System and method for positioning downhole tool

Abstract

The invention discloses a system and a method for positioning downhole tools, which are applied to drilling and completion operations, and comprise a plurality of downhole tool detection modules which are respectively arranged in each section of sleeve in a pipe string and are used for detecting whether a downhole tool passes through the position of the downhole tool in real time, when a tool is detected to pass by, a corresponding arrival signal is sent to the ground; and the depth resolving module is arranged on the ground and is used for receiving the arrival signal and positioning the well depth position which the tripping-in tool arrives at in real time according to the source of the signal. According to the method, the operation state of the tool can be accurately judged without influencing underground operation.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling and completion, and more particularly to a system and method for positioning downhole tools. Background Art

[0002] With the gradual progress of oil and gas towards deeper and unconventional reservoirs, there are more and more complex structure wells such as ultra-deep wells and horizontal wells. The drilling and completion operation conditions are becoming more and more complex. During the drilling and downhole operation processes, the probability of complex failures is increasing, and the handling difficulty is also great. For example, in the cementing operation of horizontal wells, during the displacement process of the rubber plug, due to reasons such as rubber plug deformation, the rubber plug fails to be displaced in place and cannot be bumped, resulting in incomplete displacement of the cement slurry in the casing, too long cement plug in the pipe, insufficient upward return height of the annular cement slurry, etc., affecting the cementing quality and wellbore integrity, and being unfavorable for long-term safe production; or when conducting a plugging operation with downhole motor drill tools, it is often necessary to drop a ball to open the bypass valve. Due to the influence of drilling fluid or impurities inside the drill tool, the ball may not be able to reach the position, thereby affecting the opening of the bypass valve.

[0003] Therefore, the above-mentioned drilling and completion operations all have a common problem, that is, during the downward movement of the rubber plug or ball put in, engineering technicians cannot know their downward speed and position, thus affecting the accurate analysis and judgment decision-making of the operation process.

[0004] In summary, the prior art urgently needs to provide a solution for analyzing and judging the position of downhole tools. Summary of the Invention

[0005] The purpose of the present invention is to provide a solution for exploring the positioning and analysis of the position of downhole tools by on-site technicians.

[0006] To solve the above technical problems, an embodiment of the present invention provides a system for positioning downhole tools. The system is applied to drilling and completion operations. Among them, the system includes: a plurality of downhole tool detection modules, which are respectively arranged in each section of the casing in the pipe string, used for real-time detection of whether a downhole tool passes through its own position, and sending a corresponding arrival signal to the ground when a tool is detected passing by; a depth calculation module arranged on the ground, which is used for receiving the arrival signal and positioning the well depth position where the downhole tool reaches in real time according to the source of the signal.

[0007] Preferably, the downhole tool carries a micro signal transmitter, which is used for real-time transmitting a first signal indicating arrival during the downward movement of the downhole tool. Among them, each downhole tool detection module is further used for generating the arrival signal indicating that the downhole tool reaches the current position when receiving the first signal.

[0008] Preferably, the downhole tool detection module is configured within the signal sub, and the signal sub is threadedly connected to each casing section.

[0009] Preferably, the downhole tool detection module is configured within the signal collar, and the signal collar surrounds the periphery of the coupling position of each casing section.

[0010] Preferably, the downhole tool detection module is installed inside the centralizer of each casing section.

[0011] Preferably, the downhole tool is a cementing plug or a ball for plugging leaks.

[0012] Preferably, the depth calculation module is further configured to determine the lowering speed of the downhole tool according to the real-time well depth positioning result of the downhole tool.

[0013] On the other hand, a method for positioning a downhole tool is provided, and the method is implemented by using the system as described above. Wherein, the method includes: using a plurality of downhole tool detection modules respectively arranged in each casing of the pipe string to detect in real time whether the lowering tool passes through its own position, and sending a corresponding arrival signal to the ground when a tool is detected passing by; receiving the arrival signal through the depth calculation module arranged on the ground and positioning the well depth position where the lowering tool arrives in real time according to the source of the signal.

