channels is collinear with the merging flow channel of the first group of lateral Tesla valve type flow channels and is tangent to the O-shaped cavity.

[0018] Further, the first inlet, the phase separation cavity and the Tesla valve type reverse straight flow channel are collinear.

[0019] Further, the included angle alpha of the shunt of the Tesla valve type shunt guide vane of the tail Tesla valve type flow channel is different from the included angle beta of the shunt of the Tesla valve type shunt guide vane of the lateral Tesla valve type flow channel.

[0020] The beneficial effects of the present application are as follows:

[0021] 1. In the present application, by arranging the Tesla valve type flow channel in the valve body, the separation efficiency of the gas-water two-phase fluid can be effectively enhanced; by arranging the Tesla valve type flow channel at the tail and the side of the phase separation cavity, due to the large viscosity and density of the water phase and under the action of inertia, more water will enter the tail Tesla valve type flow channel along the current path, and under the action of the special flow channel, the flow resistance of the water can be greatly increased; due to the width of the flow channel of the phase separation cavity being greater than the width of the flow channels on the front and back sides, the phase separation cavity with the special structure can make the gas with relatively smaller viscosity and density more easily deviated, so that more gas will enter the lateral Tesla valve type flow channel, and a small part of the gas will enter the tail Tesla valve type flow channel; in the same Tesla valve type flow channel, due to the smaller viscosity and density of the gas, the gas will tend to flow along the Tesla valve type reverse side flow channel, and the flow resistance is smaller. Through the above structure, the control device can effectively enhance the separation efficiency of the gas-water two-phase fluid, generate higher flow resistance to the water phase, thereby inhibiting water invasion, and the gas well water invasion inhibition effect is better, and the gas well production performance can be improved.

[0022] 2. In the present application, a plurality of reverse bending, straight flow and measuring flow channels are arranged in the Tesla valve type flow channel, the inertia effect and turbulent characteristics of the fluid are utilized, the smoothness of the fluid in the forward flow is enhanced, and when the fluid flows in the reverse direction, significant pressure difference and resistance are generated, one-way flow control is realized, and effective separation of the gas-water two-phase fluid is realized.

[0023] 3. In the present application, by adjusting the size and included angle of the shunt guide vane in the Tesla valve type flow channel, different gas well working conditions can be flexibly adapted, and the applicability of the device can be improved.

[0024] 4. In the present application, the circular structure of the O-shaped cavity is tangent to the four converging flow channels, which can ensure the uniform distribution and efficient discharge of the fluid at the outlet, and improve the separation efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0025] Fig. 1 is a three-dimensional structure schematic view of the Tesla valve type downhole flow control valve of the present application;

[0026] Fig. 2 is a sectional view of the Tesla valve type downhole flow control valve of the present application;

[0027] Figure 3 is a schematic diagram of the working principle of the downhole flow control device of the present application;

[0028] Figure 4 Figure 4 is a schematic diagram of the included angle of the shunt guide vane of the Tesla valve type in the present application;

[0029] In the drawings, the reference signs are:

[0030] 01-Tesla valve type gas well downhole flow control device, 100-Tesla valve type downhole flow control valve cover, 200-Tesla valve type downhole flow control valve body, 201-first inlet, 202-phase sorting cavity, 203-O cavity, 204-outlet, 205-second inlet, 206-carrier, 207-carrier base pipe, 2010-tail Tesla valve type flow channel, 2020-lateral Tesla valve type flow channel, 2011-Tesla valve type reverse straight flow channel, 2012-Tesla valve type curved flow channel, 2013-Tesla valve type reverse lateral flow channel, 2014-Tesla valve type shunt guide vane, 2015-converging flow channel. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.

[0032] Therefore, based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0033] Embodiment 1

[0034] The present embodiment provides a Tesla valve type gas well downhole flow control device for water drainage and gas production in a gas well, and can effectively inhibit water invasion during gas production.

