A bias variable diameter bidirectional tool for drilling operations

Abstract

The utility model discloses a kind of drilling operation offset variable-diameter type bidirectional tools, including tool body and offset edge, the outside of tool body is unevenly distributed with multiple offset edges along the circumference, the offset edge is long strip shape structure, long strip shape structure is set along tool body axial direction, and overflow passage is set between adjacent offset edges. The outside of tool body is unevenly distributed with multiple offset edges along the circumference, causing the weight distribution of drilling operation offset variable-diameter type bidirectional tool is uneven, in the process of drilling operation, eccentric rotation is formed by tool drilling operation offset variable-diameter type bidirectional tool, the wellbore trajectory formed is micro-hole enlarging wellbore trajectory, can effectively scrape and cut cleaning on the virtual thick mud cake, micro-step on well wall and the plugging material adhered on well wall, while further secondary hole enlarging is also carried out to the well section for easy shrinkage diameter formation, ensure wellbore unobstructed.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling technology, and in particular to a bidirectional tool with offset and variable diameter for drilling operations. Background Technology

[0002] Currently, as oil drilling gradually develops towards deeper and ultra-deep wells, existing drilling technologies are constantly improving, and drilling efficiency is increasing. However, when encountering gypsum-bearing formations such as Leikoupo and Jialingjiang, wellbore diameter reduction is highly likely, leading to stuck drill bits in the reduced diameter section and subsequently triggering a series of complex wellbore failures. Furthermore, well leakage is highly likely to occur in faulted, fractured, fractured, and formations with narrow safety density windows. After leakage occurs, plugging operations are performed using different concentrations of plugging slurry or cement injection. During these operations, the plugging materials and cement slurry adhere to the wellbore wall, causing micro-diameter reduction and severely affecting wellbore patency. Simultaneously, micro-steps are prone to form on the wellbore wall during drilling, greatly increasing the risk of stuck drill bits and significantly increasing drilling time and costs.

[0003] Patent publication number CN109403885B discloses a bidirectional helical wellbore shaping tool for drilling, comprising a shaping tool body and female and male threads respectively disposed at both ends of the shaping tool body. At least three sets of helices are spaced apart on the shaping tool body. The helical structures of the two sets of helices closest to both ends of the shaping tool body are arranged in opposite directions. Each set of helices consists of at least three parallel helical blades arranged at a helical angle of 10 to 45 degrees to the centerline of the shaping tool body. The outer diameter of one of the helical blades on the helice is larger than the outer diameter of the other helical blades on that set, forming an eccentric structure. The top center and one side top edge of the helical blade located at the eccentric position on the helice are respectively provided with gauge-maintaining teeth and cutting teeth. This bidirectional helical wellbore shaping tool can be run in while drilling, shaping the wellbore simultaneously with drilling operations without increasing drilling time. The wellbore can be shaped again during reaming.

[0004] However, this patent passively removes blockages through a slope transition structure, lacking the ability to guide cuttings and mud in both directions. The pointed cone design also results in low efficiency in cleaning soft deposits such as mud cake. Furthermore, this patent only achieves passive borehole enlargement through differences in the outer diameter of the cutting ribs, resulting in a regular borehole with uncontrollable trajectory during drilling. During rock breaking, the protruding cutting ribs contact the formation, easily causing rapid wear and tooth breakage of the cutting blades, potentially leading to complex downhole accidents. Utility Model Content

[0005] This utility model aims to provide a bidirectional tool with offset and variable diameter for drilling operations. By adopting the offset method of the tool during the drilling process, a slightly eccentric wellbore trajectory is formed, which solves the problems of wellbore obstruction and easy stuck drill caused by easily narrowed sections and mud cake with loose mud cake on the well wall. It reduces the contact area with the well wall, prevents stuck drill accidents, and greatly ensures wellbore safety.

[0006] To achieve the above-mentioned objectives, the technical solution of this utility model is as follows:

[0007] A drilling operation offset variable diameter bidirectional tool includes a tool body. Multiple offset edges are unevenly distributed along the circumference on the outer surface of the tool body. The offset edges are elongated structures and are arranged along the axial direction of the tool body. A flow channel is provided between adjacent offset edges.

[0008] The multiple offset edges have the same height in the radial direction of the tool body.

[0009] The multiple offset edges have inconsistent heights in the radial direction of the tool body.

[0010] The bias edge tool body is spirally arranged along its axial direction.

