阅读说明：本技术 气体流量调控管、气体流量稳定控制阀、系统及安装方法 (Gas flow regulating and controlling pipe, gas flow stable control valve, system and installation method ) 是由 陈兴隆 韩海水 林海波 张成明 邵立新 王磊 于 2020-05-25 设计创作，主要内容包括：本申请实施例提供一种气体流量调控管、气体流量稳定控制阀、系统及安装方法,气体流量调控管包括：金属筒、沿该金属筒长度方向设置在金属筒内部的孔隙柱体,以及填充在所述金属筒与孔隙柱体之间的密封层；所述孔隙柱体的内部分别形成多个单流道以使所述孔隙柱体内部形成渗流通道；其中,所述单流道的内径、长度和渗透率预先根据用于表征流经所述孔隙柱体内的气体的流动状态的雷诺数确定。本申请能够有效实现注气通道内的气体稳定流动,并能够有效实现气体在一定程度上的流动可控性,进而能够为提高注气技术的应用效果发挥辅助作用。(The embodiment of the application provides a gas flow regulation and control pipe, stable control valve of gas flow, system and installation method, and gas flow regulation and control pipe includes: the metal cylinder, the pore cylinder arranged in the metal cylinder along the length direction of the metal cylinder, and the sealing layer filled between the metal cylinder and the pore cylinder; a plurality of single channels are respectively formed inside the pore cylinders so as to form seepage channels inside the pore cylinders; wherein the inner diameter, length and permeability of the single flow passage are predetermined according to a Reynolds number for characterizing a flow state of the gas flowing through the pore column. The gas stable flow in the gas injection passageway can be effectively realized to this application to can effectively realize the flow controllability of gas to a certain extent, and then can exert the additional action for the application effect that improves the gas injection technique.)

1. A gas flow regulating tube, comprising: the metal cylinder, the pore cylinder arranged in the metal cylinder along the length direction of the metal cylinder, and the sealing layer filled between the metal cylinder and the pore cylinder;

a plurality of single channels are respectively formed inside the pore cylinders so as to form seepage channels inside the pore cylinders;

wherein the inner diameter, length and permeability of the single flow passage are predetermined according to a Reynolds number for characterizing a flow state of the gas flowing through the pore column.

2. The gas flow regulator tube according to claim 1, wherein the porous cylinder comprises: a regular pore cylinder;

the regular pore cylinder is a uniform pore cylinder made of metal powder, the inner diameters of the single channels in the uniform pore cylinder are the same, and the permeability of each single channel is 200-2000 mD.

3. The gas flow regulator tube according to claim 1, wherein the porous cylinder comprises: a rock pore cylinder;

the rock pore cylinder is a non-uniform pore cylinder made of quartz sand grains, and the permeability of each single channel in the non-uniform pore cylinder is 10-200 mD.

4. A gas flow stability control valve, comprising: the valve comprises a tubular valve body and valve covers respectively arranged at two ports of the valve body; a central passage and at least one gas flow regulating and controlling pipe according to any one of claims 1 to 3, respectively, provided inside the valve body;

at least one gas flow regulating and controlling pipe is independently arranged along the length direction of the valve body, and the central channel and the valve body are coaxially arranged;

the two ends of the central channel and at least one gas flow regulating and controlling pipe respectively penetrate through the corresponding valve covers to be connected with the unique corresponding electromagnetic valves, and each electromagnetic valve is respectively in communication connection with a controller;

each electromagnetic valve arranged at one port of the valve body is respectively used for being connected with a gas injection pipeline, and each electromagnetic valve arranged at the other port of the valve body is respectively used for being connected with a gas injection well through a single well pipeline.

5. The gas flow stability control valve of claim 4, wherein the gas flow regulator comprises: at least one first gas flow regulating and controlling pipe and at least one second gas flow regulating and controlling pipe;

the pore cylinder of the first gas flow regulating and controlling pipe is a regular pore cylinder, and the pore cylinder of the second gas flow regulating and controlling pipe is a rock pore cylinder;

the regular pore cylinder is a uniform pore cylinder made of metal powder, the inner diameters of the single channels in the uniform pore cylinder are the same, and the permeability of each single channel is 200-2000 mD;

the rock pore cylinder is a non-uniform pore cylinder made of quartz sand grains, and the permeability of each single channel in the non-uniform pore cylinder is 10-200 mD.

6. The gas flow stabilization control valve of claim 5, wherein the number of the first gas flow regulating and controlling pipe and the number of the second gas flow regulating and controlling pipe are three.

7. The gas flow stabilization control valve of claim 4, further comprising: the inlet connector is provided with a single-hole port and a multi-hole port at two ends respectively;

the single-hole port of the inlet connector is used for being connected with a trunk line of the gas injection pipeline;

the multi-hole port of the inlet joint is connected with each electromagnetic valve at one port of the valve body, and the number of each hole in the multi-hole port of the inlet joint is greater than or equal to the number of each electromagnetic valve at one port of the valve body.

8. The gas flow stabilization control valve of claim 7, further comprising: the outlet connector is provided with a single-hole port and a multi-hole port at two ends respectively;

the single-hole port of the outlet joint is used for connecting with the single-well pipeline;

the multi-hole port of the inlet joint is connected with each electromagnetic valve at the other port of the valve body, and the number of each hole in the multi-hole port of the inlet joint is larger than or equal to the number of each electromagnetic valve at the other port of the valve body.

9. The gas flow stabilization control valve according to claim 4, wherein a plurality of first bolt holes are respectively formed at both ends of the valve body;

and second bolt holes corresponding to the positions of the first bolt holes are respectively formed in the valve cover.

10. The gas flow stabilization control valve according to claim 4, wherein the valve cover is provided with a plurality of through holes corresponding to the central channel and the at least one gas flow regulation and control pipe respectively;

and one end of each through hole, which is close to the valve body, is provided with a sealing groove.

11. A gas flow stabilization control system, comprising: a plurality of gas flow stability control valves according to any one of claims 4 to 10;

each gas flow stabilization control valve is connected to a trunk line of the gas injection pipeline through each branch pipeline so that each branch pipeline is communicated with a gas injection inlet of the gas injection pipeline;

an inlet interface and an outlet interface are respectively arranged at two ends of the gas flow stable control valve;

each gas flow stabilization control valve is respectively connected with each branch pipeline through the inlet interface which is respectively and uniquely corresponding to the gas flow stabilization control valve;

each gas flow stability control valve is respectively connected with each single well pipeline through the outlet interface which is respectively and uniquely corresponding to the gas flow stability control valve.