[0035] As Figure 1As shown, the control device comprises a Tesla valve type downhole flow control valve cover 100, a Tesla valve type downhole flow control valve body 200, the bottom of the Tesla valve type downhole flow control valve cover 100 is open, the Tesla valve type downhole flow control valve cover 100 is covered on the Tesla valve type downhole flow control valve body 200, and the periphery thereof is attached to the periphery of the Tesla valve type downhole flow control valve body 200. The Tesla valve type downhole flow control valve body 200 is provided with a first inlet 201 on the side surface, a flow passage for two-phase fluid flow of gas and water in the inside, and an outlet 204 at the bottom, and the first inlet 201, the flow passage and the outlet 204 are sequentially communicated; when the Tesla valve type downhole flow control valve cover 100 is covered on the Tesla valve type downhole flow control valve body 200, a flow passage with a circumferential closure and two open ends is formed in the inside of the two.

[0036] The flow passage in the Tesla valve type downhole flow control valve body 200 comprises a phase state sorting cavity 202, a tail Tesla valve type flow passage 2010, a lateral Tesla valve type flow passage 2020 and an O-shaped cavity 203, which are all arranged in the Tesla valve type downhole flow control valve body 200; the first inlet 201 is communicated with the head end of the phase state sorting cavity 202, the tail end and the side surface of the phase state sorting cavity 202 are both provided with an opening, the phase state sorting cavity 202 is communicated with the tail Tesla valve type flow passage 2010 through the opening at the tail end thereof, the phase state sorting cavity 202 is communicated with the lateral Tesla valve type flow passage 2020 through the opening at the side surface thereof, and the tail Tesla valve type flow passage 2010 and the lateral Tesla valve type flow passage 2020 are communicated with the outlet 204 through the O-shaped cavity 203 after the other ends of the two flow passages are merged. The phase state sorting cavity 202 and the Tesla valve type downhole flow control valve cover 100 are connected in an interference fit by hot assembly, so that the device is more convenient and reliable during installation and maintenance.

[0037] The flow passage width of the phase state sorting cavity 202 is greater than that of the first inlet 201, the tail Tesla valve type flow passage 2010 and the lateral Tesla valve type flow passage 2020; the tail end of the phase state sorting cavity 202 is provided with a reduced diameter structure, the flow passage width of the reduced diameter structure close to the side of the phase state sorting cavity 202 is greater, and the flow passage width of the reduced diameter structure close to the side of the tail Tesla valve type flow passage 2010 is smaller; the lateral Tesla valve type flow passage 2020 is installed obliquely on the phase state sorting cavity 202, and the water inlet direction of the lateral Tesla valve type flow passage 2020 has an angle γ with the axis of the phase state sorting cavity 202.

[0038] As shown in the drawings, Figure 3As shown, in the wellbore position corresponding to the high-permeability area of the gas well, if no measures are taken to control water and produce in this way, this area will probably have non-uniform water permeation, and thus premature breakthrough will occur; when a large amount of water in the well flows into the wellbore, the risk of producing water will occur. In this case, the Tesla valve type gas well downhole flow control device 01 of the embodiment can be installed on the carrier base pipe 207 on the carrier 206, and then the carrier 206 provided with the Tesla valve type gas well downhole flow control device 01 is connected in the pipe string of the wellbore, when the water and gas produced in the well enter the device through the first inlet 201 of the Tesla valve type gas well downhole flow control device 01 installed on the carrier 206, the water and gas will be separated in the device.