[0011] The offset edge is set vertically along the axial direction of the tool body.

[0012] The long strip structure of the offset ridge has an upper slope and a lower slope at both ends.

[0013] Cutting teeth are arranged on the upper and lower slopes respectively; the cutting teeth are prone to causing the drill string to get stuck when encountering obstacles during tripping, obstruction during descent, or when the well wall is unstable during the drilling process and blocks fall off.

[0014] The cutting teeth are planar teeth, galloping teeth, or roof teeth.

[0015] The cutting teeth are made of diamond or cubic boron nitride.

[0016] The offset edge is spirally arranged along the axial direction of the tool body; the spiral arrangement can reduce the contact area between the tool and the well wall, improve the relative rotation efficiency with the well wall during free rotation, and reduce the risk of stuck drill.

[0017] The offset edge is set vertically along the axis of the tool body; the vertical setting can improve the hydraulic energy utilization rate of drilling fluid, improve the flushing efficiency of mud cake and plugging material adhering to the well wall, and reduce the risk of stuck drill.

[0018] The beneficial effects of this utility model are:

[0019] 1. In this utility model, multiple offset edges are unevenly distributed along the circumference on the outer surface of the tool body, resulting in uneven weight distribution of the offset variable diameter bidirectional tool for drilling operations. During the drilling operation, the offset variable diameter bidirectional tool rotates eccentrically, and the resulting wellbore trajectory is a micro-enlarged wellbore trajectory, which can effectively scrape and clean the loose mud cake, micro-steps and plugging materials adhering to the well wall. At the same time, for formations prone to narrowing, the well section will be further enlarged to ensure smooth wellbore flow.

[0020] 2. In this utility model, cutting teeth are arranged on the upper and lower slopes respectively. When encountering obstacles during drilling, encountering obstructions during drilling, or when the well wall is unstable during the drilling process, the falling blocks can easily cause the drill string to get stuck. The cutting teeth on the upper and lower slopes will effectively break up the obstruction points and falling blocks, and perform secondary repairs on the micro-steps to ensure the safety of the wellbore.

[0021] 3. The offset ridge spiral setting in this utility model can reduce the contact area with the well wall and improve the enlargement efficiency; the offset ridge vertical setting can enhance the hydraulic capacity utilization rate, improve the trimming of the thick mud cake and the adhesion section of the plugging material, and ensure the safety of the well. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the offset variable diameter bidirectional tool for drilling operations in Embodiment 1 of this utility model.

[0023] Figure 2 This is a top view of the offset variable diameter bidirectional tool for drilling operations in Embodiment 1 of this utility model.

[0024] Figure 3 This is a schematic diagram of the micro-reamed wellbore trajectory formed by the offset variable diameter bidirectional tool in embodiment 1 of this utility model.

[0025] Figure 4 This is a schematic diagram of the structure of the offset variable diameter bidirectional tool for drilling operations in Embodiment 5 of this utility model.

[0026] Figure 5 This is a top view of the offset variable diameter bidirectional tool for drilling operations in Embodiment 5 of this utility model.

[0027] Figure 6 This is a schematic diagram of the micro-reamed wellbore trajectory formed by the offset variable diameter bidirectional tool in embodiment 5 of this utility model.

[0028] The components are: 1. Tool body; 2. Offset edge; 3. Lower slope; 4. Upper slope; 5. Cutting teeth; 6. Flow channel. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0030] Example 1

[0031] This embodiment provides a method such as Figure 1 and 2 The drilling operation offset variable diameter bidirectional tool shown includes a tool body 1. Multiple offset edges 2 are unevenly distributed circumferentially on the outer surface of the tool body 1. Each offset edge 2 is an elongated structure arranged along the axial direction of the tool body 1. A flow channel 6 is provided between adjacent offset edges 2. The multiple offset edges 2 have the same radial height in the tool body 1. The offset edges 2 are vertically arranged along the axial direction of the tool body 1.