12. The gas flow stabilization control system according to claim 11, wherein a gas flow meter is disposed on each of the single well pipelines, and each of the gas flow meters is in communication with the controller.

13. A method of installing the gas flow stability control system of claim 11 or 12, comprising:

coaxially installing the pore cylinder into a metal cylinder, and filling a sealing layer between the metal cylinder and the pore cylinder to form a gas flow regulating and controlling pipe;

at least one gas flow regulating and controlling pipe is respectively arranged in the valve body;

the corresponding position information of at least one gas flow regulating and controlling pipe in the valve body is sent to the controller to be stored;

the two valve covers are respectively arranged at two ends of the valve body, and an inlet interface and an outlet interface are respectively and fixedly connected to the corresponding valve covers;

connecting each of the inlet ports to each of the branch lines, respectively, and connecting each of the outlet ports to each of the single well lines, respectively.

Technical Field

The application relates to the technical field of oilfield development, in particular to a gas flow regulating and controlling pipe, a gas flow stabilizing control valve, a system and an installation method.

Background

At present, gas injection technology in partial regions is gradually popularized and applied in various types of oil reservoirs, so that higher requirements are increasingly put on the gas injection technology, for example: how do a pipe network with the same gas injection pressure supply gas to multiple gas injection wells in a block and inject different flows of gas into the corresponding gas injection wells? Quantitative distribution methods and processes are needed. The current situation is that a single gas injection well can achieve quantitative control of flow by controlling injection pressure. While simultaneous gas injection from multiple wells is subject to uncontrolled adjustments based entirely on differences in permeability of the formation, the higher the permeability of the formation, the greater its flow rate, which is generally contrary to gas injection design.

There are also attempts in the art to control the gas flow rate by the degree of valve opening, which is effective in regulating the flow rate of liquids (water/oil, etc.) with almost negligible regulation of the gas. The reason is as follows:

the liquid flow in the pipeline belongs to pipe flow, the turbulent flow state is most in industrial application, and can be expressed by Darcy-Weisbach equation as follows:

in the formula: hf — loss of head; l is the length of the pipeline; d is the inner diameter of the pipeline; u-average velocity; f, friction coefficient, which includes comprehensive properties such as water viscosity and pipe inner wall roughness.

In the process of oil field pipeline transportation and stratum water injection/gas injection, high temperature and high pressure conditions are generally adopted. Taking underground water injection as an example, the temperature is 40-90 ℃; the pressure is 10MPa to 40 MPa; the daily water injection amount is 5m 3-50 m3 MPa. The diameter of the most end common pipeline of the water injection pipeline is only 3mm, 5mm, 8mm and the like, and the effective diameter of the pipeline is feasible to be controlled by a valve. However, because the gas has low viscosity and density, and the pressure difference (head loss), flow rate and length conditions are the same, the gas pipe diameter is only 0.03 times of the water injection pipe diameter, namely 100 μm, and obviously, the gas pipe diameter has no controllability by the existing valve adjustment. That is, there is no way in the prior art to effectively achieve gas flow controllability for the gas in the gas injection channel.

Disclosure of Invention

To solve the problems in the prior art, the application provides a gas flow regulating and controlling pipe, a gas flow stability control valve, a system and an installation method, which can effectively realize the stable flow of gas in a gas injection channel, can effectively realize the flow controllability of the gas to a certain degree, and further can play an auxiliary role in improving the application effect of the gas injection technology.

In order to solve the technical problem, the application provides the following technical scheme:

in a first aspect, the present application provides a gas flow regulating pipe, comprising: the metal cylinder, the pore cylinder arranged in the metal cylinder along the length direction of the metal cylinder, and the sealing layer filled between the metal cylinder and the pore cylinder;

a plurality of single channels are respectively formed inside the pore cylinders so as to form seepage channels inside the pore cylinders;

wherein the inner diameter, length and permeability of the single flow passage are predetermined according to a Reynolds number for characterizing a flow state of the gas flowing through the pore column.

Further, the pore cylinder includes: a regular pore cylinder;

the regular pore cylinder is a uniform pore cylinder made of metal powder, the inner diameters of the single channels in the uniform pore cylinder are the same, and the permeability of each single channel is 200-2000 mD.

Further, the pore cylinder includes: a rock pore cylinder;

the rock pore cylinder is a non-uniform pore cylinder made of quartz sand grains, and the permeability of each single channel in the non-uniform pore cylinder is 10-200 mD.

In a second aspect, the present application provides a gas flow stabilization control valve comprising: the valve comprises a tubular valve body and valve covers respectively arranged at two ports of the valve body; the central channel and the at least one gas flow regulating and controlling pipe are respectively arranged in the valve body;

at least one gas flow regulating and controlling pipe is independently arranged along the length direction of the valve body, and the central channel and the valve body are coaxially arranged;

the two ends of the central channel and at least one gas flow regulating and controlling pipe respectively penetrate through the corresponding valve covers to be connected with the unique corresponding electromagnetic valves, and each electromagnetic valve is respectively in communication connection with a controller;

each electromagnetic valve arranged at one port of the valve body is respectively used for being connected with a gas injection pipeline, and each electromagnetic valve arranged at the other port of the valve body is respectively used for being connected with a gas injection well through a single well pipeline.

Further, the gas flow rate regulating and controlling pipe comprises: at least one first gas flow regulating and controlling pipe and at least one second gas flow regulating and controlling pipe;

the pore cylinder of the first gas flow regulating and controlling pipe is a regular pore cylinder, and the pore cylinder of the second gas flow regulating and controlling pipe is a rock pore cylinder;

the regular pore cylinder is a uniform pore cylinder made of metal powder, the inner diameters of the single channels in the uniform pore cylinder are the same, and the permeability of each single channel is 200-2000 mD;

the rock pore cylinder is a non-uniform pore cylinder made of quartz sand grains, and the permeability of each single channel in the non-uniform pore cylinder is 10-200 mD.

Further, the number of the first gas flow regulating and controlling pipes and the number of the second gas flow regulating and controlling pipes are three.