[0014] Preferably, the lowering tool carries a micro signal transmitter. Wherein, in the step of using a plurality of downhole tool detection modules respectively arranged in each casing of the pipe string to detect in real time whether the lowering tool passes through its own position, and sending a corresponding arrival signal to the ground when a tool is detected passing by, it includes: using the micro signal transmitter to emit a first signal indicating arrival in real time during the downward movement of the lowering tool; each of the downhole tool detection modules generates the arrival signal indicating that the downhole tool arrives at the current position when receiving the first signal.

[0015] Preferably, the downhole tool is a cementing plug or a ball for plugging leaks.

[0016] Compared with the prior art, one or more embodiments of the above solutions may have the following advantages or beneficial effects:

[0017] The present invention provides a system and method for positioning downhole tools. The downhole tool positioning solution proposed by the present invention is applicable to various operating conditions such as cementing plugs and bypass valve ball throwing. Specifically, a signal transmitting module built into the tool forms a matching relationship with a signal detecting module on the casing string, that is, the signal transmitting module sends a in-place signal to the signal detecting module; the detecting module can be constructed in three types: a signal nipple connected to the casing thread, a signal ring sleeved at the coupling position, and a signal module placed inside the casing centralizer. In this way, without changing the structures of the downhole tool and the casing body, the present invention can accurately judge the running state of the tool without affecting downhole operations, which has positive significance.

[0018] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures specifically pointed out in the specification, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0020] Figure 1 is a schematic diagram of the overall structure of the system for positioning downhole tools according to an embodiment of the present application.

[0021] Figure 2 is a schematic diagram of the application scenario of the first example in the system for positioning downhole tools according to an embodiment of the present application.

[0022] Figure 3 is a schematic diagram of the application scenario of the second example in the system for positioning downhole tools according to an embodiment of the present application.

[0023] Figure 4 is a schematic diagram of the application scenario of the third example in the system for positioning downhole tools according to an embodiment of the present application.

[0024] Figure 5 is a schematic diagram of the steps of the method for positioning downhole tools according to an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following will describe in detail the embodiments of the present invention in conjunction with the drawings and embodiments, so as to fully understand how the present invention uses technical means to solve technical problems and achieve the realization process of technical effects and implement accordingly. It should be noted that as long as there is no conflict, the various embodiments in the present invention and the various features in each embodiment can be combined with each other, and the formed technical solutions are all within the protection scope of the present invention.

[0026] In addition, the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than herein.

[0027] The terms used herein are merely for describing specific embodiments and are not intended to limit the exemplary embodiments. Unless the context clearly dictates otherwise, the singular forms "a" and "an" used herein are also intended to include the plural. It should also be understood that the terms "comprises" and / or "comprising" specify the presence of the stated features, integers, steps, operations, units, and / or components, and do not preclude the presence or addition of one or more other features, integers, steps, operations, units, components, and / or combinations thereof.

[0028] As oil and gas gradually move towards deeper and unconventional areas, there are more and more complex structure wells such as ultra-deep wells and horizontal wells. The working conditions of drilling and completion operations are becoming more and more complex. During the drilling and downhole operations, the probability of complex failures is increasing, and the handling difficulty is great. For example, in the cementing operation of a horizontal well, during the displacement process of the rubber plug, due to reasons such as rubber plug deformation, the rubber plug fails to be displaced in place and cannot be bumped, resulting in incomplete displacement of the cement slurry in the casing, too long cement plug in the pipe, insufficient upward return height of the annular cement slurry, etc., affecting the cementing quality and wellbore integrity, and being unfavorable for long-term safe production; or when plugging leaks with downhole motor drill collars, it is often necessary to drop a ball to open the bypass valve. Due to the influence of drilling fluid or impurities inside the drill collars, the ball may not be able to reach the position, thus affecting the opening of the bypass valve.

[0029] Therefore, the above-mentioned drilling and completion operations all have a common problem, that is, during the downward movement of the rubber plug or ball put in, engineers cannot know its downward speed and position, thus affecting the accurate analysis and judgment decision-making of the operation process.

