A wire-free downhole flow pressure monitoring tool and method

Abstract

The application relates to the field of oil and gas production engineering in the petroleum industry and discloses a downhole flow pressure monitoring tool without a steel wire, which comprises a fishing unit and a monitoring unit. The monitoring unit comprises a pressure measuring tool cylinder, a battery, a control circuit and a pressure sensor. A striker is axially slidably matched in the pressure measuring tool cylinder. A clamping mechanism is arranged in the pressure measuring tool cylinder. The striker can push the clamping mechanism to pop out to both sides of the pressure measuring tool cylinder in the process of upward movement. The fishing unit comprises a fishing cylinder. The fishing cylinder can be clamped and connected with the pressure measuring tool cylinder and press the clamping mechanism back into the pressure measuring tool cylinder. The outer diameter of the fishing cylinder is larger than that of the pressure measuring tool cylinder and can be in contact with the tubing sidewall in the well. The application effectively improves the safety by eliminating the steel wire for pressure measurement.

Description

Technical Field

[0001] This invention relates to the field of oil and gas production engineering in the petroleum industry, specifically to a wire-free downhole flowing pressure monitoring tool and method. Background Technology

[0002] Dynamic monitoring is a fundamental and crucial task in gas reservoir operation and management. Establishing and improving a reasonable dynamic monitoring plan is an important link in the effective management of gas field development and production and the improvement of the recovery rate of water-bearing gas reservoirs. Therefore, it is essential to grasp the changing patterns of gas reservoir development stages, effectively understand the gas reservoir production capacity, accurately understand the gas reservoir production dynamics, scientifically select gas production technologies, and correctly analyze the application effects of gas production technologies to ensure that the entire gas reservoir development process is under effective monitoring, providing corresponding supporting technologies for the implementation and adjustment of gas reservoir development plans.

[0003] Downhole flowing pressure is crucial for dynamic analysis of gas well production and is of great significance for adjusting production systems. Currently, downhole flowing pressure data is mainly collected using two methods. One method involves inserting a steel wire into the well, with a pressure measuring tool suspended on the wire to obtain the flowing pressure data. However, continuous downhole flowing pressure monitoring using a steel wire-suspended pressure measuring tool takes anywhere from several days to several months, resulting in a long construction period. Furthermore, the use of additional tools to secure the steel wire and the tool increases costs and time. Additionally, since the steel wire needs to be suspended at the wellhead, and the wellhead seal is a dynamic seal, it can easily affect the wellhead's sealing performance, resulting in a low sealing and pressure resistance rating. This makes it prone to gas leakage when pressure surges upwards from the well, posing a certain safety hazard.

[0004] Secondly, the use of electronic release devices to directly monitor well pressure and temperature can achieve continuous monitoring for a longer period of time. However, although the electronic release device can be directly attached to the inside of the tubing without being suspended from a wire, the wire is still required during the process of lowering the electronic release device into the well and removing it from the wellhead, which still presents the aforementioned problems. Summary of the Invention

[0005] The present invention aims to provide a wireless downhole flowing pressure monitoring tool and method to improve safety by eliminating the need for wire pressure measurement.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a wireless downhole flowing pressure monitoring tool, comprising a retrieval unit and a monitoring unit. The monitoring unit includes a pressure measuring tool cylinder, a battery, a control circuit, and a pressure sensor. An axially sliding striker is fitted inside the pressure measuring tool cylinder. A locking mechanism is provided inside the pressure measuring tool cylinder. During the upward movement of the striker, the locking mechanism can be pushed to pop out to both sides of the pressure measuring tool cylinder. The retrieval unit includes a retrieval cylinder, which can engage with the pressure measuring tool cylinder and press the locking mechanism back into the pressure measuring tool cylinder. The outer diameter of the retrieval cylinder is larger than the outer diameter of the pressure measuring tool cylinder, and the retrieval cylinder can slide along the sidewall of the tubing inside the well.

