CN211174090U - Magnetic oil well optical cable capable of being adsorbed on inner side of metal pipe wall of oil and gas well - Google Patents

Abstract

The utility model relates to an optical fiber sensing technical field specifically is an adsorbable formula oil well optical cable is inhaled to magnetism inboard at oil gas well metal pipe wall, the utility model is used for solving current oil well optical cable and hanging in sheathed tube inside central authorities, can't hug closely with the intraductal wall of sleeve to the problem of the loss degree of acoustic wave energy in-process from the sleeve pipe transmission to the optical cable has been increased. The utility model discloses a coated optical fiber, the tight covering has been pasted on coated optical fiber's the surface, the enhancement layer has been pasted on tight covering's the surface, the external surface of enhancement layer is pasted and is adsorbed sheathed tube adsorption element, the external surface of adsorption element is pasted and is had the protective layer. The utility model discloses an intraductal wall of sleeve can be hugged closely to the adsorption element, and outside sound wave energy has reduced the loss that the sound wave energy transmitted the optical cable in-process from the sleeve pipe on transmitting the optical cable behind the sleeve pipe directly to improve optic fibre to the response amplitude of outside sound wave energy, increased the sound wave sensitivity of distributed sound wave sensing optical cable.

Description

Magnetic oil well optical cable capable of being adsorbed on inner side of metal pipe wall of oil and gas well

Technical Field

The utility model relates to an optical fiber sensing technical field, more specifically relate to an adsorbable formula oil well optical cable is inhaled to magnetism in oil gas well metal pipe wall inboard.

Background

Optical fibers are short for optical fibers, a fiber made of glass or plastic, and can be used as a conducting tool. The optical fiber distributed acoustic wave sensing technology is more and more widely applied to the fields of oil and gas exploration and development, underground production operation state monitoring, earthquake monitoring and the like, and the optical fiber distributed acoustic wave sensing technology utilizes the dual functions of signal transmission and sensing of the optical fiber, does not need an external sensor, only needs to connect a testing instrument at one end of the optical cable, and analyzes information such as geological structures, oil and gas distribution conditions and the like around the optical cable by detecting the micro-strain condition caused by external acoustic wave energy on the optical fiber. With the continuous development of oil and gas resources, the depth of an oil well is deeper and deeper from hundreds of meters to kilometers, and severe environments such as high temperature, chemical corrosion and the like exist underground. The detection optical cable with a multi-layer steel wire armor and a metal tube optical unit structure is usually adopted to meet the underground application requirements of large length, high temperature resistance, corrosion resistance and the like.

The existing steel wire armored and metal tube optical unit structure detection optical cable is usually hung in the center of the inner space of a sleeve when laid in the sleeve of an oil well due to large self weight and high rigidity, and the optical cable cannot be ensured to be tightly attached to the inner wall of the sleeve. During seismic exploration, after external sound wave energy is transmitted to the sleeve, the external sound wave energy needs to be transmitted to the optical cable through media such as liquid, gas or slurry in the inner space of the sleeve, the sound wave energy loss is high, the sound wave energy received by the optical fiber is weak, so that the micro-strain generated by the optical fiber is small, and the response amplitude of a sensing system for sensing the external sound wave is greatly reduced. Therefore, there is a pressing need for an oil well cable that reduces the loss of acoustic energy from the casing to the cable, thereby increasing the response amplitude of the fiber to external acoustic energy.

SUMMERY OF THE UTILITY MODEL

Based on above problem, the utility model provides an adsorbable formula oil well optical cable is inhaled to magnetism inboard at oil gas well metal pipe wall for solve current oil well optical cable and hang in the intraductal central authorities of cover, can't hug closely with the intraductal wall of sleeve, thereby increased the problem of the loss degree of acoustic energy in-process from the sleeve pipe transmission to the optical cable. The utility model discloses an intraductal wall of sleeve can be hugged closely to the adsorption element, and outside sound wave energy has reduced the loss that sound wave energy transmitted the optical cable in-process from the sleeve pipe on transmitting the optical cable behind the sleeve pipe directly to improve optic fibre to outside sound wave energy's response range, increased distributed sound wave sensing optical cable's sound wave sensitivity.