[0039] The working process (principle) of the device is as follows:

[0040] When the fluid produced by a certain reservoir is single-phase water, the water enters the phase state sorting cavity 202 through the first inlet 201; due to the relatively large viscosity and density of water, under the action of inertial force, more water will enter the tail Tesla valve type flow channel 2010 along the current path, and a small part of water will enter the lateral Tesla valve type flow channel 2020 from the side of the phase state sorting cavity 202; after the water enters the tail Tesla valve type flow channel 2010 and the lateral Tesla valve type flow channel 2020, it is further divided under the action of the Tesla valve structure inside it, and the curved flow channel in the Tesla valve structure greatly increases the flow resistance of the water; the water flowing out of the tail Tesla valve type flow channel 2010 and the lateral Tesla valve type flow channel 2020 flows into the O-cavity 203 and is finally discharged through the outlet 204. In this process, the water is first divided in the phase state sorting cavity 202, and then secondly divided in the tail Tesla valve type flow channel 2010 and the lateral Tesla valve type flow channel 2020, the flow resistance of the water is large, which can enhance the flow resistance of the water phase and thus inhibit water invasion;

[0041] When the fluid produced by a certain reservoir is single-phase gas, the gas enters the phase state sorting cavity 202 through the first inlet 201; due to the asymmetrically arranged outlet on the phase state sorting cavity 202 and the different widths of the two outlets (the outlet at the tail end has a reduced diameter structure, and the flow channel size when the gas enters the reduced diameter structure from the phase state sorting cavity 202 is larger than the flow channel size when the gas enters the lateral Tesla valve type flow channel 2020 from the phase state sorting cavity 202, which is smaller), this structural feature makes the gas with relatively smaller viscosity and density more likely to be deflected, so that more gas enters the lateral Tesla valve type flow channel 2020, and a small part of the gas enters the tail Tesla valve type flow channel 2010; after the gas enters the tail Tesla valve type flow channel 2010 and the lateral Tesla valve type flow channel 2020, it is further divided under the action of the Tesla valve type shunt guide vane 2014 and the Tesla valve flow channel structure inside it (among them, due to the smaller viscosity and density of the gas, it tends to flow along the Tesla valve type reverse side flow channel 2013 corresponding to the flow channel (i.e. the tail Tesla valve type flow channel 2010 and the lateral Tesla valve type flow channel 2020). Therefore, most of the gas will enter the Tesla valve type reverse side flow channel 2013, and a small amount of gas will enter the Tesla valve type reverse straight flow channel 2011 and the Tesla valve type curved flow channel 2012, realizing the division; the gas flowing out of the tail Tesla valve type flow channel 2010 and the lateral Tesla valve type flow channel 2020 converges and enters the O-shaped cavity 203, and is finally discharged through the outlet 204;

[0042] When the fluid produced by a certain reservoir is two-phase gas and water, the gas and water enter the phase state sorting cavity 202 through the first inlet 201; due to the structural features of the phase state sorting cavity 202, most of the water (of course, there will also be a small part of the gas) enters the tail Tesla valve type flow channel 2010, most of the gas (of course, there will also be a small part of the water) enters the lateral Tesla valve type flow channel 2020 (the principle is as described above), and the water containing a small amount of gas is further separated in the Tesla valve structure of the tail Tesla valve type flow channel 2010, and the gas containing a small amount of water is further separated in the Tesla valve structure of the lateral Tesla valve type flow channel 2020, and the separated gas and water are finally discharged into the O-shaped cavity 203, and are finally discharged through the outlet 204 (the outlet 204 discharges layered water and gas, which are collected separately at the wellhead by the existing technology). In this process, according to the flow channel of the Tesla valve structure of the present embodiment, under the two-phase flow state, the gas and water can still be divided by their own characteristics and features, effectively distinguishing the gas and water, and generating greater flow resistance to the water, limiting the water from entering the wellbore, suppressing water invasion, and improving the gas well water invasion suppression effect, thereby better solving the technical problems of the present application and improving the technical effects of the present application.

[0043] Example 2

[0044] In this embodiment, a specific structure of tail Tesla valve type flow channel 2010 and lateral Tesla valve type flow channel 2020 is provided.

