Composite continuous pipe

Abstract

The invention discloses a composite continuous pipe which sequentially comprises a continuous pipe body, a filling material and an armor layer from inside to outside. The continuous pipe is eccentrically arranged in the armor layer; the filling material is filled between the continuous pipe and the armor layer; optical fibers, hydraulic pipes and cables are embedded in the filling material. According to the composite continuous pipe, the optical fiber, the cable and the hydraulic pipe are integrated, the overall stability and uniformity are guaranteed through the filling material, the overall structure is light, and certain buoyancy is generated in deepwater drilling. The composite coiled tubing can achieve light weight and high strength in complex environments such as deep water, and the composite structure of the composite coiled tubing can be matched with an intelligent and digital drilling system.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield engineering, and in particular relates to a composite continuous pipe. Background Art

[0002] Coiled tubing units are suitable for all stages of well repair, cementing, drilling, and oil production. Known as "universal operators," they can replace conventional tubing or drill pipe for a variety of operations. With the in-depth development of oil and gas resources, especially in deepwater, ultra-deepwater, and unconventional exploration and development, operating equipment faces complex and challenging environments such as high pressure and low temperature, as well as intense rock and reservoir heterogeneity and anisotropy, complex fault and natural fracture systems, complex organic matter abundance, maturity, sediment type, and distribution, the complex hydrogeology of submarine cold seeps and gas hydrates, and the impact of salt layers and salt domes on mobility. Traditional vertical wells are severely limited in the development of these unconventional oil, gas, and hydrate resources. Currently, directional wells that can bypass obstacles and access specific formations are more commonly used; horizontal wells drilled horizontally within the reservoir; multi-lateral wells with multiple laterals drilled from a main well; and extended reach wells with very long horizontal sections. The widespread use of these well types places higher demands on real-time monitoring and control capabilities for downhole operations.

[0003] Currently, domestic and international research on coiled tubing focuses on: integrated cables and optical fibers. Integrated cables offer lower manufacturing, installation, and maintenance costs, greater resistance to physical damage, and improved compatibility. However, their data transmission speeds are lower than those of optical fibers, cables experience faster signal attenuation, require signal enhancement at fixed distances, and are more susceptible to electromagnetic interference during data transmission. Integrated optical fibers offer faster, higher-power, and longer-distance data transmission capabilities compared to cables, are more resistant to interference, and are lighter in weight. However, they are more expensive, complex to install and maintain, and more fragile than cables. Limited research is currently underway on composite coiled tubing with integrated optical fiber and cable. Currently, domestic and international researchers have two approaches to integrating optical fiber / cable into coiled tubing: one uses clips to secure the cable at the ends of the coiled tubing. However, this approach results in the cable becoming unrestricted when the tubing is long, making it prone to collision with the inner wall during construction, potentially damaging the cable. The other approach involves embedding a clip for the cable / optical fiber within the coiled tubing. While this approach secures the cable / optical fiber within the tubing, it is costly and increases the tubing's weight, making it unsuitable for complex engineering applications. Summary of the Invention

[0004] To address the above technical issues, the present invention provides a composite coiled tubing and its manufacturing method. The composite coiled tubing provided by the present invention combines optical cables, electrical cables, and hydraulic pipes, and utilizes fillers to achieve weight reduction. This not only effectively reduces well construction costs but also improves operational efficiency and safety. The optical cables and electrical cables enable real-time monitoring and data transmission of downhole operations, while the hydraulic pipes support efficient downhole tool operation.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention provides a composite continuous tube, which comprises a continuous tube, a filling material and an armor layer from the inside out; the continuous tube is eccentrically arranged in the armor layer; the filling material is filled between the continuous tube and the armor layer; and the filling material is embedded with optical fibers, hydraulic pipes and cables.

[0007] As a preferred embodiment, the centers of the continuous pipe, the hydraulic pipe and the armor layer are located on the same straight line.

[0008] As a preferred embodiment, the cables are in multiple groups; the optical fibers and the multiple groups of cables are symmetrically distributed in the filling material with the connecting line of the continuous tube and the hydraulic tube as the axis.

[0009] As a preferred embodiment, a line connecting the centers of the optical fibers, the multiple groups of cables, and the hydraulic pipes is a crescent-shaped arc.

[0010] As a preferred embodiment, the filling material is selected from at least one of polymer-based composite materials, ceramic-reinforced polymers, and inorganic-organic hybrid materials. In the technical solution of the present invention, the filling material can be selected differently in the axial direction according to the operating environment. Specifically, the pipe section from the seabed to the sea level should be filled with cheap materials that can provide high buoyancy, corrosion resistance, and impact resistance, such as polyethylene; the pipe section from the shallower stratum to the seabed should be filled with materials that can withstand certain temperatures and pressures and provide a certain buoyancy, such as polyurethane doped with hollow glass microspheres; the pipe section from the deep stratum to the shallower stratum should be filled with materials that mainly resist high temperature and pressure, such as epoxy resin doped with silicon nitride.

