Casing centralizer for optical fiber cable well

Abstract

The utility model relates to the technical field of well completion and cementing equipment, in particular to a casing centralizer for an optical fiber cable well, and aims to solve the technical problems that in the prior art, due to the fact that the casing centralizer is limited by the fixed outer diameter of rigid design, the casing centralizer is difficult to adapt to different well diameters, and a pipe string is difficult to put down or the centering degree of the casing string is low. The casing centralizer comprises a ring seat assembly and a ball cage made of an elastic material, wherein the ring seat assembly is provided with an optical fiber cable fixing hole. The ring seat assembly comprises a first ring seat and a second ring seat. The first ring base, the ball cage and the second ring base are arranged on the sleeve in a sleeving mode and are sequentially connected in the axis direction of the sleeve. According to the casing centralizer, the variable outer diameter capable of being elastically contracted is generated through the ball cage made of the elastic material, and the casing centralizer abuts against the well wall through elastic deformation of the ball cage so as to automatically adapt to well diameters of different sizes. The technical problems that due to the fact that an existing underground optical fiber cable fastening hoop is limited by the fixed outer diameter of rigid design, the existing underground optical fiber cable fastening hoop is difficult to adapt to different well diameters, and pipe string tripping-in is difficult or the centering degree of a casing pipe string is low are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of well completion and cementing equipment, in particular to a casing centralizer for optical fiber cable wells. Background Art

[0002] In oil and gas well operations, monitoring downhole pressure and temperature is extremely important. The currently used fiber optic monitoring technology, based on the principles of fiber optic Bragg gratings and FP cavities, can monitor these parameters in real time and is suitable for harsh environments. However, the downhole instrumentation of fiber optic detection wells is complex, and lowering the tubing string is extremely difficult. Conventional downhole fiber optic cable clamps are easy to connect and can effectively secure the fiber optic cable. However, fiber optic cable clamps are rigid parts with a fixed outer diameter. If the outer diameter is too large, it will be difficult to lower the tubing string. If the outer diameter is too small, the casing string will be poorly centered, resulting in poor displacement effect during cementing construction and poor cementing quality.

[0003] Existing downhole optical fiber cable fastening clamps have technical problems such as being difficult to adapt to different well diameters due to the fixed outer diameter limited by the rigid design, resulting in difficulty in lowering the pipe string or low centering of the casing string. Utility Model Content

[0004] The purpose of the utility model is to provide a casing centralizer for optical fiber cable wells, so as to solve the technical problems in the related art that the fixed outer diameter is limited by the rigid design, resulting in difficulty in adapting to different well diameters, causing difficulty in lowering the pipe string or low centering of the casing string.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0006] The casing centralizer provided by the utility model comprises:

[0007] The ring seat assembly and the ball cage are provided with a fiber optic cable fixing hole for securing the fiber optic cable. The ring seat assembly includes a first ring seat and a second ring seat. The first ring seat, the ball cage, and the second ring seat are each sleeved within the casing and sequentially connected along the casing's axis. The ball cage is made of an elastic material and abuts the wellbore wall.

[0008] Specifically, the first and second ring seats are identical in structure. The first ring seat is divided into a first half and a second half along the diameter of the casing. The first and second half rings are movably connected to allow the first ring seat to switch between a closed state and an expanded state. In the closed state, the first and second half rings are locked together with the casing. In the expanded state, the first and second half rings can be separated from the casing.

[0009] Specifically, the device further includes a bow-shaped hinge, wherein the bow-shaped hinge includes a bow-shaped movable member. One end of the bow-shaped movable member is hinged to the first half ring, and the other end is detachably connected to the first half ring. The bow-shaped movable member is provided with a raised arc segment, and the raised arc segment and the first half ring form the optical fiber cable fixing hole.

[0010] Specifically, the cage includes a bow-shaped spring piece, one end of which is connected to the first ring seat, and the other end is connected to the second ring seat, and the bow-shaped spring piece is provided with an arc that bulges radially outward along the sleeve. A plurality of the bow-shaped spring pieces are evenly distributed around the axis of the sleeve.

