Detection tool and detection method capable of distinguishing leakage of oil pipe and sleeve

Abstract

The invention relates to a detection tool and a detection method capable of distinguishing leakage of an oil pipe and a casing pipe, the detection tool comprises at least two righting assemblies, and the righting assemblies can be contracted to be separated from the inner wall of the oil pipe or expanded to be in top support contact with the inner wall of the oil pipe; the ultrasonic detection device is arranged between the at least two righting assemblies; the at least two blocking pieces are arranged on the corresponding righting assemblies respectively, and when the righting assemblies are in the contraction state, the blocking pieces are folded in the direction close to the axis of the oil pipe; when the righting assembly is in the opening state, the blocking pieces are opened in the direction close to the inner wall of the oil pipe along with the righting assembly so that a detection space can be defined between the at least two blocking pieces and the inner wall of the oil pipe, and the at least two blocking pieces are used for preventing external interference signals from entering the detection space. The technical problems that the leakage positions in the oil pipe and the casing pipe are difficult to accurately recognize, and oil pipe leakage or casing pipe leakage cannot be distinguished are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil extraction, and further relates to leakage detection of oil pipes and casings of gas storage wells and high-pressure gas wells, and in particular to a detection tool and a detection method capable of identifying oil pipe and casing leakage. Background Art

[0002] Currently, gas storage wells and high-pressure gas wells are an essential component of national oil and gas well construction. Tubing transports high-pressure natural gas, while casing provides wellbore protection and pressure control. With age, material corrosion (such as hydrogen sulfide, carbon dioxide corrosion, and hydrogen embrittlement), stress fatigue, and seal failure of specialized threaded joints become the primary causes of leakage. Especially during the cyclical injection and production processes of underground gas storage, alternating loads accelerate the propagation of microcracks in the tubing connections. Lost circulation has a severe impact on gas storage wells and high-pressure gas wells, directly threatening safe operation, storage capacity, and service life.

[0003] Compared to conventional production wells, gas storage wells and high-pressure gas wells are subject to extreme conditions of periodic high-pressure, high-flow injection and production, placing even more stringent demands on wellbore integrity. Lost circulation in the casing or tubing compromises the wellbore's sealing barrier. Tubing and casing leaks have different impacts on oil and gas wells, and accurately identifying and locating leaks is a core challenge in well integrity management. Among existing detection technologies, ultrasonic testing has become the mainstream method due to its advantages, such as not requiring production interruptions and being able to locate minute defects.

[0004] Oil pipeline leaks can directly lead to the release of high-pressure natural gas, potentially causing wellhead explosions or hydrogen sulfide poisoning. Casing leaks can contaminate the formation, damage groundwater resources, and, in severe cases, cause surface collapse. For gas storage wells, leaks can also compromise the reservoir's seal, leading to the loss of strategic gas reserves. Currently, the method of identifying the distribution characteristics of leak-induced acoustic fields is commonly used to invert the leak type and subsequently identify oil pipeline and casing leaks. However, this method cannot intuitively identify oil pipeline and casing leaks. Furthermore, the presence of upward interference signals within the oil pipeline seriously affects detection accuracy. Therefore, the problem of absorbing and shielding most of the major noise, including those within the gas storage, high-pressure gas wellbore, and the tool itself, urgently needs to be addressed. Furthermore, the leak location should be precisely located, and the root cause of the leak should be accurately and directly determined to be in the oil pipeline or casing, thereby improving the accuracy of identifying the specific leak location in gas storage wells and high-pressure gas wells.

[0005] Currently, no effective solution has been provided to the problem that due to the influence of noise, it is difficult to accurately identify the leakage location in the oil pipe and casing, and it is impossible to distinguish whether the leakage is from the oil pipe or the casing.

[0006] Therefore, the present invention proposes a detection tool and a detection method that can identify oil pipe and casing leakage, so as to overcome the defects of the prior art. Summary of the Invention

[0007] The purpose of the present invention is to provide a detection tool and detection method that can identify oil pipe and casing leakage, eliminate the interference of well noise on acoustic wave detection, improve the accuracy of detection, and accurately identify the leakage location.

[0008] The purpose of the present invention is to provide a detection tool and method that can distinguish oil pipe and casing leakage, which can identify whether the leakage is from the oil pipe or the casing, so as to take corresponding subsequent treatment measures according to different leakage scenarios, which is more targeted and avoids the harm caused by the leakage.

[0009] The purpose of the present invention can be achieved by adopting the following scheme:

[0010] The present invention provides a detection tool capable of identifying leakage of oil pipes and casings, the detection tool comprising:

[0011] At least two centralizing assemblies, when lowered into the oil pipe, can be retracted toward the axis of the oil pipe until separated from the inner wall of the oil pipe, or expanded toward the axial direction away from the oil pipe until contacting the inner wall of the oil pipe;

[0012] an ultrasonic detection device, the ultrasonic detection device being disposed between at least two of the centralizing assemblies;

[0013] At least two baffles are respectively arranged on the corresponding righting assemblies. When the righting assembly is in a retracted state, the baffles are folded and gathered toward the axial direction of the oil pipe; when the righting assembly is in an expanded state, the baffles are expanded along with the righting assembly toward the inner wall of the oil pipe to form a detection space between the at least two baffles and the inner wall of the oil pipe. The at least two baffles are used to block external interference signals from entering the detection space.

[0014] In a preferred embodiment of the present invention, the baffle includes a stacked porous sound-absorbing layer and a sound-insulating layer, the porous sound-absorbing layer is arranged toward the detection space, and the sound-insulating layer is located on the side facing away from the detection space. The porous sound-absorbing layer is used to absorb the ultrasonic signal emitted from the leakage position to the baffle, and the sound-insulating layer is used to block external interference signals from entering the detection space.

[0015] In a preferred embodiment of the present invention, the sound insulation layer includes a sound insulation cotton layer and an elastic sound insulation board, and the porous sound absorbing layer, the sound insulation cotton layer and the sound insulation board are stacked in sequence from the direction toward the detection space to the direction away from the detection space.

