Device and method for calibrating perforation depth of perforation section of oil and gas well

Abstract

The invention discloses a device and method for calibrating the depth of a perforation section of an oil and gas well. The device comprises a photoelectric composite cable, an underground pulse unit and a ground photoelectric control unit, and the two ends of the photoelectric composite cable are connected with the underground pulse unit and the ground photoelectric control unit respectively; the photoelectric composite cable is used for supplying power to the underground pulse unit and measuring vibration and temperature; the underground pulse unit is used for emitting pulse shock waves; the ground photoelectric control unit is used for controlling the underground pulse unit to emit pulse shock waves and receiving and processing vibration signals and temperature signals. The optical fiber is not interfered by external electromagnetic interference, the measurement precision is high, various measurement parameters are mutually verified, the accuracy and reliability of test data are ensured, and the service life of the device is long; the perforation section is deep and is completed with other operation measures at one time, so that the operation links are reduced, and the operation cost is reduced; the optical fiber is used for measuring vibration and temperature, the output profile of the well can be monitored in real time after other operation measures are finished, and the measure effect is rapidly evaluated.

Description

Technical Field

[0001] The invention relates to the technical field of downhole positioning tools, and in particular to a device and method for calibrating the hole depth of a perforation section in an oil and gas well. Background Art

[0002] Oil and natural gas are generally produced from underground reservoirs. Through a series of engineering methods such as drilling and fracturing, the oil and natural gas in the reservoirs flow from the casing perforations into the wellbore and reach the ground through measures such as self-flowing or artificial lifting.

[0003] In the process of oil and gas field development, accurate acquisition of the position and depth of the perforation holes in the oil and gas wells is the basis for a series of subsequent production increase and repair measures. When each oil and gas well is completed, a logging depth data will be generated through the logging instrument. Since the stretching amount of different cables is different, the corresponding perforation section position and depth under the cable need to be calibrated for each operation.

[0004] In the prior art, magnetic positioning or gamma positioning methods are usually used to calibrate the depth of the perforation holes. Generally, magnetic positioning or gamma positioning requires special equipment such as magnetic positioning subs and gamma subs, and the depth setting operation is completed through the cooperation of the logging vehicle. However, this correction method is susceptible to external electromagnetic interference, and the measurement accuracy needs to be improved; the method of measuring alone has high operating costs; there is an urgent need for a calibration device or method that is not susceptible to external electromagnetic interference, has high measurement accuracy, fewer operating links, and low operating costs to solve this problem. Summary of the invention

[0005] To this end, the present invention provides a device and method for calibrating the hole depth of a perforation section in an oil and gas well, so as to solve or alleviate one or more of the above-mentioned problems.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A first aspect of the present invention provides a device for calibrating the hole depth of a perforation section of an oil and gas well, comprising an optoelectronic composite cable, a downhole pulse unit and a ground optoelectronic control unit, wherein the two ends of the optoelectronic composite cable are respectively connected to the downhole pulse unit and the ground optoelectronic control unit; the optoelectronic composite cable comprises a copper conductor, a single-mode optical fiber and a multi-mode optical fiber, the copper conductor is used to power the downhole pulse unit, the single-mode optical fiber is used to measure vibration and transmit the vibration signal to the ground optoelectronic control unit, and the multi-mode optical fiber is used to measure temperature and transmit the temperature signal to the ground optoelectronic control unit; the downhole pulse unit is used to emit a pulse shock wave; the ground optoelectronic control unit is used to control the downhole pulse unit to emit a pulse shock wave, and to receive and process the vibration signal and the temperature signal.

[0008] Furthermore, the optoelectronic composite cable includes 5 copper conductors, 1 single-mode optical fiber and 1 multi-mode optical fiber.

[0009] Furthermore, a scale is arranged inside the optical fiber.

[0010] Furthermore, the downhole pulse unit is of comparable quality to a downhole logging tool string.

[0011] The second aspect of the present invention provides a method for calibrating the hole depth of a perforation section of an oil and gas well, which adopts the device for calibrating the hole depth of a perforation section of an oil and gas well provided by the first aspect of the present invention, and comprises the following steps:

[0012] Get the original hole depth value H1;

[0013] Use the winch to lower the downhole pulse unit, pay attention to the length H2 of the optical-electric composite cable released by the winch, and stop lowering the downhole pulse unit when H2 is greater than H1;

[0014] Under the control of the ground optoelectronic control unit, the downhole pulse unit releases a pulse shock wave, which is reflected after encountering the casing wall and the hole.

[0015] The single-mode optical fiber receives the reflected wave and forms a vibration signal which is transmitted to the ground optoelectronic control unit. At the same time, the temperature signal measured by the multi-mode optical fiber is transmitted to the ground optoelectronic control unit.

