Underground throttler and intelligent throttling system

Abstract

The invention discloses an underground throttler and an intelligent throttling system.The underground throttler comprises an upper connector, a circuit assembly, a first pressure measuring assembly, an air tap switch and an air inlet device which are sequentially connected, a second pressure measuring assembly is arranged on the air inlet device, and the circuit assembly, the first pressure measuring assembly and the air tap switch are packaged in a hollow pipeline; two ends of the hollow pipeline are respectively sealed and fixed on the upper joint and the air inlet device; the first pressure measuring assembly is used for detecting first pressure information flowing into the hollow pipeline, and the second pressure measuring assembly is used for detecting second pressure information outside the hollow pipeline; the circuit assembly is used for adjusting the opening degree of the air tap switch according to the first pressure information and / or the second pressure information. According to the method, the underground throttling cost can be reduced, and the intelligent degree of underground throttling is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil field stratified water injection and oil recovery, and in particular relates to a downhole throttle and an intelligent throttling system. Background Art

[0002] The downhole throttling technology relies on special downhole equipment to achieve wellbore throttling and pressure reduction, and uses ground temperature heating to restore the wellhead air flow temperature after throttling to the temperature before throttling, which is helpful to solve many technical problems in the wellbore and on the ground during gas well production. The failure of the throttling device will affect normal downhole operations and increase operating costs.

[0003] The downhole throttling process of gas wells installs the throttling device at the appropriate position of the oil pipe to achieve downhole pressure regulation, which can make full use of geothermal heat to heat the throttled natural gas, thereby changing the formation conditions of natural gas hydrates and playing a positive role in preventing the formation of hydrates. After downhole throttling, the gas expands due to the reduction in pressure, and the pressure energy of the gas is converted into kinetic energy, which increases the gas flow velocity and is beneficial to improving the liquid carrying capacity of the gas well.

[0004] The downhole choke commonly used in current gas fields does not have the function of automatically adjusting the gas nozzle. If the gas nozzle needs to be opened or closed, an auxiliary device needs to be sent down to the position of the downhole choke. The labor cost and operating cost required to send the auxiliary device down each time are high. Summary of the invention

[0005] The embodiments of the present invention provide a downhole throttle and an intelligent throttling system, which can solve the problems of low intelligence and high cost of the current gas nozzle adjustment method of the downhole throttle.

[0006] In a first aspect, an embodiment of the present invention provides a downhole choke, comprising: an upper joint, a circuit assembly, a first pressure measuring assembly, a gas nozzle switch, an air intake device, a second pressure measuring assembly and a hollow pipe; One end of the upper joint is fixedly connected to one end of the circuit assembly, the other end of the circuit assembly is fixedly connected to one end of the first pressure measuring assembly, the other end of the first pressure measuring assembly is fixedly connected to one end of the gas nozzle switch, the other end of the gas nozzle switch is fixedly connected to one end of the air intake device, and the second pressure measuring assembly is fixed on the air intake device; The circuit component, the first pressure measuring component and the air nozzle switch are encapsulated in the hollow pipe, and the two ends of the hollow pipe are sealed and fixed on the upper joint and the air intake device respectively; the first pressure measuring component is used to detect the first pressure information flowing into the hollow pipe, and the second pressure measuring component is used to detect the second pressure information outside the hollow pipe; the circuit component is used to adjust the opening of the air nozzle switch according to the first pressure information and / or the second pressure information.

[0007] In a possible implementation of the first aspect, the circuit component is specifically used to adjust the opening of the air nozzle switch according to the difference between the first pressure information and the second pressure information and according to a pressure difference-opening comparison table preset by the user.

[0008] In a possible implementation of the first aspect, the circuit component is specifically used to identify the air nozzle opening instruction issued by the host computer according to the first pressure information, and adjust the opening of the air nozzle switch according to the air nozzle opening instruction.