[0030] Therefore, in order to solve the above one or more technical problems, the present application proposes a system and method for positioning downhole tools. During the process of lowering the tool, the transmitting module inside the tool sends a signal to the signal receiving and transmitting module on the casing string. After receiving the signal, the signal receiving and transmitting module transmits it to the ground. The ground equipment directly decodes and calculates the transmitting position based on the signal upload source, so as to accurately judge the downward position of the tool.

[0031] Figure 1 It is a schematic diagram of the overall structure of the system for positioning downhole tools according to an embodiment of the present application. The following reference Figure 1, the system for positioning downhole tools described in the embodiments of the present invention (also referred to as the "downhole tool positioning system") will be described. First of all, it should be noted that the downhole tool positioning system described in the embodiments of the present invention is applied to the drilling and completion operation process.

[0032] As Figure 1 shown, the downhole tool positioning system includes a plurality of downhole tool detection modules 10 and a depth calculation module 20. The depth calculation module 20 is arranged on the ground. Each downhole tool detection module 10 can communicate with the depth calculation module 20. Among them, each downhole tool detection module 10 is respectively arranged in each section of the casing string.

[0033] During the implementation of the drilling and completion operation, since the downhole tool 101 will be lowered from the wellhead through the casing string into the well and needs to reach the bottom of the well. During the process of lowering the downhole tool 101 into the well, each downhole tool detection module 10 is used to detect in real time whether the downhole tool 101 passes through the position of its own detection module, and when it detects that a tool 101 passes by, it sends a corresponding arrival signal to the ground so that the depth calculation module 20 can receive the arrival signals sent from different downhole tool detection modules 10. The depth calculation module 20 is used to receive the arrival signals transmitted from different downhole tool detection modules 10, and based on the source of the arrival signals, position the well depth position where the downhole tool 101 arrives in real time.

[0034] In the embodiments of the present invention, the downhole tool 101 is a cementing plug or a ball for plugging leaks or other types of downhole tools. In this way, the downhole tool positioning system described in the embodiments of the present invention can be applicable to different operation scenarios.

[0035] Furthermore, the downhole tool 101 is equipped with a micro signal transmitter. The micro signal transmitter is used to transmit a first signal indicating (already) arrived in real time during the downward movement of the downhole tool 101. At this time, each downhole tool detection module 10 is also used to generate an arrival signal indicating that the downhole tool has arrived at the current position when receiving the first signal.

[0036] In an embodiment of the present invention, the downhole tool 101 can actively establish a communication relationship with the corresponding downhole tool detection module 10 at the corresponding position when it detects that it has arrived at the corresponding position of the downhole tool detection module 10 in different casing sections, and actively send a first signal indicating that it has arrived at the corresponding position. At this time, after receiving the first signal, the downhole tool detection module 10 actively generates an arrival signal indicating that the downhole tool 101 has arrived at the current detection module position, and thus sends the currently generated arrival signal to the ground.

[0037] In another embodiment of the present invention, the lowering tool 101 can also transmit a first signal in real time during the downward movement. The downhole tool detection module 10 located in different casing sections detects in real time based on whether it receives a first signal of a certain amplitude. When it detects that a first signal of a certain amplitude has been received, it indicates that the lowering tool 101 has reached the position of the current downhole tool detection module 10. At this time, the downhole tool detection module 10 will actively generate an arrival signal indicating that the lowering tool 101 has reached the current detection module position, and then send the currently generated arrival signal to the ground.

[0038] Furthermore, the depth calculation module 20 will receive in real time the arrival signals transmitted from the downhole tool detection modules 10 at different depths, and identify the source of the received arrival signals (i.e., which downhole tool detection module 10 sent them). Then, based on the source of the arrival signals, combined with the installation position of the source module and the length of the casing string, it determines the actual downhole depth position where the current signal source module is located, so as to locate the real-time well depth position reached by the current lowering tool 101.

[0039] In addition, the depth calculation module 20 is also used to determine the lowering speed of the downhole tool 20 based on the real-time well depth positioning result calculated for the downhole tool 101. In this way, the on-site staff can master the lowering depth and speed of the downhole tool 101 in real time.

