An eccentric spherical PDC micro-expander for oil drilling

Abstract

The utility model discloses an eccentric spherical PDC micro reamer for oil drilling, which comprises a drill body, a female buckle and a male buckle connected to the two sides of the drill body, and further comprises two symmetrical sets of upper and lower blade wing assemblies, wherein the symmetrical blade wing assemblies comprise pilot blade wings and reaming blade wings, four pilot blade wings are installed on one side of the drill body, 10 pieces of 13mm PDC teeth and 66 pieces of 12mm hard alloy chisel teeth are installed on the pilot blade wings, four reaming blade wings are arranged, the four reaming blade wings are arranged on the other side of the drill body, and the reaming blade wings are eccentric reaming blade wings. The eccentric spherical PDC micro reamer for oil drilling is designed with a small eccentricity, the tool reaming range is less than 12.7mm, the safety of the drill string is ensured, and when the horizontal well is operated, the two sets of upper and lower blade wings are designed in an eight-character shape in the rotation direction of the wellbore axis, which can effectively stir the well bottom silt, is conducive to chip removal, is suitable for reaming and reverse reaming working conditions, improves the wellbore cleaning capacity, and thus reduces the risk of sticking.

Description

Technical Field

[0001] This utility model relates to the field of PDC micro-reamer technology, specifically to an eccentric spherical PDC micro-reamer used in oil drilling. Background Technology

[0002] Oil drilling, which usually refers to oil well drilling, is a key link in the process of oil and gas exploration and development. Its core is to drill deep holes on the surface using specialized equipment and technology to establish a passage from underground oil and gas reservoirs to the surface. The downhole tools used for oil drilling can be selected according to the formation, such as roller cone bits (hard rock), PDC bits (medium-hard formations), and diamond bits (ultra-hard formations). Among them, PDC micro-reaming mainly utilizes the high hardness, high wear resistance, and good cutting performance of polycrystalline diamond composite (PDC) to carry out small-scale enlargement operations on the wellbore. In existing technologies, stuck pipe is prone to occur during directional horizontal well operations. Therefore, to reduce the risk of stuck pipe, we propose an eccentric spherical PDC micro-reamer for oil drilling. Through the micro-eccentric design, the reaming range of the tool is controlled to be less than 12.7mm, and the torque increase during tool operation can be controlled to not exceed 30% of that in conventional operations, ensuring drill string safety. At the same time, during horizontal well operations, the upper and lower sets of blades are designed in a figure-eight shape in the rotation direction of the wellbore axis, which can effectively agitate the sediment at the bottom of the well, which is conducive to cuttings removal. It is suitable for reaming and reverse reaming operations, improves the wellbore cleaning ability, and thus helps to reduce the risk of stuck pipe. Summary of the Invention

[0003] (a) Technical problems to be solved To address the shortcomings of existing technologies, this utility model provides an eccentric spherical PDC microreamer for oil drilling, which solves the problem of stuck drill bits during directional horizontal well operations mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: An eccentric spherical PDC micro-reamer for oil drilling includes a drill body, with female and male threads connected to both sides of the drill body, and two sets of symmetrical cutter wing assemblies. The symmetrical cutter wing assembly includes a pilot cutter wing and a reaming cutter wing. There are four pilot cutter wings, all of which are installed on one side of the drill body. Each pilot cutter wing is equipped with 10 13mm PDC teeth and 66 12mm carbide shaped teeth. There are also four reaming cutter wings, all of which are located on the other side of the drill body. The reaming cutter wings are eccentric and are equipped with 18 13mm PDC teeth and 42 12mm carbide shaped teeth.

[0005] Furthermore, the upper and lower symmetrical blade assemblies are designed in a figure-eight shape, with PDC teeth and carbide shaped teeth installed on the inclined surface and the gauge.

[0006] Furthermore, the micro-eccentric design has an eccentricity of 6%, a bore diameter of 213 mm, and an eye diameter of 226 mm.

[0007] Furthermore, the length of the female connector body is greater than 500mm.

[0008] Furthermore, a flaw detection assembly can be detachably installed on the drill body, the flaw detection assembly comprising: A retaining sleeve, which is detachably connected to one side of the male buckle; A drive rod, which is rotatably connected between the fixed sleeve and the drill body; A drive cylinder, which is slidably mounted on the drive rod; A positioning rod is connected through the drive rod, and two sliding grooves for sliding the positioning rod are symmetrically opened on the inner side wall of the drive cylinder. The positioning groove is provided in multiple ways, and the array of multiple positioning grooves is formed between two sliding grooves; A flaw detector, which is detachably mounted on one side of the drive cylinder.