[0045] As shown in the drawings, tail Tesla valve type flow channel 2010 and lateral Tesla valve type flow channel 2020 have the same structure, and both include Tesla valve structure. Specifically, Figure 2

[0046] Tail Tesla valve type flow channel 2010 and lateral Tesla valve type flow channel 2020 both include straight flow channel, curved flow channel and converging flow channel 2015. The straight flow channel and the curved flow channel are arranged side by side and separated by Tesla valve type shunt guide vane 2014. The straight flow channel is Tesla valve type reverse side flow channel 2013, and the curved flow channel includes Tesla valve type reverse straight flow channel 2011 and Tesla valve type curved flow channel 2012 arranged in sequence and connected. The length of the straight flow channel is less than that of the curved flow channel. The front end of the Tesla valve type reverse side flow channel 2013 and the front end of the Tesla valve type reverse straight flow channel 2011 are both communicated with phase state separation chamber 202 (the Tesla valve type reverse side flow channel 2013 and the Tesla valve type reverse straight flow channel 2011 of the tail Tesla valve type flow channel 2010 are communicated with the small-diameter end of the reduced-diameter structure of the phase state separation chamber 202), and the tail end of the Tesla valve type reverse side flow channel 2013 and the tail end of the Tesla valve type curved flow channel 2012 are both communicated with the converging flow channel 2015.

[0047] When the fluid produced by a certain reservoir is single-phase water, the water enters tail Tesla valve type flow channel 2010 (most of the water enters) and lateral Tesla valve type flow channel 2020 (a small part of the water enters), and is further shunted under the action of Tesla valve type shunt guide vane 2014. Most of the water continues to move to Tesla valve type reverse straight flow channel 2011 and turns in Tesla valve type curved flow channel 2012, greatly increasing the flow resistance of the water. A small part of the water is shunted to Tesla valve type reverse side flow channel 2013, and finally flows back at converging flow channel 2015 and enters O-type chamber 203 along converging flow channel 2015, and is finally discharged through outlet 204.

[0048] When the fluid produced by a certain reservoir is single-phase gas, the gas enters lateral Tesla valve type flow channel 2020 (most of the gas enters) and tail Tesla valve type flow channel 2010 (a small part of the gas enters), and is further shunted under the action of Tesla valve type shunt guide vane 2014. Most of the gas enters Tesla valve type reverse side flow channel 2013, and a small part of the gas enters Tesla valve type reverse straight flow channel 2011 and Tesla valve type curved flow channel 2012. Finally, it flows back at converging flow channel 2015 and enters O-type chamber 203 along converging flow channel 2015, and is finally discharged through outlet 204.

[0049] ​When the fluid produced by a certain reservoir is two-phase gas and water, the gas and water enter the lateral Tesla valve type flow channel 2020 (mostly gas and a small amount of water) and the tail Tesla valve type flow channel 2010 (mostly water and a small amount of gas), and are further diverted under the action of the Tesla valve type diversion guide vane 2014. Most of the water continues to move forward to the Tesla valve type reverse straight channel 2011 and turns in the Tesla valve type curved flow channel 2012, greatly increasing the flow resistance of the water. Most of the gas is diverted to the Tesla valve type reverse side flow channel 2013, and finally enters the O-type cavity 203 in layers through the converging flow channel 2015, and is finally discharged through the outlet 204.

[0050] Example 3

[0051] In this embodiment, two inlets and one outlet are provided on the Tesla valve type downhole flow control valve body 200 .

[0052] like Figure 1 、 Figure 2 As shown, a Tesla valve-type downhole flow control valve body 200 has a first inlet 201 and a second inlet 205 formed on its side. The first inlet 201 and the second inlet 205 are symmetrically arranged about the axis of the O-shaped cavity 203 on the Tesla valve-type downhole flow control valve body 200. Similarly, two sets of phase separation cavities 202 are provided, also symmetrically arranged about the axis of the O-shaped cavity 203. The first inlet 201 communicates with one of the phase separation cavities 202, and the second inlet 205 communicates with the other phase separation cavity 202. The Tesla valve-type downhole flow control valve body 200 also has two sets of tail Tesla valve-type flow channels 2010 and two sets of lateral Tesla valve-type flow channels 2020. The two sets of tail Tesla valve-type flow channels 2010 and the two sets of lateral Tesla valve-type flow channels 2020 are symmetrically arranged about the axis of the O-shaped cavity 203 on the Tesla valve-type downhole flow control valve body 200.