Further, still include: the inlet connector is provided with a single-hole port and a multi-hole port at two ends respectively;

the single-hole port of the inlet connector is used for being connected with a trunk line of the gas injection pipeline;

the multi-hole port of the inlet joint is connected with each electromagnetic valve at one port of the valve body, and the number of each hole in the multi-hole port of the inlet joint is greater than or equal to the number of each electromagnetic valve at one port of the valve body.

Further, still include: the outlet connector is provided with a single-hole port and a multi-hole port at two ends respectively;

the single-hole port of the outlet joint is used for connecting with the single-well pipeline;

the multi-hole port of the inlet joint is connected with each electromagnetic valve at the other port of the valve body, and the number of each hole in the multi-hole port of the inlet joint is larger than or equal to the number of each electromagnetic valve at the other port of the valve body.

Furthermore, a plurality of first bolt holes are respectively formed in two ends of the valve body;

and second bolt holes corresponding to the positions of the first bolt holes are respectively formed in the valve cover.

Furthermore, a plurality of through holes respectively corresponding to the positions of the central channel and the at least one gas flow regulating and controlling pipe are arranged on the valve cover;

and one end of each through hole, which is close to the valve body, is provided with a sealing groove.

In a third aspect, the present application provides a gas flow stabilization control system, comprising: a plurality of said gas flow stability control valves;

each gas flow stabilization control valve is connected to a trunk line of the gas injection pipeline through each branch pipeline so that each branch pipeline is communicated with a gas injection inlet of the gas injection pipeline;

an inlet interface and an outlet interface are respectively arranged at two ends of the gas flow stable control valve;

each gas flow stabilization control valve is respectively connected with each branch pipeline through the inlet interface which is respectively and uniquely corresponding to the gas flow stabilization control valve;

each gas flow stability control valve is respectively connected with each single well pipeline through the outlet interface which is respectively and uniquely corresponding to the gas flow stability control valve.

Furthermore, each individual well pipeline is provided with a gas flowmeter, and each gas flowmeter is in communication connection with the controller.

In a fourth aspect, the present application provides a method for installing the gas flow stability control system, including:

coaxially installing the pore cylinder into a metal cylinder, and filling a sealing layer between the metal cylinder and the pore cylinder to form a gas flow regulating and controlling pipe;

at least one gas flow regulating and controlling pipe is respectively arranged in the valve body;

the corresponding position information of at least one gas flow regulating and controlling pipe in the valve body is sent to the controller to be stored;

the two valve covers are respectively arranged at two ends of the valve body, and an inlet interface and an outlet interface are respectively and fixedly connected to the corresponding valve covers;

connecting each of the inlet ports to each of the branch lines, respectively, and connecting each of the outlet ports to each of the single well lines, respectively.

According to the technical scheme, the gas flow regulating and controlling pipe, the gas flow stable control valve, the system and the installation method provided by the application have the advantages that the gas flow regulating and controlling pipe comprises: the metal cylinder, the pore cylinder arranged in the metal cylinder along the length direction of the metal cylinder, and the sealing layer filled between the metal cylinder and the pore cylinder; a plurality of single channels are respectively formed inside the pore cylinders so as to form seepage channels inside the pore cylinders; the inner diameter, the length and the permeability of the single channel are determined in advance according to the Reynolds number used for representing the flowing state of the gas flowing through the pore cylinder, the gas in the gas injection channel can flow stably by firstly obtaining knowledge on a representation method of gas seepage stability and designing the pore cylinder by using the method, and the gas injection channel can flow stably and can flow controllably to a certain degree, so that an auxiliary effect can be exerted for improving the application effect of a gas injection technology.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic representation of air permeability versus pressure for rock.

Fig. 2(a) is a side sectional view of a pipeline of a water injection well pipe.

Fig. 2(b) is a schematic cross-sectional view of a pipeline of a water injection well pipe.

FIG. 3(a) is a side cross-sectional view of the pipeline after the addition of the pipe.

FIG. 3(b) is a schematic cross-sectional view of the pipeline after the addition of the tube bundle.

Fig. 4(a) is a cross-sectional side view of an aperture cylinder provided in an embodiment of the present application.

Fig. 4(b) is a schematic cross-sectional view of a pore cylinder provided in an embodiment of the present application.

Fig. 5(a) is a cross-sectional side view of a control valve coupled to a gas injection channel according to an embodiment of the present application.

Fig. 5(b) is a schematic sectional view a-a' of the control valve provided in the embodiment of the present application.

Fig. 5(c) is a schematic cross-sectional view B-B' of the control valve provided in the embodiment of the present application.

Fig. 5(d) is a schematic diagram of the conversion process of the gas flow from the unstable state to the stable seepage state provided by the embodiment of the present application.

Fig. 6 is a schematic diagram of an internal structure of a gas flow control tube including a cylinder with regular pores according to an embodiment of the present application.

Fig. 7 is a schematic diagram of an internal structure of a gas flow regulating pipe including a rock pore cylinder according to an embodiment of the present application.

Fig. 8 is a structural diagram of a gas flow stabilization control valve provided in an embodiment of the present application.

Fig. 9(a) is a side view of a valve cover of a gas flow stabilization control valve provided in an embodiment of the present application.

Fig. 9(b) is a front view of a valve cover of a gas flow stabilization control valve provided in an embodiment of the present application.

Fig. 10(a) is a side view of a valve body of a gas flow stabilization control valve provided in an embodiment of the present application.

Fig. 10(b) is a sectional view of a valve body of a gas flow stabilization control valve provided in an embodiment of the present application.

Fig. 11 is a structural diagram of a gas flow stabilization control system according to an embodiment of the present application.

FIG. 12 is a side view of a single well string provided in accordance with an embodiment of the present application.

Fig. 13 is a schematic flow chart of an installation method of a gas flow stability control system according to an embodiment of the present application.

Fig. 14 is a schematic diagram of an application of a gas flow stabilizing control valve in a main branch flow path according to an embodiment of the present application.

