Logging instrument for gas well

Abstract

The invention relates to a logging instrument for a gas well. The logging instrument comprises a sensing unit. The sensing unit comprises a base, a protection part connected with the base and a guide head connected with the protection part, the protection part defines a cavity in fluid communication with the internal space of an oil pipe of the gas well between the base and the guide head, and a temperature sensor is arranged in the cavity. Wherein the base is provided with an installation hole which extends to penetrate through the base, and the temperature sensor is installed in the installation hole in a sealed mode and extends downwards into the cavity. A simple protection structure formed by the protection part on the logging instrument not only can effectively protect the plurality of temperature sensors, but also can enable underground fluid to be in full contact. And the plurality of temperature sensors are circumferentially distributed on the base, so that the temperature of the fluid can be accurately measured. Therefore, the temperature change of the underground fluid can be effectively analyzed and distinguished, and the temperature of the gas reservoir profile can be accurately monitored. The logging instrument integrates multiple temperature acquisition points, has a magnetic positioning function, and is simple in structure and high in reliability.

Description

Technical Field

[0001] This invention relates to the field of gas well development technology, and more specifically to a logging instrument for gas wells. Background Technology

[0002] In the logging operation of natural gas reservoirs, logging tools are typically used to acquire downhole data such as temperature and pressure to measure and characterize the reservoir profile. The data obtained from logging tools allows for understanding the dynamics within the gas well, providing crucial information for intuitively and clearly identifying the main producing layers and adjusting development strategies. Temperature sensors are commonly used devices in logging tools to measure downhole temperature parameters, primarily for measuring the temperature parameters of downhole fluids. The performance of the temperature sensor is critical to the measurement results. Due to the specific operating conditions of logging tools, the temperature of the fluid at various depths in the well is generally measured during the lowering or raising of the logging tool.

[0003] Due to the complex working environment downhole, most existing logging tools are equipped with protective structures to safeguard temperature sensors during lowering or raising. While these complex protective structures effectively protect the temperature sensors, they can also prevent proper contact between the sensors and the downhole fluid, thus affecting the sensor's ability to measure fluid temperature. Furthermore, the temperature distribution of fluids downhole varies, but the temperature sensor's measurement range is limited. These complex protective structures also make it difficult for the logging instrument to accurately acquire temperature data and distribution information of the downhole gas reservoir, thereby impacting the measurement and characterization of the downhole gas reservoir profile. Summary of the Invention

[0004] In view of the above-mentioned problems in the prior art, the present invention provides a logging tool for gas wells that can effectively protect temperature sensors and accurately measure the temperature of fluids at different depths in the gas well.

[0005] The technical solution adopted by this invention to solve its technical problem is: to provide a logging instrument for gas wells, comprising,

[0006] The sensing unit, installed at the lower end of the logging tool, includes a base, a protective component connected to the base, and a guide head connected to the protective component. The protective component defines a cavity between the base and the guide head that is in fluid communication with the internal space of the oil tubing of the gas well. A temperature sensor is installed within the cavity.

[0007] The base has a mounting hole that extends through the base, and the temperature sensor is sealed in the mounting hole and extends downward into the cavity.

[0008] Furthermore, the circumferential dimension of the protective component defined on the logging instrument is greater than the circumferential dimension of the cylindrical surface where several temperature sensors are located.

[0009] Furthermore, the protective component is a hollow cylindrical structure with openings at both ends. The two ends of the protective component can be respectively fitted onto the base and the guide head. The protective component is provided with several through holes, so that the cavity can be fluidly connected to the internal space of the oil pipe of the gas well.

[0010] Furthermore, the mounting holes are configured to extend radially outward in the downward direction, such that the temperature sensors are mounted obliquely, gradually moving away from each other in the downward direction.

[0011] Furthermore, the tilt angles of each temperature sensor are different, and the lengths of each temperature sensor extending into the cavity are also different.

[0012] Furthermore, an open groove is provided on the side wall of the base, which communicates with the cavity, allowing fluid in the cavity to drain out through the groove.

[0013] Furthermore, a connecting post is provided on the base, the connecting post extending into the guide head (13) and connecting to the guide head.