The utility model discloses a realize above-mentioned purpose and specifically adopt following technical scheme:

the utility model provides an adsorbable formula oil well optical cable is inhaled to magnetism inboard at oil gas well metal pipe wall, includes the coated fiber, it has the tight covering to paste on the surface of coated fiber, it has the enhancement layer to paste on the surface of tight covering, the external surface of enhancement layer is pasted the adsorption element that has adsorbable sleeve pipe, it has the protective layer to paste on adsorption element's the surface.

The working principle is as follows: when the optical cable penetrates through the interior of the sleeve, the optical cable is provided with the adsorption element capable of adsorbing the sleeve, so that the optical cable is tightly attached to the inner wall of the sleeve by utilizing the adsorption force of the adsorption element on the sleeve, when external sound wave energy is transmitted to the sleeve, the sound wave energy can be directly transmitted to the protective layer and then sequentially transmitted to the adsorption element, the enhancement layer, the tight cladding layer and the optical fiber, thus the influence of liquid, slurry or air gaps in the sleeve on the transmission of the sound wave energy is reduced, the loss of the sound wave energy transmitted to the optical cable from the sleeve is reduced, the response amplitude of the optical fiber on the external sound wave energy is improved, and the sound wave sensitivity of the distributed sound wave sensing optical cable is increased.

Preferably, the adsorption element is a plurality of groups of magnet assemblies wrapped on the outer surface of the reinforcement layer, and the plurality of groups of magnet assemblies are distributed at intervals along the length direction of the coated optical fiber.

Preferably, the magnet assembly comprises a left semicircular magnet and a right semicircular magnet, and the left semicircular magnet and the right semicircular magnet are mutually attracted and are respectively clung to the outer surface of the reinforcing layer.

Preferably, the magnet assembly has a length of 5 mm to 30 mm.

Preferably, the adsorption element includes a belt-shaped film attached to the reinforcing layer, and the belt-shaped film is provided with a plurality of thin magnet blocks, and the plurality of thin magnet blocks are distributed at intervals along the length direction of the coated optical fiber.

In a preferred embodiment, the belt-shaped film is a single-layer film, and the plurality of thin magnet pieces are attached to the outer surface of the single-layer film; or the strip-shaped film is a double-layer film, and the plurality of magnet thin blocks are arranged in the double-layer film.

In a preferable mode, the thickness of the magnet thin block is 0.5 mm-2 mm, and the shape of the magnet thin block is rectangular, circular or oval.

Preferably, the reinforcing layer includes a sheath tightly attached to an outer surface of the tight-clad layer, a plurality of reinforcing elements are embedded in the sheath, the plurality of reinforcing elements are disposed along a longitudinal direction of the coated optical fiber, and the adsorbing element is tightly attached to an outer surface of the sheath.

Preferably, the reinforcing layer comprises a reinforcing element abutting on an outer surface of the upjacket layer, the outer surface of the reinforcing element abutting on the jacket, and the suction element abutting on the outer surface of the jacket.

Preferably, the protective layer and the sheath are made of high molecular polymer materials, and the reinforcing element is made of fiber yarns or fiber composites or non-magnetic metal wire materials.

The utility model has the advantages as follows:

(1) the utility model discloses an intraductal wall of sleeve can be hugged closely to the adsorption element, and outside sound wave energy has reduced the loss that sound wave energy transmitted the optical cable in-process from the sleeve pipe on transmitting the optical cable behind the sleeve pipe directly to improve optic fibre to outside sound wave energy's response range, increased distributed sound wave sensing optical cable's sound wave sensitivity.

(2) The utility model discloses between well optic fibre and the tight covering, be in close contact with between tight covering and the sheath, no air gap between each layer, there is not the grease to fill, make outside sound wave energy in time effectual transmission to optic fibre on, arouse optic fibre local strain, produce optical effect to improved external sound wave energy and turned into the coupling efficiency that optic fibre is strained, improved the sensitivity of optic fibre to external sound wave.