[0009] Furthermore, an elastic pad is fixedly connected inside the fixing sleeve, and a fixing groove matching the male buckle is formed on the elastic pad.

[0010] Furthermore, a mounting plate is detachably connected to the drive cylinder, and the flaw detector is mounted on the mounting plate. Two mounting blocks are symmetrically connected to the mounting plate, and each mounting block is threadedly connected to the mounting plate with mounting screws.

[0011] Furthermore, a drive plate is fixedly connected to one side of the drive rod, and multiple drive protrusions are arranged in a circumferential array on the drive plate.

[0012] Compared with the prior art, this utility model provides an eccentric spherical PDC microreamer for oil drilling, which has the following advantages: 1. In this utility model, the oil drill uses an eccentric spherical PDC micro-reamer. The eccentricity of the micro-eccentric design is controlled at about 6%. The bore diameter is 213mm and the reaming diameter is 226mm, which is suitable for working in a 216mm wellbore. At the same time, under appropriate rotation conditions, the reamer blades can rotate around the tool center to slightly enlarge the wellbore diameter to 226mm. Moreover, the torque is controllable during the reaming process, the drill string is safe, and the drilling efficiency is high, thus achieving the purpose of micro-reaming and making it easier to meet different needs such as casing running and cementing. 2. In this utility model, the figure-eight symmetrical design of the upper and lower symmetrical blade assemblies, PDC teeth and carbide shaped teeth can efficiently cut the well wall, while also facilitating the protection of the blade body. 3. In this utility model, the oil drill adopts the sinking blade design of the eccentric spherical PDC micro-reamer. The diameter of the reaming part is 150mm and the diameter of the joint part is 168mm. Compared with the prior art, it is easier to increase the chip removal space and improve the wellbore cleaning ability, thereby reducing the risk of stuck drill during directional horizontal well operations. 4. In this utility model, the flaw detection component facilitates timely detection of internal damage to the drill body, thereby improving the service life of the eccentric spherical PDC micro-reamer used in the oil drill. 5. Therefore, this oil drill uses an eccentric spherical PDC microreamer, with carbide-coated teeth protecting the body on the blade section. It has advantages in eliminating steps and doglegs, improving wellbore smoothness and drilling efficiency. The bidirectional figure-eight symmetrical design can be applied to reaming and reverse reaming conditions, improving wellbore cleaning ability, thereby reducing the risk of stuck drill in directional horizontal well operations. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this application; Figure 2 For this application Figure 1 A magnified schematic diagram of the local structure at point A; Figure 3 A schematic diagram of the planar structure for the micro-eccentric design of this application; Figure 4 This is a schematic diagram of the planar structure of the drill body, female thread, and pilot cutter wing in this application. Figure 5 This is a cross-sectional structural diagram showing the cooperation of the drive rod, drive cylinder, and positioning rod in this application; Figure 6 This is a schematic diagram of the structure of the fixing sleeve and elastic pad in this application.