[0016] In a preferred embodiment of the present invention, the straightening assembly includes a first hinge block, a second hinge block, a plurality of first connecting rods and a plurality of second connecting rods, one end of each of the plurality of first connecting rods is hinged to the first hinge block, the other end of each of the plurality of first connecting rods is hinged to one end of each of the plurality of second connecting rods, and the other end of each of the plurality of second connecting rods is hinged to the second hinge block;

[0017] The ultrasonic detection device is located between the two centralizing assemblies, and the ultrasonic detection device is respectively connected to the second hinge blocks in the two centralizing assemblies.

[0018] In a preferred embodiment of the present invention, a roller is provided between the first connecting rod and the corresponding second connecting rod;

[0019] A rotating shaft is provided in the middle of the roller, and the first connecting rod and the second connecting rod are rotatably connected to the rotating shaft. When the straightening assembly is in the expanded state, the first connecting rod and the second connecting rod rotate and push the roller toward the inner wall of the oil pipe until the outer wall of the roller abuts against the inner wall of the oil pipe.

[0020] In a preferred embodiment of the present invention, the edge of the baffle or a portion close to the edge thereof is connected to a plurality of the second connecting rods, and the baffle in the expanded state is adapted to the cross-section of the internal channel of the oil pipe to block the internal channel of the oil pipe.

[0021] In a preferred embodiment of the present invention, the ultrasonic detection device is an ultrasonic sensor.

[0022] In a preferred embodiment of the present invention, the detection tool also includes an image generating device, and the signal output end of the ultrasonic detection device is electrically connected to the signal receiving end of the image generating device. The image generating device is used to generate a waveform diagram based on the received ultrasonic signal to judge the oil pipe leakage or casing leakage based on the waveform diagram.

[0023] The present invention provides a detection method capable of identifying oil pipe and casing leakage, which uses the above-mentioned detection tool capable of identifying oil pipe and casing leakage for detection. The detection method comprises the following steps:

[0024] Step S1: lowering a detection tool into the oil pipe, the detection tool descending along the axis of the oil pipe; wherein the casing is sleeved on the outside of the oil pipe;

[0025] Step S2: at least two centralizing assemblies in the detection tool are expanded until they are in rolling contact with the inner wall of the oil pipe, and the baffles in the two centralizing assemblies are respectively expanded and closed with the inner wall of the oil pipe to form a detection space, and the ultrasonic detection device in the detection tool is located in the detection space;

[0026] Step S3: When the leakage position is located below the detection space, the ultrasonic detection device collects a first ultrasonic signal;

[0027] Step S4: the detection tool continues to descend, and when the leakage position is within the detection space, the ultrasonic detection device collects a second ultrasonic signal;

[0028] Step S5: determining the depth of the leakage position and whether the leakage position is located in the oil pipe or the casing according to the first ultrasonic signal and the second ultrasonic signal.

[0029] In a preferred embodiment of the present invention, in step S5, the depth of the leakage location is determined based on a signal surge feature from the first ultrasonic signal to the second ultrasonic signal and a depth of the detection tool in the oil pipe.

[0030] In a preferred embodiment of the present invention, the following steps are further included between step S4 and step S5:

[0031] The detection tool continues to descend, and when the leakage position is located below the detection space, the ultrasonic detection device collects a third ultrasonic signal;

[0032] The depth of the leakage position is verified according to a sudden drop feature of the signal from the second ultrasonic signal to the third ultrasonic signal and the insertion depth of the detection tool in the oil pipe.

[0033] In a preferred embodiment of the present invention, in step S5,

[0034] generating a continuous waveform graph according to the first ultrasonic signal, the second ultrasonic signal, and the third ultrasonic signal;

[0035] If there is a sudden increase band in the waveform diagram, the leakage position is located on the oil pipe;

[0036] If there is a band in the waveform graph where the waveform increases and remains stable, the leakage position is located on the casing.

[0037] As described above, the features and advantages of the detection tool and method for identifying oil pipe and casing leakage of the present invention are:

[0038] The present invention can retract the centralizing assembly toward the axial direction close to the oil pipe until it is separated from the inner wall of the oil pipe, so that the detection device can be smoothly lowered into the oil pipe; during the downward movement in the oil pipe, the centralizing assembly can be expanded toward the axial direction away from the oil pipe until it contacts the inner wall of the oil pipe, thereby ensuring the stable downward movement of the detection tool, and by changing the expansion amplitude of the centralizing assembly toward the axial direction away from the oil pipe, it can adapt to stable movement in oil pipes with different inner diameters.

[0039] In the present invention, an ultrasonic detection device is provided between the two righting assemblies, and baffles which can be folded and contracted or supported and expanded along with the righting assemblies are respectively provided on the two righting assemblies. When the righting assemblies are in the expanded state, the baffles are expanded along with the righting assemblies toward the inner wall of the oil pipe, and a detection space can be formed between the upper and lower baffles and the inner wall of the oil pipe. The sound wave signals (i.e., interference signals) outside the detection space will be blocked by the baffles. Due to the setting of the baffles, when the detection tool descends to the leakage position and is located between the two baffles, the sound waves emitted by the leakage position will enter the detection space and be received by the ultrasonic detection device. Compared with the leakage position being located outside the baffle, the sound wave signals received by the ultrasonic detection device at this time will be significantly enhanced, so that the depth of the leakage position can be accurately identified according to the changes in the sound waves, thereby eliminating the interference of well noise on sound wave detection and improving the accuracy of leakage position detection.