[0011] Specifically, the first half ring is hinged to the second half ring, and the hinge axis of the first half ring and the second half ring is parallel to the axis of the sleeve. The rotation of the first half ring around the second half ring is used to drive the first ring seat to switch between a closed state and an expanded state.

[0012] Specifically, the first ring seat further includes a stopper pin. Both the first and second half rings are provided with a rolled cylindrical hole at one hinged end. The stopper pin is inserted into the rolled cylindrical hole to achieve the hinged connection between the first and second half rings.

[0013] Specifically, the first ring seat further includes a ring seat fastening bolt. Both the first and second ring halves are provided with through holes at their ends distal from the hinge axis. The ring seat fastening bolts penetrate through the through holes to fasten the first and second ring halves together, thereby maintaining the first ring seat in a closed state.

[0014] The bow-shaped hinge further comprises a fixing member, which is mounted on the first half-end ring, and the bow-shaped movable member is hinged to the fixing member.

[0015] Specifically, the bow hinge further includes a movable fastening bolt, and the movable fastening bolt simultaneously penetrates the end of the bow movable part away from the fixed part and the first half end ring.

[0016] Specifically, the first ring seat further comprises a toothed half ring, the inner wall of which is provided with engaging teeth. The two toothed half rings are respectively mounted on the inner walls of the first half end ring and the second half end ring for engaging with the outer wall of the sleeve.

[0017] Based on the above technical solutions, the beneficial effects of the present invention are analyzed as follows:

[0018] The utility model provides a casing centralizer for optical fiber cable wells, comprising:

[0019] The ring seat assembly and the ball cage are provided with a fiber optic cable fixing hole for securing the fiber optic cable. The ring seat assembly comprises a first ring seat and a second ring seat. The first ring seat, the ball cage, and the second ring seat are each sleeved within the casing and sequentially connected along the casing's axis. The ball cage is made of an elastic material and abuts the wellbore wall.

[0020] In a specific application, the first ring seat, the ball cage, and the second ring seat are sleeved and fixed onto the casing. The optical fiber cable is inserted into the optical fiber cable fixing hole for fixation. The casing is lowered, and the optical fiber cable is strung into the well along with the casing. The ball cage is larger than the wellbore diameter. In the downhole environment, the ball cage is squeezed by the wellbore wall, and the elastic force of its elastic deformation helps the casing string to be straightened and centered. When encountering irregular wellbore or constricted wellbore, which reduces the effective diameter, the ball cage can further elastically deform to shrink its outer diameter to overcome the irregular wellbore or constricted area.

[0021] As can be seen, compared to existing technologies, this casing centralizer utilizes a flexible, retractable outer diameter created by the elastic cage. The cage's elastic deformation allows it to abut against the wellbore wall, automatically adapting to varying well diameters. This overcomes the technical issues of existing downhole fiber optic cable clamps, which, due to their rigid design and fixed outer diameter, struggle to adapt to varying well diameters, resulting in difficulty running the pipe string or poor casing string centering. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic structural diagram of a casing centralizer provided in an embodiment of the present utility model in an expanded state;

[0024] Figure 2 The structure diagram of the casing centralizer in the closed state Figure 1 ;

[0025] Figure 3 The structure diagram of the casing centralizer in the closed state Figure 2 ;

[0026] Figure 4 A schematic diagram of the structure when two first half-end rings are connected to the bow-shaped spring pieces;

[0027] Figure 5 A schematic diagram of the structure when two second half-end rings are connected to the bow-shaped spring pieces;

[0028] Figure 6 for Figure 1 Schematic diagram of the structure of the middle bow hinge.

