Bow plate centralizing pup joint for through-drill-bit well logging

Abstract

A bow plate centralizing pup joint for through-bit logging relates to the field of centralizing pup joints and comprises a pup joint body, two sliders, a connecting plate and an elastic bow plate, the pup joint body is a cylindrical rod, the two sliders are fittingly sleeved on the pup joint body, the connecting plate is a straight rigid plate, and the elastic bow plate is an arched elastic plate. The connecting plates are fixedly connected to the two ends of the elastic bow plates correspondingly, the elastic bow plates are evenly distributed around the circumference of the section of the nipple body and correspondingly arranged in the axial direction, plate bodies protrude outwards in the radial direction, and the two ends are connected with the sliding blocks through the connecting plates in a rotating fit mode. The connecting plate and the sliding block are coordinated and matched to turn over, so that the elastic deformation amplitude and stress concentration strength of a strain concentration area of the elastic arch plate can be released and relieved, the requirement standard for the elastic deformation capacity of the elastic arch plate in a drilling tool water hole is lowered, and conditions are created for improving the elastic tension of the elastic arch plate and enhancing the centralizing strength of the centralizing short section; the safety and reliability of production application are improved, and the logging precision and logging efficiency are improved.

Description

Technical Field

[0001] The utility model relates to the field of a straightening sub, in particular to a bow plate straightening sub for through-bit logging. Background Art

[0002] With the advancement of science and technology and improvements in drilling and production techniques, through-the-bit logging has rapidly gained popularity in oilfield production due to its advantages of low cost, high efficiency, good environmental adaptability, and high measurement accuracy. This method involves suspending a logging instrument string through the drill string's waterhole via a cable and feeding it into the openhole through the drill bit's bore. The instrument string is then pulled out of the drill string's waterhole to measure and collect formation data. To minimize measurement errors and ensure accuracy, most electronically controlled logging instruments, such as electrical imaging and acoustic wave measuring instruments, require alignment and smooth movement in the openhole during measurement. However, the need to ensure the logging instrument string passes through the drill string's waterhole and the drill bit's bore inevitably creates a significant distance between the instrument string and the openhole wall. Furthermore, the instrument string's long length and tendency to oscillate, coupled with the constraints of horizontal well conditions, makes it difficult to maintain natural centering during logging, often requiring the use of leaf spring centralizers for auxiliary centering. However, in through-the-bit logging, the distance between the logging instrument string and the wellbore increases, increasing the spring plate's elastic outward tension. To ensure sufficient straightening strength for the leaf spring centralizer, the spring plate must maintain sufficient elastic tension. To ensure the leaf spring centralizer can pass through the narrow borehole, the spring plate's thickness and width must be within the structural fit. Furthermore, the spring plate is directly connected to the slider. After the plate is constrained and straightened by the barrel wall in the borehole, the elastic deformation is concentrated at its ends, creating strain concentration. This requires the spring plate to have greater elastic deformation capacity, further restricting the increase in the spring plate's size. Consequently, currently used leaf spring centralizers commonly suffer from insufficient spring plate elastic tension and insufficient straightening strength. Furthermore, the high stress concentration caused by the strain concentration in the spring plate can easily lead to fatigue fracture of the spring plate and fracture of the connecting pin in the pin connection structure, causing construction accidents and logging failures. Therefore, it is necessary to study and improve the straightening device used in the through-bit logging process to solve the existing technical problems. Utility Model Content

[0003] The purpose of the utility model is to provide a bow plate straightening short section for through-bit logging, which improves the product structure, perfects the use function, improves the logging accuracy, and enhances the safety and reliability of production applications in response to the through-bit logging process requirements.

[0004] The cam is threadably connected to the side of the drive shaft by a bolt, and the bolt has a round shank to contact with the side of the drive shaft, the bolt having a camming mechanism configured to move relative to the side of the drive shaft as defined in the present invention. The cam is mounted on a track, and the track is moved along the track in such a way that the track can be adjusted relative to the track when the track is in motion, so that the track can be adjusted relative to the track when the track is in motion.