[0040] In addition, the present invention can accurately determine whether the leakage location is on the oil pipe or on the casing based on the waveform changes of the sound wave signal received by the ultrasonic detection device, that is, it can accurately identify the oil pipe leakage or the casing leakage, thereby improving the accuracy of the identification of the root cause of the leakage of the gas storage well and the high-pressure gas well, so that corresponding subsequent treatment measures can be taken according to different leakage scenarios, which is more targeted and avoids the harm caused by the leakage. It has better adaptability and strong practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0042] in:

[0043] Figure 1 This is a schematic structural diagram of a detection tool capable of identifying leakage of oil pipes and casings according to the present invention;

[0044] Figure 2 Schematic diagram of the layer structure of the baffle in the detection tool capable of identifying oil pipe and casing leakage according to the present invention;

[0045] Figure 3 Schematic diagram of a porous sound-absorbing layer in a detection tool capable of identifying oil pipe and casing leakage according to the present invention;

[0046] Figure 4This is a schematic diagram of a detection tool for detecting oil pipe and casing leakage according to the present invention under oil pipe leakage conditions;

[0047] Figure 5 This is a second schematic diagram of the detection tool for identifying oil pipe and casing leakage under oil pipe leakage conditions;

[0048] Figure 6 This is a schematic diagram of a detection tool for detecting tubing and casing leakage according to the present invention under casing leakage conditions;

[0049] Figure 7 This is a second schematic diagram of the detection tool for identifying tubing and casing leakage under casing leakage conditions;

[0050] Figure 8 The waveform diagram of the oil pipe leakage acoustic wave detection collected by the detection tool capable of distinguishing oil pipe and casing leakage of the present invention;

[0051] Figure 9 This is a waveform diagram of casing leakage acoustic wave detection collected by the detection tool of the present invention that can identify oil pipe and casing leakage;

[0052] Figure 10 This is a schematic structural diagram of the detection tool capable of identifying oil pipe and casing leakage according to the present invention, showing the baffle in an unexpanded state;

[0053] Figure 11 This is a schematic structural diagram of a partially unfolded state of a baffle in a detection tool capable of identifying oil pipe and casing leakage according to the present invention;

[0054] Figure 12 This is a structural schematic diagram of a detection tool capable of identifying oil pipe and casing leakage according to the present invention, in which the baffle is in a fully expanded state.

[0055] The accompanying drawings in the present invention are:

[0056] 1. Righting assembly; 101. First hinge block;

[0057] 102. Second hinge block; 103. First connecting rod;

[0058] 104. Second connecting rod; 105. Roller;

[0059] 2. Blocking piece; 21. Lower blocking piece;

[0060] 22. Upper baffle; 201. Porous sound-absorbing layer;

[0061] 202. Sound insulation layer; 203. Sound insulation layer;

[0062] 3. Ultrasonic detection device 4. Upper connector;

[0063] 5. Guide shoe; 6. Oil pipe;

[0064] 601. Oil pipe leak; 7. Casing;

[0065] 701. Casing leakage point; 8. Detection space. DETAILED DESCRIPTION

[0066] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0067] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be an element centered thereon. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an element centered thereon. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementations.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are intended only to describe specific embodiments and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0069] Implementation Method 1

[0070] like Figures 1 to 12 As shown, the present invention provides a detection tool that can identify oil pipe and casing leakage, which can be used to detect leakage of oil pipe 6 and casing 7, and accurately identify the depth of the leakage location. It can also identify whether the leakage location is located on the oil pipe 6 or on the casing 7 (that is, the identification of oil pipe leakage point 601 and casing leakage point 701), and can be widely used in leakage scenarios such as gas storage wells and high-pressure gas wells.

[0071] The detection tool of the present invention, which can identify oil pipe and casing leakage, includes two straightening components 1, two baffles 2 and an ultrasonic detection device 3. When the straightening component 1 is lowered into the oil pipe 6, the straightening component 1 can be retracted in the axial direction close to the oil pipe 6 until it is separated from the inner wall of the oil pipe 6, or it can be expanded in the axial direction away from the oil pipe 6 until it is in contact with the inner wall of the oil pipe 6; the ultrasonic detection device is arranged between the two straightening components 1; the two baffles 2 are respectively arranged on the corresponding straightening components 1, and when the straightening component 1 is in a retracted state, the baffles 2 are folded and gathered in the axial direction close to the oil pipe 6; when the straightening component 1 is in an expanded state, the baffles 2 are expanded along with the straightening component 1 toward the inner wall of the oil pipe 6, so as to enclose a detection space 8 between at least two baffles 2 and the inner wall of the oil pipe 6, and at least two baffles 2 are used to block external interference signals from entering the detection space 8.

[0072] The present invention can shrink the straightening assembly 1 toward the axial direction close to the oil pipe 6 until it is separated from the inner wall of the oil pipe 6, so that the detection device can be smoothly lowered into the oil pipe 6; during the downward process in the oil pipe 6, the straightening assembly 1 can be expanded toward the axial direction away from the oil pipe 6 until it contacts the inner wall of the oil pipe 6, playing a role of supporting and straightening, ensuring the stable descent of the detection tool, and by changing the expansion amplitude of the straightening assembly 1 toward the axial direction away from the oil pipe 6, it can adapt to stable movement in oil pipes with different inner diameters. The present invention has better adaptability in practical applications, saves manual operation and economic costs.

[0073] In the present invention, an ultrasonic detection device 3 is provided between the two righting assemblies 1, and a baffle 2 is provided on each of the two righting assemblies 1, which can be folded and contracted or supported and expanded along with the righting assemblies 1. The baffle 2 is made of a material with deformation ability. The baffle 2 is arranged on the righting assemblies 1 similar to the umbrella surface, and can change its own expansion state as the righting assemblies 1 contract or expand. When the straightening assembly 1 is in the expanded state, the baffle 2 is expanded along with the straightening assembly 1 toward the inner wall of the oil pipe 6, and a detection space 8 can be formed between the upper and lower baffles 2 and the inner wall of the oil pipe 6. The sound wave signal (i.e., the interference signal) outside the detection space 8 will be blocked by the baffle 2. Due to the setting of the baffle 2, when the detection tool descends to the leakage position between the two baffles 2, the sound wave emitted from the leakage position will enter the detection space 8 and be received by the ultrasonic detection device 3. Compared with the leakage position being located outside the baffle 2, the sound wave signal received by the ultrasonic detection device 3 at this time will be significantly enhanced, so that the depth of the leakage position can be accurately identified according to the change of the sound wave, eliminating the interference of the well noise (most of the noise generated by the gas storage reservoir and high-pressure gas wellbore and the detection tool itself) on the sound wave detection, and improving the accuracy of the leakage position detection.