[0014] Furthermore, it includes a first connector connected to the upper end of the base, the first connector having a circuit board electrically connected to the temperature sensor, so that the temperature data measured by the temperature sensor can be stored in a memory chip on the circuit board.

[0015] Furthermore, the first connector is also provided with a magnetic locator electrically connected to the circuit board. The magnetic locator is configured to sense the coupling of the tubing in order to obtain depth data of the logging tool's movement.

[0016] Furthermore, it also includes a second connector connected to the upper end of the first connector. The second connector contains a battery electrically connected to the magnetic locator and the circuit board. The upper end of the second connector has a connecting part for connecting a continuous tubing.

[0017] The beneficial effects of this invention are as follows: This invention provides a logging tool for gas wells, including a sensing unit installed at the lower end of the logging tool. The sensing unit includes a base, a protective member connected to the base, and a guide head connected to the protective member. The protective member defines a cavity between the base and the guide head that is in fluid communication with the internal space of the oil tubing of the gas well. A temperature sensor is disposed within the cavity. The base has a mounting hole extending through it, and the temperature sensor is sealed and installed within the mounting hole, extending downward into the cavity.

[0018] The simple protective structure formed by the protective components on the logging tool effectively protects several temperature sensors and ensures full contact with the downhole fluid. Several temperature sensors are circumferentially distributed on the base, allowing for precise temperature measurement. The angled mounting holes increase the temperature measurement radius by arranging the sensors at an angle. This effectively analyzes and distinguishes temperature changes in the downhole fluid, enabling accurate temperature monitoring of the gas reservoir profile. Furthermore, the logging tool integrates magnetic positioning functionality, increasing its overall capabilities. Based on these features, the logging tool combines multiple temperature acquisition points with magnetic positioning capabilities, boasting a simple structure and high reliability. During logging operations, the tool exhibits excellent maneuverability and durability. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 The image shown is a structural cross-sectional view of a logging instrument for gas wells according to Embodiment 1.

[0021] Figure 2 The diagram shown is a structural schematic of the base of the logging instrument in Embodiment 1.

[0022] Figure 3 As shown Figure 2 The base shown is a side view plan.

[0023] Figure 4 The image shown is a partial structural cross-sectional view of the logging instrument for gas wells in Embodiment 2.

[0024] Figure 5 The diagram shown is a schematic diagram of the sensing unit of the logging tool in Embodiment 2.

[0025] Figure 6 As shown Figure 5 The image shows a cross-sectional view of the sensing unit.

[0026] Figure 7 The image shown is a partial structural cross-sectional view of the logging tool for gas wells in Embodiment 3.

[0027] Figure 8 The diagram shown is a schematic diagram of the sensing unit of the logging tool in Embodiment 3.

[0028] Figure 9 As shown Figure 8 The image shows a cross-sectional view of the sensing unit.

[0029] In the figure, the following labels are used: 100, logging tool; 10, sensing unit; 11, base; 111, mounting hole; 112, temperature sensor; 113, groove; 114, connecting post; 115, wire hole; 12, protective component; 121, cavity; 122, arc surface; 123, inclined surface; 124, straight surface; 125, through hole; 13, guide head; 131, mounting groove;

[0030] 20. First connector; 21. Circuit board; 22. Magnetic locator;

[0031] 30. Second connector; 31. Battery; 32. Connecting part. Detailed Implementation

[0032] To make the technical problem to be solved, the technical solution, and the beneficial effects of this invention clearer, the invention will now be described in detail with reference to the accompanying drawings. This drawing is a simplified schematic diagram, illustrating only the basic structure of the invention, and therefore only shows the components relevant to the invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0033] Example 1

[0034] refer to Figure 1 As shown, the logging tool 100 for gas wells provided by the present invention includes a first connector 20, and a sensing unit 10 and a second connector 30 respectively disposed at both ends of the first connector 20. In this application, the direction toward the sensing unit 10 is defined as downward, the direction toward the second connector 30 is defined as upward, and the direction along the axis of the logging tool 100 is defined as axial. When the logging tool 100 is lowered into the tubing inside the gas well, the second connector 30 is first connected to the end of a continuous tubing, and then the sensing unit 10 is lowered from the wellhead into the tubing of the gas well. Finally, the logging tool 100 is lowered to the depth of the gas well by sequentially connecting several of the continuous tubings.