[0014] In the diagram: 1. Drill body; 2. Female thread; 3. Male thread; 4. Pilot cutter wing; 5. Reamer wing; 6. Fixing sleeve; 7. Drive rod; 8. Drive cylinder; 9. Positioning rod; 10. Flaw detector; 11. Elastic pad; 12. Mounting plate; 13. Mounting block; 14. Mounting screw; 15. Drive plate. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] Please see Figures 1 to 6 An oil drill employs an eccentric spherical PDC micro-reamer, comprising a drill body 1, with female and male threads 2 and 3 respectively connected to its two sides. It also includes two sets of symmetrical cutter wing assemblies, each comprising a pilot cutter wing 4 and a reaming cutter wing 5. Four pilot cutter wings 4 are mounted on one side of the drill body 1, each equipped with 10 13mm PDC teeth and 66 12mm carbide shaped teeth. Four reaming cutter wings 5 ​​are located on the other side of the drill body 1. These reaming cutter wings are eccentric and equipped with 18 13mm PDC teeth and 42 12mm carbide shaped teeth. The two sets of symmetrical cutter wing assemblies are designed in a figure-eight shape, with PDC teeth and carbide shaped teeth mounted on both the inclined surface and the gauge surface. Carbide-coated teeth and PDC teeth are placed in front of the cutter wing. Multiple cutting teeth can fully cover the reaming area, ensuring smooth reaming. Carbide-coated teeth are installed behind the PDC teeth or on the gauge, which can protect the cutter wing body and thus efficiently cut the well wall (usually 8-14mm diameter cutting teeth are selected, and cutting teeth with too large a diameter are not selected. Carbide-coated teeth (10-14mm diameter) on the gauge part have a micro-cutting effect, which can make the contact between the gauge and the well wall smooth, with less resistance and reduced torque fluctuation). In addition, the sinking cutter wing design has a reaming part body diameter of 150mm and a joint part diameter of 168mm, which effectively increases the chip removal space. The micro-eccentric design has an eccentricity of 6%, a nominal diameter of 213mm, and a reaming diameter of 226mm. This oil drill uses an eccentric spherical PDC micro-reamer. The micro-eccentric design controls the eccentricity to about 6% in small wellbore conditions. The bore diameter is 213mm and the reaming diameter is 226mm, which is suitable for working in 216mm wellbore. Under appropriate rotation, the reamer blades can rotate around the tool center to slightly enlarge the wellbore diameter to 226mm. The torque is controllable during the reaming process, the drill string is safe, and the drilling efficiency is high, achieving the purpose of micro-reaming and meeting the needs of subsequent casing running and cementing. It should be further explained that the variable connection design of the female thread 2 and male thread 3 is usually NC50 thread, with a total tool length of 1500mm to 3000mm. The male thread 3 end has sufficient length, and customers can also process the connecting thread themselves as needed after arriving on site. This ensures two opportunities to change the thread to adapt to different drill string combinations on site. The upper female thread 2 connector body length is greater than 500mm, leaving sufficient retrieval length. When there are complex well bottoms, there is space for thread making and retrieval, ensuring safety (usually the lower male thread 3 and the upper female thread 2. In special cases, the male thread 3 needs to be changed to the female thread 2 on site). Moreover, the variable connection design adopts a one-piece design of 4145H alloy steel, which is stronger than the strength of the drill pipe connected to it, adapting to high torque operations and enhancing safety.

[0017] refer to Figure 1 , Figure 2 , Figure 5 as well as Figure 6 A flaw detection assembly can be detachably installed on the drill body 1. The flaw detection assembly includes a fixed sleeve 6, a drive rod 7, a drive cylinder 8, a positioning rod 9, a positioning groove, and a flaw detector 10. The fixed sleeve 6 is detachably connected to one side of the male thread 3. An elastic pad 11 is fixedly connected inside the fixed sleeve 6. The elastic pad 11 has a fixing groove that matches the male thread 3, which facilitates the quick installation and removal of the fixed sleeve 6 and drive rod 7 on the male thread 3. Thus, the flaw detection assembly can be quickly installed and removed on the drill body 1. The drive rod 7 is rotatably connected between the fixed sleeve 6 and the drill body 1. A drive plate 15 is fixedly connected to one side of the drive rod 7. The drive plate 15 has multiple drive protrusions arranged in a circumferential array to facilitate the rotation, pushing, and pulling of the drive rod 7. The drive cylinder 8 is slidably fitted on the drive rod 7 for positioning. Rod 9 is connected to drive rod 7. Two sliding grooves for sliding of positioning rod 9 are symmetrically opened on the inner side wall of drive cylinder 8. Multiple positioning grooves are arranged in an array between the two sliding grooves. Flaw detector 10 is detachably installed on one side of drive cylinder 8. Mounting plate 12 is detachably connected to drive cylinder 8. Flaw detector 10 is installed on mounting plate 12. Two mounting blocks 13 are symmetrically connected to mounting plate 12. Mounting screws 14 are threaded between mounting blocks 13 and mounting plate 12. By turning the mounting screws 14 between mounting blocks 13 and mounting plate 12, mounting plate 12 and mounting blocks 13 can be connected and disassembled, which facilitates the installation and disassembly of flaw detector 10 on drive rod 7, and the replacement and maintenance of flaw detector 10. When it is necessary to inspect the inside of the drill body 1, the flaw detector 10, drive cylinder 8, and drive rod 7 are inserted into the drill body 1, and the fixing sleeve 6 is installed on the male thread 3. Then, the drill body 1 is tilted so that the flaw detector 10 and drive cylinder 8 move bufferedly inside the drill body 1 under gravity. At the same time, the positioning rod 9 will also move stably between the two sliding grooves, so that the flaw detector 10 can stably inspect the inside of the drill body 1. When the flaw detector 10 moves to a suitable position and needs to be fixed, the drive rod 7 is rotated so that the positioning rod 9 rotates into the corresponding positioning groove, so that the positions of the positioning rod 9 and the drive rod 7 can be fixed, thereby fixing the positions of the drive cylinder 8 and the flaw detector 10.

