Optical cable centralizer structure for logging while drilling and drilling device

Abstract

The application provides a cable righting structure for logging while drilling and a drilling device, wherein the cable righting structure comprises a support ring, a protective sleeve, a sealing clamp and a pressing part; the support ring comprises an inner ring and an outer ring; one end of the inner ring is provided with a limiting part, and a penetrating slot penetrating through the peripheral wall is arranged on the inner ring in the axial direction, and the penetrating slot allows the cable to pass through; the outer ring is coaxial with the inner ring and is connected with the inner ring, and the outer ring is anchored to the inner wall of the drill pipe; the peripheral wall of the protective sleeve is provided with a spiral gap extending from one end to the other end, the cable is arranged in the protective sleeve through the spiral gap, an axial shoulder is arranged on the protective sleeve, and the protective sleeve is made of elastic material; the sealing clamp is arranged outside the axial shoulder, and the sealing clamp and the protective sleeve are integrally inserted into the inner ring, and one end of the axial shoulder abuts against the limiting part; the pressing part is detachably connected with the inner ring, and the pressing part abuts against the other end of the axial shoulder. The pressing part applies a pressing force to the axial shoulder, so that the clamping force of the protective sleeve increases in the axial direction, the cable is clamped and straightened while being righted, and fatigue damage caused by the swing of the cable during the drilling process is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of logging optical cable protection devices, and in particular to an optical cable centralizing structure and a drilling device for logging while drilling. Background Art

[0002] Currently, my country's oil and gas exploration and development are continuously advancing into complex oil and gas fields such as low permeability, unconventional, deep and ultra-deep formations, and deepwater. This poses significant challenges to the efficiency, safety, and quality of drilling projects, leading to the emergence of logging-while-drilling (LWD) technology. Optical cable LWD is an innovative logging technology designed to address the low transmission rate of LWD. Compared to traditional wireline logging, optical cable is less susceptible to electromagnetic interference and boasts much higher signal propagation speeds than wireline. This allows for stable signal transmission under complex geological conditions, with data transmission rates reaching up to GB per second, enabling more efficient data transmission.

[0003] Although fiber-optic logging while drilling (LOD) has many technical advantages, the optical cable inside the drill pipe must constantly withstand the erosion of downhole mud and the strong vibration environment during drilling, making it difficult to ensure the reliability of the optical cable. These factors directly determine the ground information processing end's reception of downhole measurement signals. Therefore, the optical cable straightening structure is a key component in optical cable sensing.

[0004] In the existing technology, the optical cable straightening structure only provides straightening but cannot provide pre-tightening force for the optical cable. The failure of the optical fiber to be straightened may cause large swings, which may easily lead to optical cable breakage and fail to ensure the reliability of optical cable data transmission. Summary of the Invention

[0005] In view of this, the present invention proposes an optical cable straightening structure and a drilling device for logging while drilling, so as to solve the technical problems that the optical cable straightening structures proposed in the above background technology only provide straightening but cannot provide pre-tightening force for the optical cable, the optical fiber cannot be straightened, which may cause large swings, easily lead to breakage of the optical cable, and cannot ensure the reliability of data transmission by the optical cable.

[0006] The technical solution of the present invention is achieved as follows:

[0007] In a first aspect, the present invention provides an optical cable centralizing structure for logging while drilling, comprising a support ring, a protective sleeve, a sealing card and a pressing member, wherein:

[0008] The support ring includes an inner ring and an outer ring; a stopper is provided at one end of the inner ring, and a penetration groove is provided on the inner ring along the axial direction and penetrates the peripheral wall, and the penetration groove allows the optical cable to pass through; the outer ring and the inner ring are connected to each other and are coaxial, and the outer ring is anchored to the inner wall of the drill pipe;

[0009] The peripheral wall of the protective sleeve is provided with a spiral slit extending from one end to the other end, and the optical cable is installed in the protective sleeve through the spiral slit. The protective sleeve is provided with a shoulder and is made of elastic material;

[0010] The sealing sleeve is arranged outside the shaft shoulder, and the sealing sleeve and the protective sleeve are integrally inserted into the inner ring, and one end of the shaft shoulder abuts against the limiting portion;

[0011] The pressing piece is detachably connected to the inner ring, and the pressing piece abuts against the other end of the shaft shoulder.