[0005] The bow plate straightening short section for through-bit logging preferably has a sliding block composed of an inner sleeve and an outer jacket, and the inner sleeve and the outer jacket are respectively split combined sleeves that can be fixedly connected by screws, the inner sleeve can be fitted on the rod body of the short section main body, and the outer jacket can be fitted on the outside of the inner sleeve in an alternating manner with the split seams of the inner sleeve. The provision of a double-layer locking sleeve structure is beneficial to improving the overall structural strength of the sliding block.

[0006] The bow plate straightening short section for through-bit logging is preferably such that the staggered angle of the split seams between the outer sleeve and the inner sleeve is 90 degrees, and the split seams on the opposite sides of the inner sleeve are respectively provided with first cylindrical wedge grooves composed of the inner sleeve combination, and the positions of the two first cylindrical wedge grooves are symmetrical to each other, and the split seams on the opposite sides of the outer sleeve are respectively provided with second cylindrical wedge grooves composed of the outer sleeve combination, and the positions of the two second cylindrical wedge grooves are symmetrical to each other. At the same time, cylindrical wedges are respectively provided on the connecting ends of the connecting plate and the sliding block, and the cylindrical wedges are connected with the first cylindrical wedge groove and the second cylindrical wedge groove. The structures correspond to each other and can be respectively fitted and embedded in the first cylindrical wedge groove or the second cylindrical wedge groove, so that a rotational fitting connection of a cylindrical wedge groove structure is formed between the connecting plate and the sliding block. Compared with the connection method of the conventional pin structure, the connection method of the cylindrical wedge groove structure is not only structurally stable and reliable, but more importantly, it has the advantages of simple structure, easy installation, and relatively small space occupation, which can free up a wider structural adaptation space range for the elastic bow plate, so that the elastic bow plate can further increase its own elastic tension by increasing its thickness or width, thereby enhancing the straightening strength of the bow plate straightening short section for through-bit logging.

[0007] The bow plate straightening sub for through-drill tool logging is preferably provided with two limiting protrusions on the circumferential surface of the rod body of the sub main body, and the two limiting protrusions respectively cooperate with the reducing shoulders at both ends of the sub main body, correspondingly limiting the movement stroke area of ​​the sliding block on the sub main body rod, limiting the opening range of the elastic bow plate, ensuring that the elastic bow plate is not damaged due to excessive opening range, and improving the stability of the overall structure and working state of the bow plate straightening sub for through-drill tool logging.

[0008] The beneficial effect of the present invention is that, in response to the process requirements and working conditions of through-bit logging, a bow plate straightening sub for through-bit logging is provided, wherein a connecting plate is compositely connected and installed at both ends of the elastic bow plate, and the connecting plate is used to coordinate and flip with the sliding block that slides axially, thereby releasing and relieving the elastic deformation amplitude and stress concentration strength of the strain concentration area of ​​the elastic bow plate, thereby reducing the requirement standard for the elastic deformation ability of the elastic bow plate when the straightening sub passes through the water hole of the drill bit, creating conditions for selecting materials, optimizing structures, improving the elastic tension of the elastic bow plate, and enhancing the straightening strength of the straightening sub; further, the connection method of the cylindrical wedge groove structure is adopted between the connecting plate and the sliding block, which can also simplify the structure, reduce the occupied space, improve the structural strength, and free up a wider structural adaptation space range for the elastic bow plate, so that the elastic tension of the elastic bow plate can be increased by increasing the thickness or width, thereby further enhancing the straightening strength of the straightening sub; and application in actual production can enhance the safety and reliability of production applications, and improve the logging accuracy and logging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Cross-sectional view of the bow plate straightening sub structure for through-bit logging.

[0010] Figure 2 This is a three-dimensional structural diagram of the connecting plate.