[0009] In a possible implementation manner of the first aspect, the circuit component is specifically used to adjust the opening of the air nozzle switch according to the time that the second pressure information continues to be less than a preset pressure threshold.

[0010] In a possible implementation manner of the first aspect, the downhole choke further includes a motor reducer, and the motor reducer is disposed between the first pressure measuring assembly and the air nozzle switch.

[0011] In a possible implementation manner of the first aspect, the air nozzle switch includes an air nozzle switch valve sleeve having a triangular cross-section.

[0012] In a second aspect, an embodiment of the present invention provides an intelligent throttling system, comprising: a host computer, a ground controller, an electric needle valve, a vertical shaft pipeline, and a downhole throttling device as described in the first aspect; The host computer is connected to the ground controller signal, the ground controller is connected to the electric needle valve signal, the valve needle of the electric needle valve is circumferentially fixed to the outer surface of the ground pipe of the shaft pipe, and the downhole throttle is fixed to the inner wall of the underground pipe of the shaft pipe.

[0013] In a possible implementation of the second aspect, a sliding sleeve is further fixed on the inner wall of the underground pipeline above the downhole choke, and a pipeline nipple is further fixed on the inner wall of the underground pipeline above the sliding sleeve; When the maximum flow rate after throttling by the downhole throttle still cannot meet the flow demand of the underground pipeline, the pipeline short section falls off and breaks the sliding sleeve to achieve oil-casing connection, so as to provide the underground pipeline with a larger gas flow rate.

[0014] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the downhole choke provided by the present invention automatically adjusts the valve opening through the pressure information detected by the two pressure measuring components, and there is no need to send other physical auxiliary equipment downhole, which can improve the intelligence of the downhole choke and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of a downhole choke provided by an embodiment of the present invention; Figure 2 A schematic diagram of the relationship between opening, pressure loss and flow rate provided in an embodiment of the present invention; Figure 3 A schematic diagram of a wave code communication sequence provided by an embodiment of the present invention; Figure 4 A schematic diagram of the specific structure of the gas nozzle switch provided in an embodiment of the present invention; Figure 5 A schematic diagram of the structure of an intelligent throttling system provided in an embodiment of the present invention.

[0016] Reference numerals: 1: upper connector; 2: circuit assembly; 3: first pressure measuring assembly; 4: air nozzle switch; 41: air nozzle switch valve sleeve; 5: air intake device; 51: first air inlet; 52: second air inlet; 6: second pressure measuring assembly; 7: hollow pipe; 8: motor reducer; 9: battery assembly; 100: downhole throttle; 510: host computer; 520: ground controller; 530: electric needle valve; 540: vertical shaft pipeline; 550: sliding sleeve; 560: pipeline short section; 500: intelligent throttling system. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0018] Example 1 Figure 1 The structure diagram of a downhole choke provided by an embodiment of the present invention is shown. As an example but not limitation, the downhole choke 100 may include an upper connector 1, a circuit component 2, a first pressure measuring component 3, a nozzle switch 4, an air intake device 5, a second pressure measuring component 6 and a hollow pipe 7.

[0019] In a possible implementation, one end of the upper connector 1 is fixedly connected to one end of the circuit assembly 2, the other end of the circuit assembly 2 is fixedly connected to one end of the first pressure measuring assembly 3, the other end of the first pressure measuring assembly 3 is fixedly connected to one end of the air nozzle switch 4, the other end of the air nozzle switch 4 is fixedly connected to one end of the air intake device 5, and the second pressure measuring assembly 6 is fixed on the air intake device 5. In addition, the upper connector 1 and the air intake device 5 are both along the first direction (see Figure 1 The circuit assembly 2, the first pressure measuring assembly 3 and the air nozzle switch 4 can be encapsulated in the hollow pipe 7, and the two ends of the hollow pipe 7 are sealed and fixed on the upper joint 1 and the air intake device 5 respectively.