[0074] In addition, the present invention can accurately determine whether the leakage location is on the oil pipe 6 or on the casing 7 based on the waveform changes of the sound wave signal received by the ultrasonic detection device 3, that is, it can accurately identify the oil pipe leakage point 601 or the casing leakage point 701, thereby improving the accuracy of identifying the root cause of leakage in gas storage wells and high-pressure gas wells, so that corresponding subsequent treatment measures can be taken according to different leakage scenarios, which is more targeted and avoids the harm caused by leakage, and has better adaptability and strong practical value.

[0075] In the present invention, the ultrasonic detection device 3 can be but not limited to an ultrasonic sensor. The detection tool further includes an image generating device (not shown). The signal output end of the ultrasonic detection device 3 is electrically connected to the signal receiving end of the image generating device. The ultrasonic detection device 3 can transmit the received sound wave signal of the oil pipe leakage or casing leakage to the ground in real time. The image generating device is used to generate an image based on the received ultrasonic signal. Figure 8 and Figure 9 The waveform graph shown is used to determine tubing or casing leaks. The image generation device in the present invention can be an existing ultrasonic imaging device that generates a waveform graph based on the signals received from the ultrasonic sensor. The specific type and structure of the ultrasonic imaging device are not limited herein. The method for determining tubing or casing leaks based on the waveform graph is described in detail below.

[0076] In an optional embodiment of the present invention, Figures 1 to 3 As shown, the baffle 2 includes a porous sound-absorbing layer 201 and a sound insulation layer that are stacked. When the baffle 2 is set on the straightening assembly 1, the porous sound-absorbing layer 201 is set toward the detection space 8, and the sound insulation layer is located on the side facing away from the detection space 8. The sound insulation layer can block external interference signals from entering the detection space 8, thereby preventing external interference signals from interfering with the sound wave signals received by the ultrasonic detection device 3 at the leakage position; and the porous sound-absorbing layer 201 can absorb the ultrasonic signal emitted from the leakage position to the baffle 2, thereby preventing excess ultrasonic signals from being emitted and reflected at the baffle 2 and interfering with the signal reception of the ultrasonic detection device 3.

[0077] Further, such as Figure 3As shown, the sound insulation layer comprises a sound-insulating cotton layer 202 and an elastic sound-insulating layer 203. From the direction facing the detection space 8 to the direction facing away from the detection space 8, the porous sound-absorbing layer 201, the sound-insulating cotton layer 202, and the sound-insulating layer 203 are stacked in this order. The sound-insulating layer of the present invention blocks most ultrasonic signal interference outside the range of the upper and lower baffles 2, preventing interference signals generated by upward flow within the oil pipe 6, sliding of the detection tool, and other leaks. The sound-insulating cotton layer 202 serves as an intermediate medium between the porous sound-absorbing layer 201 and the sound-insulating layer 203, providing secondary processing and further weakening of any acoustic signals escaping from the two. Specifically, the sound insulation cotton layer 202 is placed as a filling layer between the porous sound-absorbing layer 201 and the sound insulation layer 203, and the noise reduction effect is optimized through the following mechanisms: 1. The sound insulation cotton layer 202 has the function of damping and shock isolation. The sound insulation cotton layer 202 is attached to the substrate on the sound source side to suppress the conduction of solid vibration and reduce structure-borne noise; the sound insulation cotton layer 202 can adopt a density gradient design (such as polyester fiber cotton) to consume sound energy from low frequency to high frequency layer by layer; 2. The sound insulation cotton layer 202 has the function of sound absorption spectrum compensation. The sound insulation cotton layer 202 can compensate for the poor absorption of high-frequency sound waves by the sound insulation layer 203 and reduce reverberation; in addition, the sound insulation cotton layer 202 can also block sound bridges and weaken standing waves; 3. The sound insulation cotton layer 202 has the function of energy conversion. The sound wave signal entering the sound insulation cotton layer 202 will be repeatedly refracted between the pores of the sound insulation cotton layer 202, and the friction will convert the sound energy into heat energy.

[0078] The detection tool of the present invention is in the process of downlink, such as Figure 4 and Figure 6 As shown, when the oil pipe leak point 601 or the casing leak point 701 is outside the area where the ultrasonic detection device 3 can receive signals, that is, when the oil pipe leak point 601 or the casing leak point 701 is located above the upper baffle 22 (a baffle 2 located above the oil pipe 6) or below the lower baffle 21 (another baffle 2 located below the oil pipe 6), the ultrasonic signal induced by the leakage of the oil pipe 6 or the casing 7 will first be largely blocked by the sound insulation layer 203 in the baffle 2, and the remaining small amount of sound wave signal will be absorbed by the sound insulation cotton layer 202 in the middle position, so that most of the external interference signals that can be received by the ultrasonic detection device 3 are shielded; as shown in FIG. Figure 5 and Figure 7As shown, when the detection tool descends to the oil pipe leakage point 601 or the casing leakage point 701 and is located in the area where the ultrasonic detection device 3 can receive signals (that is, when the leakage position is between the upper baffle 22 and the lower baffle 21), the sound wave signal received by the ultrasonic detection device 3 will suddenly increase, and the excess sound wave signal will be absorbed by the porous sound-absorbing layer 201 after being emitted to the upper baffle 22 and the lower baffle 21, thereby preventing the excess sound wave signal from being reflected and interfering with the sound wave signal detection by the ultrasonic detection device 3. The present invention accurately locates the position of the oil pipe leakage point 601 or the casing leakage point 701 based on the sudden change information of the sound wave signal received by the ultrasonic detection device 3.