[0016] The ground photoelectric control unit determines the scale value H3 in the optical fiber corresponding to the reflected wave of the hole through the amplitude of the vibration signal;

[0017] The difference △H between the hole and H3 is calculated;

[0018] The calculated and verified hole depth H=H3+△H.

[0019] Furthermore, when the downhole pulse unit is lowered by the winch, the winch reading returns to zero when the pulse unit is at the wellhead.

[0020] Furthermore, the energy of the reflected wave formed by the pulse shock wave at the casing wall is higher than that of the reflected wave formed by the pulse shock wave at the hole; in the vibration signal, the amplitude of the reflected wave corresponding to the casing wall is greater than the amplitude of the reflected wave corresponding to the hole, and the scale corresponding to the weakest amplitude in the vibration signal is taken as H3.

[0021] Further, ΔH=H2-H1, H=H+H2-H1.

[0022] The present invention has the following advantages:

[0023] According to the original logging depth data, the downhole pulse unit is lowered into the well through the optoelectronic composite cable. When the depth of the perforation hole exceeds the position, the downhole pulse unit emits a pulse shock wave. The pulse shock wave encounters the casing around the perforation hole and then reflects. The single-mode optical fiber in the optoelectronic composite cable receives the vibration caused by the reflected wave. When the incident wave of the pulse shock wave hits the perforation hole position, part of the vibration will be incident from the hole into the formation. The perforation hole area will not cause reflection or very little reflection wave. In this way, when the single-mode optical fiber receives the vibration, the characteristics of the reflected wave corresponding to the perforation hole position and other casing reflection areas will be significantly different. The perforation area of ​​the well can be effectively determined by this difference. Combining the original logging data with the optical fiber vibration depth, the position and depth of the perforation section corresponding to this optical fiber composite can be corrected by calculation. Optical fiber is not subject to external electromagnetic interference, has high measurement accuracy, and multiple measurement parameters are cross-checked to ensure that the test data is accurate and reliable and the device has a long service life. The perforation section is deep and can be completed in one trip with other operating measures, reducing operation links and lowering operating costs. Fiber optic vibration and temperature measurement can be used to monitor the output profile of the well in real time after other operating measures are completed, and the effectiveness of the measures can be quickly evaluated.

[0024] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present application will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0026] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0027] Figure 1 A schematic diagram of the structure and use of a device for calibrating the hole depth of a perforation section in an oil and gas well provided by an embodiment of the present invention;

[0028] Figure 2A schematic diagram of an amplitude curve of a single-mode optical fiber vibration measurement during use of a device for calibrating the hole depth of a perforation section in an oil and gas well provided by an embodiment of the present invention;

[0029] Figure 3 An auxiliary calculation diagram for a device for calibrating the hole depth of a perforation section in an oil and gas well provided in an embodiment of the present invention when performing hole depth calibration.

[0030] In the figure: 1, casing; 2, optoelectronic composite cable; 3, perforation hole; 4, downhole pulse unit; 5, reflected wave; 51, hole reflected wave; 52, pipe wall reflected wave; 6, incident wave; 7, ground optoelectronic control unit. DETAILED DESCRIPTION

[0031] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0032] The present application provides a device and method for calibrating the hole depth of a perforation section in an oil and gas well, and adopts optical fiber vibration measurement (DAS) technology to realize the positioning of the perforation section in the well.

[0033] like Figure 1 As shown, Example 1 provides a device for calibrating the hole depth of the perforation section of an oil and gas well, including an optoelectronic composite cable 2, a downhole pulse unit 4 and a ground optoelectronic control unit 7, wherein the two ends of the optoelectronic composite cable 2 are respectively connected to the downhole pulse unit 4 and the ground optoelectronic control unit 7; the optoelectronic composite cable 2 includes a copper conductor, a single-mode optical fiber and a multi-mode optical fiber, wherein the copper conductor is used to power the downhole pulse unit 4, the single-mode optical fiber is used to measure vibration and transmit the vibration signal to the ground optoelectronic control unit 7, and the multi-mode optical fiber is used to measure temperature and transmit the temperature signal to the ground optoelectronic control unit 7; the downhole pulse unit 4 is used to emit a pulse shock wave; and the ground optoelectronic control unit 7 is used to control the downhole pulse unit 4 to emit a pulse shock wave, receive and process the vibration signal and the temperature signal. Among them, the optoelectronic composite cable 2 includes 5 copper conductors, 1 single-mode optical fiber and 1 multi-mode optical fiber. Among them, a scale is set in the optical fiber. Among them, the downhole pulse unit 4 is of equivalent quality to the downhole logging tool string.

[0034] Embodiment 2 provides a method for calibrating the hole depth of a perforation section in an oil and gas well, which uses the device in Embodiment 1 and includes the following steps:

[0035] Step S1, obtaining an original hole depth value H1, wherein the original hole depth H1 may be measured during well logging or during the last operation (such as hydraulic jet fracturing).