[0011] And / or, the continuous tube and armor layer are made of high-strength, lightweight materials to reduce overall weight and improve corrosion resistance and pressure resistance, and are selected from at least one of titanium alloy, aluminum alloy and nickel-based alloy.

[0012] As a preferred embodiment, the hydraulic pipe is externally connected to a hydraulic peristaltic crawler.

[0013] As a preferred embodiment, the optical fiber includes multiple groups of fiber cores, aramid reinforcement layers and armor reinforcement layers from the inside to the outside; optical fiber grease is filled between the multiple groups of fiber cores and the aramid reinforcement layers; in the technical solution of the present invention, the optical fiber grease is preferably high-temperature and high-pressure resistant optical fiber grease; the high-temperature resistance is to withstand a temperature of 180°C; the high-pressure resistance is to withstand a pressure of 30MPa.

[0014] As a preferred embodiment, the cable is a single-core cable, which comprises a copper core, an insulation layer and a protective layer from the inside to the outside.

[0015] Preferably, the protective layer is plated with a magnetic material; the magnetic material is a high magnetic permeability material selected from at least one of iron-nickel alloy, manganese-zinc ferrite and iron-based amorphous alloy.

[0016] As a preferred embodiment, the diameter of the composite continuous tube is 3 to 3.5 inches.

[0017] In the technical solution of the present invention, the composite continuous tube ensures overall structural balance and stability through the positioning of various structures. Furthermore, the filling material can be gradiently filled according to the operating position, better meeting the needs of the working environment. The optical fiber utilizes an aramid reinforcement layer and an armor reinforcement layer wrapped around the inner core, while also being filled with high-temperature and high-pressure resistant optical fiber jelly, achieving improved counterweight balance and applicability. The cable, abandoning the traditional hinged design, utilizes a single-core copper cable with an outer layer of insulation and protective layers, saving space while reducing the mutual influence of electromagnetic fields.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] The present invention provides a composite coiled tubing that integrates optical fibers and cables. The optical fibers are used for efficient data transmission, transmitting downhole data such as temperature, pressure, sound, and vibration to the surface in real time. The cables provide necessary power to downhole tools and equipment, supporting various downhole operations such as drilling, logging, perforating, and well intervention. The coiled tubing, through its internally integrated design, effectively avoids the shortcomings of conventional built-in bayonet integration, which lacks the ability to position the cables and optical fibers, as well as the high manufacturing cost and heavy weight of the coiled tubing, which makes it unsuitable for practical engineering applications. Furthermore, the coiled tubing is lightweight, and the filler material located between the seabed and sea level during deepwater drilling generates a certain amount of buoyancy, achieving a weight-reducing effect. This achieves lightweight and high strength in complex environments such as deepwater. The coiled tubing provided by the present invention meets the operational requirements of today's drilling operations in complex and extreme environments.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) The present invention achieves multifunctional integration and optimizes the pipeline structure by rationally integrating the continuous pipe, optical cable, electrical cable, and hydraulic pipe. The filling material in the present invention can be in the form of gradient filling, which greatly considers economic benefits, reduces the weight of the pipeline, and improves the overall performance of the pipeline, ensuring its long-term stable operation in harsh deep-sea environments.

[0022] (2) The coiled tubing provided by the present invention can significantly reduce the cost of deepwater well construction. On the one hand, the reduced pipe weight reduces the burden on deepwater operating platforms and lowers transportation and installation costs. On the other hand, the multifunctional, integrated design reduces the need for additional equipment, further reducing operating costs.

[0023] (3) The continuous pipe provided by the present invention can dynamically adjust the filling material formula according to different geological data, and can be customized for production to adapt to various scenarios such as polar regions and high-temperature geothermal wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention and its features, configurations, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals indicate like parts throughout the drawings. The drawings are not drawn to scale, emphasis instead being placed on illustrating the subject matter of the present invention.

[0025] Figure 1 4 is a cross-sectional view of the composite coiled tube in Example 1 of the present invention.

[0026] Figure 2 This is a structural diagram of the optical fiber in Example 1 of the present invention.

[0027] Figure 3 This is a structural diagram of the cable in Example 1 of the present invention.