[0020] The air inlet device 5 may also be provided with a first air inlet 51 penetrating through one side and a second air inlet 52 provided at the bottom of the inner hollow cavity. Figure 1 The direction indicated by the middle arrow 102) can be perpendicular to the first direction. When multiple downhole throttles are connected in series, the gas transmitted by the throttle of the next layer can be input from the second air inlet 52 of the air inlet device 5 of the throttle of this layer along the first direction, and the gas in the same layer as the throttle of this layer is input from the first air inlet 51. The two are mixed at the air inlet and flow through the hollow pipe 7 and the upper joint 1 to be transmitted to the throttle of the upper layer. The lower end of the second air inlet 52 of the throttle at the bottom can be connected to a blind pipe. When no gas flows in, pipeline impurities can be temporarily stored in the blind pipe. When a single throttle is used, the lower end of its second air inlet 52 is also connected to a blind pipe. No gas flows into the second air inlet 52. The blind pipe temporarily stores pipeline impurities. The gas is input from the first air inlet 51 and flows through the hollow pipe 7 and the upper joint 1.

[0021] In one example, the downhole choke 100 may further include a motor reducer 8 , and the motor reducer 8 may be disposed between the first pressure measuring assembly 3 and the air nozzle switch 4 .

[0022] In one example, the downhole choke 100 may further include a battery assembly 9 , which may be disposed between the upper connector 1 and the circuit assembly 2 to supply power to the circuit assembly 2 .

[0023] For example, the circuit assembly 2 can be connected to the first pressure measurement assembly 3 and the second pressure measurement assembly 6 to receive pressure information from the first pressure measurement assembly 3 and the second pressure measurement assembly 6. Meanwhile, the battery assembly 9 can be connected to the circuit assembly 2 to supply power to the circuit assembly 2.

[0024] In a possible implementation, the first pressure measuring component 3 can detect the first pressure information in the hollow pipe 7 after the gases from different formations are mixed, and the second pressure measuring component 6 can detect the second pressure information around the second air inlet 52 outside the hollow pipe 7. The circuit component 2 can adjust the opening of the gas nozzle switch 4 according to the first pressure information and / or the second pressure information.

[0025] In one example, the circuit component 2 can adjust the valve opening according to the difference between the first pressure information and the second pressure information and according to a pressure difference-valve opening comparison table set by the user.

[0026] Specifically, the circuit assembly 2 can drive the internal motor to rotate, and the motor reducer 8 can adjust the rotation of the motor inside the circuit assembly 2 and transmit it to the air nozzle switch 4, thereby adjusting the opening of the air nozzle switch 4.

[0027] For example, see Figure 2 According to the pressure loss theory ,in, is the pressure difference, is the friction coefficient, is the gas density, is the gas flow rate; the equivalent intake area of ​​the downhole choke 100 will change with the opening of the gas nozzle switch 4, and the gas flow rate of the downhole choke 100 may have a certain relationship with the pressure loss of the downhole choke 100 and the opening of the gas nozzle switch 4. The user can test before going down the well to obtain the opening-pressure loss-flow relationship diagram of the downhole choke 100, thereby obtaining a pressure difference-gas nozzle opening comparison table; according to the table, adjust the opening of the gas nozzle switch 4 according to the desired flow.

[0028] For details, see Figure 2 The flow-opening relationship curves under different pressure differences are shown, where the pressure difference △P1>△P2>△P3. It can be seen that when the pressure difference is constant, the nozzle opening and the flow rate have a certain linear relationship.

[0029] In another example, the circuit component 2 can also identify the air nozzle opening instruction transmitted by the upper computer based on wave code communication according to the first pressure information, and then drive the motor inside the circuit component 2 to adjust the opening of the air nozzle switch 4 according to the air nozzle opening instruction.

[0030] For example, the downhole choke 100 is generally arranged in the downhole pipeline, and the gas pressure in the pipeline can be determined according to the gas flow rate of the surface pipeline. When the gas flow rate of the surface pipeline is different, the first pressure information will also change accordingly. If the gas flow rate of the surface pipeline is based on a certain sequence (see Figure 3 The first pressure measuring component 3 can monitor the sequence, so that the circuit component 2 can identify the air nozzle opening instruction according to the preset sequence comparison table and control the opening of the air nozzle switch 4.