[0079] In the above embodiment, the porous sound-absorbing layer 201 can be made of, but is not limited to, a sound-absorbing board material with micropores. For example, the porous sound-absorbing layer 201 can be made of a porous fiber material (such as a polyester fiber board), and a cocoon-like porous structure is formed by high-temperature hot pressing. After the sound waves enter the micropores, they are converted into heat energy due to friction, and the absorption rate of some medium and high-frequency noise can reach more than 0.9; the sound insulation layer 203 can be made of a high-density damping material, such as rubber aluminum foil sound insulation cotton, which has high density and strong elasticity and can weaken the propagation of low-frequency vibrations.

[0080] In an optional embodiment of the present invention, Figure 1 、 Figures 4 to 7 As shown, the straightening assembly 1 includes a first hinge block 101, a second hinge block 102, a plurality of first connecting rods 103 and a plurality of second connecting rods 104. The first hinge block 101 and the second hinge block 102 are both cylindrical structures, and the first hinge block 101 and the second hinge block 102 are arranged up and down along the notification axis. The plurality of first connecting rods 103 are spaced and evenly distributed along the circumference of the first hinge block 101. One end of the plurality of first connecting rods 103 is respectively hinged to the edge position of one end face of the first hinge block 101 (rotatably connected), and the plurality of second connecting rods 104 There are one-to-one correspondences with the multiple first connecting rods 103, and the multiple second connecting rods 104 are spaced and evenly distributed along the circumference of the second hinge block 102, the other ends of the multiple first connecting rods 103 are respectively hinged (rotatably connected) to one end of the corresponding multiple second connecting rods 104, and the other ends of the multiple second connecting rods 104 are respectively hinged (rotatably connected) to the edge position of one end face of the second hinge block 102; the ultrasonic detection device 3 is located between the two straightening assemblies 1, and the ultrasonic detection device 3 is respectively connected to the second hinge blocks 102 in the two straightening assemblies 1.

[0081] Furthermore, a driving element may be provided between the first articulated block 101 and the second articulated block 102, and the relative position of the first articulated block 101 and the second articulated block 102 may be adjusted by the driving element, thereby realizing the contraction or expansion control of the first connecting rod 103 and the second connecting rod 104, wherein the driving element may be, but is not limited to, a driving cylinder, which is connected between the first articulated block 101 and the second articulated block 102, and by controlling the contraction of the piston rod of the driving cylinder, the first articulated block 101 and the second articulated block 102 are moved closer to each other. The hinged position of the first connecting rod 103 and the second connecting rod 104 moves in the axial direction away from the oil pipe 6, until it can abut against the inner wall of the oil pipe 6, thereby achieving the function of straightening and supporting. By controlling the piston rod of the drive cylinder to extend, the first hinge block 101 and the second hinge block 102 move in the direction away from each other, thereby making the hinged position of the first connecting rod 103 and the second connecting rod 104 move in the axial direction close to the oil pipe 6, until it can separate from the inner wall of the oil pipe 6, thereby ensuring the smooth lowering of the detection tool.

[0082] In the initial stage of lowering the detection tool into the oil pipe 6, as shown in FIG. Figure 10 As shown, the first connecting rod 103 and the second connecting rod 104 can be retracted toward the axis of the oil pipe 6 to reduce the outer diameter of the detection tool, thereby facilitating the detection tool to be smoothly lowered into the oil pipe 6 without contacting the inner wall of the oil pipe 6; Figure 11 and 12 As shown, after the detection tool is lowered into the oil pipe 6 for a certain distance, the first connecting rod 103 and the second connecting rod 104 can be gradually opened until the hinge position of the first connecting rod 103 and the second connecting rod 104 is against the inner wall of the oil pipe 6. At this time, the baffle 2 is fully opened to achieve the best use effect.

[0083] Further, such as Figure 12 As shown, the edge of the baffle 2 or the area close to the edge is connected to the plurality of second connecting rods 104 , and the baffle 2 in the expanded state is adapted to the cross section of the internal passage of the oil pipe 6 to block the internal passage of the oil pipe 6 .

[0084] In an optional embodiment of the present invention, Figure 1 、 Figures 4 to 7 、 Figures 10 to 12 As shown, a roller 105 is provided between the first connecting rod 103 and the corresponding second connecting rod 104; a rotating shaft is provided in the middle of the roller 105, and the first connecting rod 103 and the second connecting rod 104 are rotatably connected to the rotating shaft. When the straightening assembly 1 is in the expanded state, the first connecting rod 103 and the second connecting rod 104 rotate and push the roller 105 toward the inner wall of the oil pipe 6 until the outer wall of the roller 105 abuts against the inner wall of the oil pipe 6, which can ensure that the detection tool can move steadily downward along the oil pipe 6.

[0085] In an optional embodiment of the present invention, Figure 1 、 Figures 4 to 7 、 Figures 10 to 12 As shown, the inspection tool also includes an upper connector 4 and a guide shoe 5. The upper connector 4 and the guide shoe 5 are respectively connected to the first hinge blocks 101 in the two centralizing assemblies 1. The upper connector 4 facilitates the connection of the inspection tool to the lowered tubing string, achieving the required lowering of the inspection tool. The guide shoe 5 serves as a guide, ensuring that the inspection tool is smoothly lowered into the oil pipe 6. When the inspection tool is lowered into the oil pipe 6, the upper connector 4, one centralizing assembly 1, the ultrasonic detection device 3, the other centralizing assembly, and the guide shoe 5 are arranged in sequence from top to bottom along the axial direction of the oil pipe 6.

[0086] The features and advantages of the detection tool for identifying oil pipe and casing leakage of the present invention are:

[0087] 1. The detection tool supports and straightens through the straightening assembly 1 to ensure the stable downward movement of the detection tool. By changing the expansion amplitude of the straightening assembly 1 in the axial direction away from the oil pipe 6, it can adapt to stable movement in oil pipes with different inner diameters. The present invention has better adaptability in practical applications, saving manual operation and economic costs.