(3) The utility model discloses the material of the outer protective layer of well optic fibre, sheath is the thermoplasticity macromolecular material mixture, and the material of reinforcing element is fibre class material or fibre combined material or thin wire, does not have steel band and metal armor in the optical cable, therefore the rigidity of optical cable is little, and is softer, and on external local sound wave vibration can in time transmit optic fibre, produces local strain at the relevant position, makes the response of optical effect more showing in the optic fibre, and the position is more accurate, and the SNR is higher.

(4) The utility model discloses the material of the outer protective layer of well optic fibre, sheath is the thermoplasticity macromolecular material mixture, and the material of reinforcing element is fibre class material or fibre combined material or thin wire, does not have steel band and metal armor in the optical cable, therefore the optical cable has the diameter little, light in weight, soft advantage, and the installation of optical cable scene, construction are more convenient.

(5) The utility model discloses well sheath distributes along optical cable length direction outward has the banded film of a plurality of magnet subassemblies or take a plurality of magnet thin blocks, makes the optical cable have magnetism, has the effect of attractive force to the ferromagnetic metal pipe wall around the optical cable. After the optical cable is laid in the shaft, the optical cable is tightly attached to the inner wall of the shaft sleeve due to the attraction between the magnet and the shaft sleeve, so that the intensity of sound waves transmitted to the optical cable by external sound waves and vibration energy is improved, and the sensitivity of the optical cable to external sound waves and vibration signals is enhanced. Therefore, the optical cable in the scheme is particularly suitable for optical fiber sensing application laid in a well casing.

Drawings

FIG. 1 is a schematic cross-sectional view of an optical cable with reinforcing members of the present invention embedded in a jacket;

FIG. 2 is a schematic cross-sectional view of a fiber optic cable having a strength member disposed between a tight-buffered layer and a jacket according to the present invention;

FIG. 3 is a schematic view of the three-dimensional structure of the cable with the magnet assembly as the adsorbing element of the present invention;

fig. 4 is a schematic view of the magnet assembly according to the present invention;

FIG. 5 is a schematic view of the three-dimensional structure of the present invention when the adsorption element is a thin magnet block and the belt-like thin film is a single-layer thin film;

FIG. 6 is a schematic view of the three-dimensional structure of the present invention when the adsorption element is a thin magnet block and the belt-like thin film is a double-layer thin film;

reference numerals: 1 protective layer, 2 magnet components, 21 left semicircular magnet, 22 right semicircular magnet, 3 reinforcing elements, 4 sheaths, 5 tightly-covered layers, 6 coated optical fibers, 7 ribbon films and 8 magnet thin blocks.

Detailed Description

For a better understanding of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and the following embodiments.

Example 1:

as shown in fig. 1-6, a magnetic oil well optical cable capable of being adsorbed on the inner side of the metal pipe wall of an oil and gas well comprises a coated optical fiber 6, a tight cladding layer 5 is attached to the outer surface of the coated optical fiber 6, a reinforcing layer is attached to the outer surface of the tight cladding layer 5, an adsorbing element capable of adsorbing a sleeve is attached to the outer surface of the reinforcing layer, and a protective layer 1 is attached to the outer surface of the adsorbing element.

The working principle is as follows: when the optical cable penetrates through the interior of the sleeve, the optical cable is provided with the adsorption element capable of adsorbing the sleeve, so that the optical cable is tightly attached to the inner wall of the sleeve by utilizing the adsorption force of the adsorption element on the sleeve, when external sound wave energy is transmitted to the sleeve, the sound wave energy can be directly transmitted to the protective layer 1 and then sequentially transmitted to the adsorption element, the enhancement layer, the tight cladding layer 5 and the optical fiber, thus the influence of liquid, slurry or sound wave energy in the air gap sleeve on the transmission of the sound wave energy is reduced, the loss of the sound wave energy transmitted to the optical cable from the sleeve is reduced, the response amplitude of the optical fiber on the external sound wave energy is improved, and the sound wave sensitivity of the distributed sound wave sensing optical cable is increased.