[0031] Alternatively, see Figure 3 In the sequence for indicating the valve opening instruction, the absolute values ​​of the positive peak duration T1 and its corresponding pressure peak and the negative peak duration T2 and its corresponding pressure peak are not necessarily the same.

[0032] In yet another example, the circuit component 2 may also adjust the opening of the air nozzle switch 4 according to the time that the second pressure information is continuously less than a preset pressure threshold.

[0033] For example, when the circuit component 2 detects that the second pressure information is continuously less than the preset pressure threshold for a period longer than the preset time threshold, the circuit component 2 adjusts the opening of the air valve switch 4 .

[0034] Optionally, a flowback time may be set before the downhole choke 100 is lowered into the well. After the downhole choke 100 is lowered into the well, the gas nozzle opening is kept at a maximum within the flowback time, and throttling is automatically performed when the flowback time is exceeded.

[0035] In one possible implementation, see Figure 4 The air nozzle switch 4 may include an air nozzle switch valve sleeve 41 .

[0036] For example, a circular hole can be opened in the center of the air nozzle switch 4, and the air nozzle switch valve sleeve 41 can be pushed by a piston fixed therebehind. When the user needs a smaller air nozzle opening, the piston blocks the circular hole in a first direction to prevent the gas in the air intake device 5 from entering the hollow pipe; when the user needs a larger air nozzle opening, the piston drives the air nozzle switch valve sleeve to move in the opposite direction of the first direction, reducing the blocked area of ​​the circular hole, thereby increasing the air nozzle opening.

[0037] In one example, the cross-section of the air nozzle switch valve sleeve 41 can be triangular. Compared with valve sleeves of other shapes such as rectangle and circle, the triangular valve sleeve has more obvious adjustment characteristics and better adjustment effect.

[0038] According to the downhole throttle provided by the present invention, the air nozzle opening is automatically adjusted by the pressure difference detected by the two pressure measuring components, or the air nozzle opening instruction is automatically adjusted by the air nozzle switch based on the wave code communication, and there is no need to send other physical auxiliary equipment to the underground, which can improve the intelligence of the downhole throttle and reduce costs.

[0039] Example 2 Figure 5 The structure diagram of an intelligent throttling system provided by an embodiment of the present invention is shown. As an example but not limitation, the intelligent throttling system 500 may include a host computer 510, a ground controller 520, an electric needle valve 530, a shaft pipeline 540, and a downhole throttling device 100.

[0040] In one possible implementation, the host computer 510 is connected to the ground controller 520 by signal (for example, via a bridge signal connection), the ground controller 520 is connected to the electric needle valve 530 by signal (for example, via a cable signal connection), the valve needle of the electric needle valve 530 is circumferentially fixed to the outer surface of the ground pipe of the shaft pipe 540, and the downhole throttle 100 is fixed to the inner wall of the underground pipe of the shaft pipe 540.

[0041] For example, the user can input the valve opening instruction in the host computer 510, which is sent by the host computer 510 to the ground controller 520. The ground controller 520 can control the electric needle valve 530 to squeeze the ground pipeline according to the valve opening instruction, so that the gas flow of the ground pipeline is in accordance with the sequence corresponding to the valve opening instruction (see Figure 3) changes. The first pressure information of the underground pipeline detected by the first pressure measuring component 3 inside the downhole choke 100 can indicate the change of gas flow. The downhole choke 100 can identify the gas nozzle opening instruction through the first pressure information and change its gas nozzle opening according to the gas nozzle opening instruction.

