Logging optical cable used for being installed outside casing pipe

Abstract

The utility model discloses a logging optical cable used for being installed outside a sleeve, which relates to the technical field of optical fiber oil logging and comprises an outer sheath and a protection assembly, the protection assembly is sleeved in the outer sheath and comprises enhanced steel tube optical cables and steel wire ropes, and the enhanced steel tube optical cables and the steel wire ropes are arranged at intervals in the same direction along the length direction of the outer sheath. Wherein the enhanced steel tube optical cable comprises an optical cable outer armor, at least one optical fiber unit and a plurality of steel wires, the optical fiber unit and the plurality of steel wires are twisted to form a cable-shaped structure, and the cable-shaped structure is embedded in the optical cable outer armor; according to the utility model, the pressure measurement resistance and fluid pressure resistance of the optical cable are greatly improved, pressure can be effectively dispersed in a high-pressure environment, fluid invasion is prevented, the optical fiber unit is protected, and the optical cable adapts to complex working conditions at the bottom of a well.

Description

Technical Field

[0001] This utility model relates to the field of fiber optic oil logging technology, specifically to a logging optical cable for external casing installation. Background Technology

[0002] In the field of geophysical exploration in oil wells, with the continuous advancement of distributed fiber optic logging technology, numerous challenges are faced in the installation of external optical cables. Especially in high-difficulty wells such as ultra-deep wells, high-friction wells, and wells with large horizontal sections, as well as wells with high bottomhole pressure, the operating environment places higher demands on logging optical cables.

[0003] Currently, the characteristics of distributed fiber optic sensing technology necessitate ensuring the integrity of the fiber optic cable during well logging operations. However, existing conventional fiber optic cables exhibit significant limitations in these types of well installation operations. Towards the end of the installation process, weight loss often occurs. This weight loss leads to repeated raising and lowering of the cable, subjecting it to frequent tensile and torsional stresses. In the complex downhole environment, such stress can easily cause the cable to break or be damaged.

[0004] On the one hand, the structural design of conventional optical cables makes them unable to withstand the enormous pressure in high-pressure wells. The high-pressure environment at the bottom of the well poses a severe test to the pressure resistance of optical cables, and conventional optical cables cannot meet the requirements in terms of pressure resistance level. They are prone to deformation or even damage under high pressure, which in turn affects the transmission and acquisition of logging data.

[0005] On the other hand, the various complex media in the underground environment, such as corrosive liquids and gases, can corrode optical cables. Conventional optical cables have limited corrosion resistance, and prolonged exposure to such an environment will gradually reduce their performance, eventually leading to cable failure.

[0006] Furthermore, when the optical cable is damaged or water gets in, conventional optical cables cannot effectively prevent further intrusion of complex media downhole. This will not only accelerate the damage to the optical cable, but may also affect the stability and accuracy of the entire logging system.

[0007] In conclusion, there is an urgent need for a logging fiber optic cable to meet the needs of geophysical exploration operations in oil wells. Utility Model Content

[0008] The purpose of this utility model is to provide a logging optical cable for external casing installation. This logging optical cable has the ability to withstand pressure measurement and fluid pressure, ensuring the integrity of the optical cable during on-site construction operations, especially in high-difficulty wells such as ultra-deep wells, high friction wells, or wells with large horizontal sections and high bottom hole pressure.

[0009] This utility model is achieved through the following technical solution:

[0010] A logging fiber optic cable for external casing installation includes:

[0011] Outer sheath;

[0012] A protective component is fitted inside the outer sheath. The protective component includes a reinforced steel tube optical cable and a steel wire rope, which are spaced apart in the same direction along the length of the outer sheath.

[0013] The reinforced steel tube optical cable includes an optical cable outer armor, at least one optical fiber unit, and multiple steel wires. The optical fiber unit and the multiple steel wires are twisted together to form a cable-like structure, which is embedded in the optical cable outer armor.

[0014] In this design, the reinforced steel tube optical cable and steel wire rope in the protection assembly are spaced apart and run in the same direction along the outer sheath, providing strong mechanical support for the optical cable. The cable-like structure formed by the optical cable armor, fiber optic units, and multiple stranded steel wires inside the reinforced steel tube optical cable is embedded in the outer sheath, giving it excellent compressive and tensile strength. This allows it to withstand enormous formation pressure and tensile stress during operation, preventing cable deformation and damage, and ensuring stable signal transmission. This structural design significantly improves the optical cable's resistance to pressure testing and fluid pressure. In high-pressure environments, it effectively disperses pressure, prevents fluid intrusion, protects fiber optic units, and adapts to complex wellbore conditions. Simultaneously, it enables the optical cable to maintain stable performance and extend its service life under harsh conditions such as high temperatures and corrosive media in downhole environments, thanks to the synergistic effect of its components, providing reliable data transmission for geophysical exploration operations in oil wells.