[0012] On the basis of the above technical solution, preferably, it further includes a set screw, the peripheral wall of the outer ring is provided with a plurality of mounting holes in the radial direction, the set screw is threadedly connected to the mounting hole, the two ends of the set screw are respectively an operating end and a connecting end, the operating end is located on one side of the inner wall of the inner ring, and the connecting end protrudes from the outer wall of the outer ring and abuts against the inner wall of the drill rod.

[0013] On the basis of the above technical solution, preferably, the connecting end is provided with an inner recess.

[0014] On the basis of the above technical solution, preferably, it also includes a connecting screw, the clamping part includes a pressure cap and a gasket, the pressure cap is provided with a first connecting hole, the end face of the inner ring is provided with a second connecting hole, the second connecting hole is a threaded hole, the connecting screw passes through the first connecting hole and is threadedly connected to the second connecting hole; the gasket is sleeved on the protective sleeve and is located between the pressure cap and the end of the shaft shoulder away from the limiting portion.

[0015] On the basis of the above technical solution, preferably, the outer ring at least includes a ring body, and the ring body is provided with a notch for allowing the cable to pass through.

[0016] On the basis of the above technical solution, preferably, the outer ring further includes a sealing block and a connecting piece, the sealing block is movably inserted into the notch, and the connecting piece connects the sealing block and the ring body.

[0017] On the basis of the above technical solution, preferably, a guide surface is provided on the outer wall of the outer ring, the guide surface is in contact with the inner wall of the drill rod, and the guide surface is located at one end of the outer ring close to the bottom of the drill rod.

[0018] On the basis of the above technical solution, preferably, the support ring further includes an intermediate rod, a gap is provided between the outer wall of the inner ring and the inner wall of the outer ring, and the intermediate rod is connected between the inner ring and the outer ring.

[0019] In a second aspect, the present invention provides a drilling device comprising a drill pipe and an optical cable, and the optical cable straightening structure for logging while drilling described in the first aspect, wherein the outer ring is connected to the inner wall of the drill pipe, and the optical cable is installed in the protective sleeve through the spiral gap.

[0020] On the basis of the above technical solution, preferably, the drill pipe includes a plurality of short sections connected in sequence, and the optical cable righting structure is located at the connection between two adjacent short sections.

[0021] The optical cable centralizing structure and drilling device for logging while drilling of the present invention have the following beneficial effects compared with the prior art:

[0022] (1) A spiral slit is provided through the peripheral wall of the protective sleeve extending from one end to the other end, and the optical cable is installed in the protective sleeve through the spiral slit. The protective sleeve is provided with a shoulder, and the protective sleeve is made of elastic material; the outer ring is anchored to the inner wall of the drill pipe, and the sealing sleeve is arranged outside the shoulder and then inserted into the inner ring together, one end of the shoulder abuts against the limiting part, and the clamping member abuts against the other end of the shoulder, and the clamping member applies a clamping force to the shoulder, so that the clamping force of the protective sleeve increases in the axial direction, and while straightening the optical cable, the optical cable is clamped and straightened, thereby reducing fatigue damage caused by the swing of the optical cable during the drilling process;

[0023] (2) The fixing screw is threadedly connected to the mounting hole, and the two ends of the fixing screw are respectively an operating end and a connecting end. The operating end is located on the inner wall side of the inner ring, and the connecting end protrudes from the outer wall of the outer ring and abuts against the inner wall of the drill pipe, thereby realizing the anchoring of the outer ring and the inner wall of the drill pipe, so that the outer ring is fixed to the specified position of the drill pipe, preventing it from moving under various external forces, providing stable support and fixation for the optical cable straightening structure, and improving the stability and reliability of the device;

[0024] (3) The connection end is provided with an inner concave portion to reduce the contact area between the connection end and the inner wall of the drill pipe, thereby increasing the pressure, increasing the ability of the supporting structure to withstand the forces such as tension, torque and pressure during the drilling process, and improving the reliability of the device;

