Drilling tool combination for casing windowing sidetrack drilling

Abstract

The utility model discloses a casing windowing sidetrack drilling tool combination which comprises a PDC drill bit connected to the lower end of a single-bend screw drill, a centralizer, a directional connector and a non-magnetic drill collar are connected to the upper end of a screw in a screwed mode, a wireless MWD directional device is installed in an inner cavity of the non-magnetic drill collar, and a weighting rod is connected to the upper end of the non-magnetic drill collar. The middle section of the single-bend screw drill is provided with a bend-adjustable shell, the bend-adjustable shell comprises a bend-adjustable upper shell body, a double-male-bend connector, a sliding lock sleeve and a bend-adjustable lower shell body, an included angle is formed between thread axes of the two ends of the double-male-bend connector, and the sliding lock sleeve is arranged on the periphery of the middle section of the double-male-bend connector in a sleeving mode and located in the radial direction through a flat key. The lower end of the double-male-bend connector is screwed in female threads at the upper end of the bend-adjusting lower shell, and the axes of the female threads at the upper end and the lower end of the bend-adjusting lower shell also form an included angle; reaming cutting teeth are welded to the outer wall of the sliding lock sleeve and the outer wall of the bending adjusting lower shell correspondingly. The drilling tool can be used for reaming, the service time of single drilling is long, the drilling speed is high, the tripping frequency can be reduced, and the drilling period is shortened.

Description

Technical Field

[0001] The utility model relates to a sidetracking downhole drilling tool, in particular to a casing window sidetracking drilling tool assembly, and belongs to the technical field of sidetracking tools. Background Art

[0002] In the later stages of oilfield production, if casing damage and other factors render the original well inoperable, drilling additional or new wells significantly increases production costs and, in many cases, involves land acquisition and other expenses and approvals. Running a small casing (also known as a liner) in the original well casing, or creating a window in the original well casing to sidetrack a new hole and then run the small casing, can utilize existing surface infrastructure, reduce construction costs, recover the remaining oil between wells, and give abandoned wells a new lease of life. This approach offers low investment, rapid results, and significant economic benefits. Countries around the world attach great importance to the research and application of this technology, which has become a key tool in many oilfield exploration and development efforts to re-evaluate mature oilfields, increase reserves and production, and enhance ultimate recovery. It demonstrates broad development prospects and widespread application value. Therefore, research into sidetracking technologies to accelerate and improve the efficiency of sidetracking operations and enable early production is crucial.

[0003] Oilfield sidetracking techniques primarily include casing windowing, MWD directional drilling, composite drilling, and subsequent electrical logging and casing cementing. After successful windowing, drilling is often performed using a Φ118 single-cone drill bit / 5-blade PDC + Φ95mm single-bend screw drill bit + Φ89mm non-magnetic drill collar + Φ48mm wired MWD directional tool. This drill tool combination presents the following issues:

[0004] 1. The upper end of the non-magnetic drill collar is a female buckle, and the lower end is a male buckle. The annular space gap between the Φ89mm non-magnetic drill collar and the Φ48mm wired MWD directional tool is only 3mm. The annular space pressure loss is large, the pump pressure during sidetracking construction is high, and the mud pump is easily damaged, which increases the time for drilling and pump repair, affecting the construction time.

[0005] 2. In this drill string assembly, the battery life of the MWD directional tool is 270-300 hours, the safe use time of the single-cone drill bit is 100 hours, and the effective use time of the single-bend screw drill tool is 120 hours. The most significant impact on service life is that the single-cone drill bit and the single-bend screw drill tool have a limited safe use life. Generally, the drill bit and screw need to be pulled out of the hole and replaced after about 100 hours, which limits production efficiency and benefits. After pulling out of the hole, tools that have not reached the end of their life must also be replaced to delay the next pull-out. Therefore, the mismatch in tool life also results in significant waste and increases drilling costs.