[0015] As a further solution for logging optical cables, to improve the structural stability of the optical cable, the outer diameter of the outer armor of the optical cable is not greater than the outer diameter of the steel wire rope.

[0016] This design balances stress distribution, reduces stress concentration, enhances tensile and bending resistance, adapts to different stress environments, and extends service life. Simultaneously, it facilitates installation and maintenance, making it easier for operators to install and operate, improving efficiency, reducing the risk of errors, and also aiding in later maintenance and repair. It facilitates the location and handling of various components, ensuring the long-term stable operation of the logging system.

[0017] As a further embodiment of the logging optical cable, the outer diameter of the optical fiber unit is the same as the outer diameter of the steel wire.

[0018] In this design, the uniform outer diameter allows for a tighter and more uniform bond between the fiber optic unit and the steel wire when they are twisted together to form a cable-like structure and embedded in the outer armor of the optical cable. This tight bond helps to enhance the structural strength of the entire reinforced steel tube optical cable. When subjected to external mechanical stress (such as tension, compression, bending, etc.), the fiber optic unit and the steel wire can share the stress, reducing local stress concentration caused by diameter differences. This effectively prevents the fiber optic unit from breaking or being damaged due to excessive stress, ensuring the structural integrity of the optical cable in complex environments outside the casing (such as ultra-deep wells, high friction wells, or large horizontal sections of wells).

[0019] As a further embodiment of the logging optical cable, the protection component also includes a central steel pipe optical cable, which is located between the reinforced steel pipe optical cable and the steel wire rope.

[0020] In this design, the addition of the central steel tube optical cable further optimizes the structural layout of the protection components. Between the reinforced steel tube optical cable and the wire rope, the central steel tube optical cable provides excellent buffering and support. When subjected to external pressure, such as formation pressure or fluid pressure outside the casing, it shares the pressure with the reinforced steel tube optical cable and the wire rope, enhancing the overall pressure resistance of the logging optical cable. This allows the cable to better adapt to the high-pressure environment of challenging wells such as ultra-deep wells, high-friction wells, or wells with large horizontal sections, effectively preventing deformation or damage due to excessive pressure and ensuring the smooth operation of logging activities in harsh environments.

[0021] As a further embodiment of the logging optical cable, the outer diameter of the central steel pipe optical cable is smaller than the outer diameter of the outer armor of the optical cable.

[0022] In this design, the smaller outer diameter of the central steel tube optical cable allows it to be tightly fitted between the reinforced steel tube optical cable and the steel wire rope, forming a more compact and rational structure. This compact structure facilitates the optimized combination of components within a limited space, enhancing the overall integrity and stability of the protection components. Furthermore, the difference in diameter between the central steel tube optical cable and the outer armor of the optical cable allows for a more rational stress distribution under load. When subjected to external pressure, the larger-diameter outer armor of the optical cable bears the primary pressure, while the central steel tube optical cable provides auxiliary support and distributes stress within it.

[0023] As a further embodiment of the logging optical cable, the central steel tube optical cable includes an optical fiber unit inside, and the optical fiber unit is surrounded by a protective layer.

[0024] In this solution, the protective layer provides a direct protective barrier for the optical fiber unit. In complex environments outside the sheath, such as when there are corrosive media, high temperatures, or impacts from small particles, the protective layer can effectively block these adverse factors from eroding and damaging the optical fiber unit, significantly reducing the risk of optical fiber damage and ensuring that the optical performance of the optical fiber is not affected.

[0025] As a further option for the logging optical cable, the protective layer is an aluminum layer.

[0026] In this solution, in the complex downhole environment outside the casing, especially in the presence of various corrosive media (such as acidic or alkaline liquids, gases, etc.), the aluminum layer can form an effective protective film, preventing corrosive substances from contacting the internal fiber optic unit and greatly reducing the possibility of corrosion of the fiber optic unit.

[0027] As a further option for logging optical cables, the optical fiber unit contains tightly packed optical fibers.

[0028] In this design, the use of tight-buffered optical fibers makes the internal structure of the optical fiber unit more compact and stable. When the optical cable is subjected to external forces such as tension and bending, the tight-buffered optical fibers can better coordinate with the deformation of the optical fiber unit, reducing the displacement and swaying of the optical fibers within the unit, lowering the risk of signal interruption caused by excessive displacement of the optical fibers, and enhancing the reliability and durability of the logging optical cable under different working conditions (such as ultra-deep wells, high friction wells, or large horizontal section wells).