[0035] Combination Figure 1-3 As shown, in some embodiments, the sensing unit 10 includes a base 11 connected to the first connector 20 and used for mounting a temperature sensor 112, a protective member 12 connected to the base 11, and a guide head 13 connected to the protective member 12. The base 11 has a through-hole 111 for mounting the temperature sensor 112. The base of the temperature sensor 112 can be installed in the mounting hole 111 using a sealing ring, sealant, or other sealing filler. The measuring part of the temperature sensor 112, used for measuring temperature, can contact the downhole fluid to measure its temperature.

[0036] The mounting hole 111 is configured to extend radially outward in the downward direction, so that the temperature sensors 112 are installed obliquely, gradually moving away from each other in the downward direction. This allows the temperature sensor 112 to have a larger measuring radius, which is more conducive to accurately measuring the temperature of the fluid in the gas well. In this embodiment, the base 11 can be connected to the lower end of the first connector 20 by screwing, bolting, or snapping.

[0037] In this embodiment, four temperature sensors 112 are uniformly arranged circumferentially on the base 11. These four temperature sensors 112 can fully contact the fluid downhole and simultaneously and independently measure the fluid temperature. This improves fault tolerance and reduces measurement errors caused by accidental factors. Furthermore, the four temperature sensors 112 also enhance the reliability of the logging tool 100. Even if one or two temperature sensors 112 are damaged or malfunction during the lowering or raising of the logging tool 100, the logging tool 100 will not become completely inoperable.

[0038] Combination Figure 1 and Figure 3 As shown, in this embodiment, a connecting post 114 extending into the guide head 13 is provided at the center of the base 11. The connecting post 114 is connected to the guide head 13 by threads at its end for easy assembly. A groove 113 is also provided on the side wall of the base 11, connecting the cavity 121 and the internal space of the tubing, so that fluid entering the cavity 121 through the through hole 125 can be discharged from the groove 113. The groove 113 extends axially along the base 11, allowing the fluid in the cavity 121 to be discharged quickly, thereby quickly and accurately measuring the temperature of the fluid at different depths in the gas well, so as to accurately measure and characterize the gas reservoir profile.

[0039] refer to Figure 1 As shown, in this embodiment, the protective member 12 is a hollow cylindrical structure with openings at both ends, and its two ends are connected to the lower end face of the base 11 and the upper end face of the guide head 13, respectively. The protective member 12, the base 11, and the guide head 13 together define the cavity 121, which communicates with the internal space of the oil pipe through several through holes 125 provided on the protective member 12. The fluid in the oil pipe can enter the cavity 121 through the several through holes 125 and come into contact with the temperature sensor 112 on the base 11. In some preferred embodiments, the tilt angles of the temperature sensors 112 are different, and the lengths of the temperature sensors 112 extending into the cavity 121 are also different, so that the temperature sensors 112 can fully contact the fluid in the cavity 121 for accurate measurement of the fluid temperature.

[0040] refer to Figure 1As shown, the first connector 20 is a hollow cylindrical structure open at both ends. The first connector 20 is sealed to both the base 11 and the second connector 30 to prevent fluid from the gas well from entering the logging tool 100. The first connector 20 contains a circuit board 21 electrically connected to the temperature sensor 112, and a magnetic locator 22 electrically connected to the circuit board 21. A memory chip is mounted on the circuit board 21 to store the temperature value of the fluid measured by the temperature sensor 112. In some embodiments, the logging tool 100 is pulled out of the gas well after measurement via coiled tubing. Then, a computer is electrically connected to the memory chip on the circuit board 21 to read the data stored in the memory chip. In other preferred embodiments, the data in the memory chip can be transmitted to the computer in real time using wired or wireless transmission.