[0006] 3. If a 5-blade PDC drill bit is used, there are problems such as difficulty in controlling the tool face during directional construction, difficulty in orientation, easy mud packing of the drill bit, and frequent drilling. Utility Model Content

[0007] The purpose of the utility model is to overcome the problems existing in the prior art and provide a casing window side drilling drill tool combination, which can expand the aperture of the side drilling wellbore, increase the annular space gap between the non-magnetic drill collar and the directional instrument, reduce the circulating pressure loss, extend the use time of a single drilling trip, increase the drilling speed, reduce the number of drilling and drilling, and shorten the drilling cycle.

[0008] The PDC drill bit is a very powerful tool used in drill rigs, but it is not as versatile as the PDC drill itself, so it is a great choice for those looking to drill deeper and deeper into rock or rock formations. The PDC drill bit is made up of several pieces of wood, which can be used to drill deeper and deeper into the rock or rock foundation. The PDC drill bit is made up of several pieces of wood, which can be used to drill deeper and deeper into the rock foundation. The PDC drill bit is a very powerful tool used in drill rigs, but it is not as versatile as the PDC drill bit. A bending joint, a sliding locking sleeve and a bending adjustment lower shell. The male thread at the upper end of the bending adjustment upper shell is connected to the motor shell of the single-bend screw drill. The thread axes at both ends of the double male bending joint have an angle of 1.5°. The upper end of the double male bending joint is screwed into the female thread at the lower end of the bending adjustment upper shell. The sliding locking sleeve is sleeved on the outer periphery of the middle section of the double male bending joint and is radially positioned by a flat key. The lower end of the double male bending joint is screwed into the female thread at the upper end of the bending adjustment lower shell. The female thread axes at the upper and lower ends of the bending adjustment lower shell also have an angle of 1.5°. The outer walls of the sliding locking sleeve and the bending adjustment lower shell are respectively welded with reaming cutting teeth.

[0009] As an improvement of the present invention, hole-reaming cutting teeth are welded to the outer wall of the lower end of the bending adjustment upper shell.

[0010] As a further improvement of the present invention, the reaming cutting teeth are cylindrical tungsten steel sheets with a diameter of 9 mm and a height of 10-13 mm.

[0011] As a further improvement of the present invention, the outer diameter of the non-magnetic drill collar is 102 mm, the inner diameter is 60 mm, and both the upper and lower ends are female buckles. The lower end of the non-magnetic drill collar is screwed to the upper end of the directional joint through a double male joint.

[0012] As a further improvement of the present invention, both upper and lower ends of the non-magnetic drill collar are 210-type female buckles, and the double male connector is a 211×211 double male connector.

[0013] As a further improvement of the present invention, the outer diameter of the wireless MWD direction finder is 48 mm, the outer diameter of the weighted rod is 89 mm, and the inner diameter is 54.6 mm.

[0014] When the closure is opened, the closure is opened and the closure is opened, and the closure is opened by the spring, and the closure is opened by the spring. When the closure is opened, the closure is opened and the closure is opened, and the closure is opened and the closure is opened. When the closure is opened, the closure is opened and the closure is opened, the closure is opened.

[0015] As a further improvement of the present invention, the lower end of the bypass valve outer cylinder is screwed onto an anti-drop outer cylinder, and the lower end of the anti-drop outer cylinder is screwed onto a motor outer cylinder, and the inner cavity of the motor outer cylinder is provided with a motor rotor; the middle section of the inner cavity of the anti-drop outer cylinder is provided with an anti-drop outer cylinder reducing section, and the middle section of the anti-drop shaft passes through the center hole of the anti-drop outer cylinder reducing section, and the lower end of the anti-drop shaft is provided with an anti-drop shaft expanding section and is screwed onto the upper end of the motor rotor, and the upper end of the anti-drop shaft is screwed onto a mushroom head nut, and the outer diameters of the mushroom head nut and the anti-drop shaft expanding section are larger than the inner diameter of the anti-drop outer cylinder reducing section.