[0032] In this embodiment, as Figure 2 As shown, there are three offset edges 2, which are unevenly distributed. This uneven distribution of offset edges 2 causes uneven weight distribution in the offset variable-diameter bidirectional drilling tool, resulting in eccentricity. During drilling operations, when the offset variable-diameter bidirectional drilling tool rotates, the eccentricity generates an unbalanced centrifugal force. The magnitude and direction of this centrifugal force change continuously with the rotation angle. During drilling, the resultant force generated by the superposition of the weights of the edges drives the entire tool to achieve micro-offset, forming a micro-reaming trajectory, as shown in the figure. Figure 3 As shown, the dashed line represents the micro-reaming trajectory. The micro-reaming trajectory increases the well diameter formed by the tool's center offset due to its own weight by 1-3 mm compared to the well diameter formed by the drill bit. In this embodiment, the widths of the three offset edges are M1, M2, and M3, respectively. The widths of the different offset edges 2 can be the same (M1=M2=M3) or different (M1≠M2≠M3). In particular, two of the edges can have the same width (M1=M2≠M3). The included angles of the three offset edges 2 are β1, β2, and β3, respectively. The three included angles between the three offset edges 2 can be different (β1≠β2≠β3). In particular, two of the included angles can be the same, and the third included angle can be different (β1=β2≠β3). This allows each straightening edge to make intermittent contact with the well wall and cut the formation, ensuring the reliability and stability of the tool. This also helps to repair the reduced diameter section, the thick mud cake, and the section where the plugging material adheres, ensuring wellbore safety.

[0033] In this embodiment, the offset ridge is a straight structure, which can improve the hydraulic energy utilization rate of drilling fluid, improve the flushing efficiency of mud cake and plugging material adhering to the well wall, and reduce the risk of stuck drill bit.

[0034] Example 2

[0035] The difference between this embodiment and Embodiment 1 is that, in this embodiment, the multiple offset edges 2 have inconsistent radial heights on the tool body 1. The rest of the structure is the same as in Embodiment 1.

[0036] In this embodiment, due to the inconsistent height of the offset edge 2, when the offset variable diameter bidirectional tool forms a micro-reaming trajectory during drilling operations, the contact area between the offset edge 2 and the well wall is reduced, avoiding the generation of rotational resistance due to the excessive contact area of ​​the offset edge 2, reducing the contact area with the well wall, and preventing the occurrence of stuck drill accidents.

[0037] Example 3

[0038] The difference between this embodiment and Embodiment 1 is that, in this embodiment, the two ends of the elongated structure of the offset edge 2 are respectively provided with an upper inclined surface 4 and a lower inclined surface 3. The upper inclined surface 4 and the lower inclined surface 3 form a pointed conical structure along the axial direction of the tool body 1 away from the offset edge 2. The upper inclined surface 4 and the lower inclined surface 3 are vertically arranged along the axial direction of the tool body 1. The rest of the structure is the same as in Embodiment 1.

[0039] In this embodiment, the upper slope 4 and the lower slope 3 can reduce the resistance of the offset variable diameter bidirectional tool in drilling operations when it moves upward or downward, and avoid stuck drill accidents caused by the micro-steps of the well wall.

[0040] In this embodiment, the tips of the pointed conical upper slope surface 4 and lower slope surface 3 can pierce / break hard mud cakes, cement sheaths, or loose blocks on the well wall, reducing stuck drill resistance. The conical design concentrates pressure at the contact point, reducing the friction area between the tool and the well wall and preventing stuck drill adhesion. The conical slope guides the cutting teeth 5 into the reduced diameter section, assisting in the formation of the micro-reaming trajectory and improving dressing efficiency. The pointed conical structure improves the tool's passability in the reduced diameter section and the section where plugging material adheres. At the same time, it can guide the flow when encountering loose blocks during tripping, and can guide rock cuttings and mud during drilling, facilitating wellbore cleaning.

[0041] In this embodiment, the upper slope 4 and the lower slope 3 are arranged vertically and each is equipped with cutting teeth 5. When encountering blockage during drilling, encountering obstruction during drilling, or when the well wall is unstable during the drilling process, the falling blocks can easily cause the drill string to get stuck. The cutting teeth 5 of the upper slope 4 and the lower slope 3 will effectively break up the blockage points and falling blocks, and perform secondary repair on the micro-steps to ensure the safety of the wellbore.

[0042] Example 4

[0043] Compared with Example 3, the difference in this embodiment is that, in this embodiment, cutting teeth 5 are respectively arranged on the upper slope surface 4 and the lower slope surface 3; the cutting teeth 5 are planar teeth, camber teeth or ridge teeth; the cutting teeth 5 are made of diamond or cubic boron nitride material; the rest of the structure is the same as in Example 3.