[0007] The principle and advantages of this scheme are as follows: In practical application, a limiter is pre-installed in the well, located at the bottom of the tubing. The inner diameter of the pressure testing tool cylinder is smaller than that of the tubing, facilitating the smooth entry of the pressure testing tool cylinder and other mechanisms into the well. Simultaneously, the gas in the well can pass through, reducing the pushing force exerted by the gas pressure on the pressure testing tool cylinder, making it easier for the tool cylinder to stop in the well. Furthermore, it facilitates the later connection and assembly of the pressure testing tool cylinder and the retrieval cylinder; the retrieval cylinder is fitted outside the pressure testing tool cylinder, pressing the locking mechanism back into the tool cylinder. After the monitoring unit is deployed into the well, the striker inside the pressure testing tool cylinder impacts the limiter in the well, causing the striker to move upwards along the tool cylinder. During this upward movement, the striker pushes the locking mechanism to both sides of the tool cylinder, thus abutting against the inner wall of the tubing and fixing it in place. This ensures the entire monitoring unit stops downhole, preventing the pressure testing tool cylinder from moving upwards due to the pressure of the gas in the well.

[0008] In this design, the retrieval tube can be integrated with the pressure testing tool tube. Simultaneously, the retrieval tube can press the locking mechanism back into the pressure testing tool tube, thus disengaging it from the tubing. The retrieval tube can slide along the tubing sidewall within the well. In actual design, the gap between the retrieval tube and the tubing sidewall is very small, approximately 1-2 mm, resulting in a small gas flow. This allows the retrieval tube and pressure testing tool tube to be pushed upwards using the pressure of the gas inside the well when data needs to be obtained, facilitating data acquisition.

[0009] In this solution, when pressure monitoring is required, simply open the wellhead, insert the monitoring unit into the well, and then close the wellhead. This avoids the impact of using steel wire on the wellhead's sealing performance. This solution does not alter the wellhead's sealing structure itself, effectively improving the sealing level and thus increasing the pressure resistance level. The pressure inside the well is less likely to leak, making it safer.

[0010] Furthermore, since this solution eliminates the need for steel wire, it reduces the number of components required for fixing and installing the wire, shortening the construction period. This solution incurs no additional costs; only a monitoring unit and a retrieval unit are needed to achieve the purpose of monitoring and data acquisition. The entire pressure measurement process in this solution does not require steel wire, which improves wellhead sealing, increases monitoring efficiency, shortens the construction period, reduces monitoring costs, and enhances safety. This solution provides a new monitoring method for gas well flowing pressure monitoring and has broad application prospects.

[0011] Preferably, as an improvement, the locking mechanism includes a locking slip that slides radially along the pressure measuring tool cylinder, a through hole is provided on the side wall of the pressure measuring tool cylinder, the locking slip slides with the through hole, and a reset member is connected between the locking slip and the pressure measuring tool cylinder.

[0012] In this design, when the firing pin moves upward, it will push the slip to pop out of the pressure testing tool tube. When the retrieval tube and the pressure testing tool tube are connected, the slip will be pushed into the pressure testing tool tube. In this design, the slip can freely retract or pop out of the pressure testing tool tube as a reset component. Its structure is simple.

[0013] Preferably, as an improvement, the pressure measuring tool cylinder has slots on both sides, the slots being located above the slips. The pressure measuring tool cylinder contains vertical and horizontal rods that are perpendicular to each other. One end of the vertical rod is connected to the firing pin, and the other end is connected to the horizontal rod. Both ends of the horizontal rod are slidably fitted with locking components along its axial direction. A locking spring connects the locking component to the horizontal rod, and a compression spring connects the horizontal rod to the top wall of the pressure measuring tool cylinder. When the vertical rod moves upward, causing the locking component to move to the slot position, the locking component can be locked in the slot. During the engagement of the retrieval unit and the monitoring unit, the locking component can be pressed back against the inner wall of the pressure measuring tool cylinder.

[0014] In this design, the cooperation between the slot and the locking element allows the locking element to pop out of the pressure testing tool cylinder under the action of the locking spring and lock onto the slot during the upward movement of the impact pin, thus achieving a limit. This ensures the stability of the impact pin's support for the slips, prevents the slips from rebounding, and allows the pressure testing tool cylinder and the oil pipe to form a stable fixed state, thereby facilitating stable monitoring.