[0053] Among them, the first group of tail Tesla valve type flow channels 2010 and the head ends of the lateral Tesla valve type flow channels 2020 are connected to the first inlet 201 through one of the phase separation cavities 202, and the second group of tail Tesla valve type flow channels 2010 and the head ends of the lateral Tesla valve type flow channels 2020 are connected to the second inlet 205 through another phase separation cavity 202, and the other ends (tail ends) of the two groups of tail Tesla valve type flow channels 2010 and the lateral Tesla valve type flow channels 2020 are connected to the O-type cavity 203.

[0054] As preferred, the converging flow channel 2015 of the first group of tail Tesla valve type flow channel 2010 is collinear with the converging flow channel 2015 of the second group of lateral Tesla valve type flow channel 2020, and tangent to the O-shaped cavity 203; the converging flow channel 2015 of the second group of tail Tesla valve type flow channel 2010 is collinear with the converging flow channel 2015 of the first group of lateral Tesla valve type flow channel 2020, and tangent to the O-shaped cavity 203.

[0055] As preferred, the first inlet 201, the corresponding phase separation cavity 202, and the Tesla valve type reverse straight flow channel 2011 are collinear. Similarly, the second inlet 205, the corresponding phase separation cavity 202, and the Tesla valve type reverse straight flow channel 2011 are also collinear.

[0056] Due to the fact that the four converging flow channels 2015 are collinear in pairs, and the flow rates of the two converging flow channels 2015 in the same collinear line present a "large-small" complementary advantage, the water diversion effect can be enhanced; at the same time, the water entering the O-shaped cavity 203 can produce a more sufficient cyclone effect, and a greater flow resistance when passing through the outlet 204.

[0057] Embodiment 4

[0058] In this embodiment, the included angle α of the diversion of the Tesla valve type diversion guide vane 2014 of the tail Tesla valve type flow channel 2010 and the included angle β of the diversion of the Tesla valve type diversion guide vane 2014 of the lateral Tesla valve type flow channel 2020 are both 35°-60°, and the included angle α≠ the included angle β, as shown in Figure 4 .

[0059] Due to the fact that the phase separation cavity 202 realizes the preliminary diversion and phase separation effect, the gas and water entering the tail Tesla valve type flow channel 2010 and the lateral Tesla valve type flow channel 2020 have flow rate differences, and further flow into the lateral Tesla valve type flow channel 2020 or the lateral Tesla valve type flow channel 2020. Due to the fact that the included angle α≠ the included angle β, the Tesla valve type diversion guide vane 2014 can realize secondary diversion in different flow channels, and increase the diversion control effect on the high water flow channel. For example, when the gas flow rate entering the lateral Tesla valve type flow channel 2020 is higher, the included angle α> the included angle β, so that more water entering the tail Tesla valve type flow channel 2010 enters the Tesla valve type curved flow channel 2012, greatly increasing the flow resistance of the water, while more gas entering the lateral Tesla valve type flow channel 2020 tends to enter the Tesla valve type reverse side flow channel 2013 due to the relatively small included angle α, and the flow resistance is relatively small.