[0044] In this embodiment, the cutting teeth 5 of the upper slope 4 and the lower slope 3 will effectively break up the obstruction points and falling blocks, and perform secondary repair on the micro-steps to ensure the safety of the well shaft.

[0045] In this embodiment, the planar teeth can increase the cutting area between the cutting teeth 5 and the well wall, making it easier to quickly repair and break up irregular well walls and thick mud cakes. The non-planar tooth shape of the Mercedes teeth and the ridge teeth achieves efficient crushing and self-sharpening through geometric cutting edges. Ultra-hard materials such as diamond or cubic boron nitride provide durability under extreme working conditions. The two work together to enable the offset variable diameter bidirectional tool to complete the enlargement-repairing-anti-sticking in one go in complex well sections such as reduced diameter, mud cake, and micro-steps, significantly reducing the drilling cycle.

[0046] Example 5

[0047] The difference between this embodiment and Embodiment 1 is that, as Figure 4 and 5 As shown, the offset ridge 2 is spirally arranged along the axial direction of the tool body 1; the two ends of the elongated structure of the offset ridge 2 are respectively provided with an upper inclined surface 4 and a lower inclined surface 3. The upper inclined surface 4 and the lower inclined surface 3 form a pointed conical structure along the axial direction of the tool body 1 away from the offset ridge 2. The upper inclined surface 4 and the lower inclined surface 3 are vertically arranged along the axial direction of the tool body 1. The remaining structure is the same as in Embodiment 1.

[0048] In this embodiment, the offset edge is a spiral structure, which can reduce the contact area between the tool and the well wall, improve the relative rotation efficiency with the well wall during free rotation, and reduce the risk of stuck drill bit.

[0049] In this embodiment, the micro-expansion eye trajectory is formed as follows: Figure 6 As shown, the dashed line represents the micro-expansion trajectory, which is formed by the superposition of offset edges with inconsistent radial heights and unevenly distributed offset edges in the circumferential direction. The combined effect of these two factors will make the wellbore trajectory smoother and greatly reduce the risk of stuck drill bit.

[0050] In this embodiment, the helical angles of the three offset edges are α1, α2, and α3, respectively, and the included angles of the three offset edges 2 are β1, β2, and β3, respectively. The helical angles of different offset edges 2 can be the same (α1=α2=α3) or different (α1≠α2≠α3). In particular, two of the edges can have the same helical angle (α1=α2≠α3). The included angles of the three offset edges 2 are β1, β2, and β3, and the three included angles between the three offset edges 2 can be different (β1≠β2≠β3). In particular, two of the three included angles can be the same, and the other included angle can be different (β1=β2≠β3). This allows each straightening edge to make intermittent contact with the well wall and cut the formation, ensuring the reliability and stability of the tool. This, in turn, helps to repair the reduced diameter section, the thick mud cake, and the section where the plugging material adheres, ensuring wellbore safety.

[0051] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A bidirectional tool for drilling operations with offset and variable diameter, characterized in that: The tool body (1) has multiple offset edges (2) unevenly distributed along the circumferential direction on its outer surface. The offset edges (2) are elongated structures and are arranged along the axial direction of the tool body (1). A flow channel (6) is provided between adjacent offset edges (2). The heights of the multiple offset edges (2) in the radial direction of the tool body (1) are inconsistent. An upper slope (4) and a lower slope (3) are provided at both ends of the elongated structure of the offset edges (2). The upper slope (4) and the lower slope (3) form a pointed cone structure along the direction away from the offset edges (2).

2. The drilling operation offset variable diameter bidirectional tool according to claim 1, characterized in that: The offset edge (2) is spirally arranged along the axis of the tool body (1).

3. The drilling operation offset variable diameter bidirectional tool according to claim 1, characterized in that: The offset edge (2) is set vertically along the axis of the tool body (1).

4. The drilling operation offset variable diameter bidirectional tool according to claim 1, characterized in that: Cutting teeth (5) are arranged on the upper slope (4) and the lower slope (3), respectively.

5. The drilling operation offset variable diameter bidirectional tool according to claim 4, characterized in that: The cutting teeth (5) are planar teeth, galloping teeth, or ridge teeth.

6. The drilling operation offset variable diameter bidirectional tool according to claim 5, characterized in that: The cutting teeth (5) are made of diamond or cubic boron nitride.

7. The drilling operation offset variable diameter bidirectional tool according to claim 1, characterized in that: The upper slope (4) and lower slope (3) are vertically arranged along the axis of the tool body (1).

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