[0088] Second, this detection tool can accurately identify the depth of the leak location based on the changes in sound waves, eliminating the interference of well noise (most of the noise generated by the gas storage reservoir and high-pressure gas wellbore and the detection tool itself) on sound wave detection, and improving the accuracy of leak location detection.

[0089] Third, this detection tool can accurately determine whether the leak is located on the oil pipe 6 or the casing 7 based on the waveform changes of the sound wave signal received by the ultrasonic detection device 3, that is, it can accurately identify the oil pipe leak point 601 or the casing leak point 701, thereby improving the accuracy of identifying the root cause of leakage in gas storage wells and high-pressure gas wells. It can also help to take corresponding subsequent treatment measures according to different leakage scenarios, which is more targeted and avoids the harm caused by the leakage. It has better adaptability and strong practical value.

[0090] Implementation Method 2

[0091] The present invention provides a detection method capable of identifying oil pipe and casing leakage, which uses the above-mentioned detection tool capable of identifying oil pipe and casing leakage for detection. The detection method comprises the following steps:

[0092] Step S1: lowering the detection tool into the oil pipe 6, and the detection tool descends along the axis of the oil pipe 6; wherein, the casing 7 is sleeved on the outside of the oil pipe 6;

[0093] Furthermore, in the above step S1, if Figure 10As shown, the first connecting rod 103 and the second connecting rod 104 in the detection tool can be retracted toward the axial direction of the oil pipe 6 so that the outer diameter of the detection tool is smaller than the inner diameter of the wellhead, so that the detection tool can be smoothly lowered into the oil pipe 6 without contacting the inner wall of the oil pipe 6, and can be lowered a distance to the bottom of the oil pipe 6.

[0094] Step S2: At least two centralizing assemblies 1 in the detection tool are expanded until they are in rolling contact with the inner wall of the oil pipe 6. The baffles 2 in the two centralizing assemblies 1 are expanded and enclosed with the inner wall of the oil pipe 6 to form a detection space 8. The ultrasonic detection device 3 in the detection tool is located in the detection space 8.

[0095] Furthermore, in the above step S2, if Figure 11 and Figure 12 As shown, after the detection tool enters the oil pipe 6, the first connecting rod 103 and the second connecting rod 104 are gradually extended until the hinged position of the first connecting rod 103 and the second connecting rod 104 abuts against the inner wall of the oil pipe 6, ensuring the stability of the detection tool as it descends within the oil pipe 6. At this time, the upper baffle 22 and the lower baffle 21 are both extended along with the first connecting rod 103 and the second connecting rod 104, so that the ultrasonic detection device 3 is located within the detection space 8. The upper baffle 22 and the lower baffle 21 cooperate to block interference signals above and below the detection tool.

[0096] Step S3: During the downward movement of the detection tool, when the leakage position is located below the detection space 8, the ultrasonic detection device 3 collects the first ultrasonic signal; at this time, due to the blocking effect of the lower baffle 21 on the ultrasonic signal, as shown in FIG. Figure 8 and Figure 9 As shown, the first ultrasonic signal collected by the ultrasonic detection device 3 is very weak (the boost pressure is almost close to 0);

[0097] Step S4: The detection tool continues to descend. When the detection tool descends to the point where the leakage is located within the detection space 8, the ultrasonic detection device 3 collects a second ultrasonic signal.

[0098] At this time, since the oil pipe leakage point 601 or the casing leakage point 701 has been exposed between the upper baffle 22 and the lower baffle 21, the sound wave signal emitted by the oil pipe leakage point 601 or the casing leakage point 701 can avoid the obstruction of the baffle 2 and enter the detection space 8. The ultrasonic signal received by the ultrasonic detection device 3 will suddenly increase (that is, the second ultrasonic signal will suddenly increase compared to the first ultrasonic signal), and it can be determined that the leakage point position has passed the position of the lower baffle 21.

[0099] Step S5: Determine the depth of the leakage position and whether the leakage position is located in the oil pipe 6 or the casing 7 according to the first ultrasonic signal and the second ultrasonic signal.

[0100] Specifically, in step S5, the depth of the leak is determined based on the sudden increase in the signal from the first ultrasonic signal to the second ultrasonic signal and the depth of the detection tool lowered into the oil pipe 6. During the actual lowering of the detection tool, the distance below the detection tool (specifically, the lower baffle 21) can be directly recorded. If the detected acoustic signal suddenly increases, it indicates that the leak has passed the lower baffle 21 and entered the detection space 8. At this time, the depth of the detection tool lowered into the oil pipe 6 is the depth of the leak.

[0101] Furthermore, between step S4 and step S5, the following steps are further included:

[0102] The detection tool continues to descend, and when the leakage position is located below the detection space 8, the ultrasonic detection device 3 collects a third ultrasonic signal;

[0103] The depth of the leakage position is verified based on the sudden drop feature of the signal from the second ultrasonic signal to the third ultrasonic signal and the depth of the detection tool in the oil pipe 6.

[0104] At this point, based on the sudden decrease in the signal from the second ultrasonic signal to the third ultrasonic signal, it can be determined that the leak location has passed through the upper baffle 22 and moved above the detection space 8. Since the spacing between the upper baffle 22 and the lower baffle 21 is predetermined, by determining whether the distance the detection tool descends during the process of the detected acoustic signal increasing and decreasing is consistent with the spacing between the upper baffle 22 and the lower baffle 21, it can be verified whether the sudden change in the acoustic signal collected by the ultrasonic detection device 3 is caused by the presence of a leak in the oil pipe 6 or casing 7. If the distance the detection tool descends during the process of the detected acoustic signal increasing and decreasing is consistent with the spacing between the upper baffle 22 and the lower baffle 21, it indicates that a leak location does exist in the oil pipe 6 or casing 7, and that the leak location has sequentially passed through the lower baffle 21 and the upper baffle 22 during the lowering of the detection tool, thereby verifying the depth of the leak location.