Reference numerals:

101. a tube wall;

102. a flow channel;

103. a pore region;

104. a fluid state conversion zone;

1. a pore cylinder;

11. a pipeline;

12. a tube bundle;

13. a single flow path;

14. a regular pore cylinder;

15. a rock pore cylinder;

2. a control valve;

20. a gas flow stabilization control valve;

21. a valve body;

211. a first bolt hole;

22. a valve cover;

221. a second bolt hole;

222. a through hole;

223. sealing the groove;

23. a central channel;

24. a gas flow regulating pipe;

241. a first gas flow regulating and controlling pipe;

242. a second gas flow regulating pipe;

25. an electromagnetic valve;

26. a controller;

27. an inlet interface;

28. an outlet interface;

3. a trunk line;

4. a signal line;

5. a metal cylinder;

6. a sealing layer;

7. a gas injection inlet;

8. a single well pipeline;

81. a gas flow meter;

9. a steam injection well;

10. a branch line.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The flow of gas in a porous medium is generally considered to be consistent with fluid seepage conditions, and is theoretically represented by Darcy's law, which is as follows:

assuming the porous medium is a cylinder, Q represents the flow rate. The flow rate of a laboratory is low, and the unit is usually mL/min; the flow rate of industrial field is high, and the unit is usually m³And d. And delta P is the pressure difference between the two ends, A is the section area of the column body, and L is the length of the column body. μ is the gas viscosity. K is the permeability of the column.

The Darcy formula is generally used for fluid seepage under the condition of pore media. In the oil layer physical field, the permeability Kw (water permeability) or Ko (oil permeability) of rock (pore medium) is measured by using liquid (water or oil), and the permeability value calculated by Darcy formula has stability. When the gas is used for measuring the permeability Kg (gas permeability) of the rock (pore medium), under different pressure test conditions, the permeability value calculated by the Darcy formula has obvious linear gradient, and the gas permeability value of the rock is determined only by correcting the value measured under the low-pressure condition. This phenomenon has traditionally been thought to be caused by the "slip-off effect" or "Klinkenberg effect" of the gas, which has recently been thought by researchers to be related to boundary layer, gas viscosity, as a variable. Without discussing the mechanism, it can be seen that the gas permeability measured by the darcy formula is unstable, and thus the formula must be used to guide the gas injection process on the basis of satisfying the condition of seepage.

The embodiment of the application provides a method for characterizing the stability of gas seepage, and the method for characterizing the stability of gas seepage is utilized to determine the geometric parameter boundary of a pore medium under different temperature and pressure conditions, so that a theoretical basis is provided for application, stable gas flow in a gas injection channel can be effectively realized, and an auxiliary effect can be exerted for improving the application effect of a gas injection technology.

The embodiment of the application also provides a pore cylinder, which is firstly recognized on the characterization method of the gas seepage stability, and the pore cylinder is designed by using the method, so that the stable flow of the gas in the gas injection channel can be effectively realized, and further, the pore cylinder can play an auxiliary role in improving the application effect of the gas injection technology.

The embodiment of the application still provides a gas flow regulation and control pipe, through the metal cylinder, set up at the inside hole cylinder of metal cylinder along this metal cylinder length direction, and fill the setting of the sealing layer between metal cylinder and the hole cylinder can effectively realize that the gas in the gas injection passageway stably flows, and then can exert the additional action for the application effect that improves the gas injection technique.

The embodiment of the application also provides a gas flow stable control valve which comprises a tubular valve body and valve covers respectively arranged at two ports of the valve body; the gas flow control valve is characterized in that the gas flow control valve is arranged on a central channel inside the valve body and at least one gas flow control pipe, gas in the gas injection channel can be effectively stably flowed, gas can stably flow, flow regulation in a certain range can be implemented, gas flow control in the gas injection channel can be effectively achieved, the gas flow control valve capable of achieving flow regulation is convenient to use and easy to regulate, on the theoretical basis of analyzing stable flow of gas flow, the large-flow gas control valve capable of meeting industrial field application is designed, gas injection precision is greatly improved, and quantitative separate injection is achieved.

The embodiment of the application still provides a gas flow stable control system, through each gas flow stable control valve is connected to through each lateral pipeline respectively the trunk line of gas injection pipeline, so that each the lateral pipeline all with the setting of gas injection entry intercommunication of gas injection pipeline, when the multiwell is injected simultaneously, can play the effect of adjusting the single well flow.

The embodiment of the application also provides an installation method of the gas flow stability control system, which can effectively improve the installation convenience and efficiency of the gas flow stability control system and improve the application reliability of the gas flow stability control system.

The object of the present application includes at least three aspects:

1. the geometric parameter limit of the pore medium under different temperature and pressure conditions is determined by taking the stable gas seepage state as a basis, and a theoretical basis is provided for application;

2. the gas flow stabilization control valve and the gas flow stabilization control system which always meet the requirement that large-flow gas forms stable flow are provided, and the function of adjusting the flow of a single well is achieved when multiple wells are injected simultaneously;

3. the gas flow stability control valve has simple structure and convenient core replacement operation, and the working range of the control valve can be adjusted. The method for representing the stable gas seepage flow is established by taking the Reynolds number as a standard, and the adjustment parameters are determined, so that the application feasibility is realized.

Principle of method

(1) The reason for the "slip-off effect" of the gas

The "slip effect" or "Klinkenberg (clinkenberg) effect" of a gas states: the gas permeability of the same rock and the same gas measured under different average pressures is different, the permeability and the reciprocal of the evaluation pressure have a better linear relationship, taking the measurement of the air permeability of a certain rock sample as an example, see fig. 1, and P is the average value of the inlet pressure and the outlet pressure. The measured values of the locus positions in fig. 1 are liquid equivalent permeabilities.

The percolation state can also be considered as the state when the pipe is gradually reduced to the level of micro-pores, and is first analyzed by using the pipe flow equation:

at τ ≠ 0 and μ ≠ 0, the Bernoulli equation for fluid tube flow is as follows:

in the formula: the first term is the bit head; the second term is dynamic pressure head; the third term is static head; the fourth term is head loss; the sum of the four terms is a constant.

The flow regime of pipe flow is generally characterized by the reynolds number, which is a dimensionless number.

Wherein v, rho and mu are respectively the flow velocity, density and viscosity coefficient of the fluid; d is the characteristic length, and if a circular pipe, d is the equivalent diameter of the pipe. The Reynolds number is usually used as the basis for determining the flow characteristics, in the pipe flow, Re <2300 is laminar flow, Re is in a transition state within the range of 2300 to 4000, and Re >4000 is turbulent flow.