[0016] As a further improvement of the present invention, the PDC drill bit includes a drill head upper body and a drill head lower body with a coaxial axis and a center hole passing through the drill head. The upper part of the drill head lower body is provided with a drill head lower body boss, and the drill head lower body boss is embedded in the countersunk hole of the drill head upper body. A pulse generator is embedded in the center hole of the drill head upper body, and a pulse oscillation cavity is provided along the axis of the pulse generator. The pulse oscillation cavity includes a conical bell mouth, a water inlet throat, an expanded diameter resonance cavity and a pulse outflow channel from top to bottom. The upper end of the expanded diameter resonance cavity is connected to the lower end of the water inlet throat by a chamfer, and the lower end of the expanded diameter resonance cavity is connected to the upper end of the pulse outflow channel by a chamfer. The water inlet throat and the pulse outflow channel are both cylindrical; the lower part of the center hole of the drill head lower body is provided with a diversion cavity with a downward conical expansion, and the lower part of the drill head lower body is provided with a blade, and water holes are respectively provided between adjacent blades. The inner end of each water hole is respectively communicated with the diversion cavity, and a nozzle is respectively installed in each water hole.

[0017] As a further improvement of the present invention, the middle section of the pulse generator is provided with a pulse generator outer boss, the upper shoulder of the pulse generator outer boss abuts against the inner step under the center hole of the upper body of the drill bit, the lower shoulder of the pulse generator outer boss abuts against the top of the lower body boss of the drill bit, and the lower part of the pulse generator is inserted into the center hole of the lower body of the drill bit.

[0018] As a further improvement of the present invention, the diameter of the water inlet throat is the same as the diameter of the pulse outflow channel, the aspect ratio of the pulse outflow channel is (1.8~2):1, and the diameter of the expanded diameter resonant cavity is 1.78 times the diameter of the water inlet throat.

[0019] As a further improvement of the present invention, the distance between the bottom of the blade and the water outlet is greater than 10 mm.

[0020] Compared with the existing technology, the utility model has achieved the following beneficial effects: 1. By welding the hole-reaming cutting teeth on the outer wall of the bend section of the single-bend screw drill, the side drilling wellbore diameter can be expanded by 13-20% while ensuring the smooth entry of the drill assembly into the well, which facilitates the smooth running of small casing and tools into the well and increases the thickness of the cement sheath;

[0021] 2. The problem of unstable tool face and difficult orientation during directional construction of 5-blade PDC drill bits has been solved. The PDC drill bit has a stronger attack on the formation, the tool face is more stable during directional construction, orientation is easier, and the drill bit is less likely to be mud-filled.

[0022] 3. The annular space between the non-magnetic drill collar and the MWD instrument is increased, which reduces the circulating pressure loss and realizes low pump pressure drilling, causing less damage to the directional tool and equipment, extending the service life of the mud pump wearing parts and reducing the pump maintenance time;

[0023] 4. PDC drill bits are used to replace single-cone drill bits. The pulse generator is designed according to the drill bit size and hydraulic parameters. The key structure and size of the expanded diameter resonant cavity are determined based on repeated verification. The shape of the expanded diameter resonant cavity is easier to process, reducing the scrap rate while maintaining a large amplitude of the pulse excitation. It is easy to accurately control the size and structure of the pulse oscillation cavity during processing. When the size of the pulse oscillation cavity needs to be changed, it is only necessary to replace the pulse generator before assembling the upper and lower drill bits. There is no need to replace the upper and lower drill bits as a whole, which reduces production costs.

[0024] 5. The service life of the PDC drill bit is up to 500 hours, the safe service life of the single-bend screw drill is more than 300 hours, and the battery life of the MWD directional instrument is 270-300 hours. The single-trip well usage time of this drill bit combination has been increased from about 100 hours to more than 250 hours, which is 2.5 times the single-trip well usage time of conventional drill tools. This reduces the number of trips and drilling, shortens the drilling cycle, and improves construction efficiency by more than 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The accompanying drawings are only provided for reference and illustration and are not intended to limit the present invention.