[0025] (4) The connecting screw passes through the first connecting hole and is threadedly connected to the second connecting hole. The gasket is sleeved on the protective sleeve and is located between the pressure cap and the end of the shoulder away from the limiting portion. By adjusting the depth of the connecting screw screwed into the second connecting hole, the pressing force of the shoulder of the protective sleeve can be adjusted. Since the shoulder of the protective sleeve is covered with a sealing clamp, the shoulder part of the protective sleeve can only shrink inward to clamp the optical cable, thereby increasing the clamping force on the optical cable, ensuring that the optical cable remains in a taut state, and improving the reliability and stability of the device;

[0026] (5) The connection piece connects the sealing block and the ring body, the gap of the ring body facilitates the cable to be loaded, the sealing block makes the ring body complete, and the overall stability and reliability of the cable centralizing structure are improved;

[0027] (6) The gap is arranged between the outer wall of the inner ring and the inner wall of the outer ring, the middle rod is connected between the inner ring and the outer ring, the support ring is a hollow structure, a larger flow area can be provided, the flow resistance of the drilling fluid can be reduced, the impact and abrasion of the drilling fluid on the cable can be reduced, the external force acting on the cable is reduced, and the service life of the cable is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0029] Figure 1 It is a perspective view of the cable centralizing structure for logging while drilling in the embodiment of the present application;

[0030] Figure 2 It is a sectional view of the cable centralizing structure for logging while drilling in the embodiment of the present application;

[0031] Figure 3 It is an explosion view of the cable centralizing structure for logging while drilling in the embodiment of the present application;

[0032] Figure 4 It is a structural schematic view of the support ring in the embodiment of the present application;

[0033] Figure 5 It is a perspective view of the protective sleeve in the embodiment of the present application;

[0034] Figure 6 It is a sectional view of the locking screw in the embodiment of the present application;

[0035] Figure 7 It is a structural schematic view of the drilling device in the embodiment of the present application;

[0036] Figure 8 It is a partial enlarged view of part A in the embodiment of the present application. Figure 7

[0037] Explanation of reference numerals: 1-support ring, 2-protective sleeve, 3-sealing clamp, 4-pressing piece, 5-locking screw, 6-connecting screw;

[0038] ​100 - drill pipe, 101 - sub, 1011 - connecting surface, 200 - optical cable;

[0039] 11 - inner ring, 111 - limiting portion, 112 - through slot, 113 - second connecting hole, 12 - outer ring, 121 - ring body, 1211 - mounting hole, 1212 - notch, 1213 - first pin hole, 122 - block, 1221 - second pin hole, 123 - connecting piece, 124 - guide surface, 13 - intermediate rod;

[0040] 21 - helical slit, 22 - shoulder;

[0041] 41 - pressure cap, 411 - first connecting hole, 42 - gasket;

[0042] 51 - operating end, 52 - connecting end, 521 - inner recess. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0044] Reference Figure 1-8 The first aspect embodiment of the present application proposes an optical cable centralizing structure for logging while drilling, which comprises a support ring 1, a protective sleeve 2, a sealing clamp 3 and a pressing piece 4, wherein:

[0045] The support ring 1 comprises an inner ring 11 and an outer ring 12; one end of the inner ring 11 is provided with a limiting portion 111, and a through slot 112 extending through the peripheral wall in the axial direction is arranged on the inner ring 11, the through slot 112 extends from the inner wall to the outer wall, and the through slot 112 allows the optical cable 200 to pass through; the outer ring 12 is coaxially connected with the inner ring 11, and the outer ring 12 is anchored to the inner wall of the drill pipe 100;

[0046] The peripheral wall of the protective sleeve 2 is provided with a helical slit 21 extending from one end to the other end, and the helical slit 21 is opened from the outer wall to the inner wall, so that the optical cable 200 can be loaded into the protective sleeve 2 through the helical slit 21, and the optical cable 200 is straightened after being loaded into the protective sleeve 2, the protective sleeve 2 is provided with a shoulder 22, and the protective sleeve 2 is made of elastic material;

[0047] The sealing clip 3 is sleeved on the outside of the shoulder 22, and the sealing clip 3 and the protective sleeve 2 are integrally inserted into the inner ring 11, with one end of the shoulder 22 abutting against the limiting portion 111. The sealing clip 3 is a hollow cylinder with an opening on the outer wall along the axial direction. The inner diameter of the sealing clip 3 is slightly larger than the outer diameter of the protective sleeve 2 when it is not compressed. The sealing clip 3 can be sleeved on the outside of the protective sleeve 2 and can limit the expansion of the protective sleeve 2 toward the outer wall.