[0040] Furthermore, the installation position points of each downhole tool detection module 10 can be calculated according to factors such as the positioning accuracy requirements and the length of the casing string. In the embodiments of the present invention, the downhole tool detection modules 10 at different depths can be set at installation position points such as the casing shoe, the A target point, and the kick-off point.

[0041] Figure 2 It is a schematic diagram of the application scenario of the first example in the system for positioning downhole tools according to the embodiments of the present application. As Figure 2 shown, each downhole tool detection module 10 described in the embodiments of the present invention can be constructed in different signal nipples. Each signal nipple can be threadedly connected to each casing section, so that each downhole tool detection module 10 is respectively arranged in each casing section.

[0042] Figure 3 It is a schematic diagram of the application scenario of the second example in the system for positioning downhole tools according to the embodiments of the present application. As Figure 3 shown, each downhole tool detection module 10 described in the embodiments of the present invention can be constructed in different signal collars. Each signal collar can surround the periphery of the coupling position of each casing section, so that each downhole tool detection module 10 is respectively arranged in each casing section.

[0043] Figure 4 Schematic diagram of the application scenario of the third example in the system for positioning downhole tools according to the embodiments of the present application. As Figure 4 shown, each downhole tool detection module 10 described in the embodiments of the present invention can be installed inside the centralizer of each casing section, so that each downhole tool detection module 10 is respectively arranged in each casing.

[0044] In the actual application process, the working process of the downhole tool positioning system described in the embodiments of the present invention is as follows:

[0045] S1. A micro signal transmission module is pre-placed inside the downhole tool 101, so as not to affect the structural strength and working performance of the tool itself;

[0046] S2. When lowering the casing string, according to the positioning requirements and in combination with the calculation of the string length, at predetermined key points such as the casing shoe, A target point, kick-off point, etc., according to the signal transmission distance, install signal receiving and transmitting devices (i.e., downhole tool detection modules 10), and then lower the casing to the predetermined well depth;

[0047] S3. The signal receiving and transmitting devices include three types. One is in the form of a short joint, which is directly connected to the casing thread; the second is in the form of a signal ring, which is sleeved on the outside of the casing coupling position; the third is a micro signal module, which is pre-placed inside the casing centralizer to make it have the function of signal receiving and transmitting;

[0048] S4. Put a plug or other type of tool 101 into the well. When the tool 101 is descending, when it passes through the first casing signal short joint (or signal ring), it actively emits a signal. After the signal receiving and transmitting device receives it, it sends a #1 in-place signal to the ground. After the ground equipment receives it, it confirms that the tool has passed the #1 position, and determines the specific well depth according to the casing string length and the installation position of the #1 signal short joint;

[0049] S5. The tool 101 continues to descend, and successively passes through the 2nd, 3rd, 4th, 5th... signal receiving and transmitting devices, repeating the signal receiving and decoding process until the tool 101 reaches the predetermined well depth position;

[0050] S6. According to the decoding result of the position signal, technicians can grasp the whole process of the tool lowering in real time and accurately judge the specific position and speed of the tool.

[0051] On the other hand, based on the above downhole tool positioning system, the embodiments of the present invention also provide a method for positioning downhole tools (also referred to as "downhole tool positioning method"). This downhole tool positioning method is implemented by using the above-mentioned downhole tool positioning system.

[0052] Figure 5 Schematic diagram of the steps of the method for positioning downhole tools according to the embodiments of the present application. As Figure 5As shown in the figure, the downhole tool positioning method according to the embodiment of the present invention includes the following steps: Step S510 uses a plurality of downhole tool detection modules 10 respectively arranged in each section of the casing in the pipe string to detect in real time whether the lowering tool 101 passes through its own position, and sends a corresponding arrival signal to the ground when it detects that a tool has passed; Step S520 receives the arrival signal through the depth calculation module 20 arranged on the ground and locates the well depth position where the lowering tool 101 arrives in real time according to the source of the signal.

[0053] Further, the lowering tool 101 is equipped with a micro signal transmitter. Among them, in step S510, first, the micro signal transmitter is used to transmit a first signal indicating arrival in real time during the downward movement of the lowering tool 101; then, each downhole tool detection module 10 generates an arrival signal representing the current position of the downhole tool when it receives the first signal.