[0029] As a further option for the logging optical cable, the outer sheath is a component made of one of the following: high-density polyethylene, nylon, polypropylene, perfluoroethylene propylene, or polyvinylidene fluoride. This further ensures the safety and stability of the optical cable in complex chemical environments, providing reliable protection for logging operations.

[0030] As a further embodiment of the logging optical cable, the wire rope comprises several identical steel wires, which are twisted together to form a cable-like structure.

[0031] In this solution, when the optical cable is subjected to external impact forces, such as collisions or vibrations that may occur during downhole operations, the steel wire rope can absorb and disperse part of the impact force through the minute displacement and friction between the steel wires. This reduces the direct impact of the impact force on sensitive components such as internal optical fiber units, protects the normal operation of the optical fiber, reduces the risk of signal transmission interruption, and improves the stability and reliability of the logging optical cable in complex dynamic environments.

[0032] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0033] This invention employs a unique multi-layered structural design, including a reinforced steel tube optical cable, a central steel tube optical cable, a steel wire rope structure, and an outer sheath. The steel wires inside the reinforced steel tube optical cable are intertwined with the optical fiber units, providing excellent tensile and compressive strength. The central steel tube optical cable is placed in the middle, with its internal aluminum layer surrounding the optical fiber units, enhancing corrosion resistance, and the tightly packed optical fibers within the optical fiber units further protect the optical fibers. The steel wire rope structure further improves the overall tensile strength. This composite structure enables the optical cable to better resist various external forces and chemical corrosion in complex sheath environments, greatly improving the structural stability and durability of the optical cable. Attached Figure Description

[0034] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0035] Figure 1 This is a schematic diagram of the structure of a logging optical cable provided in Embodiment 1 of this utility model;

[0036] Figure 2 This is a schematic diagram of the structure of a logging optical cable provided in Embodiment 2 of this utility model.

[0037] The attached diagram shows the markings and corresponding component names:

[0038] 1-Steel wire rope, 11-Steel wire, 2-Reinforced steel tube optical cable, 21-Optical cable outer armor, 22-Fiber optic unit, 3-Outer sheath, 4-Central steel tube optical cable, 41-Tightly wrapped fiber optic cable, 42-Protective layer. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0040] Example 1

[0041] This embodiment 1 provides a logging optical cable for external casing installation, such as... Figure 1 As shown, it includes an outer sheath 3 and a protective component, which is tightly fitted into the outer sheath 3 to form an integral structure.

[0042] Among them, such as Figure 1As shown, the protective components include a reinforced steel tube optical cable 2 and a steel wire rope 1. The reinforced steel tube optical cable 2 and the steel wire rope 1 are arranged at intervals in the same direction along the length of the outer sheath 3, providing strong mechanical support for the optical cable. Specifically, the steel wire rope 1 includes 7 identical steel wires 11, which are twisted together to form a cable-like structure. The reinforced steel tube optical cable 2 includes an optical cable outer armor 21, an optical fiber unit 22, and 6 steel wires 11. The optical fiber unit 22 and the 6 steel wires 11 are twisted together to form a cable-like structure. The cable-like structure is embedded in the optical cable outer armor 21, giving it good compressive and tensile strength, enabling it to withstand huge ground pressure and tensile stress during operation, and preventing the optical cable from deforming and being damaged.

[0043] Meanwhile, to improve the stability of the cable structure, the outer diameter of the optical fiber unit 22 in the reinforced steel tube optical cable 2 is the same as the outer diameter of the steel wire 11, and the outer diameter of the steel wire 11 in the steel wire rope 1 is the same as the outer diameter of the steel wire 11 in the reinforced steel tube optical cable 2. This makes the outer diameter of the optical cable outer armor 21 equal to the outer diameter of the steel wire rope 1, thus balancing the force distribution, reducing stress concentration, enhancing tensile and bending resistance, adapting to different stress environments, and extending service life.

[0044] Example 2

[0045] This embodiment 2 provides a logging optical cable for external casing installation, such as... Figure 2 As shown, it includes an outer sheath 3 made of one of high-density polyethylene, nylon, polypropylene, perfluoroethylene, and polyvinylidene fluoride, and a protective component, which is tightly fitted into the outer sheath 3 to form an integral structure.