[0015] Once the salvage unit and the monitoring unit are engaged, and the locking piece is pressed back into the pressure testing tool cylinder, the firing pin will be pushed downwards by the rebound of the compression spring, thus losing support for the locking piece. The locking piece will then retract into the pressure testing tool cylinder under the action of the reset piece.

[0016] Preferably, as an improvement, the inner diameter of the retrieval tube is larger than the outer diameter of the pressure measuring tool tube, the bottom end of the retrieval tube is an open end, and a pressure groove is provided at the bottom of the retrieval tube. When the pressure groove moves to the slot position, it can press the clamp back into the pressure measuring tool tube.

[0017] The bottom of the retrieval tube in this design has a pressure groove that can press the retaining element back into the pressure testing tool tube during the process of the retrieval tube and the pressure testing tool tube being combined, making its structure and usage simpler.

[0018] Preferably, as an improvement, the top end of the pressure testing tool cylinder is connected to a first retrieval neck, and the top end of the retrieval cylinder is connected to a second retrieval neck. The longitudinal sections of both the first and second retrieval necks are T-shaped. The retrieval cylinder is also provided with two connecting plates. The connecting plates and the inner wall of the retrieval cylinder are both connected to tension springs. The sides of the connecting plates that are directly opposite each other are connected to a locking protrusion. The locking protrusion is located above the pressure groove. When the pressure groove presses the locking piece back into the pressure testing tool cylinder, the locking protrusion can be locked onto the first retrieval neck.

[0019] In this design, the first and second retrieval necks are swan neck structures, which facilitates the removal of the monitoring unit and retrieval unit from the wellbore through retrieval operations in the later stages.

[0020] In addition, in this solution, a connecting plate is set on the inner wall of the retrieval cylinder and a locking protrusion is set on the connecting plate. The locking protrusion will retract and pop out under the action of the tension spring. When the locking protrusion contacts the upper part of the first retrieval neck, the tension spring will be compressed to ensure that the locking protrusion passes through the upper part of the first retrieval neck. After the locking protrusion passes through the upper part of the first retrieval neck, the tension spring returns to its original position and the locking protrusion is located at the neck of the first retrieval neck. This realizes the connection between the retrieval cylinder and the pressure measuring tool cylinder, thus forming a whole, which is convenient for the whole to be pushed upward by gas.

[0021] Preferably, as an improvement, the number of slips is greater than or equal to two, and the slips are distributed circumferentially along the pressure measuring tool cylinder.

[0022] With this configuration, the valve can enhance the uniform contact between the pressure testing tool barrel and the oil pipe, allowing the pressure testing tool barrel to maintain a relatively stable pressure testing state.

[0023] Preferably, as an improvement, both the top end of the firing pin and the bottom end of the slip are provided with inclined surfaces, and when the slip is located inside the pressure measuring tool cylinder, the inclined surface at the top end of the firing pin and the inclined surface at the bottom end of the slip are directly opposite each other.

[0024] With this configuration, a wedge-shaped fit is formed between the striker and the slip in this solution, making it easier for the striker to push the slip out of the pressure testing tool cylinder during its upward movement.

[0025] Preferably, as an improvement, the outer side of the pressure measuring tool cylinder is connected with a plurality of straightening wings along its circumference.

[0026] This design requires the outer diameter of the pressure testing tool barrel to be smaller than the outer diameter of the tubing so that the pressure testing tool barrel can be placed smoothly in the well. However, this will result in a gap between the pressure testing tool barrel and the tubing, which may cause the pressure testing tool barrel to tilt. The straightening wing in this design can straighten the pressure testing tool barrel and ensure that it is in a centered position. This facilitates the connection and integration of the retrieval barrel and the pressure testing tool barrel later, while also meeting the fluid flow requirements.

[0027] Preferably, as an improvement, the outer side of the retrieval tube is provided with rectangular teeth, which are located above the retrieval tube.

[0028] With this design, the rectangular teeth on the retrieval cylinder can carry out the dirt in the well as the retrieval cylinder moves upward, which is more conducive to the floating of the retrieval unit and the monitoring unit.