In the flow equation, if the Reynolds number is small, the viscous force is a main factor, and the pressure term is mainly balanced with the viscous force term; if the reynolds number is large, the viscous force term becomes a secondary factor, and the pressure term is mainly balanced with the inertial force term. When the reynolds number is low, the resistance is proportional to the velocity, viscosity and characteristic length; at high reynolds numbers, the drag is generally proportional to the velocity squared, the density squared and the feature length squared.

Flow conditions within pipes of different diameters are illustrated in connection with actual single pipe testing. The comparison is carried out by using water, oil and nitrogen under the same pressure difference and temperature. The basic parameters are shown in Table 1, where the water and oil flow rates are 1mL/min (the values are the rates often used in core experiments), and the nitrogen flow rate corresponding to the conditional experiments is about 100 mL/min.

TABLE 1 basic parameters

	Water (W)	Oil	Nitrogen gas
				Density kg/m3	1000	800	1.16(21℃，1 atmosphere pressure)
Viscosity mpa.s	0.8	3	0.0017

TABLE 2 Reynolds numbers for different pipe diameters

From the results in Table 2, it is clear that the gas flow in the pipe is still turbulent and unstable at 100 μm. The tube diameter continues to shrink and the degree of instability increases linearly. Obviously, the condition of measuring the gas permeability by the conventional method is not met, and the Reynolds number Re is usually less than 1 and far less than 2300 as can be known from the liquid phase test data of the permeability of the conventional core, namely the condition is a very stable laminar flow state. Thus, permeability testing and research has a prerequisite that the flow must be in a seepage state, as well as a laminar steady state. For gases, once flowing at high velocity, even in pore structures, with Re values much greater than 4000, it is unstable and not well described by darcy's formula.

Seepage essentially means that the high-speed pipe flow is reduced by the large resistance of the pore structure and conforms to Darcy's law, so that laminar flow is a boundary for stable flow, i.e., Re <2300 in the draught pipe flow is a boundary value for seepage conditions.

(2) Method for realizing gas seepage stability

The gas achieves the seepage stability, i.e. reaches the seepage state. In this state, the gas conforms to the darcy formula, and thus can be expressed by the darcy formula when the flow is distributed.

The length and the section of the sample are the same, the gas viscosity is the same as the state, the pressure drop of the two permeabilities is almost the same, and the flow ratio is simplified into the ratio of the permeabilities.

It is known that under percolation conditions, the component of the flux can be achieved by exploiting the difference in sample permeability. This effect can be achieved by using a micro-porous structure in the rock structure. The size of the resistance can be adjusted through the compactness degree and the length of the pore structure. The degree of densification is reflected in the number of pores per unit area and the pore diameter, and it is clear that the larger the number, the smaller the pore diameter, the lower the reynolds number Re in a single tube. Varying the length also achieves the purpose of varying the resistance with a constant degree of densification. The lower the Reynolds number Re becomes, the longer the length increases, the higher the resistance increases, and the longer the length limit value L becomes_limThe flow state is made to be a stable laminar flow state.

The following are described as practical examples:

referring to fig. 2(a) and 2(b), the water injection well injects 20m of water³D, a flow channel 102 is formed in the pipe wall 101 of the pipeline, and the inner diameter of the pipeline is 3cm, so that the water flow Re is about 12000 and is in an unstable state; under the same conditions, the gas flow Re is about 670000, and the unstable state is serious.

Referring to fig. 3(a) and fig. 3(b), under the same area condition, when the flow rate of a single tube is reduced by 100 times by changing to a 3mm tube bundle, the airflow Re is about 67000, the unstable state is reduced, but the airflow is still serious.

According to the principle, the same area is 106 by adopting the tube bundle with the diameter of 30 mu m, the airflow Re is about 670 at the moment, the stable laminar flow state is met, the tube diameter is reduced and the number of the tube bundles is increased in a mode of keeping the sectional area of the flow channel the same, and obviously, the outer diameter of the whole structure is increased.

Based on this, in order to effectively realize stable gas flow in the gas injection channel and further to play an auxiliary role in improving the application effect of the gas injection technology, the embodiment of the present application provides a pore cylinder, referring to fig. 4(a) and 4(b), the pore cylinder 1 specifically includes the following contents:

a pipe 11 for being disposed in the gas injection passage and a plurality of tube bundles 12 filled inside the pipe 11 in a length direction of the pipe 11; a single flow channel 13 is formed inside each tube bundle 12 so that a seepage channel 25 is formed inside the tube 11; wherein the inner diameter, length and permeability of the tube bundle 12 are determined in advance in accordance with a reynolds number for characterizing a flow state of the gas flowing through the inside of the tube 11, and the reynolds number is a positive number smaller than 2300.

Specifically, the specific manner in which the inner diameter, length and permeability of the tube bundle 12 are determined in advance according to the reynolds number used to characterize the flow state of the gas flowing through the pipe 11 is described in detail in the foregoing characterization method of gas seepage stability, and the permeability is reflected in the number of pores and the pore diameter per unit area, and it is obvious that the larger the number is, the smaller the pore diameter is, the lower the reynolds number Re in a single tube is. Varying the length of the tube bundle 12 can also achieve the purpose of varying the resistance at a constant permeability. The resistance increases with increasing length, which in turn lowers the reynolds number Re.

Wherein, if the inner diameter and the permeability of the tube bundle 12 are both preset fixed values, the length limit value of the tube bundle 12 is obtained based on the reynolds number to make the flow state of the gas flowing through the pipeline 11 a laminar flow state, so that the length limit value L of the tube bundle 12 can be determined_limThe flow state is made to be a stable laminar flow state.

From the above analysis, it can be seen that a stable percolation state that the darcy formula conforms to can be achieved by utilizing the pore structure. The pore size of 30 μm is still a hypertonic core for the rock porosity, which is much less spacious.

The pore diameter was analyzed above, and the limit value L of the length of the pore medium (column)_limReferring to fig. 5(a) with specific pressure value, pressure difference and pore space, a control valve 2 is connected in the middle of the pipeline 11, the core component inside the control valve 2 is a pore cylinder 1 with a pore structure, the compactness (permeability) needs to be designed in a targeted way, and the length of the pore cylinder is not less than a limit value L_lim. The flow rate of the gas during the inflow is Q_tinAfter pore structure is Q_poWhen flowing out, it is Q_toutObviously, the three are equal. FIG. 5(b) is a cross-section A-A 'of the control valve 2 inlet line 11 of FIG. 5(a), and FIG. 5(c) is a cross-section A-A' of the control valve 2 inlet line 1 of FIG. 5(a)1, wherein a single flow channel 13 is formed, and the process of conversion of the gas flow from the unstable state to the stable percolation state is shown in fig. 5 (d).