[0026] Figure 1This is a structural diagram of the casing window sidetracking drill assembly of the utility model;

[0027] Figure 2 This is a schematic structural diagram of the single-bend screw drill tool in the utility model;

[0028] Figure 3 This is a cross-sectional view of the bypass valve and anti-drop assembly in a single-bend screw drilling tool;

[0029] Figure 4 It is a cross-sectional view of the adjustable bending housing in the single-bend screw drilling tool;

[0030] Figure 5 It is a cross-sectional view of the PDC drill bit in the present utility model.

[0031] In the figure: A. PDC drill bit; B. Single-bend screw drill tool; C. Stabilizer; D. Directional joint; E. Double male joint; F. Non-magnetic drill collar; G. Weight rod; H. Drill pipe;

[0032] 1. Bypass valve; 1a. Bypass valve outer tube; 1a1. Bypass hole in outer tube; 1b. Valve core; 1b1. Radial hole in valve core; 1c. Spring; 1d. Valve sleeve; 1e. Retaining ring;

[0033] 2. Anti-drop assembly; 2a. Anti-drop outer cylinder; 2b. Anti-drop shaft; 2c. Mushroom nut;

[0034] 3. Motor; 3a. Motor outer cylinder; 3b. Motor rotor;

[0035] 4. Adjustable bending housing; 4a. Adjustable upper housing; 4b. Double male bend joint; 4c. Adjustable lower housing; 4d. Sliding locking sleeve; 4e. Reaming cutting teeth;

[0036] 5. Universal joint assembly; 6. Drive shaft assembly;

[0037] 7a. Drill bit upper body; 7b. Pulse generator; 7b1. Conical bell mouth; 7b2. Water inlet throat; 7b3. Expanded diameter resonant cavity; 7b4. Pulse outflow channel; 7b5. Pulse generator outer boss; 7c. Drill bit lower body; 7c1. Drill bit lower body boss; 7c2. Diverter cavity; 7d. Blade; 7e. Nozzle. DETAILED DESCRIPTION

[0038] In the following description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not mean that the device must have a specific direction.

[0039] like Figure 1As shown, the casing window side drilling drill tool assembly of the present invention includes a PDC drill bit A connected to the lower end of a single-bend screw drill tool B, the upper end of the single-bend screw drill tool B is screwed with a stabilizer C, the upper end of the stabilizer C is screwed with a directional joint D, the upper end of the directional joint D is connected to a non-magnetic drill collar F through a double male joint E, the inner cavity of the non-magnetic drill collar F is installed with an MWD directional instrument, the upper end of the non-magnetic drill collar F is connected to a weight rod G, and the upper end of the weight rod G is connected to a drill pipe H.

[0040] The non-magnetic drill collar F is custom-made by the manufacturer, with an increased outer diameter of Φ102mm and an inner diameter expanded from 54.6mm to 60mm. The annular clearance between the drill collar and the Φ48mm MWD directional tool has been increased from 3mm to 6mm. This reduces circulating pressure loss by approximately 5.5MPa, extending the service life of mud pump consumables and reducing tripping and pump repair time. To ensure that the thickness and strength of the connecting thread do not change significantly, the male connector at the bottom of the non-magnetic drill collar F has been removed. Both ends are machined with 210 female connectors. A 211×211 double male connector is installed at the bottom for connection to the directional connector D.

[0041] The weight rod G is an integral Φ89mm outer diameter and 54.6mm inner diameter, purchased from the drilling tool manufacturer. The directional joint D is a conventional directional joint, the centralizer C is a conventional centralizer, and the single-bend screw drilling tool B is a long-life, high-torque screw drilling tool.

[0042] The diameter of the PDC drill bit A is 118 mm, the outer diameter of the single-bend screw drill tool B is 95 mm, and the upper end of the weight rod G is connected to the 73 mm drill rod.