[0029] A wireless downhole flowing pressure monitoring method, using the aforementioned wireless downhole flowing pressure monitoring tool, comprises the following steps:

[0030] Step 1: A limiter is pre-installed in the well. The monitoring unit is then inserted into the well from the tubing. The striker abuts against the limiter in the well. The striker moves upward, causing the locking mechanism to pop out to both sides of the pressure measuring tool cylinder and abut against the side wall of the tubing, and stop downhole. The monitoring unit then monitors the downhole flowing pressure in real time.

[0031] Step two: The monitoring unit collects and stores downhole pressure data;

[0032] Step 3: When pressure data is needed, close the wellhead and deploy the retrieval unit. The retrieval unit and the monitoring unit are engaged to form a single unit. At the same time, the retrieval unit pushes the locking mechanism back into the pressure measuring tool cylinder.

[0033] Step four: Open the well. The gas generated inside the well will push the monitoring unit and the retrieval unit upwards and back into the blowout preventer at the wellhead. After retrieving the monitoring unit and the retrieval unit, obtain the pressure data.

[0034] During production, the monitoring unit is lowered from the tubing into the well. In the actual design, the pressure testing tool cylinder has a lantern-shaped frame to ensure the tool is centered while allowing sufficient fluid flow. This ensures that the pressure testing tool cylinder rests on the tubing's pre-set limiter during production, enabling real-time monitoring of downhole flowing pressure. After shutting in the well, the retrieval unit is deployed. Once the retrieval cylinder and the pressure testing tool cylinder are aligned, they are retrieved via the wellhead blowout preventer and the downhole pressure and temperature data are read back, achieving wireline-free downhole flowing pressure monitoring.

[0035] This invention employs two tools—a monitoring unit and a retrieval unit—to collect and read downhole flowing pressure data based on the gas well's production stage, thus forming a wire-free downhole flowing pressure testing method. This technology shortens the construction cycle, reduces monitoring costs, and improves safety. Furthermore, through comprehensive consideration of technical and economic aspects, it enables more efficient and safer downhole flowing pressure monitoring, providing a new monitoring method for gas well flowing pressure monitoring with broad application prospects. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the monitoring unit in an embodiment of a wireless downhole flowing pressure monitoring tool of the present invention.

[0037] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle.

[0038] Figure 3 This is a schematic diagram of the retrieval unit in an embodiment of a wireless downhole flowing pressure monitoring tool of the present invention.

[0039] Figure 4 This is a schematic diagram showing the state of the device and slips after the impact pin moves upward and pops out, as described in an embodiment of the wireless downhole pressure monitoring tool of the present invention.

[0040] Figure 5 This is a top view of the retrieval cylinder and the straightening wing in an embodiment of a wireless downhole flowing pressure monitoring tool of the present invention. Detailed Implementation

[0041] The following detailed description illustrates the specific implementation method:

[0042] The reference numerals in the accompanying drawings include: 1. High-temperature battery; 2. Control circuit; 3. Pressure sensor; 4. Pressure tapping hole; 5. Buffer spring; 6. Impact pin; 7. Locking clip; 701. Reset spring; 8. Locking clip; 9. Compression spring; 10. First retrieval neck; 11. Locking groove; 12. Locking spring; 13. Vertical rod; 14. Horizontal rod; 15. Straightening wing; 16. Pressure measuring tool cylinder; 20. Retrieval cylinder; 21. Second retrieval neck; 22. Rectangular tooth; 23. Connecting plate; 24. Tension spring; 25. Locking protrusion; 27. Pressure groove.

[0043] Example 1

[0044] The basic implementation examples are as follows: Figure 1 As shown: A wireless downhole flowing pressure monitoring tool includes a retrieval unit and a monitoring unit. The monitoring unit includes a pressure measuring tool cylinder 16, a battery, a control circuit 2, and a pressure sensor 3. The pressure sensor is electrically connected to the control circuit 2.

[0045] The pressure testing tool cylinder 16 has a cylindrical structure, resembling a lantern-shaped frame. An impact pin 6 is axially slidably fitted inside the pressure testing tool cylinder 16. The battery is a high-temperature battery 1, and the high-temperature battery 1, control circuit 2, and pressure sensor 3 are sequentially installed inside the impact pin 6 from top to bottom. The pressure sensor 3 has a pressure tapping hole 4 for easy data acquisition.