[0048] The pressing member 4 is detachably connected to the inner ring 11 , and the pressing member 4 abuts against the other end of the shaft shoulder 22 .

[0049] The optical cable straightening structure for logging while drilling proposed in this embodiment, the optical cable 200 is installed in the protective sleeve 2 through the spiral gap 21, the protective sleeve 2 is provided with a shoulder 22, the protective sleeve 2 is made of elastic material, the outer ring 12 is anchored to the inner wall of the drill pipe 100, the sealing clamp 3 is sleeved outside the shoulder 22 and inserted into the inner ring 11 together, one end of the shoulder 22 abuts against the limiting portion 111, and the clamping member 4 abuts against the other end of the shoulder 22, and the clamping member 4 applies a clamping force to the shoulder 22, so that the clamping force of the protective sleeve 2 increases in the axial direction. While straightening the optical cable 200, the optical cable 200 is clamped and straightened, reducing fatigue damage caused by the swing of the optical cable 200 during the drilling process.

[0050] In some embodiments, the optical cable straightening structure further includes a set screw 5. The peripheral wall of the outer ring 12 is provided with a plurality of mounting holes 1211 in a radial direction. The set screw 5 is threadedly connected to the mounting holes 1211. The two ends of the set screw 5 are respectively an operating end 51 and a connecting end 52. The operating end 51 is located on one side of the inner wall of the inner ring 11, and the connecting end 52 protrudes from the outer wall of the outer ring 12 and abuts against the inner wall of the drill rod 100. The set screw 5 can be a straight columnar structure without a cap end. The mounting holes 1211 are threaded holes without steps, which makes the aperture of the mounting holes 1211 smaller, thereby improving the strength of the outer ring 12. The operating end 51 can be a hexagonal structure, which facilitates operation in confined spaces. By protruding the outer wall of the outer ring 12 and abutting against the inner wall of the drill rod 100, the outer ring 12 is anchored to the inner wall of the drill rod 100, so that the outer ring 12 is fixed to the specified position of the drill rod 100, preventing it from moving under the action of various external forces, providing stable support and fixation for the optical cable straightening structure, and improving the stability and reliability of the device. The anchoring effect of the outer ring 12 and the inner wall of the drill rod 100: on the one hand, it firmly fixes the optical cable straightening structure in a specific position like an anchor, preventing it from moving under the action of various external forces, and providing stable support and fixation for the optical cable straightening structure; on the other hand, this anchoring effect can ensure that the optical cable straightening structure maintains the correct position and posture during operation, thereby effectively exerting its straightening function. Whether it is responding to vibration, impact or other dynamic loads, the anchoring effect of the set screw 5 can keep the optical cable straightening structure stable and ensure the normal operation of the equipment.

[0051] In some embodiments, the connecting end 52 is provided with an inner recess 521. By providing the inner recess 521, the contact area between the connecting end 52 and the inner wall of the drill pipe 100 can be reduced, thereby increasing the pressure, increasing the ability of the supporting structure to withstand the forces such as tension, torque and pressure during the drilling process, and improving the reliability of the device.