[0043] The wireless MWD directional tool has an outer diameter of Φ48mm, which is significantly smaller than the outer diameter of the wired MWD directional tool. This increases the annular space gap between the drill collar and the tool to 6mm, greatly reducing the circulating pressure loss.

[0044] The drilling tool assembly is lowered into the wellbore, connected to the upper drill pipe, and the mud pump is started to establish positive circulation. The displacement is increased to 8-10L / s and the drilling pressure is 10-40KN. The driller operates the brake handle according to the changes in the drilling pressure and the tool face to carry out directional drilling construction, or the rotary table is started and the drilling pressure is 5-20KN. The driller operates the brake handle according to the changes in the drilling pressure to carry out composite drilling construction.

[0045] like Figure 2 、 Figure 3 As shown, the single-bend screw drilling tool B includes, from top to bottom, a bypass valve 1, an anti-drop assembly 2, a motor 3, a universal joint assembly 5, and a transmission shaft assembly 6. The universal joint assembly 5 is located in an adjustable bending housing 4. The bypass valve 1 is arranged above the motor 3.

[0046] The bypass valve 1 includes a bypass valve outer tube 1a, a valve core 1b is provided in the middle of the central hole of the bypass valve outer tube 1a, the top of the valve core 1b is supported under the inner step in the middle of the bypass valve outer tube 1a, and a spring 1c is supported under the outer step of the valve core 1b. The lower end of the spring 1c is supported on the top of the valve sleeve 1d, and the lower part of the valve sleeve 1d is provided with a valve sleeve convex ring, which abuts under the lower inner step of the bypass valve outer tube 1a. The bottom of the valve sleeve 1d abuts on the retaining ring 1e, and the retaining ring 1e is embedded in the inner wall annular groove of the bypass valve outer tube 1a; a plurality of valve core radial holes 1b1 are evenly distributed on the lower circumference of the valve core 1b, and the lower end of the valve core 1b is inserted into the inner cavity of the valve sleeve 1d.

[0047] The bypass valve's outer tube 1a is symmetrically circumferentially arranged with multiple outer tube bypass holes 1a1. The inner end of each outer tube bypass hole 1a1 communicates with the annular space surrounding the valve core 1b. An enlarged countersunk hole is located at the outer end of each outer tube bypass hole 1a1. A filter cap, uniformly provided with multiple small holes, is mounted on the outer end of the countersunk hole.

[0048] When drilling, the outer tube bypass hole 1a1 and the valve core radial hole 1b1 are in a through-state. The drilling fluid in the wellbore enters the inner cavity of the bypass valve outer tube 1a from the outer tube bypass hole 1a1, and then enters the valve core center hole from the valve core radial hole 1b1. The drilling fluid in the wellbore is introduced into the drill pipe through the outer tube bypass hole 1a1, reducing the resistance during the drilling process and balancing the liquid column pressure inside and outside the drill pipe.

[0049] When drilling, the drilling fluid in the drill pipe flows into the casing annulus through the outer tube bypass hole 1a1, so that the drilling fluid will not overflow on the well platform, which is beneficial to protecting the environment.

[0050] When the drilling tool is working, high-pressure drilling fluid pushes the valve core 1b downward, compressing the spring 1c, and the radial hole 1b1 of the valve core enters the valve sleeve 1d and is closed; all the drilling fluid flows through the motor 3, which converts the pressure energy into mechanical energy.

[0051] The housing of the anti-drop assembly 2 is screwed onto the bottom of the bypass valve 1. Its primary function is to prevent the stator housing from breaking and disengaging due to abnormal reasons, thereby preventing single-bend screw drill bits from falling into the well and avoiding downhole accidents. The anti-drop assembly 2 comprises an anti-drop outer cylinder 2a, an anti-drop shaft 2b, and a mushroom nut 2c. The lower end of the bypass valve outer cylinder is screwed onto the anti-drop outer cylinder 2a, which is screwed onto the motor outer cylinder. The motor outer cylinder has a motor rotor within its inner cavity. The middle section of the inner cavity of the anti-drop outer cylinder 2a is provided with an anti-drop outer cylinder reduced diameter section. The middle section of the anti-drop shaft 2b passes through the center hole of the anti-drop outer cylinder reduced diameter section. The lower end of the anti-drop shaft 2b is provided with an anti-drop shaft expanded diameter section, which is screwed onto the upper end of the motor rotor. The upper end of the anti-drop shaft 2b is screwed onto the mushroom nut 2c. The outer diameters of the mushroom nut 2c and the anti-drop shaft expanded diameter section are greater than the inner diameter of the anti-drop outer cylinder reduced diameter section.