[0046] Both the upper and lower parts of the impact pin 6 are equipped with buffer springs 5. The buffer spring 5 at the upper part of the impact pin 6 is located between the top of the impact pin 6 and the high-temperature battery 1, and the buffer spring 5 at the lower part of the impact pin 6 is located between the bottom of the impact pin 6 and the pressure sensor 3.

[0047] The pressure testing tool cylinder 16 is equipped with a locking mechanism. During the upward movement of the striking pin 6, the locking mechanism can be pushed to pop out to both sides of the pressure testing tool cylinder 16. In this embodiment, the locking mechanism includes a slip 7 that slides along the radial direction of the pressure testing tool cylinder 16. A through hole is provided on the side wall of the pressure testing tool cylinder 16. The slip 7 slides with the through hole. A reset element is connected between the slip 7 and the pressure testing tool cylinder 16. The reset element is a reset spring 701.

[0048] In this embodiment, the number of slips 7 is greater than or equal to two, and the slips 7 are distributed circumferentially along the pressure testing tool cylinder 16. This embodiment takes the setting of two slips 7 as an example for explanation. The two slips 7 are symmetrically arranged. The top end of the firing pin 6 and the bottom end of the slips 7 are both provided with inclined surfaces. The number of inclined surfaces at the top end of the firing pin 6 is the same as the number of slips 7. When the return spring 701 is in a compressed state and the slips 7 are located inside the pressure testing tool cylinder 16, the inclined surface at the top end of the firing pin 6 and the inclined surface at the bottom end of the slips 7 are directly opposite each other.

[0049] like Figure 3 As shown, the retrieval unit includes a retrieval cylinder 20, which can engage with the pressure testing tool cylinder 16 and press the locking mechanism back into the pressure testing tool cylinder 16. The outer diameter of the retrieval cylinder 20 is larger than the outer diameter of the pressure testing tool cylinder 16, and the retrieval cylinder 20 can slide along the side wall of the tubing in the well. The gap between the retrieval cylinder 20 and the tubing is small; in this embodiment, the gap between the retrieval cylinder 20 and the tubing is 1-2 mm. The outer diameter of the pressure testing tool cylinder 16 is smaller than the inner diameter of the tubing in the well, creating a gap between the pressure testing tool cylinder 16 and the tubing. This reduces the pushing force exerted by the gas pressure in the well on the pressure testing tool cylinder 16, facilitating the successful pressure testing of the pressure testing tool cylinder 16 while it is positioned in the well.

[0050] In this embodiment, the gap between the retrieval cylinder 20 and the tubing is small, and the amount of gas passing through the well is small. When it is necessary to read the pressure measurement data, the gas pressure in the well will push the retrieval cylinder 20 upward, so that the retrieval cylinder 20 can slide upward along the side wall of the tubing and bring the pressure measurement tool cylinder 16 to the blowout preventer at the wellhead to read the data.

[0051] like Figure 1 and Figure 2As shown, in this embodiment, the pressure testing tool cylinder 16 has slots 11 on both sides, and the slots 11 are located above the slip 7. The pressure testing tool cylinder 16 contains a vertical rod 13 and a horizontal rod 14 that are perpendicular to each other. One end of the vertical rod 13 is connected to the top of the firing pin 6, and the other end of the vertical rod 13 is located in the middle of the horizontal rod 14 and connected to it. The horizontal rod 14 and the vertical rod 13 form a T-shaped structure. The two ends of the horizontal rod 14 are slidably fitted with clamps 8 along its axial direction. Figure 2 As shown, a locking spring 12 is connected between the locking piece 8 and the crossbar 14. The locking spring 12 is located inside the locking piece 8, and the crossbar 14 passes through the locking spring 12. One end of the locking spring 12 is connected to the crossbar 14, and the other end of the locking spring 12 is connected to the end of the locking piece 8 away from the vertical bar 13.