[0028] Figure 4 This is a three-dimensional diagram of the composite continuous tube in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. It is obvious that the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative work shall fall within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be noted that when terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", and "outside" appear, the orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections, direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0032] Example 1:

[0033] like Figure 1-4 As shown, this embodiment provides a composite coiled tubing. The composite coiled tubing provided in this embodiment comprises, from the inside out, a coiled tubing 1, a filling material 2, and an armor layer 3. The coiled tubing 1 is eccentrically positioned within the armor layer 3. The filling material 2 is filled between the coiled tubing 1 and the armor layer 3. The filling material is embedded with an optical fiber 4, a hydraulic pipe 5, and an electrical cable 6. The electrical cable provides power for the near-bit monitoring and control section, the electronically controlled emergency disconnect section, and the drill bit rotary drive. The optical fiber provides real-time data transmission for the logging while drilling section and the near-bit monitoring and control section.

[0034] Furthermore, the centers of the coiled tubing 1, hydraulic tubing 5, and armor layer 3 lie on the same straight line. In this embodiment, the coaxial arrangement of the centers of the coiled tubing 1, hydraulic tubing 5, and armor layer 3 creates a mechanically symmetrical structural system, enhancing the composite coiled tubing's resistance to coupled bending and torsional deformation when subjected to the complex multi-directional loads encountered in deep-sea operations. This also facilitates alignment and calibration during the manufacturing process.

[0035] In this embodiment, multiple cables 6 are provided. Furthermore, the optical fibers 4 and the multiple cables are symmetrically distributed within the filler material 2 about the axis connecting the continuous tube 1 and the hydraulic tube 5. This symmetrical distribution in this embodiment achieves dynamic balance through the symmetrical cables, preventing tube deflection due to gravity.

[0036] Furthermore, the line connecting the centers of the optical fibers 4, the multiple cables, and the hydraulic pipe 5 forms a crescent-shaped arc. This unique geometric arrangement of crescent-shaped arcs in this embodiment optimizes space utilization. Furthermore, the crescent-shaped topology forms an adaptive stress buffer when the pipe bends.

[0037] Furthermore, filling material 2 is selected from at least one of polymer-based composite materials, ceramic-reinforced polymers, and inorganic-organic hybrid materials. Filling with these materials not only stabilizes the composite coiled tubing structure but also provides a certain degree of buoyancy in the deep sea, reducing its weight and wellhead pressure. In this embodiment, filling material 2 can be selected differently in the axial direction depending on the operating environment. Specifically, the pipe section from the seabed to the sea surface should be filled with inexpensive polyethylene that provides high buoyancy, corrosion resistance, and impact resistance; the pipe section from the shallower strata to the seabed should be filled with polyurethane doped with hollow glass microspheres that is resistant to certain temperatures and pressures and provides a certain degree of buoyancy; and the pipe section from the deep strata to the shallower strata should be filled with epoxy resin doped with silicon nitride, which is primarily resistant to high temperatures and pressures.

[0038] Furthermore, the coiled tube 1 and the armor layer 3 are made of high-strength, lightweight materials to reduce the overall weight and improve corrosion resistance and pressure resistance, and are selected from at least one of titanium alloy, aluminum alloy and nickel-based alloy.

[0039] Furthermore, the hydraulic pipe 5 is externally connected to a hydraulic peristaltic crawler, and a hydraulic pump provides a power source.

[0040] Furthermore, the optical fiber 4 includes a fiber core 7, an aramid reinforcement layer 9 and an armor reinforcement layer 10 from the inside to the outside; the fiber core 7 and the aramid reinforcement layer 9 are filled with optical fiber grease 8; in the technical solution of the present invention, the optical fiber grease 8 is preferably an optical fiber grease that can withstand a temperature of 180°C and a pressure of 30 MPa.

[0041] Furthermore, the cable 6 is a single-core cable, which includes a copper core 11 , an insulating layer 12 and a protective layer 13 from the inside out.

[0042] Furthermore, the protective layer 13 is plated with a magnetic material; the magnetic material is a high-permeability material selected from at least one of an iron-nickel alloy, a manganese-zinc ferrite, and an iron-based amorphous alloy. In this embodiment, the magnetic material plated in the protective layer 13 can produce an electromagnetic shielding effect.