Fig. 5(b) and 5(c) show cross-sectional views of the conduit 11 and the aperture cylinder 1, respectively, with equal flowable areas in the cross-sections. Can be expressed as:

S_A-A′＝S_B-B′·S_g

in the formula: s_A-A′Is the inner diameter section of the flow passage; s_B-B′The cross section of the inner diameter of the control valve 2; s_gThe gas saturation of the pore cylinder 1.

The gas flow direction in fig. 5(d) is the flow direction from the left side duct to the right side duct, showing a flow state in which the gas flow in the left side duct is an unstable flow; after the gas enters the pore area 103 of the control valve, the flow state gradually changes to a stable flow, and a stable flow state is realized within the effective length; after the gas enters the flow state conversion area 104 of the control valve, the stable flow state is gradually converted to unstable state, and the gas in the right pipeline is converted to unstable flow state again after a certain distance.

From the above analysis, it can be seen that in the pore region of the control valve 2, the flow regime is stabilized. The method provides theoretical guidance for quantitative distribution of gas flow.

(II) gas flow regulating and controlling pipe

Based on the above-mentioned control valve 2, in order to effectively realize the stable flow of gas in the gas injection passageway, and then can exert an auxiliary action for improving the application effect of gas injection technique, the embodiment of the present application provides a gas flow control pipe 24, the gas flow control pipe 24 specifically includes as follows:

the metal tube 5, the pore cylinder 1 arranged in the metal tube 5 along the length direction of the metal tube 5, and the sealing layer 6 filled between the metal tube 5 and the pore cylinder 1; a plurality of single channels 13 are respectively formed inside the pore cylinders 1 so that seepage channels are formed inside the pore cylinders 1; wherein, the inner diameter, the length and the permeability of the single flow passage 13 are determined in advance according to the Reynolds number for characterizing the flow state of the gas flowing through the pore cylinder 1, and the Reynolds number is a positive number smaller than 2300.

It is understood that the metal cylinder 5 may be a steel cylinder.

Referring to fig. 6, the pore cylinder 1 may be specifically a regular pore cylinder 14; the regular pore cylinder 14 is a uniform pore cylinder made of metal powder, and the inner diameter of each single flow channel 13 inside the uniform pore cylinder is the same, and the permeability of each single flow channel 13 is 200 to 2000 mD.

Referring to fig. 7, the pore cylinder 1 may be specifically a rock pore cylinder 15; the rock pore cylinder 15 is a non-uniform pore cylinder made of quartz sand, and the permeability of each of the single flow channels 13 inside the non-uniform pore cylinder is 10 to 200 mD.

The gas flow regulating and controlling pipe 24 has a 3-layer structure, the outer layer is a steel cylinder, and the pressure resistance is 40 MPa; the two end surfaces are smooth and are sealed with the O-shaped ring. The middle layer is a sealing layer 6 which is formed by curing epoxy resin and is resistant to pressure of 40 MPa. The interior is a pore cylinder 1, and the two types of pores are regular pores and rock pores.

The parameters described for the pore cylinder 1 are: permeability, diameter, length. The regular pore cylinder 14 is formed by sintering and pressing metal powder and is characterized by uniform pores and strong uniformity; the permeability is in the range of 200-2000 mD. The rock pore cylinder 15 is formed by uniformly cementing and pressing quartz sand grains, and the permeability can be adjusted to be in a range of 10-200 mD.

When the porous column body 1 is manufactured, the porous column body 1 is placed in the middle of a steel cylinder to be cast with epoxy resin, so that a 3-layer structure is integrated.

(III) gas flow stabilization control valve 20

Existing CO₂The multi-stage control valve adopting the needle valve structure principle is used in the large-scale injection existing place, the mechanism still utilizes the needle sealing position of the valve cover 22 and the tiny ring surface and the gap of the valve body 21 to form the control of the gas flow, the calibration error is not less than 10 percent, and the application effect is worse. The valve body 21 is bulky and the height of the valve body 21 controlling a 6cm diameter pipeline is over 70 cm. The valve is expensive, and the unit price is not less than 20 ten thousand yuan. The prior art considers the characteristic that the gas flow and the liquid flow have great difference, and a valve line is arranged on the valve lineIn control, a maze, a corner and other modes are adopted, but the idea is only the extension of the traditional idea, and the principle is not changed.

In order to solve the above problem, based on the control valve 2, on the basis of the theory of analyzing the stable flow of gas flow, to provide a large-flow gas-stabilization control valve that can meet the industrial field application, greatly improve the gas injection precision and achieve quantitative dispensing, an embodiment of the present application further provides a gas-flow-stabilization control valve 20, and referring to fig. 8, the gas-flow-stabilization control valve 20 specifically includes the following contents:

a tubular valve body 21, and valve caps 22 respectively provided at both ends of the valve body 21; a central passage 23 and at least one gas flow rate control pipe 24 respectively disposed inside the valve body 21; at least one gas flow regulating and controlling pipe 24 is independently arranged along the length direction of the valve body 21, and the central channel 23 and the valve body 21 are coaxially arranged; both ends of the central channel 23 and at least one gas flow regulating and controlling pipe 24 respectively pass through the corresponding valve covers 22 to be connected with the respective unique corresponding electromagnetic valves 25, and each electromagnetic valve 25 is respectively in communication connection with a controller 26, and particularly can be connected through a signal line 4; each of the solenoid valves 25 provided at one port of the valve body 21 is adapted to be connected to a gas injection line, and each of the solenoid valves 25 provided at the other port of the valve body 21 is adapted to be connected to a gas injection well 9 via a single well line 8.

Wherein the gas flow rate regulating pipe 24 comprises: at least one first gas flow regulating pipe 241 and at least one second gas flow regulating pipe 242; referring to fig. 6, the pore cylinder 1 of the first gas flow regulating and controlling pipe 241 is a regular pore cylinder 14, and referring to fig. 7, the pore cylinder 1 of the second gas flow regulating and controlling pipe 242 is a rock pore cylinder 15; the regular pore cylinder 14 is a uniform pore cylinder made of metal powder, the inner diameter of each single flow passage 13 in the uniform pore cylinder is the same, and the permeability of each single flow passage 13 is 200 to 2000 mD; the rock pore cylinder 15 is a non-uniform pore cylinder made of quartz sand, and the permeability of each of the single flow channels 13 inside the non-uniform pore cylinder is 10 to 200 mD.