[0029] icon:

[0030] 100, ring seat assembly; 101, optical fiber cable fixing hole; 110, first ring seat; 111, first half ring; 102, rolled cylindrical hole; 103, through hole; 112, second half ring; 120, second ring seat; 130, bow hinge; 131, bow movable member; 132, fixing member; 133, hinge fastening bolt; 140, limit cotter pin; 150, ring seat fastening bolt; 160, toothed half ring;

[0031] 200. Ball cage; 210. Bow-shaped spring. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0034] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0035] Existing downhole optical fiber cable fastening clamps have technical problems such as being difficult to adapt to different well diameters due to the fixed outer diameter limited by the rigid design, resulting in difficulty in lowering the pipe string or low centering of the casing string.

[0036] In view of this, the utility model provides a casing centralizer for optical fiber cable wells, comprising:

[0037] The ring seat assembly 100 and the cage 200 are provided with a fiber optic cable fixing hole 101 for securing the fiber optic cable. The ring seat assembly 100 includes a first ring seat 110 and a second ring seat 120. The first ring seat 110, the cage 200, and the second ring seat 120 are each sleeved within the casing and connected in sequence along the casing's axis. The cage 200 is made of an elastic material and abuts the wellbore wall.

[0038] Based on the above technical solutions, the casing centralizer provided by the present invention can achieve the following technical effects:

[0039] This casing centralizer utilizes an elastic cage 200 to create a variable outer diameter that can be elastically contracted. The cage 200's elastic deformation allows it to abut against the wellbore wall, automatically adapting to varying well diameters. This overcomes the technical issues of existing downhole fiber optic cable clamps, which are limited by their rigid, fixed outer diameter, making them difficult to adapt to varying well diameters, resulting in difficulty running the pipe string or poor casing string centering.

[0040] The following combination Figures 1 to 6 The structure and shape of the casing centralizer provided in this embodiment are described in detail:

[0041] Regarding the structural composition of the ball cage 200, specifically:

[0042] The cage 200 includes a bow-shaped spring clip 210, one end of which is connected to the first ring seat 110 and the other end to the second ring seat 120. The bow-shaped spring clip 210 is configured to have a curvature that bulges outward radially along the sleeve. Multiple bow-shaped spring clips 210 are evenly distributed around the sleeve axis. The elastic material of the bow-shaped spring clips 210 can be stainless steel (SUS301), stainless steel (SUS304), or alloy spring steel. The spacing between the first and second ring seats 110, 120 along the sleeve axis allows for adjustment of the curvature of the bow-shaped spring clips 210, thereby adjusting the outer diameter of the cage 200.

[0043] In order to avoid interference between the bow-shaped spring piece 210 and the optical fiber cable, in the solution of this embodiment, the axial direction of the bow-shaped spring piece 210 and the optical fiber cable fixing hole 101 do not coincide, and the optical fiber cable passes through the gap between two adjacent bow-shaped spring pieces 210 and is connected to the first ring seat 110 and the second ring seat 120 respectively.

[0044] Regarding how the first ring seat 110 and the second ring seat 120 are connected to the casing, specifically:

[0045] The first ring seat 110 and the second ring seat 120 are identical in structure. The first ring seat 110 is divided into a first half ring 111 and a second half ring 112 along the diameter of the casing. The first half ring 111 and the second half ring 112 are flexibly connected to allow the first ring seat 110 to switch between a closed state and an expanded state. In the closed state, the first half ring 111 and the second half ring 112 are locked to the casing. In the expanded state, the first half ring 111 and the second half ring 112 can be separated from the casing.

[0046] In this embodiment, the first ring half 111 is hinged to the second ring half 112. The first and second ring halves 111, 112 are bolted together at one end away from the hinge axis. The hinge axis between the first and second ring halves 111, 112 is parallel to the axis of the sleeve. The rotation of the first ring half 111 about the second ring half 112 is used to switch the first ring seat 110 between a closed and an extended state.