In addition, the coated optical fiber 6 is a photo-cured acrylate coated quartz optical fiber, other coatings such as polyimide coatings can be selected, the type of the optical fiber can also be a single mode optical fiber, a multimode optical fiber, a grating array optical fiber, or a special optical fiber such as a hollow optical fiber, a multi-core optical fiber or a few-mode optical fiber, and the number of the cores of the optical fiber is at least 1 core, and can be two cores or multiple cores.

Example 2:

as shown in fig. 1-4, this embodiment provides a preferred mechanism of the suction element based on embodiment 1, that is, the suction element is a plurality of sets of magnet assemblies 2 wrapped on the outer surface of the reinforcement layer, and the plurality of sets of magnet assemblies 2 are spaced along the length direction of the coated optical fiber 6.

Preferably, the magnet assembly 2 comprises a left semicircular magnet 21 and a right semicircular magnet 22, and the left semicircular magnet 21 and the right semicircular magnet 22 are mutually attracted and are respectively attached to the outer surface of the reinforcement layer.

Preferably, the magnet assembly 2 has a length of 5 mm to 30 mm.

In this embodiment: the cross section of the left semicircular magnet 21 and the right semicircular magnet 22 can be semicircular, two magnets with the same shape and size are mutually attracted to form a hollow cylinder, and the hollow cylinder is wrapped on the outer surface of the enhancement layer. The circular arc inner surfaces and the circular arc outer surfaces of the left semicircular magnet 21 and the right semicircular magnet 22 are respectively two poles of the magnets and have different polarities, and the polarities of the left semicircular magnet 21 and the right semicircular magnet 22 forming a pair are distributed oppositely, so that the left semicircular magnet 21 and the right semicircular magnet can attract each other to form a ring-shaped cylinder. For example, if the inner surface of the left semicircular magnet 21 is an S pole and the outer surface is an N pole, the inner surface of the right semicircular magnet 22 is an N pole and the circular arc outer surface is an S pole. The length of the magnet may be varied depending on the diameter of the optical cable, and is preferably 5 mm to 30 mm. The spacing of the magnet assemblies 2 on the cable may be considered according to the construction tension requirements of the cable during the cable downhole construction, for example, 10 meters, 20 meters, or 50 meters.

The other parts of this embodiment are the same as embodiment 1, and are not described herein again.

Example 3:

as shown in fig. 5-6, this embodiment provides another preferred structure of the suction element on the basis of embodiment 1, that is, the suction element includes a belt-shaped film 7 attached to the reinforcing layer, a plurality of thin magnet blocks 8 are provided on the belt-shaped film 7, and the plurality of thin magnet blocks 8 are distributed at intervals along the length direction of the coated optical fiber 6.

Preferably, the belt-shaped film 7 is a single-layer film, and a plurality of thin magnet blocks 8 are attached to the outer surface of the single-layer film; or the belt-shaped film 7 is a double-layer film, and a plurality of magnet thin blocks 8 are arranged in the double-layer film.

Preferably, the thickness of the magnet thin block 8 is 0.5 mm-2 mm, and the shape of the magnet thin block 8 is rectangular, circular or oval.

In this embodiment, the thin magnet block 8 may be packaged and fixed in advance by using a band-shaped thin film 7 made of a non-magnetic material so as to facilitate continuous automatic production in the process of being mounted on the reinforcement layer, and the thin magnet block 8 may be made of a material that is easy to bend and deform or be made into an arc shape that is attached to the outer surface of the reinforcement layer so as to be attached to the outer surface of the reinforcement layer tightly. The width and length of the magnet thin block 8 can be considered according to the diameter of the optical cable, the wrapping range of the reinforced layer and the bending performance of the optical cable, and generally, for the optical cable with the diameter of the reinforced layer ranging from 3 mm to 5 mm, the length of the magnet thin block 8 is about 5 mm to 15 mm. The spacing between the magnet thin blocks 8 on the thin film strip 7 can be considered according to the construction tension requirement of the optical cable during the down-hole construction process of the optical cable, such as 10 meters, 20 meters, or 50 meters.