[0105] In an optional embodiment of the present invention, in the above step S6,

[0106] generating a continuous waveform graph according to the first ultrasonic signal, the second ultrasonic signal, and the third ultrasonic signal;

[0107] like Figure 8 As shown, if there is a sudden increase band in the waveform diagram, it can be determined that the leakage location is on the oil pipe 6;

[0108] like Figure 9 As shown, if there is a band with an increased waveform in the waveform diagram and the fluctuation amplitude remains stable, the leakage position is located on the sleeve 7.

[0109] The reason why the waveforms are different depending on whether the leak is located on the oil pipe 6 or the casing 7 is that during the lowering of the detection tool, the inner wall of the oil pipe 6 is in close contact with the detection tool, and the sound wave signal emitted by the oil pipe leak point 601 on the oil pipe 6 will be directly received by the ultrasonic detection device 3. Figure 8 As shown, the oil pipe leakage point 601 will have a band of obvious and sharp increase in sound pressure waveform (i.e., a sudden increase band) before and after entering the detection space 8; and since the casing 7 is arranged on the outside of the oil pipe 6, and there is an annulus between the casing 7 and the oil pipe 6 and an annulus protection liquid in the annulus, if there is a leakage position on the casing 7, the sound wave signal generated by the casing leakage point 701 will be dispersed to a certain extent by the annulus and the annulus protection liquid. Although the sound wave signal received by the ultrasonic detection device 3 will also increase, there will be no clear sudden increase band, as shown in FIG. Figure 9 As shown, the pressure waveform will increase to a certain extent before and after the oil pipe leakage point 601 enters the detection space 8 and then maintain the fluctuation amplitude. Therefore, the casing leakage will increase the sound pressure waveform and present a relatively stable waveform.

[0110] As mentioned above, during the tool's descent, a sudden increase in the real-time recorded acoustic pressure waveform indicates a tubing leak, while a relatively stable increase within a certain range indicates a casing leak. During this process, the depth at which the acoustic signal suddenly changes is recorded, representing the wellbore depth of the leak.

[0111] The specific implementation process of the detection method for identifying oil pipe and casing leakage of the present invention is as follows:

[0112] When the detection tool is lowered into Figure 4 and Figure 6 When the position is shown, at this time, the oil pipe leakage point 601 or the casing leakage point 701 is located below the detection tool, and the sound wave signal generated by the oil pipe leakage point 601 or the casing leakage point 701 will first be largely blocked by the sound insulation layer 203 outside the lower baffle 21, and the remaining small amount of sound wave signal is absorbed by the sound insulation cotton layer 202, so that the ultrasonic detection device 3 located in the detection space 8 will basically not receive the sound wave signal generated by the oil pipe leakage point 601 or the casing leakage point 701. Therefore, the ultrasonic signal received by the ultrasonic detection device 3 at this position is extremely weak (such as Figure 8 and Figure 9 As shown by the dotted waveform in the figure, the sound pressure is close to 0). Figure 5 and Figure 7When the position is displayed, the oil pipe leak point 601 or the casing leak point 701 is already within the detection space 8, and the acoustic wave signal emitted by the oil pipe leak point 601 or the casing leak point 701 received by the ultrasonic detection device 3 suddenly increases. According to the band information of the sudden increase in the acoustic wave signal received by the ultrasonic detection device 3, the depth of the oil pipe leak point 601 or the casing leak point 701 can be accurately located.

[0113] When the acoustic wave signal of the oil pipe leakage is received by the ultrasonic detection device 3, its sound pressure waveform may be in the form of sudden sudden increase (such as Figure 8 As shown in the solid line waveform in FIG, the oil pipe leak point 601 will have a band of significant and sharp increase in sound pressure waveform before and after entering the detection space 8 (i.e., a sudden increase band); and when the acoustic wave signal of the casing leakage is received by the ultrasonic detection device 3, its sound pressure waveform has a certain amplitude increase and presents a relatively more stable fluctuation form (as shown in FIG. Figure 9 In the actual detection process, it can be determined whether the oil pipe 6 or the casing 7 is leaking based on different waveform characteristics.

[0114] As the detection tool continues to slide downward, the leakage location will gradually move away from the main signal receiving area of ​​the ultrasonic detection device 3. When the upper baffle 22 slides with the detection tool to the bottom of the leakage location, due to the blocking of the sound wave signal by the upper baffle 22, the sound wave signal received by the ultrasonic detection device 3 will suddenly change from strong to weak. At this time, the sudden change of the sound wave signal can be recorded again as the depth data of the detection tool, so as to verify the depth of the leakage location.

[0115] After obtaining the acoustic wave data, the present invention can complete the detection, identification and positioning of the leak position based on the Helmholtz acoustic formula (known formula), wherein the formula involved is:

[0116]

[0117] Where ρ0 is the density of the medium where the sound wave propagates at the leakage location; c s is the propagation speed of the sound wave at the leakage position in the medium; p1 is the static pressure change; t is the sound wave propagation time at the leakage position; M1 is the monopole sound source.

[0118] The characteristics and advantages of the detection method for identifying oil pipe and casing leakage of the present invention are:

[0119] First, this detection method can be applied to gas storage wells of different sizes and high-pressure gas well oil pipes to detect leaks in the oil pipe 6 or casing 7, and has a wider range of applicability.

[0120] Second, this detection method can accurately identify the leakage type and depth of the oil pipe 6 or casing 7, and has better adaptability and stronger practical value.

[0121] 3. This detection method can be applied to gas storage reservoirs and high-pressure gas wellbores of different sizes. On the basis of being able to precisely locate the leakage position, it can accurately and directly determine whether the leakage source occurs in the oil pipe 6 or the casing 7, thereby improving the accuracy of the leakage source identification of gas storage reservoir wells and high-pressure gas wells.

[0122] The detection method capable of identifying oil pipe and casing leakage of the present invention has the same characteristics and advantages as the above-mentioned detection tool capable of identifying oil pipe and casing leakage, which will not be described in detail here.

[0123] It should be noted that, in the description of this application, the terms "first," "second," etc., are used solely for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, nor should they be understood to indicate or imply relative importance. Furthermore, in the description of this application, unless otherwise specified, "plurality" means two or more.