[0036] Step S2, use the winch to lower the downhole pulse unit 4, pay attention to the length value H2 of the optical composite cable 2 released by the winch, and when H2 is greater than H1, stop lowering the downhole pulse unit 4. The perforation section is mostly in the area of ​​hundreds to thousands of meters underground, so the value of H1 is very large, and H2 only needs to be 0.2-2m more than H1. Generally, the entire device is installed on the logging vehicle, and the winch is a device of the logging vehicle. The optical composite cable 2 is wound on the winch of the winch; the ground optical control unit 7 can be a controller or a processor; the optical composite cable 2 has the characteristics of high temperature resistance and corrosion resistance, and has a certain pressure resistance performance. It is used as a steel wire or cable for the downhole pulse unit 4 to go down the well, one end is connected to the ground optical control unit 7, and the other end is connected to the downhole pulse unit 4; the downhole pulse unit 4 is essentially a device for releasing pulse shock waves underground, and has the characteristics of high temperature resistance, corrosion resistance, waterproof and oil proof. When the downhole pulse unit 4 is lowered by the winch, when the pulse unit is at the wellhead, the winch reading returns to zero.

[0037] Step S3, under the control of the ground optoelectronic control unit 7, the downhole pulse unit 4 releases a pulse shock wave, and the pulse shock wave is reflected after encountering the wall of the casing 1 and the hole. The pulse shock wave directed to the wall of the casing 1 and the hole is called the incident wave 6, and the incident wave 6 is directed to the single-mode optical fiber after being emitted from the wall of the casing 1 and the hole, and is called the reflected wave 5. The single-mode optical fiber captures the reflected wave 5 for vibration measurement. As shown in the figure, the reflected wave 5 of the wall of the casing 1 causes a large amplitude in the single-mode optical fiber, and a part of the incident wave 6 enters the reservoir at the hole, and the energy of the reflected wave 5 is small, causing a small amplitude.

[0038] Step S4 , the single-mode optical fiber receives the reflected wave 5 to form a vibration signal which is transmitted to the ground photoelectric control unit 7 ; at the same time, the temperature signal measured by the multi-mode optical fiber is transmitted to the ground photoelectric control unit 7 .

[0039] Step S5, the ground optoelectronic control unit 7 determines the scale value H3 in the optical fiber corresponding to the reflected wave 5 of the hole through the amplitude of the vibration signal. The energy of the reflected wave 5 formed by the pulse shock wave at the wall of the casing 1 is higher than the reflected wave 5 formed by the pulse shock wave at the hole; in the vibration signal, the amplitude of the reflected wave 5 corresponding to the wall of the casing 1 is greater than the amplitude of the reflected wave 5 corresponding to the hole, and the scale corresponding to the weakest amplitude in the vibration signal is taken as H3. When determining the reflected wave 5 of the hole, you can refer to Figure 2 In the amplitude curve shown, the position with smaller amplitude in the amplitude curve corresponds to the reflected wave 5 of the hole, that is, the amplitude of the reflected wave 51 of the hole is significantly smaller than the reflected wave 52 of the pipe wall.

[0040] Step S6, calculate the difference △H between the hole and H3, △H=H2-H1. Figure 3 As shown, the incident angle ∠CAD = the reflection angle ∠BAD, so CD = BD, where CD = H2-H1, BD = △H, so △H = H2-H1.

[0041] Step S7, calculate the verified hole depth H=H3+△H, H=H+H2-H1.

[0042] The ground photoelectric control unit 7 mainly controls the downhole pulse unit 4 to emit pulse shock waves, and sends and receives processed optical signals at the same time; the ground photoelectric control unit 7 is connected to the downhole pulse unit 4 through the photoelectric composite cable 2. The weight of the downhole pulse unit 4 is roughly equivalent to the weight of the logging downhole tool string. There are two optical fibers (1 single-mode optical fiber and 1 multi-mode optical fiber) and 5 copper cables in the photoelectric composite cable 2. The single-mode optical fiber is used for optical fiber vibration measurement, and the multi-mode optical fiber completes the optical fiber temperature measurement function. The copper cable is responsible for supplying high voltage electricity to the downhole pulse unit 4. According to the original logging depth data, the photoelectric composite cable 2 lowers the pulse excitation device into the well to a position about 1 meter beyond the logging perforation depth (estimated based on the cable stretching amount and the well depth data); the ground photoelectric control unit 7 issues a command, and high voltage electricity is applied to both ends of the downhole pulse unit 4 through the photoelectric composite cable 2. The downhole pulse unit 4 sends out a pulse shock wave. The pulse shock wave encounters the casing 1 around the perforation hole 3 to form an incident wave 6 and a reflected wave 5. The single-mode optical fiber in the photoelectric composite cable 2 receives the vibration caused by the reflected wave 5. When the pulse shock wave reaches the perforation hole 3, most of the vibration generated by the pulse shock wave will be incident on the ground. In the layer, the perforation hole 3 area will not cause reflection or very little reflected wave 5, so when the optical fiber receives vibration, the reflected wave 5 characteristics corresponding to the perforation hole 3 position and other casing 1 reflection areas will have obvious differences, and the perforation section area of ​​the well can be effectively determined by this difference; at the same time, due to the water and gas outflow of some perforation holes 3, the temperature near this hole is different from that at other positions. When another multimode optical fiber is in a static state, the temperature change curve is collected, so that the original logging depth is combined with the optical fiber vibration depth and temperature characteristics for verification, and the position and depth of the perforation section corresponding to this optical fiber composite can be corrected by calculation.