[0052] In some embodiments, the optical cable straightening structure also includes a connecting screw 6, the clamping member 4 includes a pressure cap 41 and a gasket 42, the pressure cap 41 is provided with a first connecting hole 411, the end face of the inner ring 11 is provided with a second connecting hole 113, the second connecting hole 113 is a threaded hole, the connecting screw 6 passes through the first connecting hole 411 and is threadedly connected to the second connecting hole 113; the gasket 42 is sleeved on the protective cover 2, and is located between the pressure cap 41 and the end of the shoulder 22 away from the limiting portion 111. The gasket 42 is placed in the inner hole of the outer ring 12, one end of the pressure cap 41 is inserted into the outer ring 12 and is sleeved on the protective sleeve 2, and the pressure cap 41 is pressed against the gasket 42. By adjusting the depth of the connecting screw 6 screwed into the second connecting hole 113, the clamping force on the shoulder 22 can be adjusted. Since the shoulder 22 of the protective sleeve 2 is covered with a sealing card 3 on the outside, the shoulder 22 of the protective sleeve 2 can only shrink inward to clamp the optical cable 200, thereby increasing the clamping force on the optical cable 200, ensuring that the optical cable 200 remains in a taut state, and improving the reliability and stability of the device.

[0053] In some embodiments, the outer ring 12 includes at least a ring body 121, and the ring body 121 is provided with a notch 1212 for allowing the cable to pass through. The notch 1212 facilitates the insertion of the optical cable 200, improves assembly convenience, and improves assembly efficiency.

[0054] In some embodiments, the outer ring 12 further includes a sealing block 122 and a connector 123. The sealing block 122 is movably inserted into the notch 1212, and the connector 123 connects the sealing block 122 and the ring body 121. The sealing block 122 completes the ring body 121 into a full circle, thereby improving the overall stability and reliability of the optical cable straightening structure. The connector 123 can be a pin. The end face of the ring body 121 at the notch 1212 is respectively provided with a first pin hole 1213 perpendicular to the end face. The sealing block 122 is provided with a second pin hole 1221 corresponding to the first pin hole 1213. The pin passes through the first pin hole 1213 and the second pin hole 1221 to achieve the connection between the sealing block 122 and the ring body 121.

[0055] In some embodiments, a guide surface 124 is provided on the outer wall of the outer ring 12. The guide surface 124 mates with the inner wall of the drill rod 100 and is located at the end of the outer ring 12 near the bottom of the drill rod 100. The guide surface 124 is a tapered surface, larger at the top and smaller at the bottom. The guide surface 124 is located at the end of the outer ring 12 near the bottom of the drill rod 100. The drill rod 100 can provide an upward support force on the outer ring 12, allowing the outer ring 12 to withstand greater axial tension, further improving the reliability and stability of the device.

[0056] In some embodiments, the support ring 1 further includes an intermediate rod 13. A gap is provided between the outer wall of the inner ring 11 and the inner wall of the outer ring 12, and the intermediate rod 13 is connected between the inner ring 11 and the outer ring 12. By providing a gap between the outer wall of the inner ring 11 and the inner wall of the outer ring 12, the support ring 1 has a hollow structure, which can provide a larger flow area, reduce the flow resistance of the drilling fluid, reduce the impact and wear of the drilling fluid on the optical cable 200, reduce the external forces acting on the optical cable 200, and extend the service life of the optical cable 200.

[0057] The working principle of the optical cable straightening structure for logging while drilling in this embodiment is as follows: the outer ring 12 is anchored to the inner wall of the drill pipe 100, so that the optical cable straightening structure is fixed at a specified position in the drill pipe 100; the optical cable 200 is installed in the protective sleeve 2 through the spiral gap 21, and the protective sleeve 2 is made of elastic material. The sealing card 3 is sleeved outside the shoulder 22 and then inserted into the inner ring 11 together. One end of the shoulder 22 abuts against the limiting portion 111, and the clamping member 4 abuts against the other end of the shoulder 22. The clamping member 4 applies a clamping force to the shoulder 22, so that the clamping force of the protective sleeve 2 increases in the axial direction. While straightening the optical cable 200, the optical cable 200 is clamped and straightened, reducing fatigue damage caused by the swing of the optical cable 200 during the drilling process.

[0058] Based on the same concept, the second embodiment of the present invention proposes a drilling device, including a drill pipe 100 and an optical cable 200, as well as the optical cable straightening structure for logging while drilling described in the first embodiment, wherein the outer ring 12 is connected to the inner wall of the drill pipe 100, and the optical cable 200 is installed in the protective cover 2 through the spiral gap 21.