[0047] Specifically, the first ring seat 110 further includes a retaining cotter pin 140 and a ring seat fastening bolt 150. Both the first and second ring halves 111, 112 are provided with a rolled cylindrical hole 102 at their hinged ends. The retaining cotter pin 140 is inserted into the rolled cylindrical hole 102 to achieve the hinged connection between the first and second ring halves 111, 112. Both the first and second ring halves 111, 112 are provided with a through hole 103 at their ends away from the hinge axis. The ring seat fastening bolt 150 penetrates through hole 103 to fasten the first and second ring halves 111, 112 together, thereby maintaining the first ring seat 110 in a closed state.

[0048] To enhance the engagement of the first and second ring seats 110, 120 with the outer wall of the casing and prevent relative twisting or slippage between the first and second ring seats 110, 120, which could damage the optical fiber cable, in this embodiment, the first ring seat 110 further includes a toothed half-ring 160, with engaging teeth disposed on its inner wall. The two toothed half-rings 160 are mounted on the inner walls of the first and second half-end rings 111, 112, respectively, to engage the outer wall of the casing. The connection between the toothed half-rings 160 and the first and second half-end rings 111, 112 can be welded.

[0049] Regarding how the optical fiber cable fixing hole 101 is arranged, specifically:

[0050] The hinge 130 further includes an arcuate hinge 130, which includes an arcuate movable member 131. One end of the arcuate movable member 131 is hinged to the first half ring 111, and the other end is detachably connected to the first half ring 111. The arcuate movable member 131 is provided with a raised arc segment, which, together with the first half ring 111, forms the optical fiber cable fixing hole 101.

[0051] In this embodiment, the bow hinge 130 further includes a fixing member 132 and a hinge fastening bolt 133. The fixing member 132 is mounted on the first half ring 111, and the bow movable member 131 is hingedly connected to the fixing member 132. The hinge fastening bolt 133 penetrates both the end of the bow movable member 131 away from the fixing member 132 and the first half ring 111. The fixing member 132 and the first half ring 111 can be connected by welding.

[0052] To prevent the bow-shaped movable member 131 from interfering with the pipe wall during entry into the well, in this embodiment, the outer diameter of the bow-shaped movable member 131 is smaller than the outer diameter of the cage 200, on a plane perpendicular to the axis of the ring seat assembly 100, with the axis of the ring seat assembly 100 as the center. During entry into the well, the bow-shaped movable member 131 does not come into contact with the well wall.

[0053] In summary, the specific working process of the casing centralizer provided in this embodiment is as follows:

[0054] During on-site construction, first rotate the first and second half rings 111, 112 around the retaining pin 140 and snap them onto the casing. At this point, the first and second ring seats 110, 120 are located at the upper and lower ends of the casing collar, respectively. Slightly adjust the installation spacing between the first and second ring seats 110, 120 based on the wellbore diameter to adjust the outer diameter of the cage 200. The outer diameter of the cage 200 should be slightly larger than the current wellbore diameter. Use the ring seat fastening bolts 150 through the through-holes 103 to secure the first and second ring seats 110, 120 in the closed position. Insert the optical fiber cable between the raised arc segments of the bow-shaped movable member 131 and tighten with the loose-leaf fastening bolts 133. Due to the engagement of the toothed half rings 160 with the outer wall of the casing, the first and second ring seats 110, 120 are fixed relative to the casing, preventing relative twisting or slippage that could deflect or damage the optical fiber cable.

[0055] After installation, the casing is lowered, and the fiber optic cable is lowered into the wellbore along with the casing string. Because the cage 200 is larger than the wellbore's inner diameter, it is squeezed by the wellbore wall in the downhole environment. The elastic force of the cage 200 helps center the casing string through elastic deformation. When encountering irregular wellbores or constricted boreholes that reduce the effective diameter, the cage 200 further elastically shrinks its outer diameter to facilitate passage. After passage, the cage returns to its original position due to its elastic force, consistently centering the casing string and improving cementing quality.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A casing centralizer for optical fiber cable wells, characterized in that: include: A ring seat assembly (100) and a ball cage (200), wherein the ring seat assembly (100) is provided with an optical fiber cable fixing hole (101) for fixing the optical fiber cable; the ring seat assembly (100) comprises a first ring seat (110) and a second ring seat (120); the first ring seat (110), the ball cage (200) and the second ring seat (120) are respectively sleeved on a casing and sequentially connected along the axial direction of the casing; the ball cage (200) is made of elastic material and abuts against a well wall.