[0052] Motor 3 comprises a motor outer cylinder 3a and a motor rotor 3b. A vulcanized rubber stator with a spiral inner cavity is housed within motor outer cylinder 3a. Motor rotor 3b is also spiral and mates with each other within motor outer cylinder 3a. The rotor and stator form a series of continuous, unconnected spiral sealing lines along the axial direction, forming a sealed chamber for the power section. When sufficient pressure is applied, mud enters the chamber, where its hydraulic energy is converted into mechanical energy, generating a torque on the rotor's spiral surface, forcing the rotor to move within the stator. The chamber then shifts axially, with energy constantly generated and dissipated, completing the energy conversion process. Drilling fluid pumped from the mud pump flows through bypass valve 1 and into the screw, creating a pressure differential between the screw's inlet and outlet, driving the screw's rotation and transmitting torque and speed to the drill bit via the universal joint and drive shaft.

[0053] like Figure 4 As shown, the outer shell of the universal joint assembly 5 is an adjustable housing 4, which includes an upper housing 4a, a double male bend joint 4b, a sliding lock sleeve 4d, and a lower housing 4c. The male thread at the upper end of the upper housing 4a is connected to the motor housing of the single-bend screw drill. The thread axes at both ends of the double male bend joint 4b are at a 1.5° angle. The upper end of the double male bend joint 4b is screwed into the female thread at the lower end of the upper housing 4a. The sliding lock sleeve 4d is mounted on the outer periphery of the middle section of the double male bend joint 4b and is radially positioned by two or three symmetrically arranged flat keys, allowing axial sliding. The lower end of the double male bend joint 4b is screwed into the female thread at the upper end of the lower housing 4c. The female thread axes at the upper and lower ends of the lower housing 4c also have a 1.5° angle. The lower end of the lower housing 4c is connected to the upper end of the transmission shaft assembly 6.

[0054] The lower portion of the upper bend adjustment housing 4a and the upper portion of the sliding locking sleeve 4d are radially aligned by tooth engagement. To adjust the bend angle, the connection between the lower bend adjustment housing 4c and the double male bend joint 4b is loosened, and the sliding locking sleeve 4d is lowered a distance to disengage its upper end from the tooth engagement of the upper bend adjustment housing 4a. The upper bend adjustment housing 4a is then rotated to the desired angle, and the sliding locking sleeve 4d is then raised to reengage the tooth engagement, locking the angle. The connection between the lower bend adjustment housing 4c and the double male bend joint 4b is then tightened and loosened. When the deflection of the double male bend joint 4b and the deflection of the lower bend adjustment housing 4c cancel each other out, a minimum bend angle of 0° is achieved; when the two deflections are superimposed, a maximum bend angle of 3° is achieved. Other phases are between 0° and 3°. This single-bend screw drill has a long service life and can withstand high torque. The screw curvature can be adjusted on-site according to construction needs. Compared to screw drills with fixed curvatures, this reduces the procurement and inventory requirements for various curvatures.

[0055] The outer walls of the sliding lock sleeve 4d and the lower bending adjustment housing 4c are each welded with reaming cutting teeth 4e. Specifically, four reaming cutting teeth 4e are welded along the height of the sliding lock sleeve 4d, and two reaming cutting teeth 4e are welded along the height of the lower bending adjustment housing 4c. To enhance the reaming effect, two reaming cutting teeth 4e are welded to the outer wall of the lower end of the upper bending adjustment housing 4a. The reaming cutting teeth are cylindrical X-57 tungsten steel sheets with a diameter of 9mm and a height of 10-13mm. As the adjustable bending housing 4 rotates, the reaming cutting teeth 4e on the convex portion of the bend can expand by 13-20%.