In an embodiment of the gas flow stability control valve 20 provided in the present application, the number of the first gas flow regulating and controlling pipes 241 and the number of the second gas flow regulating and controlling pipes 242 are three.

In an embodiment of the gas flow stabilizing control valve 20 provided in the present application, referring to fig. 8, the gas flow stabilizing control valve 20 further includes the following components: an inlet interface 27, and two ends of the inlet interface are respectively a single-hole port and a multi-hole port; the single-hole port of the inlet connector is used for connecting with a trunk line 3 of the gas injection pipeline; the multi-hole port of the inlet joint is connected with each of the electromagnetic valves 25 at one port of the valve body 21, and the number of each hole in the multi-hole port of the inlet joint is greater than or equal to the number of each of the electromagnetic valves 25 at one port of the valve body 21.

In an embodiment of the gas flow stabilizing control valve 20 provided in the present application, referring to fig. 8, the gas flow stabilizing control valve 20 further includes the following components: an outlet port 28, and both ends of the outlet port are respectively a single-hole port and a multi-hole port; the single-bore port of the outlet connection is used for connecting with the single-well pipeline 8; the multi-hole port of the inlet joint is connected with each of the electromagnetic valves 25 at the other port of the valve body 21, and the number of each hole in the multi-hole port of the inlet joint is greater than or equal to the number of each of the electromagnetic valves 25 at the other port of the valve body 21.

Wherein, a plurality of first bolt holes 211 are respectively arranged at two ends of the valve body 21; correspondingly, referring to fig. 9(a) and 9(b), the valve cover 22 is provided with a second bolt hole 221 corresponding to the position of each first bolt hole 211.

The valve cover 22 is provided with a plurality of through holes 222 corresponding to the central channel 23 and the at least one gas flow regulating and controlling pipe 24 respectively; one end of each through hole 222 close to the valve body 21 is provided with a sealing groove 223.

Specifically, an example of the gas flow stabilizing control valve 20 specifically includes the following:

the cross section of the control valve structure is shown in fig. 8, the cross section has 3 passages, and the number of the passages can be increased or decreased according to the situation.

The control valve consists of a connecting joint, an electromagnetic valve 25, a valve cover 22, a valve body 21 and an electromagnetic valve 25 controller 26. The valve body 21 in fig. 8 is shown with a channel type in the middle, through which the gas passes in a pipe flow; and gas flow regulating pipes 24 are arranged on two sides to regulate the stable flow of gas.

(1) Structure of the product

Connecting joint

The two sides of the joint are respectively provided with a single-hole structure and a porous structure. One side of the single hole is connected with an air injection pipeline, and the multiple holes are respectively connected with the corresponding channel pipelines of the valve body 21.

The joints at the inlet enable the gas to enter the control valve and then be dispersed into each channel, and the joints at the outlet enable the gas flowing out of each channel of the control valve to be collected and output into the single well pipeline 8.

② valve cover 22

The bolt holes in the valve cover 22 are used for bolt fixing; the channel hole has a sealing groove 223 structure, and the inner gas flow regulating and controlling pipe 24 is sealed in the two valve covers 22 after the sealing ring is added.

③ valve body 21

The valve body 21 shown in fig. 10(a) and 10(b) has 7 passages inside, a pipe flow passage at the center, and a seepage passage at the edge. The seepage channels are independent from each other.

The valve body 21 is made of steel. The corresponding position of the valve cover 22 is provided with a bolt hole and an inner screw thread. The seepage channel has larger interval and is convenient to operate. The integral pressure resistance is 40 MPa.

Gas flow regulating and controlling pipe 24

The gas flow regulating and controlling pipe 24 has a 3-layer structure, the outer layer is a steel cylinder, and the pressure resistance is 40 MPa; the two end surfaces are smooth and are sealed with the O-shaped ring. The middle layer is a sealing layer 6 which is formed by curing epoxy resin and is resistant to pressure of 40 MPa. The interior is a pore structure cylinder, and the two types of pores are regular pores and rock pores.

The description parameters of the pore structure cylinder are as follows: permeability, diameter, length. The regular pore cylinder 14 is formed by sintering and pressing metal powder and is characterized by uniform pores and strong uniformity; the permeability is in the range of 200-2000 mD. The rock pore cylinder 15 is formed by uniformly cementing and pressing quartz sand grains, and the permeability can be adjusted to be in a range of 10-200 mD.

When the porous column body 1 is manufactured, the porous column body 1 is placed in the middle of a steel cylinder to be cast with epoxy resin, so that a 3-layer structure is integrated.

Controller 26

The controller 26 is a computer with a hardware interface, collects instantaneous values of the gas flow meter 81, automatically calculates and allocates permeability matching of a plurality of groups of control valves according to the stored permeability parameters of the gas flow adjusting and controlling pipe 24, and controls the on-off of the corresponding electromagnetic valves 25.

(IV) gas flow stable control system

Based on the gas flow stabilizing control valve 20, the embodiment of the present application further provides a gas flow stabilizing control system, referring to fig. 11, which specifically includes the following contents:

a plurality of gas flow stabilization control valves 20; each of the gas flow stabilization control valves 20 is connected to the trunk line 3 of the gas injection line via each of the branch lines 10, respectively, so that each of the branch lines 10 communicates with the gas injection inlet 7 of the gas injection line; an inlet interface 27 and an outlet interface 28 are respectively arranged at two ends of the gas flow stable control valve 20; each of the gas flow stabilization control valves 20 is connected to each of the branch lines 10 via the inlet ports 27 that uniquely correspond to each of the branch lines; each gas flow stability control valve 20 is connected to each individual well line 8 via its respective outlet port 28.

Wherein, each single well pipeline 8 is provided with a gas flowmeter 81, and each gas flowmeter 81 is in communication connection with the controller 26.

The characteristics of the present application will be described below in conjunction with actual conditions at the oilfield site.