The strip-shaped film 7 can be made of a plastic film strip or a non-woven cloth strip, or can be made of double-layer wrapping tapes, magnets are placed in the middle of the double-layer wrapping tapes, and the double-layer wrapping tapes are made in a hot-pressing bonding or middle glue coating bonding mode; or a single-layer wrapping belt can be adopted, and one surface of the thin magnet block 8 is glued and then stuck and fixed on the wrapping belt. The surface of the thin magnet block 8 close to the reinforcing layer and the surface far from the reinforcing layer are respectively of different polarities, for example, the surface close to the reinforcing layer is an N pole, and the opposite surface, namely the surface far from the sheath 4 is an S pole. The belt-shaped film 7 with the magnet thin blocks 8 can be longitudinally wrapped on the surface of the enhancement layer, and can also be wrapped on the surface of the enhancement layer.

The magnet external protective layer 1 can also be formed by weaving a non-metal fiber material or weaving a non-magnetic metal wire and then coating resin paint or extruding a polymer to coat to form the protective layer 1, or formed by wrapping the magnet external protective layer with a thermoplastic hose and then performing thermal shrinkage to form the tightly-wrapped protective layer 1.

The other parts of this embodiment are the same as embodiment 1, and are not described herein again.

Example 4:

as shown in fig. 1, this embodiment provides a preferred structure of the reinforcing layer based on embodiment 1, that is, the reinforcing layer includes a sheath 4 tightly attached to the outer surface of a tight cladding layer 5, a plurality of reinforcing elements 3 are embedded in the sheath 4, the plurality of reinforcing elements 3 are arranged along the length direction of a coated optical fiber 6, and a suction element tightly attached to the outer surface of the sheath 4.

When external acoustic energy is transmitted to the sleeve, the acoustic energy can be directly transmitted to the protective layer 1, then sequentially transmitted to the absorbing element, the sheath 4 and the reinforcing element 3, the tight cladding layer 5 and finally transmitted to the optical fiber.

The other parts of this embodiment are the same as embodiment 1, and are not described herein again.

Example 5:

as shown in fig. 2, this embodiment provides another preferred structure of the reinforcing layer on the basis of embodiment 1, i.e. the reinforcing layer comprises a reinforcing element 3 tightly attached to the outer surface of the tight-wrapping layer 5, a sheath 4 tightly attached to the outer surface of the reinforcing element 3, and a suction element tightly attached to the outer surface of the sheath 4.

When external acoustic energy is transmitted to the sleeve, the acoustic energy can be directly transmitted to the protective layer 1, and then sequentially transmitted to the adsorption element, the sheath 4, the reinforcing element 3, the tight cladding layer 5 and finally transmitted to the optical fiber.

Common parts of example 4 and example 5 are: the protective layer 1 is made of a non-magnetic material, and may be coated with a polymer plastic or rubber or a composite material by extrusion or coating with a paint, for example, nylon, polypropylene, fluoroplastic, or other materials by extrusion. The protective layer 1 can also be made of polymer materials with better high temperature resistance and oil resistance according to the requirements of the use environment, such as fluoroplastic materials, and the outer diameter of the protective layer 1 is 0.5 mm-1.5 mm.

The sheath 4 is made of high polymer material, such as polyvinyl chloride, nylon, polypropylene, elastomer, fluoroplastic, etc. The outer diameter of the sheath 4 is 2.0mm-8.0 mm; the material of the reinforcing element 3 is a fiber yarn material or a fiber composite material and other non-magnetic materials, such as aramid fiber, carbon fiber, ceramic fiber, glass fiber, polyimide fiber, glass fiber composite plastic rod, aramid fiber composite rod, demagnetized steel wire or stainless steel wire. The number of the fiber bundles or the number of the fiber composite materials or the number of the nonmagnetic metal wires in the reinforcing element 3 is at least 1, and the type, the specification and the number of the reinforcing element 3 can be selected according to the actual application environment requirement of the optical cable, so that the mechanical performance indexes of the optical cable, such as tensile strength, tensile elastic modulus, rigidity and the like, can reach the indexes of the application environment requirement.