[0011] Figure 3 This is a three-dimensional structural diagram of the sliding block.

[0012] Among them: 1 is the short section body, 2 is the sliding block, 3 is the connecting plate, 4 is the elastic bow plate, 5 is the female core socket, 6 is the male core plug, 7 is the inner sliding sleeve, 8 is the outer jacket, 9 is the slot, 10 is the cylindrical wedge, 11 is the first cylindrical wedge groove, 12 is the second cylindrical wedge groove, 13 is the split screw sleeve, and 14 is the limiting protrusion. DETAILED DESCRIPTION

[0013] The technical solution claimed for protection of the present utility model will be described in detail with reference to the specific embodiments and the accompanying drawings.

[0014] A bow plate straightening short sub for through-bit logging, such as Figure 1 As shown, it is composed of a short section body 1, a sliding block 2, a connecting plate 3 and an elastic bow plate 4. The upper end of the short section body 1 is equipped with a split screw sleeve 13 and a sealing structure. A female core socket 5 is installed in the inner cavity hole, and a connecting internal thread is opened at the lower end. A male core plug 6 is installed in the inner cavity hole. The diameter of the middle rod body of the short section body 1 is smaller than the large diameter of the end heads at both ends, and a reducing shoulder is formed between each other. Two annular limiting protrusions 14 are provided on the circumferential surface of the rod body of the short section body 1. The limiting protrusions 14 respectively correspond to the reducing shoulders at both ends to limit the movement stroke area of ​​the sliding block 2 on the rod body of the short section body 1; the sliding block 2, as shown Figure 3 As shown, it is composed of an inner sleeve 7 and an outer sleeve 8, and the inner sleeve 7 and the outer sleeve 8 are both symmetrical split combined sleeve structures. The two inner sleeves 7 are respectively connected and matched by screws and sleeved on the said movement stroke area on the rod body of the short section main body 1, and can move relative to the said short section main body 1, and the outer sleeve 8 is respectively connected and fastened by screws and sleeved on the outer circumferential surface of the inner sleeve 7, so that the sliding block 2 is sleeved and installed on the said short section main body 1, and the split seams of the outer sleeve 8 and the split seams of the inner sleeve 7 on the sliding block 2 are staggered at an angle of 90°. The split seams on the radially opposite sides of the inner sleeve 7 are respectively provided with a first cylindrical wedge groove 11 of the combined structure, and the split seams on the radially opposite sides of the outer sleeve 8 are respectively provided with a second cylindrical wedge groove 12 of the combined structure. The first cylindrical wedge groove 11 and the second cylindrical wedge groove 12 are both cylindrical inlay grooves; the connecting plate 3, as shown Figure 2As shown, a slot 9 with a fork-mounted splint structure is provided at one end, and a cylindrical wedge 10 is provided at the other end. The cylindrical wedge 10 corresponds to the first cylindrical wedge groove 11 and the second cylindrical wedge groove 12 structures respectively. The connecting plate 3 is inserted into the slot 9 with the end of the elastic bow plate 4 and is fixedly connected to the two ends of the elastic bow plate 4 by means of screws. At the same time, the elastic bow plate 4 is connected and installed on the sliding block 2 by a rotational fitting connection method in which the cylindrical wedge 10 is respectively embedded in the first cylindrical wedge groove 11 and the second cylindrical wedge groove 12.