The application conditions are as follows: daily gas production of high-pressure gas compressor is 10000Nm at maximum³And d, outputting the highest pressure of 25 MPa. The pressure is 20-23 MPa, and the daily output gas is 7000-9000 Nm³/d。

There are usually not less than 5 orifices between the gas injectionsWells were supplied with gas from the main line and distributed into single-well lines via branch lines, as shown in fig. 11. According to the oil layer condition, the daily water injection amount of the 1# well to the 6# well is designed to be 3000Nm in sequence³、2000Nm³、1500Nm³、1000Nm³、1000Nm³And 500Nm³。

The prior art typically installs a conventional needle-type control valve in the control valve position shown in fig. 11.

The high pressure gas compressor produces gas which enters a branch pipeline after passing through a main pipeline, the flow component processing can not be realized in practical application by utilizing the adjustment method of the clearance between the valve needle and the valve body of the common needle type control valve, and only the control of the relative size of the injection amount can be approximately obtained. The gas distribution can be carried out only according to the gas suction condition of the stratum of each well, and the gas distribution is actually in a state that manual operation cannot be controlled.

② process and effect of using industrial large flow gas stable control valve

The side view of the single well string of FIG. 12 is combined with the two figures to describe the design of the control valve parameters, the installation of the gas flow control tube, and the application of the control valve in the gas injection process.

a. Control valve design

And (4) acquiring parameters such as air suction condition, bottom hole pressure, temperature, oil layer thickness and the like by combining the initial test result of the injection well, and preferably selecting the parameters of the pore structure cylinder in the gas flow regulating and controlling pipe. Since the diameter and length of the internal channel of the machined valve body are determined, only the permeability of the pore structure cylinder is adjusted.

Usually, 3 regular pore cylinders and 3 rock pore cylinders are installed in the control valve, and the pore cylinders with different permeability levels are beneficial to the adjustment of the gas distribution of a single well in a main line. According to the design amount of gas injection, the permeability of the flow control valves of the 1# well to the 6# well is reduced in sequence according to a certain proportion. Exemplary partitioning is shown in table 3, where 1# and 2# are identically configured and have the highest average permeability; 3#, 4# and 5# are configured identically; the average permeability was lowest for the 6# configuration.

TABLE 3 gas flow control pipe Permeability design

b. Installation of gas flow regulating and controlling pipe

The gas flow regulating and controlling pipe is required to be manufactured into a series of products according to the permeability grade and cast into a whole. Parameters are determined by permeability testing and their values are accurate to a single bit, e.g., 1788 mD. The permeability example values in table 3 are also corresponding values and may fluctuate by a certain magnitude, for example a 2000mD gas flow regulator tube is typically replaced by a 1788mD tube.

Specifically, the installation method of the gas flow stability control system provided in the embodiment of the present application, referring to fig. 13, specifically includes the following steps:

s100: and coaxially installing the pore cylinder into the metal cylinder, and filling a sealing layer between the metal cylinder and the pore cylinder to form the gas flow regulating and controlling pipe.

S200: and respectively installing at least one gas flow regulating and controlling pipe into the valve body.

S300: and sending the corresponding position information of at least one gas flow regulating and controlling pipe in the valve body to the controller for storage.

S400: and respectively installing the two valve covers at two ends of the valve body, and respectively and fixedly connecting the inlet interface and the outlet interface to the corresponding valve covers.

S500: connecting each of the inlet ports to each of the branch lines, respectively, and connecting each of the outlet ports to each of the single well lines, respectively.

And respectively installing the regular pore control pipe and the rock pore control pipe in the valve body, recording corresponding positions, and inputting the corresponding positions into corresponding files of the controller.

After the gas flow regulating and controlling pipe is installed in the valve body, the valve covers on two sides are installed well, and the gas flow regulating and controlling pipe is ensured to be in an independent and sealed state. The single flow control valve is installed.

c. Use of control valve in gas injection process

And respectively installing the installed control valves at corresponding positions, namely connecting the control valves with the main line and the single-well pipeline.

When the method is applied, the target gas injection quantity of the corresponding single well is input in the controller computer, and the data corresponding to the permeability of each control valve is determined to be accurate.

Step 1: the solenoid valves on both sides of the central passage in the 6 control valves are all opened, and the other solenoid valves are all closed.

Step 2: the high pressure gas compressor is turned on and gas is injected into the main line and the single well. After the operation is stable (5min), the automatic configuration function of the controller is started.

And 3, step 3: the computer automatically controls the electromagnetic valves on two sides of the gas flow regulating and controlling pipe corresponding to the parallel large-flow control valve.

For example: following the design in table 3 and the parallel flow scheme in fig. 14. The computer may first turn on well # 1: 2000; 2# well: 1000 and 500; 3# well: 1000, parts by weight; 4# well: 500, a step of; 5# well: 500 and 6# wells: 200, where K1-Kn represents the permeability value or range of values for each well, where n equals 6 in fig. 14. In practical application, n may be set to be a positive integer greater than 6. And adjusting the corresponding control valve according to the instantaneous flow feedback of the single well. The process continues to adjust until the flow in the branch flow reaches the allowed range.

And 4, step 4: if the controller fails to adjust the balance comprehensively, the suggested permeability value of the gas flow regulating and controlling pipe or the whole set of control pipes in a certain control valve is given. A new control valve adjustment is required which is performed at most once for a design shot size.

To sum up, the gas flow regulating and controlling pipe, the gas flow stability control valve, the gas flow stability control system and the installation method of the gas flow stability control provided by the embodiment of the application have the following advantages:

1. the invention provides a control device which can meet the requirement that large-flow gas forms stable flow, and has the function of adjusting the flow of a single well when multiple wells are injected simultaneously;

2. the control valve has simple structure and convenient core replacement operation, and the working range of the control valve can be adjusted.

3. The flow regulation of the control valve is controlled by a program, and the comprehensive regulation and control of the number of multiple wells on the whole trunk line are realized.

4. The control valve has relatively low price and is suitable for comprehensive conditions of domestic gas injection oil fields.

It is noted that, in this document, relational terms are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element. The terms "upper", "lower", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention is not limited to any single aspect, nor is it limited to any single embodiment, nor is it limited to any combination and/or permutation of these aspects and/or embodiments. Moreover, each aspect and/or embodiment of the present invention may be utilized alone or in combination with one or more other aspects and/or embodiments thereof.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.