[0041] The magnetic locator 22 contains a magnetic component (not shown) and a Hall sensor (not shown) that detects changes in the intensity of the induced magnetic field. When the logging tool 100 moves within the tubing of the gas well, the magnetic field of the magnetic component induces a current within the tubing. Simultaneously, this induced current generates an induced magnetic field. Since the inner diameter of the tubing remains constant axially, the superimposed magnetic field formed by the magnetic field of the magnetic component and the induced magnetic field remains constant as the logging tool 100 moves at a uniform speed within the tubing. When the logging tool 100 passes a coupling connecting the tubing, the intensity of the induced magnetic field at the coupling is less than that at the tubing because the inner diameter of the coupling is larger than that of the tubing. Therefore, the superimposed magnetic field sensed by the Hall sensor changes each time the logging tool 100 passes a coupling. The Hall sensor converts this change into an electrical signal and sends it to the circuit board 21, which converts the electrical signal into depth data stored in a memory chip. Since the length of the tubing inside the gas well is known, the fluid temperature at the specific depth of the gas well can be determined by combining the depth data, the length of the tubing, and the temperature data measured by the temperature sensor 112.

[0042] refer to Figure 1 As shown, the second connector 30 is a hollow cylindrical structure with one open end. A battery 31, electrically connected to the magnetic locator 22 and the circuit board 21, is disposed inside the second connector 30 to supply power to the magnetic locator 22 and the circuit board 21. A connecting portion 32 is provided at the upper end of the second connector 30 for connection to the continuous tubing.

[0043] Example 2

[0044] Combination Figure 4-6As shown, the protective component 12 of the logging tool 100 in Embodiment 2 of the present invention is generally a columnar structure. The protective components 12 are spaced apart to define a cavity 121 between the base 11 and the guide head 13 for accommodating the measuring portion of the temperature sensor 112. The cavity 121 extends from the end face of the guide head 13 to the end face of the base 11 and is in direct communication with the internal space of the tubing. During the lowering or raising of the logging tool 100 within the tubing of the gas well, the fluid in the tubing flows directly into the cavity 121 and comes into full contact with the measuring portion of the temperature sensor 112, thereby accurately measuring the fluid temperature.

[0045] Combination Figure 6 As shown, the circumferential dimension defined by all the protective components 12 is the maximum circumferential dimension of the logging tool 100. This ensures that the logging tool 100 remains coaxial with the tubing inside the gas well during lowering or raising, and also protects the temperature sensors 112. In this embodiment, the cross-section of the protective component 12 is approximately a pentagonal cross-section with one side curved, giving it an arc surface 122 with the same curvature as the base 11, two inclined surfaces 123 adjacent to the arc surface 122, and two perpendicular straight surfaces 124 opposite to the arc surface 122. The four temperature sensors 112 are located between the straight surfaces 124 of two adjacent protective components 12, such that the circumferential dimension of the cylindrical surface containing the four temperature sensors 112 is smaller than the circumferential dimension of the protective component 12 defined by all the protective components 12, thereby preventing the temperature sensors 112 from colliding with the inner wall of the tubing. The inclined surfaces 123 extend towards each other in a radially outward direction, creating a radially outwardly expanding flow cross-section between the cavity 121 and the internal space of the tubing, facilitating fluid inflow into the cavity 121. The straight surfaces 124 of each protective element 12 are parallel and opposite to each other, allowing fluid to flow freely within the cavity 121. The simple structure formed by the combination of the protective elements 12 not only effectively protects the temperature sensor 112 but also ensures that the fluid in the gas well can fully contact the temperature sensor 112, thereby enabling the temperature sensor 112 to more accurately measure the temperature of the fluid in the gas well.

[0046] In this embodiment, the guide head 13 has a hemispherical structure, which is used to guide the fluid downhole to the surrounding area. The guide head 13 can also guide some obstacles in the tubing to the surrounding area, on the one hand to avoid the obstacles directly colliding with the temperature sensor 112, and on the other hand to effectively improve the passage of the logging tool 100 in the tubing.

[0047] Example 3

[0048] refer to Figure 7-9As shown, the difference between the logging tool 100 provided in Embodiment 3 and the logging tool 100 provided in Embodiment 2 is that the top of the guide head 13 has an installation groove for sealing and installing a pressure sensor (not shown). The pressure sensor can measure the fluid pressure in the gas well, thereby increasing the parameters that the logging tool 100 can measure, so as to facilitate multi-dimensional and comprehensive measurement and characterization of the gas reservoir profile.