[0046] Among them, such as Figure 2 As shown, the protective components include a reinforced steel tube optical cable 2, a central steel tube optical cable 4, and a steel wire rope 1. The reinforced steel tube optical cable 2, the central steel tube optical cable 4, and the steel wire rope 1 are arranged sequentially and at intervals along the length of the outer sheath 3, further providing strong mechanical support for the optical cable. Specifically, the steel wire rope 1 includes seven identical steel wires 11, which are twisted together to form a cable-like structure. The reinforced steel tube optical cable 2 includes an outer armor 21, an optical fiber unit 22, and six steel wires 11. Here, the optical fiber unit 22 and the six steel wires 11 are twisted together to form a cable-like structure, which is embedded in the outer armor 21, giving it good compressive and tensile strength, enabling it to withstand huge ground pressure and tensile stress during operation, and preventing the optical cable from deforming and being damaged. Meanwhile, to improve the stability of the cable structure, the outer diameter of the optical fiber unit 22 in the reinforced steel tube optical cable 2 is the same as the outer diameter of the steel wire 11, and the outer diameter of the steel wire 11 in the steel wire rope 1 is not less than the outer diameter of the steel wire 11 in the reinforced steel tube optical cable 2, so that the outer diameter of the optical cable outer armor 21 is not greater than the outer diameter of the steel wire rope 1. This can further balance the stress distribution, reduce stress concentration, enhance tensile and bending resistance, adapt to different stress environments, and extend service life.

[0047] Among them, please again Figure 2 As shown, to further enhance the integrity and stability of the protective components, the outer diameter of the central steel tube optical cable 4 is smaller than the outer diameter of the optical cable outer armor 21. The central steel tube optical cable 4 also includes an optical fiber unit 22 inside. The outer side of the optical fiber unit 22 is surrounded by a protective layer 42. The tightly packed optical fiber 41 is placed inside the optical fiber unit 22. In this embodiment, the tightly packed optical fiber 41 can better coordinate with the deformation of the optical fiber unit, reducing the displacement and shaking of the optical fiber within the unit. The protective layer 42 is an aluminum layer, which can enhance the corrosion resistance of the optical cable. This structure can be made more compact than the existing structure. Under the joint protection of the reinforced steel tube optical cable 2 and the steel wire rope 1, the survival rate of the optical cable can be significantly improved. Of course, the protective layer 42 can also be made of other corrosion-resistant materials, such as a copper layer, a stainless steel layer, a polymer coating, or a composite protective layer.

[0048] In summary, this technical solution, through the multi-layer structure design of reinforced steel pipe optical cable 2, central steel pipe optical cable 4, steel wire rope 1, and outer sheath 3, enables the logging optical cable to have strong resistance to pressure measurement and fluid pressure, ensuring the integrity of the optical cable during on-site construction operations, especially in high-difficulty wells such as ultra-deep wells, high friction wells, or wells with large horizontal sections, as well as wells with high bottom hole pressure.

[0049] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A logging optical cable for external casing installation, characterized in that, include: Outer sheath (3); The protective component is fitted inside the outer sheath (3). The protective component includes an enhanced steel pipe optical cable (2), a steel wire rope (1), and a central steel pipe optical cable (4). The enhanced steel pipe optical cable (2), the central steel pipe optical cable (4), and the steel wire rope (1) are arranged at intervals in the same direction along the length of the outer sheath (3). The central steel pipe optical cable (4) is located between the enhanced steel pipe optical cable (2) and the steel wire rope (1), and the outer diameter of the central steel pipe optical cable (4) is smaller than the outer diameter of the optical cable outer armor (21) of the enhanced steel pipe optical cable (2). The reinforced steel tube optical cable (2) includes an optical cable outer armor (21), at least one optical fiber unit (22) and multiple steel wires (11). The outer diameters of the optical fiber unit (22) and the multiple steel wires (11) are the same and they are twisted together to form a cable-like structure. The cable-like structure is embedded in the optical cable outer armor (21). The interior of the central steel tube optical cable (4) includes an optical fiber unit (22). An aluminum protective layer (42) surrounds the outer side of the optical fiber unit (22). A tightly packed optical fiber (41) is placed inside the optical fiber unit (22).

2. The logging optical cable for external casing installation according to claim 1, characterized in that, The outer diameter of the optical cable outer armor (21) is not greater than the outer diameter of the steel wire rope (1).

3. A logging optical cable for external casing installation according to claim 1, characterized in that, The outer diameter of the optical fiber unit (22) is the same as the outer diameter of the steel wire (11).

4. A logging optical cable for external casing installation according to any one of claims 1-3, characterized in that, The outer sheath (3) is a component made of one of the following: high-density polyethylene, nylon, polypropylene, perfluoroethylene, or polyvinylidene fluoride.

5. A logging optical cable for external casing installation according to any one of claims 1-3, characterized in that, The wire rope (1) comprises several identical wires (11) twisted together to form a cable-like structure.

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