[0043] Furthermore, in this embodiment, the diameter of the composite continuous pipe is 3 to 3.5 inches. This range not only meets the upper limit of the use of existing engineering winches, but also meets the hydraulic pressure and annular displacement requirements during drilling. The outer diameter of the armor layer 3 is 3.5 inches and the wall thickness is 3.5 mm. Such a size design can meet the pressure resistance requirements of the deep water environment and the maximum limit of the winch in the project; the outer diameter of the continuous pipe 1 is 2 inches and the wall thickness is 4 mm. While maintaining the lightweight characteristics of titanium alloy, this wall thickness can withstand the bending stress generated by a certain complex wellbore trajectory; the cross-sectional area of ​​the continuous pipe 1 accounts for 32.6% of the total cross-sectional area of ​​the composite continuous pipe; the outer diameter of the cable 6 is 6.2 mm, and the diameter of the copper core 11 is 3.2 mm. This combination can reduce the AC resistance caused by the skin effect, and the insulation layer The thickness of the outer layer 12 is 1 mm, and the thickness of the protective layer 13 is 0.5 mm. This configuration can attenuate electromagnetic interference. The outer diameter of the optical fiber 4 is 5.6 mm, and the inner diameter (excluding the aramid reinforcement layer 9 and the armor reinforcement layer 10) is 4.0 mm. The thickness of the armor reinforcement layer 10 is 0.5 mm, and the thickness of the aramid reinforcement layer 9 is 0.3 mm. This composite reinforcement structure significantly enhances the tensile strength of the optical fiber. The outer diameter of the hydraulic pipe 5 is 20 mm, the inner diameter is 13 mm, and the wall thickness is 3.5 mm. The cross-sectional area of ​​the filling material 2 accounts for 58.6% of the total cross-sectional area of ​​the composite continuous pipe.

[0044] The performance test of the composite coiled tube provided in this embodiment is as follows:

[0045] Signal transmission testing: An optical time-domain reflectometer (OTDR) was used at a wavelength of 1550nm, based on a standard link with a fiber splice spacing of ≤2km. A voltage withstand tester was used to apply 500VDC between the conductor and shield for 60 seconds. The optical cable attenuation and insulation resistance were measured.

[0046] Hydraulic performance test: Use a high-pressure pump station to pressurize to 200 MPa at a rate of 10 MPa / min, maintain the pressure for 1 hour, and the leakage rate is ≤0.01 mL / min.

[0047] Electromagnetic compatibility verification: Using a spectrum analyzer, the shielding effectiveness was measured to be ≥60dB in the 1kHz-1GHz frequency band.

[0048] Mechanical load test: A three-point bending test was conducted using a hydraulic servo testing machine. The deflection was measured to be ≤5mm when the three-point bending load was 10kN, which meets the API 5ST standard.

[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A composite coiled tube, characterized in that: From the inside to the outside, it comprises a continuous tube, a filling material and an armor layer. The continuous tube is eccentrically arranged in the armor layer. The filling material is filled between the continuous tube and the armor layer. The filling material is embedded with optical fibers, hydraulic pipes and cables.

2. The composite coiled tube according to claim 1, characterized in that: The centers of the continuous pipe, the hydraulic pipe and the armor layer are located on the same straight line.

3. The composite coiled tube according to claim 1, characterized in that: The cables are in multiple groups; the optical fibers and the multiple groups of cables are symmetrically distributed in the filling material with the connecting line of the continuous tube and the hydraulic tube as the axis.

4. The composite coiled tube according to claim 1, characterized in that: The line connecting the centers of the optical fibers, the multiple groups of cables and the hydraulic pipes is a crescent-shaped arc.

5. The composite coiled tube according to claim 1, characterized in that: The filling material is selected from at least one of a polymer material, a ceramic reinforced polymer material and an inorganic-organic hybrid material; And / or, the material of the continuous tube and the armor layer is selected from at least one of titanium alloy, aluminum alloy and nickel-based alloy.

6. The composite coiled tube according to claim 1, characterized in that: The hydraulic pipe is externally connected to a hydraulic peristaltic crawler.

7. The composite coiled tube according to claim 1, characterized in that: The optical fiber includes a fiber core, an aramid reinforcement layer and an armor reinforcement layer from the inside to the outside; the fiber core and the aramid reinforcement layer are filled with optical fiber grease; the optical fiber grease is a high-temperature and high-pressure resistant optical fiber grease; the high-temperature resistance is to withstand a temperature of 180°C; the high-pressure resistance is to withstand a pressure of 30MPa.

8. The composite coiled tube according to claim 1, characterized in that: The cable is a single-core cable, which comprises a copper core, an insulating layer and a protective layer from the inside to the outside.

9. The composite coiled tube according to claim 8, characterized in that: The protective layer is plated with a magnetic material; the magnetic material is a high magnetic permeability material selected from at least one of an iron-nickel alloy, a manganese-zinc ferrite and an iron-based amorphous alloy.

10. The composite coiled tube according to claim 1, characterized in that: The diameter of the composite continuous tube is 3 to 3.5 inches.

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