[0059] In some embodiments, the drill pipe 100 includes a plurality of sequentially connected short sections 101, and the optical cable straightening structure is located at the connection between two adjacent short sections 101. The inner wall of the upper end of the short section 101 is provided with a connecting surface 1011, which is a conical surface. The guide surface 124 contacts the connecting surface 1011, and the connecting end 52 of the set screw 5 contacts the inner wall of the drill pipe 100, thereby anchoring the outer ring 12 to the inner wall of the drill pipe 100, thereby fixing the outer ring 12 at a designated position on the drill pipe 100 and preventing it from moving under various external forces.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An optical cable centralizing structure for logging while drilling, characterized in that: It includes a support ring, a protective sleeve, a sealing card, a pressing piece and connecting screws, of which: The support ring includes an inner ring and an outer ring; a stopper is provided at one end of the inner ring, and a penetration groove is provided on the inner ring along the axial direction and penetrates the peripheral wall, and the penetration groove allows the optical cable to pass through; the outer ring and the inner ring are connected to each other and are coaxial, and the outer ring is anchored to the inner wall of the drill pipe; The peripheral wall of the protective sleeve is provided with a spiral slit extending from one end to the other end, and the optical cable is installed in the protective sleeve through the spiral slit. The protective sleeve is provided with a shoulder and is made of elastic material; The sealing sleeve is arranged outside the shaft shoulder, and the sealing sleeve and the protective sleeve are integrally inserted into the inner ring, and one end of the shaft shoulder abuts against the limiting portion; The clamping piece is detachably connected to the inner ring, and the clamping piece abuts against the other end of the shaft shoulder; the clamping piece includes a pressure cap and a gasket, the pressure cap is provided with a first connecting hole, the end face of the inner ring is provided with a second connecting hole, the second connecting hole is a threaded hole, the connecting screw passes through the first connecting hole and is threadedly connected to the second connecting hole; the gasket is sleeved on the protective sleeve and is located between the pressure cap and the end of the shaft shoulder away from the limiting portion.

2. The optical cable centralizing structure for logging while drilling according to claim 1, characterized in that: It also includes a set screw, and the peripheral wall of the outer ring is provided with a plurality of mounting holes in the radial direction. The set screw is threadedly connected to the mounting hole. The two ends of the set screw are respectively an operating end and a connecting end. The operating end is located on one side of the inner wall of the inner ring, and the connecting end protrudes from the outer wall of the outer ring and abuts against the inner wall of the drill rod.

3. The optical cable centralizing structure for logging while drilling according to claim 2, characterized in that: The connecting end is provided with an inner recess.

4. The optical cable centralizing structure for logging while drilling according to claim 1, characterized in that: The outer ring at least comprises a ring body, and the ring body is provided with a notch for allowing the cable to pass through.

5. The optical cable centralizing structure for logging while drilling according to claim 4, characterized in that: The outer ring further comprises a sealing block and a connecting piece. The sealing block is movably inserted into the notch, and the connecting piece connects the sealing block and the ring body.

6. The optical cable centralizing structure for logging while drilling according to claim 1, characterized in that: A guide surface is provided on the outer wall of the outer ring, and the guide surface is in contact with the inner wall of the drill rod. The guide surface is located at one end of the outer ring close to the bottom of the drill rod.

7. The optical cable centralizing structure for logging while drilling according to claim 1, characterized in that: The support ring further includes an intermediate rod, a gap is provided between the outer wall of the inner ring and the inner wall of the outer ring, and the intermediate rod is connected between the inner ring and the outer ring.

8. A drilling device, characterized in that: It comprises a drill pipe and an optical cable, and an optical cable straightening structure for logging while drilling according to any one of claims 1 to 7, wherein the outer ring is connected to the inner wall of the drill pipe, and the optical cable is installed in the protective sleeve through the spiral gap.

9. The drilling device according to claim 8, wherein: The drill pipe includes a plurality of short sections connected in sequence, and the optical cable straightening structure is located at the connection between two adjacent short sections.

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