[0052] like Figure 1 and Figure 4 As shown, multiple compression springs 9 connect the crossbar 14 to the top wall of the pressure measuring tool cylinder 16. During the upward movement of the striker 6, which in turn drives the vertical bar 13 upward, the striker 6 pushes the two slips 7 outward from the pressure measuring tool cylinder 16, providing support and preventing the slips 7 from rebounding. Simultaneously, when the striker 6 moves the locking piece 8 to the slot 11, since the locking piece 8 is not compressed at this time, it is ejected by the locking spring 12 and locked into the slot 11. This ensures the striker 6 remains stable and provides stable support for the slips 7, preventing them from rebounding.

[0053] During the engagement of the retrieval unit and the monitoring unit, the locking piece 8 can be pressed back against the inner wall of the pressure measuring tool cylinder 16. Specifically, the inner diameter of the retrieval cylinder 20 is larger than the outer diameter of the pressure measuring tool cylinder 16, allowing the retrieval cylinder 20 to fit over the outside of the pressure measuring tool cylinder 16. Figure 3 As shown, the bottom end of the retrieval tube 20 is an open end. Two pressure grooves 27 are provided on the bottom of the retrieval tube 20 and on its inner side wall. The two pressure grooves 27 are symmetrically arranged. When the pressure grooves 27 move to the position of the slot 11, they can press the clamping piece 8 back into the pressure measuring tool tube 16. In this embodiment, the clamping piece 8 is cylindrical, and the end of the clamping piece 8 away from the vertical rod 13 is an arc end. The pressure grooves 27 are arc grooves.

[0054] Combination Figure 1 and Figure 3 As shown, the top of the pressure testing tool cylinder 16 is connected to the first retrieval neck 10, and the top of the retrieval cylinder 20 is connected to the second retrieval neck 21. The longitudinal sections of the first retrieval neck 10 and the second retrieval neck 21 are both T-shaped. The first retrieval neck 10 and the second retrieval neck 21 are both designed with a gooseneck structure, which facilitates the connection of the first retrieval neck 10 and the second retrieval neck 21 through retrieval operations to remove the retrieval unit and the monitoring unit from the wellbore.

[0055] like Figure 3As shown, the retrieval tube 20 is also provided with two connecting plates 23. The two connecting plates 23 are symmetrically arranged. Multiple tension springs 24 are connected to the connecting plates 23 and the inner wall of the retrieval tube 20. Each side of the connecting plates 23 facing each other is connected with a locking protrusion 25. The locking protrusion 25 is located above the pressure groove 27. In the natural state, the distance between the two locking protrusions 25 is less than the width of the transverse part of the first retrieval neck 10. The sides of the two locking protrusions 25 facing each other are arc-shaped. The two arc surfaces on the locking protrusions 25 can abut against the two side walls of the transverse part of the first retrieval neck 10.

[0056] After the pressure groove 27 presses the locking piece 8 back into the pressure testing tool cylinder 16, the retrieval cylinder 20 can drive the locking protrusion 25 to contact the transverse part of the first retrieval neck 10 during its downward movement. At this time, the tension spring 24 will be compressed, and the two locking protrusions 25 will move away from each other, so that the locking protrusion 25 can pass smoothly through the transverse part of the first retrieval neck 10. After the locking protrusion 25 passes through the transverse part of the first retrieval well, the tension spring 24 will reset and make the two locking protrusions 25 move closer to each other, thereby locking at the bottom of the transverse part of the first retrieval neck 10, realizing the purpose of connecting the retrieval cylinder 20 and the pressure testing tool cylinder 16 into one unit.

[0057] When the retrieval cylinder 20 and the pressure testing tool are connected as one unit, the gas pressure generated in the well will push the retrieval cylinder 20 and the pressure testing tool cylinder 16 to float upward to the blowout preventer at the wellhead to obtain data or retrieve them, because the retrieval cylinder 20 is in contact with the side wall of the tubing and can slide along the side wall of the tubing.

[0058] Combination Figure 1 and Figure 5 As shown, in this embodiment, multiple straightening wings 15 are connected to the outside of the pressure testing tool cylinder 16 along its circumference. In this embodiment, three straightening wings 15 are connected as an example. The three straightening wings 15 are evenly distributed along the circumference of the pressure testing tool cylinder 16, and there is a gap between the straightening wings 15 and the inner wall of the oil pipe.