[0049] Combination Figure 7 and Figure 8 As shown, a square-section connecting post 114 is provided on the base 11, extending from the lower end face of the base 11 to the upper end face of the guide head 13. An axial wire hole 115 is provided within the connecting post 114, extending from the bottom of the mounting groove to the upper end face of the base 11. By arranging wires within the wire hole 115, the pressure sensor can be electrically connected to the circuit board 21 within the first connector 20, allowing the pressure data measured by the pressure sensor to be stored in the memory chip on the circuit board 21.

[0050] Combination Figure 9 As shown, in this embodiment, the inclined surface 123 of the protective member 12 extends in an arc away from the temperature sensor 112, allowing the temperature sensor 112 to be as far away from the sidewall of the protective member 12 as possible. Only one straight surface 124 is provided opposite to the arc surface 122, and it is parallel to and opposite to the sidewall of the connecting column 114. The portion of the cavity 121 located between the inclined surfaces 123 of two adjacent protective members 12 axially penetrates the guide head 13, allowing the temperature sensor 112 to contact the fluid in the gas well immediately. This avoids heat transfer between the fluid and the guide head 13, preventing temperature changes and enabling more accurate temperature measurement of the fluid.

[0051] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] It should be understood that the terms "length", "width", "up", "down", "front and back", "left and right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0053] The above description, based on the preferred embodiments of the present invention, provides guidance. Those skilled in the art can make various changes and modifications without departing from the scope of the invention. The technical scope of this invention is not limited to the contents of the specification but must be determined according to the claims.

Claims

1. A logging instrument for gas wells, comprising: The sensing unit (10), installed at the lower end of the logging tool (100), includes a base (11), a protective member (12) connected to the base (11), and a guide head (13) connected to the protective member (12). The protective member (12) defines a cavity (121) between the base (11) and the guide head (13) that is in fluid communication with the internal space of the oil pipe of the gas well. A temperature sensor (112) is provided in the cavity (121). in, The base (11) has a mounting hole (111) extending through the base (11), and the temperature sensor (112) is installed in the mounting hole (111) in a sealed manner and extends downward into the cavity (121).

2. The logging instrument for gas wells according to claim 1, characterized in that, The circumferential dimension of the protective component (12) defined on the logging instrument (100) is greater than the circumferential dimension of the cylindrical surface where several of the temperature sensors (112) are located.

3. The logging instrument for gas wells according to claim 2, characterized in that, The protective component (12) is a hollow cylindrical structure with openings at both ends. The two ends of the protective component (12) can be sleeved with the base (11) and the guide head (13) respectively. The protective component (12) is provided with several through holes (125) so that the cavity (121) is in fluid communication with the internal space of the oil pipe used for the gas well.

4. The logging instrument for gas wells according to claim 1, characterized in that, The mounting hole (111) is configured to extend radially outward in the downward direction, such that the temperature sensors (112) are mounted obliquely, gradually moving away from each other in the downward direction.

5. The logging instrument for gas wells according to claim 4, characterized in that, The tilt angles of each of the temperature sensors (112) are different, and the lengths of each of the temperature sensors (112) extending into the cavity (121) are also different.

6. The logging instrument for gas wells according to claim 1, characterized in that, An open groove (113) is also provided on the side wall of the base (11), the groove (113) is connected to the cavity (121), so that the fluid in the cavity (121) can be discharged from the groove (113).

7. The logging instrument for gas wells according to claim 1, characterized in that, A connecting post (114) is provided on the base (11), the connecting post (114) extends into the guide head (13) and is connected to the guide head (13).

8. The logging instrument for gas wells according to any one of claims 1-7, characterized in that, Includes a first connector (20) connected to the upper end of the base (11), and the first connector (20) is provided with a circuit board (21) electrically connected to the temperature sensor (112), so that the temperature data measured by the temperature sensor (112) can be stored in the memory chip on the circuit board (21).

9. The logging instrument for gas wells according to claim 8, characterized in that, The first connector (20) is also provided with a magnetic locator (22) electrically connected to the circuit board (21). The magnetic locator (22) is configured to sense the coupling of the tubing in order to obtain the depth data of the logging instrument (100).

10. The logging instrument for gas wells according to claim 9, characterized in that, It also includes a second connector (30) connected to the upper end of the first connector (20). The second connector (30) is provided with a battery (31) electrically connected to the magnetic locator (22) and the circuit board (21). The upper end of the second connector (30) is provided with a connecting part (32) for connecting a continuous tubing.

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