[0015] In the through-bit logging operation, the bow plate straightening short section for through-bit logging described in this embodiment is applied. The split screw sleeve 13 provided at the upper end of the short section body 1 and the internal thread provided at the lower end are used to connect the bow plate straightening short section for through-bit logging to the logging instrument string and then send it into the drilling tool water hole. During the downward movement in the drilling tool water hole, the dynamic cooperation between the connecting plate 3 and the sliding block 2 effectively releases and alleviates the elastic deformation amplitude and stress concentration intensity of the strain concentration area on the elastic bow plate 4, thereby reducing the gap between the elastic bow plate 4 and the side wall of the drilling tool. The friction resistance is reduced, so that the efficiency of logging operations is improved; at the same time, due to the use of the connecting plate 3 and the connection method of the cylindrical wedge groove structure between the connecting plate 3 and the sliding block 2, the occupation of the water hole space of the drilling tool is reduced. Compared with the existing technology, an effective structural adaptation space range is vacated for the elastic bow plate 4, and sufficient conditions are created for increasing the thickness and width of the elastic bow plate 4, optimizing the specifications and dimensions, and improving the elastic tension, so as to achieve the purpose of enhancing the straightening strength of the bow plate straightening short section for through-bit logging and improving the accuracy of through-bit logging.

Claims

1. A bow plate straightening sub for through-bit logging, characterized in that: include: A short section body (1), a sliding block (2), a connecting plate (3) and an elastic bow plate (4), wherein the short section body (1) is a cylindrical rod body with an axially penetrating inner cavity hole, and mechanical connection mechanisms are respectively provided at both ends, and a female core socket (5) and a male core plug (6) are correspondingly arranged in the inner cavity hole, and a connecting wire connecting the female core socket (5) and the male core plug (6) is provided in the inner cavity hole, and the two sliding blocks (2) are fitted on the rod body of the short section body (1) and can slide axially in the movement stroke area defined on the rod body of the short section body (1). The connecting plate (3) is a straight rigid plate body, the elastic bow plate (4) is an elastic plate body in the shape of a bow, the connecting plate (3) is fixedly connected to the two ends of the elastic bow plate (4), the elastic bow plate (4) is evenly distributed around the cross-section circumference of the short section main body (1) and is correspondingly arranged along the axial direction, the plate body is radially convex, and the two ends are respectively connected to the two sliding blocks (2) through the correspondingly connected connecting plates (3), so that the connecting plate (3) can adaptively rotate relative to the sliding block (2) as the elastic bow plate (4) is elastically deformed.

2. The through-bit logging bow plate straightening sub as claimed in claim 1, characterized in that: The sliding block (2) is composed of an inner sleeve (7) and an outer jacket (8), wherein the inner sleeve (7) and the outer jacket (8) are respectively split combined sleeves that can be fixedly connected by screws. The inner sleeve (7) can be fitted on the rod body of the short section main body (1), and the outer jacket (8) can be fitted on the outside of the inner sleeve (7) by interlacing with the split seam of the inner sleeve (7).

3. The through-bit logging bow plate straightening sub as claimed in claim 2, characterized in that: The staggered angle of the split seams of the outer jacket (8) and the inner sleeve (7) is 90 degrees. The split seams on the opposite sides of the inner sleeve (7) are respectively provided with first cylindrical wedge grooves (11) composed of the inner sleeve (7). The two first cylindrical wedge grooves (11) are symmetrically positioned. The split seams on the opposite sides of the outer jacket (8) are respectively provided with second cylindrical wedge grooves (12) composed of the outer jacket (8). The two second cylindrical wedge grooves (1 2) The positions are symmetrical with each other. At the same time, cylindrical wedges (10) are respectively provided on the connecting ends of the connecting plate (3) and the sliding block (2). The cylindrical wedges (10) correspond to the first cylindrical wedge groove (11) and the second cylindrical wedge groove (12) structures and can be respectively fitted and embedded in the first cylindrical wedge groove (11) or the second cylindrical wedge groove (12), so that a rotational fitting connection of the cylindrical wedge groove structure is formed between the connecting plate (3) and the sliding block (2).

4. The bow plate righting sub for through-bit logging according to any one of claims 1 to 3, characterized in that: Two limiting protrusions (14) are provided on the circumferential surface of the rod body of the short section main body (1). The two limiting protrusions (14) respectively cooperate with the reducing shoulders at both ends of the short section main body (1) to limit the movement travel area of ​​the sliding block (2) on the rod body of the short section main body (1) and limit the opening range of the elastic bow plate (4).

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