[0124] The above-mentioned various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0125] The above are only a few embodiments of the present invention. Although the embodiments disclosed in the present invention are as above, the contents are only for the purpose of facilitating understanding of the present invention and are not intended to limit the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A detection tool capable of identifying leakage in oil pipes and casings, characterized in that: The detection tool comprises: At least two centralizing assemblies, when lowered into the oil pipe, can be retracted toward the axis of the oil pipe until separated from the inner wall of the oil pipe, or expanded toward the axial direction away from the oil pipe until contacting the inner wall of the oil pipe; an ultrasonic detection device, the ultrasonic detection device being disposed between at least two of the centralizing assemblies; At least two baffles are respectively arranged on the corresponding righting assemblies. When the righting assembly is in a retracted state, the baffles are folded and gathered toward the axial direction of the oil pipe; when the righting assembly is in an expanded state, the baffles are expanded along with the righting assembly toward the inner wall of the oil pipe to form a detection space between the at least two baffles and the inner wall of the oil pipe. The at least two baffles are used to block external interference signals from entering the detection space.

2. The detection tool capable of identifying leakage of oil pipes and casings according to claim 1, characterized in that: The baffle includes a porous sound-absorbing layer and a sound-insulating layer stacked together. The porous sound-absorbing layer is arranged toward the detection space, and the sound-insulating layer is located on the side facing away from the detection space. The porous sound-absorbing layer is used to absorb the ultrasonic signal emitted from the leakage position to the baffle, and the sound-insulating layer is used to block external interference signals from entering the detection space.

3. The detection tool capable of identifying oil pipe and casing leakage according to claim 2, characterized in that: The sound insulation layer includes a sound insulation cotton layer and an elastic sound insulation board. From the direction toward the detection space to the direction away from the detection space, the porous sound absorbing layer, the sound insulation cotton layer and the sound insulation board are stacked in sequence.

4. The detection tool capable of identifying oil pipe and casing leakage according to claim 1, characterized in that: The straightening assembly includes a first hinge block, a second hinge block, a plurality of first connecting rods and a plurality of second connecting rods, one end of each of the plurality of first connecting rods is hinged to the first hinge block, the other end of each of the plurality of first connecting rods is hinged to one end of each of the plurality of second connecting rods, and the other end of each of the plurality of second connecting rods is hinged to the second hinge block; The ultrasonic detection device is located between the two centralizing assemblies, and the ultrasonic detection device is respectively connected to the second hinge blocks in the two centralizing assemblies.

5. The detection tool capable of identifying oil pipe and casing leakage according to claim 4, characterized in that: A roller is provided between the first connecting rod and the corresponding second connecting rod; A rotating shaft is provided in the middle of the roller, and the first connecting rod and the second connecting rod are rotatably connected to the rotating shaft. When the straightening assembly is in the expanded state, the first connecting rod and the second connecting rod rotate and push the roller toward the inner wall of the oil pipe until the outer wall of the roller abuts against the inner wall of the oil pipe.

6. The detection tool capable of identifying leakage of oil pipes and casings according to claim 4, characterized in that: The edge of the baffle or a portion close to the edge is connected to a plurality of the second connecting rods. The baffle in the expanded state is adapted to the cross section of the internal passage of the oil pipe to block the internal passage of the oil pipe.

7. The detection tool capable of identifying leakage of oil pipes and casings according to claim 1, characterized in that: The ultrasonic detection device is an ultrasonic sensor.

8. The detection tool capable of identifying leakage of oil pipes and casings according to claim 1 or 7, characterized in that: The detection tool also includes an image generating device. The signal output end of the ultrasonic detection device is electrically connected to the signal receiving end of the image generating device. The image generating device is used to generate a waveform diagram based on the received ultrasonic signal to judge the oil pipe leakage or casing leakage based on the waveform diagram.

9. A method for detecting leakage of oil pipes and casings, which is performed using the detection tool for detecting leakage of oil pipes and casings according to any one of claims 1 to 8, characterized in that: The detection method comprises the following steps: Step S1: lowering a detection tool into the oil pipe, the detection tool descending along the axis of the oil pipe; wherein the casing is sleeved on the outside of the oil pipe; Step S2: at least two centralizing assemblies in the detection tool are expanded until they are in rolling contact with the inner wall of the oil pipe, and the baffles in the two centralizing assemblies are respectively expanded and closed with the inner wall of the oil pipe to form a detection space, and the ultrasonic detection device in the detection tool is located in the detection space; Step S3: When the leakage position is located below the detection space, the ultrasonic detection device collects a first ultrasonic signal; Step S4: the detection tool continues to descend, and when the leakage position is within the detection space, the ultrasonic detection device collects a second ultrasonic signal; Step S5: determining the depth of the leakage position and whether the leakage position is located in the oil pipe or the casing according to the first ultrasonic signal and the second ultrasonic signal.

10. The detection method capable of identifying leakage of oil pipes and casings according to claim 9, characterized in that: In step S5 , the depth of the leakage location is determined based on a signal sudden increase feature from the first ultrasonic signal to the second ultrasonic signal and the depth of the detection tool in the oil pipe.

11. The detection method capable of identifying leakage of oil pipes and casings according to claim 9, characterized in that: The following steps are included between step S4 and step S5: The detection tool continues to descend, and when the leakage position is located below the detection space, the ultrasonic detection device collects a third ultrasonic signal; The depth of the leakage position is verified according to a sudden drop feature of the signal from the second ultrasonic signal to the third ultrasonic signal and the insertion depth of the detection tool in the oil pipe.

12. The detection method capable of identifying leakage of oil pipes and casings according to claim 9, characterized in that: In the step S5, generating a continuous waveform graph according to the first ultrasonic signal, the second ultrasonic signal, and the third ultrasonic signal; If there is a sudden increase band in the waveform diagram, the leakage position is located on the oil pipe; If there is a band in the waveform graph where the waveform increases and remains stable, the leakage position is located on the casing.

Images