[0018] In summary, this oil drill uses an eccentric spherical PDC micro-reamer. Through its micro-eccentric design, the tool's reaming range is controlled to be less than 12.7mm. The torque increase during tool operation can be controlled to not exceed 30% of that in conventional operations, ensuring drill string safety. Furthermore, the borehole diameter is smaller than the working well diameter. It gradually enters the cutting state through four pilot blades and utilizes four large eccentric reaming blades to achieve a micro-reaming effect. The upper and lower blades are symmetrically designed, with PDC teeth installed on the inclined surface and gauge, making it suitable for reaming and reverse reaming operations. It uses both hydraulic and mechanical action to destroy and remove cuttings beds. In horizontal well operations, the upper and lower blades are designed in a figure-eight shape in the rotation direction of the wellbore axis, which can effectively agitate the sediment at the bottom of the well, which is beneficial for cuttings removal. At the same time, the sinking blade design, with the reaming part body smaller than the joint body, effectively increases the cuttings removal space, reduces mud flow resistance, and improves cuttings removal efficiency and wellbore cleaning ability. Meanwhile, the oil drill uses an eccentric spherical PDC microreamer, with carbide-coated teeth protecting the body on the blade wing. It has advantages in eliminating steps and doglegs, improving wellbore smoothness and drilling efficiency. The bidirectional figure-eight symmetrical design can be used for reaming and reverse reaming operations, improving wellbore cleaning ability, thereby reducing the risk of stuck drill in directional horizontal well operations.

[0019] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An oil drill using an eccentric spherical PDC micro-reamer, employing a micro-eccentric design, comprising a drill body (1), wherein a female thread (2) and a male thread (3) are respectively connected to both sides of the drill body (1), characterized in that, It also includes two sets of symmetrical blade wing assemblies, one above the other, wherein the symmetrical blade wing assemblies include: The pilot blade (4) is configured as four, and all four pilot blades (4) are installed on one side of the drill body (1). The pilot blades (4) are equipped with 10 13mm PDC teeth and 66 12mm carbide shaped teeth. The reaming blade (5) is configured as four blades, all of which are located on the other side of the drill body (1). The reaming blade (5) is equipped with 18 13mm PDC teeth and 42 12mm carbide shaped teeth.

2. The oil drilling tool using an eccentric spherical PDC microreamer according to claim 1, characterized in that, The upper and lower symmetrical blade assemblies are designed in a figure-eight shape, with PDC teeth and carbide shaped teeth installed on the inclined surface and the gauge.

3. The oil drilling tool using an eccentric spherical PDC microreamer according to claim 1, characterized in that, The micro-eccentric design has an eccentricity of 6%, a bore diameter of 213 mm, and an eye diameter of 226 mm.

4. The oil drilling tool using an eccentric spherical PDC microreamer according to claim 3, characterized in that, The length of the female buckle (2) connector body is greater than 500mm.

5. The oil drilling tool using an eccentric spherical PDC microreamer according to claim 4, characterized in that, A flaw detection assembly can also be detachably installed on the drill body (1), the flaw detection assembly including: A fixing sleeve (6) is detachably connected to one side of the male buckle (3); Drive rod (7), which is rotatably connected between the fixed sleeve (6) and the drill body (1); A drive cylinder (8) is slidably mounted on the drive rod (7); Positioning rod (9), which is connected through the drive rod (7), and two sliding grooves for sliding the positioning rod (9) are symmetrically opened on the inner side wall of the drive cylinder (8); The positioning groove is provided in multiple ways, and the array of multiple positioning grooves is formed between two sliding grooves; Flaw detector (10), which is detachably mounted on one side of the drive cylinder (8).

6. The oil drilling tool using an eccentric spherical PDC microreamer according to claim 5, characterized in that, An elastic pad (11) is fixedly connected inside the fixed sleeve (6), and a fixing groove matching the male buckle (3) is provided on the elastic pad (11).

7. The oil drilling tool using an eccentric spherical PDC microreamer according to claim 6, characterized in that, The drive cylinder (8) is detachably connected to a mounting plate (12), the flaw detector (10) is mounted on the mounting plate (12), and two mounting blocks (13) are symmetrically connected on the mounting plate (12). Both mounting blocks (13) are threadedly connected to the mounting plate (12) with mounting screws (14).

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