Claims

1. A downhole flow control device for a gas well of the Tesla valve type, characterized in that: The application relates to a Tesla valve type downhole flow control valve cover (100) and a Tesla valve type downhole flow control valve body (200). The Tesla valve type downhole flow control valve body (200) is internally provided with a phase state sorting cavity (202), a tail Tesla valve type flow channel (2010), a lateral Tesla valve type flow channel (2020) and an O-shaped cavity (203). The first inlet (201) is in communication with the first end of the phase state sorting cavity (202), the side surface of the phase state sorting cavity (202) is in communication with the lateral Tesla valve type flow channel (2020), the tail end of the phase state sorting cavity (202) is in communication with the tail Tesla valve type flow channel (2010), the tail Tesla valve type flow channel (2010) and the lateral Tesla valve type flow channel (2020) are in communication with the O-shaped cavity (203) and the outlet (204) after being converged at the other ends. The flow channel widths of the first inlet (201), the tail Tesla valve type flow channel (2010) and the lateral Tesla valve type flow channel (2020) are all smaller than the flow channel width of the phase state sorting cavity (202), and the tail end of the phase state sorting cavity (202) is in communication with the tail Tesla valve type flow channel (2010) through a reduced-diameter structure.

2. A downhole flow control device for a gas well of the Tesla valve type as defined in claim 1, characterized in that: The tail Tesla valve type flow channel (2010) and the lateral Tesla valve type flow channel (2020) each comprise a converged flow channel (2015) and parallel straight flow channels and curved flow channels divided by Tesla valve type shunt guide vanes (2014), the straight flow channels are Tesla valve type reverse lateral flow channels (2013), and the curved flow channels are Tesla valve type reverse straight flow channels (2011) and Tesla valve type curved flow channels (2012) arranged in sequence, the first ends of the Tesla valve type reverse lateral flow channels (2013) and the Tesla valve type reverse straight flow channels (2011) are in communication with the phase state sorting cavity (202), and the tail ends of the Tesla valve type reverse lateral flow channels (2013) and the Tesla valve type curved flow channels (2012) are in communication with the converged flow channel (2015).

3. A downhole flow control device for a gas well of the Tesla valve type according to claim 1 or 2, characterized in that: The Tesla valve type downhole flow control valve body (200) is further provided with a second inlet (205) on the side surface, the phase state sorting cavity (202) has two, and the tail Tesla valve type flow channel (2010) and the lateral Tesla valve type flow channel (2020) each have two groups; the first inlet (201) and the second inlet (205), the two phase state sorting cavities (202), the first group of tail Tesla valve type flow channels (2010) and the second group of tail Tesla valve type flow channels (2010), the first group of lateral Tesla valve type flow channels (2020) and the second group of lateral Tesla valve type flow channels (2020) are all symmetrically arranged around the axis center of the O-shaped cavity (203). The first group of tail Tesla valve type flow passages (2010) and the lateral Tesla valve type flow passages (2020) are communicated with the first inlet (201) through one of the phase state sorting cavities (202), the second group of tail Tesla valve type flow passages (2010) and the lateral Tesla valve type flow passages (2020) are communicated with the second inlet (205) through another phase state sorting cavity (202), and the other ends of the two groups of tail Tesla valve type flow passages (2010) and the lateral Tesla valve type flow passages (2020) are communicated with the O-shaped cavity (203).

4. A downhole flow control device for a gas well of the Tesla valve type as defined in claim 3, characterized in that: The converging flow passages (2015) of the first group of tail Tesla valve type flow passages (2010) are collinear with the converging flow passages (2015) of the second group of lateral Tesla valve type flow passages (2020) and are tangent to the O-shaped cavity (203); The converging flow passages (2015) of the second group of tail Tesla valve type flow passages (2010) are collinear with the converging flow passages (2015) of the first group of lateral Tesla valve type flow passages (2020) and are tangent to the O-shaped cavity (203).

5. A downhole flow control device for a gas well of the Tesla valve type as defined in claim 2, characterized in that: The first inlet (201), the phase state sorting cavity (202) and the Tesla valve type reverse straight flow passage (2011) are collinear.

6. A downhole flow control device for a gas well of the Tesla valve type as defined in claim 2, characterized in that: The included angle α of the shunt of the Tesla valve type shunt guide vane (2014) of the tail Tesla valve type flow passage (2010) and the included angle β of the shunt of the Tesla valve type shunt guide vane (2014) of the lateral Tesla valve type flow passage (2020) are both 35°-60°, and the included angle α≠ the included angle β.

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