[0043] This embodiment provides the following advantages:

[0044] 1. The optical fiber is not subject to external electromagnetic interference, has high measurement accuracy, and multiple measurement parameters are mutually verified to ensure that the test data is accurate and reliable, and the device has a long service life;

[0045] 2. The perforation section is deep and can be completed in one trip with other operation measures, reducing operation links and lowering operation costs;

[0046] 3. By using optical fiber vibration and temperature measurement, the output profile of the well can be monitored in real time after other operation measures are completed, and the effectiveness of the measures can be quickly evaluated.

[0047] In the description of this specification, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0049] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0051] The disclosure above provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described above. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numerals and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0052] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A device for calibrating the hole depth of a perforation section in an oil and gas well, characterized in that: It comprises an optoelectronic composite cable, a downhole pulse unit and a ground optoelectronic control unit, wherein two ends of the optoelectronic composite cable are respectively connected to the downhole pulse unit and the ground optoelectronic control unit; the optoelectronic composite cable comprises a copper conductor, a single-mode optical fiber and a multi-mode optical fiber, the copper conductor is used to supply power to the downhole pulse unit, the single-mode optical fiber is used to measure vibration and transmit the vibration signal to the ground optoelectronic control unit, and the multi-mode optical fiber is used to measure temperature and transmit the temperature signal to the ground optoelectronic control unit; the downhole pulse unit is used to emit a pulse shock wave; and the ground optoelectronic control unit is used to control the downhole pulse unit to emit a pulse shock wave, and to receive and process the vibration signal and the temperature signal.

2. The device for calibrating the perforation depth of the oil and gas well according to claim 1, characterized in that: The optoelectronic composite cable comprises 5 copper conductors, 1 single-mode optical fiber and 1 multi-mode optical fiber.

3. The device for calibrating the perforation depth of an oil and gas well according to claim 1, characterized in that: A scale is arranged inside the optical fiber.

4. The device for calibrating the perforation depth of an oil and gas well according to claim 1, characterized in that: The downhole pulse unit is of comparable quality to a downhole logging tool string.

5. A method for calibrating the hole depth of a perforation section in an oil and gas well, characterized in that: Using the device according to any one of claims 1 to 4, the method comprises: Get the original hole depth value H1; Use the winch to lower the downhole pulse unit, pay attention to the length H2 of the optical-electric composite cable released by the winch, and stop lowering the downhole pulse unit when H2 is greater than H1; Under the control of the ground optoelectronic control unit, the downhole pulse unit releases a pulse shock wave, which is reflected after encountering the casing wall and the hole. The single-mode optical fiber receives the reflected wave and forms a vibration signal which is transmitted to the ground optoelectronic control unit. At the same time, the temperature signal measured by the multi-mode optical fiber is transmitted to the ground optoelectronic control unit. The ground photoelectric control unit determines the scale value H3 in the optical fiber corresponding to the reflected wave of the hole through the amplitude of the vibration signal; The difference △H between the hole and H3 is calculated; The calculated and verified hole depth H=H3+△H.

6. The method for calibrating the perforation depth of a perforation section in an oil and gas well according to claim 5, characterized in that: When the downhole pulse unit is lowered by a winch, the winch reading returns to zero when the pulse unit is at the wellhead.

7. The method for calibrating the perforation depth of an oil and gas well according to claim 5, characterized in that: The energy of the reflected wave formed by the pulse shock wave at the casing wall is higher than that of the reflected wave formed by the pulse shock wave at the hole; in the vibration signal, the amplitude of the reflected wave corresponding to the casing wall is greater than the amplitude of the reflected wave corresponding to the hole, and the scale corresponding to the weakest amplitude in the vibration signal is taken as H3.

8. The method for calibrating the perforation depth of a perforation section in an oil and gas well according to claim 5, characterized in that: △H=H2-H1, H=H+H2-H1.

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