The rest of this embodiment is the same as embodiment 1, and will not be described again

The embodiment of the present invention is the above. The specific parameters in the above embodiments and examples are only for the purpose of clearly showing the verification process of the present invention, and are not used to limit the protection scope of the present invention, which is still subject to the claims, and all the equivalent structural changes made by using the contents of the specification and drawings of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The utility model provides an adsorbable is at inboard magnetism of oil gas well metal pipe wall and is inhaled formula oil well optical cable which characterized in that: including coating optic fibre (6), the surface of coating optic fibre (6) is laminated tight cladding (5), the surface of tight cladding (5) is laminated the enhancement layer, the surface of enhancement layer is laminated the adsorption element that can adsorb the sleeve pipe outward, the surface of adsorption element is laminated protective layer (1).

2. The magnetic oil well optical cable capable of being adsorbed on the inner side of the metal pipe wall of an oil and gas well as claimed in claim 1, wherein: the adsorption element is a plurality of groups of magnet assemblies (2) wrapped on the outer surface of the enhancement layer, and the plurality of groups of magnet assemblies (2) are distributed at intervals along the length direction of the coated optical fiber (6).

3. The magnetic oil well optical cable capable of being adsorbed on the inner side of the metal pipe wall of an oil and gas well as claimed in claim 2, wherein: the magnet assembly (2) comprises a left semicircular magnet (21) and a right semicircular magnet (22), and the left semicircular magnet (21) and the right semicircular magnet (22) are mutually attracted and are tightly attached to the outer surface of the enhancement layer.

4. The magnetic oil well optical cable capable of being adsorbed on the inner side of metal pipe wall of oil and gas well according to claim 2 or 3, characterized in that: the length of the magnet assembly (2) is 5 mm-30 mm.

5. The magnetic oil well optical cable capable of being adsorbed on the inner side of the metal pipe wall of an oil and gas well as claimed in claim 1, wherein: the adsorption element comprises a strip-shaped film (7) attached to the enhancement layer, a plurality of thin magnet blocks (8) are arranged on the strip-shaped film (7), and the plurality of thin magnet blocks (8) are distributed at intervals along the length direction of the coated optical fiber (6).

6. The magnetic oil well optical cable capable of being adsorbed on the inner side of the metal pipe wall of an oil and gas well as claimed in claim 5, wherein: the belt-shaped thin film (7) is a single-layer thin film, and a plurality of thin magnet blocks (8) are attached to the outer surface of the single-layer thin film; or the strip-shaped thin film (7) is a double-layer thin film, and the plurality of magnet thin blocks (8) are arranged in the double-layer thin film.

7. The magnetic oil well optical cable capable of being adsorbed on the inner side of metal pipe wall of oil and gas well according to claim 5 or 6, characterized in that: the thickness of the magnet thin block (8) is 0.5-2 mm, and the shape of the magnet thin block (8) is rectangular, circular or elliptical.

8. The magnetic oil well optical cable capable of being adsorbed on the inner side of the metal pipe wall of an oil and gas well as claimed in claim 1, wherein: the enhancement layer comprises a sheath (4) tightly attached to the outer surface of the tight cladding layer (5), a plurality of enhancement elements (3) are embedded into the sheath (4), the enhancement elements (3) are arranged along the length direction of the coated optical fiber (6), and the adsorption elements are tightly attached to the outer surface of the sheath (4).

9. The magnetic oil well optical cable capable of being adsorbed on the inner side of the metal pipe wall of an oil and gas well as claimed in claim 1, wherein: the reinforcing layer comprises a reinforcing element (3) which is tightly attached to the outer surface of the tightly-packed layer (5), the outer surface of the reinforcing element (3) is tightly attached to the sheath (4), and the adsorption element is tightly attached to the outer surface of the sheath (4).

10. The magnetic oil well optical cable capable of being adsorbed on the inner side of metal pipe wall of oil and gas well according to claim 8 or 9, characterized in that: the protective layer (1) and the sheath (4) are made of high polymer materials, and the reinforcing element (3) is made of fiber yarn or fiber composite materials or non-magnetic metal wire materials.

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