2. The casing centralizer according to claim 1, characterized in that: The first ring seat (110) and the second ring seat (120) have the same structure; the first ring seat (110) is evenly divided into a first half-end ring (111) and a second half-end ring (112) along the diameter direction of the sleeve; the first half-end ring (111) and the second half-end ring (112) are movably connected to enable the first ring seat (110) to switch between a closed state and an expanded state; in the closed state, the first half-end ring (111) and the second half-end ring (112) are locked together with the sleeve; In the expanded state, the first half-end ring (111) and the second half-end ring (112) can be separated from the sleeve.

3. The casing centralizer according to claim 2, characterized in that: The invention also includes a bow-shaped hinge (130), wherein the bow-shaped hinge (130) includes a bow-shaped movable part (131); one end of the bow-shaped movable part (131) is hinged to the first half-end ring (111), and the other end is detachably connected to the first half-end ring (111); the bow-shaped movable part (131) is provided with a raised arc segment, and the raised arc segment and the first half-end ring (111) enclose the optical fiber cable fixing hole (101).

4. The casing centralizer according to claim 1, characterized in that: The ball cage (200) includes a bow-shaped spring piece (210), one end of which is connected to the first ring seat (110) and the other end is connected to the second ring seat (120), and the bow-shaped spring piece (210) is provided with an arc that protrudes radially outward along the sleeve; a plurality of the bow-shaped spring pieces (210) are evenly distributed around the axis of the sleeve.

5. The casing centralizer according to claim 2, characterized in that: The first half-end ring (111) is hinged to the second half-end ring (112), and the hinge axis of the first half-end ring (111) and the second half-end ring (112) is parallel to the axis of the sleeve; the rotation of the first half-end ring (111) around the second half-end ring (112) is used to drive the first ring seat (110) to switch between a closed state and an expanded state.

6. The casing centralizer according to claim 5, characterized in that: The first ring seat (110) also includes a limiting cotter pin (140); the first half-end ring (111) and the second half-end ring (112) are both provided with a rolled cylindrical hole (102) at one hinged end; the limiting cotter pin (140) is inserted into the rolled cylindrical hole (102) to realize the hinge connection of the first half-end ring (111) and the second half-end ring (112).

7. The casing centralizer according to claim 5, characterized in that: The first ring seat (110) also includes a ring seat fastening bolt (150); the first half-end ring (111) and the second half-end ring (112) are both provided with a through hole (103) at one end away from the hinge axis; the ring seat fastening bolt (150) penetrates the through hole (103) to fasten the first half-end ring (111) and the second half-end ring (112) together, so that the first ring seat (110) remains in a closed state.

8. The casing centralizer according to claim 3, characterized in that: The bow-shaped hinge (130) further comprises a fixing member (132), wherein the fixing member (132) is mounted on the first half-end ring (111), and the bow-shaped movable member (131) is hinged to the fixing member (132).

9. The casing centralizer according to claim 3, characterized in that: The bow-shaped hinge (130) further comprises a hinge fastening bolt (133), and the hinge fastening bolt (133) simultaneously penetrates the end of the bow-shaped movable part (131) away from the fixed part (132) and the first half-end ring (111).

10. The casing centralizer according to claim 2, characterized in that: The first ring seat (110) further comprises a toothed half ring (160), wherein the toothed half ring (160) is provided with engaging teeth on the inner wall; the two toothed half rings (160) are respectively mounted on the inner walls of the first half end ring (111) and the second half end ring (112) for engaging with the outer wall of the sleeve.

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