[0059] like Figure 3 As shown, rectangular teeth 22 are provided on the outer side of the retrieval tube 20. The rectangular teeth 22 are located above the retrieval tube 20. The rectangular teeth 22 can carry away the dirt in the well during the process of the retrieval tube 20 floating, which is more conducive to the floating of the retrieval tube 20 and the pressure measuring tool tube 16.

[0060] This embodiment also provides a wireless downhole flowing pressure monitoring method. The downhole flowing pressure is monitored using a wireless downhole flowing pressure monitoring tool provided in this embodiment. The steps are as follows:

[0061] Step 1: When the gas well needs to obtain downhole flowing pressure, the monitoring unit is deployed from the tubing inside the well to a predetermined position inside the well. In this embodiment, a limiter is pre-installed inside the well, located at the bottom of the tubing. The monitoring unit rests on the pre-installed limiter inside the tubing. The striking pin 6 inside the pressure measuring tool cylinder 16 of the monitoring unit impacts the limiter inside the well, causing the striking pin 6 to move upward. This causes the locking mechanism to pop out to both sides of the pressure measuring tool cylinder 16 and abut against the sidewall of the tubing, thereby fixing the relative position of the pressure measuring tool cylinder 16 and the tubing. This allows the entire monitoring unit to rest downhole, and the monitoring unit monitors the downhole flowing pressure in real time.

[0062] Step two: The monitoring unit collects and stores downhole pressure data. Specifically, the monitoring unit is powered by a high-temperature battery 1, and the pressure sensor 3 collects pressure data and transmits it to the control circuit 2 for storage. The downhole flowing pressure is monitored by a pre-set sampling frequency. When monitoring gas well flowing pressure, considering both the downhole battery consumption and the sampling frequency, a reasonable monitoring cycle needs to be set for collecting downhole flowing pressure data. The control circuit 2 collects and stores the downhole flowing pressure data according to the pre-set sampling frequency.

[0063] Step 3: When pressure data is needed, close the wellhead and deploy the retrieval unit. After the retrieval unit and monitoring unit are aligned, the retrieval unit will press the locking mechanism back into the pressure testing tool cylinder 16. Specifically, the pressure groove 27 on the retrieval cylinder 20 will press the locking piece 8 back into the pressure testing tool cylinder 16. At this time, the compression spring 9 will rebound and eject the striker 6 downwards. The striker 6 will no longer support the slip 7. Simultaneously, the slip 7 will retract into the pressure testing tool cylinder 16 under the action of the return spring 701. At this time, the pressure testing tool cylinder 16 and the tubing are in a loose state, making it easy to be pushed upwards with the retrieval unit.

[0064] Step four: Open the well. The gas generated inside the well will push the monitoring unit and the retrieval unit upwards and back into the blowout preventer at the wellhead. After retrieving the monitoring unit and the retrieval unit, obtain the pressure data.

[0065] In existing technologies, downhole flowing pressure data for gas wells is mainly obtained through wireline pressure measurement, employing a continuous monitoring method with wireline suspension. This invention fully utilizes the characteristics of the monitoring and retrieval units, enabling phased implementation of downhole flowing pressure monitoring and data retrieval, achieving a wireline-free downhole flowing pressure monitoring method, significantly saving costs and reducing operational risks. Flow pressure, as a key parameter for gas well production, is crucial for dynamic tracking and adjustment of gas well production. This invention simplifies monitoring methods, improves the security of downhole flowing pressure data acquisition, expands the monitoring range of well inclination, and directly monitors changes in downhole flowing pressure, providing a new and effective means of obtaining downhole flowing pressure for gas wells.