[0054] In one embodiment, the downhole tool 101 is a cementing plug or a ball for plugging leakage.

[0055] The present invention discloses a system and method for positioning downhole tools. The downhole tool positioning solution proposed by the present invention is applicable to various operation conditions such as cementing plugs and bypass valve balls. Specifically, the signal emission module built in the tool forms a matching relationship with the signal detection module on the casing string, that is, the signal emission module sends a in-place signal to the signal detection module; the detection module can be constructed into three types: a signal short joint connected to the casing thread, a signal ring sleeved at the collar position, and a signal module placed inside the casing centralizer. In this way, without changing the structures of the downhole tool and the casing body, the present invention can accurately judge the operation state of the tool without affecting downhole operations, which has positive significance.

[0056] As described above, only the specific preferred embodiments of the present invention are described, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those familiar with the technology within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

[0057] In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0058] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should extend to equivalent alternatives of these features understood by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are only for the purpose of describing specific embodiments and do not mean to limit.

[0060] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in connection with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" that appear throughout the specification do not necessarily refer to the same embodiment.

[0061] Although the embodiments disclosed in the present invention are as above, the content described above is only an embodiment adopted for the convenience of understanding the present invention and is not intended to limit the present invention. Any person skilled in the art within the technical field to which the present invention pertains may make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A system for positioning downhole tools, characterized in that, the system is applied to drilling and completion operations, wherein the system comprises: a plurality of downhole tool detection modules, which are respectively arranged in each casing of the pipe string, for real-time detection of whether a downhole tool passes through its own position, and sending a corresponding arrival signal to the ground when a tool is detected passing by; a depth calculation module arranged on the ground, which is used for receiving the arrival signal and positioning the well depth position where the downhole tool arrives in real time according to the source of the signal.

2. The system according to claim 1, characterized in that, the downhole tool carries a micro signal transmitter, and the micro signal transmitter is used for transmitting a first signal indicating arrival in real time during the downward movement of the downhole tool, wherein, each of the downhole tool detection modules is further used for generating the arrival signal indicating that the downhole tool arrives at the current position when receiving the first signal.

3. The system according to claim 2, characterized in that, the downhole tool detection module is constructed in a signal nipple, and the signal nipple is threadedly connected to each casing section.

4. The system according to claim 2, characterized in that, the downhole tool detection module is constructed in a signal collar, and the signal collar surrounds the periphery of the coupling position of each casing section.

5. The system according to claim 2, characterized in that, the downhole tool detection module is installed inside the centralizer of each casing section.

6. The system according to any one of claims 1 to 5, characterized in that, the downhole tool is a cementing plug or a ball for plugging leaks.

7. The system according to any one of claims 1 to 6, characterized in that, the depth calculation module is further used for determining the downward speed of the downhole tool according to the real-time well depth positioning result of the downhole tool.

8. A method for positioning downhole tools, characterized in that, the method is implemented by using the system according to any one of claims 1 to 7, wherein the method comprises: using a plurality of downhole tool detection modules respectively arranged in each casing of the pipe string to real-time detect whether a downhole tool passes through its own position, and sending a corresponding arrival signal to the ground when a tool is detected passing by; receiving the arrival signal through a depth calculation module arranged on the ground and positioning the well depth position where the downhole tool arrives in real time according to the source of the signal.

9. The method according to claim 8, characterized in that, the downhole tool carries a micro signal transmitter, wherein, in the step of using a plurality of downhole tool detection modules respectively arranged in each casing of the pipe string to real-time detect whether a downhole tool passes through its own position, and sending a corresponding arrival signal to the ground when a tool is detected passing by, it includes: using the micro signal transmitter to transmit a first signal indicating arrival in real time during the downward movement of the downhole tool; each of the downhole tool detection modules generates the arrival signal indicating that the downhole tool arrives at the current position when receiving the first signal.

10. The system according to any one of claims 7 to 9, characterized in that, The downhole tool is a cementing plug or a ball used for plugging leaks.

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