[0042] In one example, see Figure 5 On the inner wall of the underground pipeline of the shaft pipeline 540, a sliding sleeve 550 can also be arranged above the downhole choke 100, and the sliding sleeve 550 is connected to the inner wall of the underground liquid delivery pipeline through shear nails. Inside the underground liquid delivery pipeline, above the sliding sleeve 550, a pipeline short section 560 is also arranged near the ground.

[0043] When a larger gas nozzle opening is needed later, the pipeline short section 560 can be controlled to fall and break the shear nails connecting the sliding sleeve 550 and the inner wall of the underground liquid delivery pipeline, so as to achieve oil-casing connection and ensure smooth gas extraction.

[0044] According to the intelligent throttling system provided by the present invention, the intelligence of the system can be improved by adopting a downhole throttle that can intelligently adjust the gas nozzle opening, and the cost of adjusting the gas nozzle opening of the system can be reduced. Furthermore, by setting a sliding sleeve and a tubing nipple, the final guarantee for gas collection can be provided to ensure the efficiency of gas collection.

[0045] In the above embodiments, the description of each embodiment has its own emphasis. For the part that is not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

Claims

1. A downhole choke, characterized in that: include: An upper joint, a circuit assembly, a first pressure measuring assembly, a nozzle switch, an air intake device, a second pressure measuring assembly and a hollow pipe; One end of the upper joint is fixedly connected to one end of the circuit assembly, the other end of the circuit assembly is fixedly connected to one end of the first pressure measuring assembly, the other end of the first pressure measuring assembly is fixedly connected to one end of the gas nozzle switch, the other end of the gas nozzle switch is fixedly connected to one end of the air intake device, and the second pressure measuring assembly is fixed on the air intake device; The circuit assembly, the first pressure measuring assembly and the air nozzle switch are encapsulated in the hollow pipe, and the two ends of the hollow pipe are sealed and fixed on the upper joint and the air intake device respectively; the first pressure measuring assembly is used to detect the first pressure information flowing into the hollow pipe, and the second pressure measuring assembly is used to detect the second pressure information outside the hollow pipe; The circuit component is used to adjust the opening of the air nozzle switch according to the first pressure information and / or the second pressure information.

2. The downhole choke according to claim 1, characterized in that: The circuit component is specifically used to adjust the opening of the air nozzle switch according to the difference between the first pressure information and the second pressure information and according to a pressure difference-opening comparison table preset by the user.

3. The downhole choke according to claim 1, characterized in that: The circuit component is specifically used to identify the air nozzle opening instruction sent by the host computer according to the first pressure information, and adjust the opening of the air nozzle switch according to the air nozzle opening instruction.

4. The downhole choke according to claim 1, characterized in that: The circuit component is specifically used to adjust the opening of the air nozzle switch according to the time that the second pressure information is continuously less than a preset pressure threshold.

5. The downhole choke according to claim 1, characterized in that: The downhole choke further includes a motor reducer, and the motor reducer is arranged between the first pressure measuring assembly and the air nozzle switch.

6. The downhole choke according to claim 1, characterized in that: The air nozzle switch comprises an air nozzle switch valve sleeve with a triangular cross section.

7. An intelligent throttling system, characterized in that: include: A host computer, a ground controller, an electric needle valve, a shaft pipeline, and a downhole choke as claimed in any one of claims 1 to 6; The host computer is connected to the ground controller signal, the ground controller is connected to the electric needle valve signal, the valve needle of the electric needle valve is circumferentially fixed to the outer surface of the ground pipe of the shaft pipe, and the downhole throttle is fixed to the inner wall of the underground pipe of the shaft pipe.

8. The intelligent throttling system according to claim 7, characterized in that: A sliding sleeve is also fixed on the inner wall of the underground pipeline above the downhole choke, and a pipeline nipple is also fixed on the inner wall of the underground pipeline above the sliding sleeve; When the maximum flow rate after throttling by the downhole throttle still cannot meet the flow demand of the underground pipeline, the pipeline short section falls off and breaks the sliding sleeve to achieve oil-casing connection, so as to provide the underground pipeline with a larger gas flow rate.

Images