[0066] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A wireless downhole flowing pressure monitoring tool, comprising a retrieval unit and a monitoring unit, wherein the monitoring unit includes a pressure measuring tool cylinder, a battery, a control circuit, and a pressure sensor, and an impact pin is axially slidably fitted inside the pressure measuring tool cylinder, characterized in that: The pressure testing tool cylinder is equipped with a locking mechanism. During the upward movement of the striking pin, the locking mechanism can be pushed to pop out to both sides of the pressure testing tool cylinder. The retrieval unit includes a retrieval cylinder. The retrieval cylinder can engage with the pressure testing tool cylinder and press the locking mechanism back into the pressure testing tool cylinder. The outer diameter of the retrieval cylinder is larger than the outer diameter of the pressure testing tool cylinder, and the retrieval cylinder can slide along the side wall of the oil pipe in the well. The locking mechanism includes a locking piece that slides radially along the pressure measuring tool cylinder. A through hole is provided on the side wall of the pressure measuring tool cylinder. The locking piece slides with the through hole. A reset member is connected between the locking piece and the pressure measuring tool cylinder. The pressure testing tool cylinder has slots on both sides, located above the slips. Inside the pressure testing tool cylinder are perpendicular vertical and horizontal rods. One end of the vertical rod is connected to the firing pin, and the other end is connected to the horizontal rod. Both ends of the horizontal rod are slidably fitted with locking components along its axis. Each locking component and the horizontal rod is connected with a locking spring. A compression spring is connected between the horizontal rod and the top wall of the pressure testing tool cylinder. When the vertical rod moves upward, it drives the locking components to the slot position, where the locking components can lock into the slot. During the engagement of the retrieval unit and the monitoring unit, the locking components can be pressed back against the inner wall of the pressure testing tool cylinder.

2. The wire-free downhole flowing pressure monitoring tool according to claim 1, characterized in that: The inner diameter of the retrieval tube is larger than the outer diameter of the pressure testing tool tube. The bottom end of the retrieval tube is an open end, and a pressure groove is provided at the bottom of the retrieval tube. When the pressure groove moves to the slot position, it can press the clamp back into the pressure testing tool tube.

3. The wire-free downhole flowing pressure monitoring tool according to claim 1, characterized in that: The top end of the pressure testing tool cylinder is connected to a first retrieval neck, and the top end of the retrieval cylinder is connected to a second retrieval neck. The longitudinal sections of both the first and second retrieval necks are T-shaped. The retrieval cylinder is also provided with two connecting plates. The connecting plates and the inner wall of the retrieval cylinder are both connected to tension springs. The two sides of the connecting plates that are directly opposite each other are connected to a locking protrusion. The locking protrusion is located above the pressure groove. When the pressure groove presses the locking piece back into the pressure testing tool cylinder, the locking protrusion can be locked onto the first retrieval neck.

4. The wire-free downhole flowing pressure monitoring tool according to claim 1, characterized in that: The number of slips is greater than or equal to two, and the slips are distributed circumferentially along the pressure measuring tool cylinder.

5. A wire-free downhole flowing pressure monitoring tool according to claim 1, characterized in that: The top of the firing pin and the bottom of the slip are both provided with inclined surfaces, and when the slip is located inside the pressure measuring tool cylinder, the inclined surface at the top of the firing pin and the inclined surface at the bottom of the slip are directly opposite each other.

6. The wire-free downhole flowing pressure monitoring tool according to claim 1, characterized in that: The pressure measuring tool cylinder has multiple straightening wings connected to its outer side along its circumference.

7. A wire-free downhole flowing pressure monitoring tool according to claim 2, characterized in that: The outer side of the retrieval tube is provided with rectangular teeth, which are located above the retrieval tube.

8. A wireless downhole flowing pressure monitoring method, characterized in that: The steps for using the wireless downhole flowing pressure monitoring tool according to any one of claims 1-7 are as follows: Step 1: A limiter is pre-installed in the well. The monitoring unit is then inserted into the well from the tubing. The striker abuts against the limiter in the well. The striker moves upward, causing the locking mechanism to pop out to both sides of the pressure measuring tool cylinder and abut against the side wall of the tubing, and stop downhole. The monitoring unit then monitors the downhole flowing pressure in real time. Step two: The monitoring unit collects and stores downhole pressure data; Step 3: When pressure data is needed, close the wellhead and deploy the retrieval unit. The retrieval unit and the monitoring unit are engaged to form a single unit. At the same time, the retrieval unit pushes the locking mechanism back into the pressure measuring tool cylinder. Step four: Open the well. The gas generated inside the well will push the monitoring unit and the retrieval unit upwards and back into the blowout preventer at the wellhead. After retrieving the monitoring unit and the retrieval unit, obtain the pressure data.

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