[0056] like Figure 5 As shown, the PDC drill bit includes a drill bit upper body 7a and a drill bit lower body 7c with a coaxial axis and a center hole. The upper part of the drill bit lower body 7c is provided with a drill bit lower body boss 7c1, and the drill bit lower body boss 7c1 is embedded in the countersunk hole of the drill bit upper body 7a. A pulse generator 7b is embedded in the center hole of the drill bit upper body.

[0057] A pulse oscillation cavity is provided along the axis of the pulse generator 7b, which includes a conical trumpet mouth 7b1, a water inlet throat 7b2, an expanded diameter resonance cavity 7b3 and a pulse outflow channel 7b4 from top to bottom. The upper end of the expanded diameter resonance cavity 7b3 is connected to the lower end of the water inlet throat 7b2 by a chamfer, and the lower end of the expanded diameter resonance cavity 7b3 is connected to the upper end of the pulse outflow channel 7b4 by a chamfer. The water inlet throat 7b2 and the pulse outflow channel 7b4 are both cylindrical; the diameter of the water inlet throat 7b2 is the same as that of the pulse outflow channel 7b4, the aspect ratio of the pulse outflow channel 7b4 is (1.8~2):1, and the diameter of the expanded diameter resonance cavity 7b3 is 1.78 times the diameter of the water inlet throat.

[0058] The middle section of pulse generator 7b is equipped with a pulse generator external boss 7b5. The upper shoulder of pulse generator external boss 7b5 abuts the lower inner step of the drill bit upper center hole, while the lower shoulder of pulse generator external boss 7b5 abuts the top of drill bit lower body boss 7c1. The lower portion of pulse generator 7b is inserted into the drill bit lower center hole, facilitating quick assembly and accurate positioning. To change the size of the pulse oscillation cavity, pulse generator 7b only needs to be replaced before the drill bit upper body 7a and drill bit lower body 7c are assembled. There is no need to replace the drill bit upper body 7a and drill bit lower body 7c as a whole. Pulser 7b is a centrally symmetrical rotating component, which is easy to process, has a high yield rate, reduces scrap rate, and lowers production costs.

[0059] A diversion chamber 7c2 with a downward conical expansion is provided at the lower part of the center hole of the drill lower body, and a blade wing 7d is provided at the lower part of the drill lower body 7c. Water holes are provided between adjacent blade wings 7d. The inner end of each water hole is communicated with the diversion chamber 7c2 respectively. A nozzle 7e is installed in each water hole. The distance between the bottom of the blade wing 7d and the water hole outlet is greater than 10mm, which reduces the risk of mud balling, stabilizes the tool surface, and adapts to a high-speed screw of 300R / Min.

[0060] The foregoing description is merely a preferred embodiment of the present invention and does not limit the scope of patent protection for the present invention. In addition to the foregoing embodiments, the present invention may also have other implementations. Any technical solution formed by equivalent substitution or equivalent transformation falls within the scope of protection claimed by the present invention. Technical features not described in the present invention may be implemented by or using existing technologies and will not be further described here.

Claims

1. A casing window sidetracking drill assembly, comprising a PDC drill bit connected to the lower end of a single-bend screw drill, a centralizer screwed to the upper end of the single-bend screw drill, a directional joint screwed to the upper end of the centralizer, a non-magnetic drill collar provided at the upper end of the directional joint, a wireless MWD directional instrument installed in the inner cavity of the non-magnetic drill collar, and a weighting rod connected to the upper end of the non-magnetic drill collar; an adjustable bend housing provided in the middle section of the single-bend screw drill, a universal shaft assembly installed in the inner cavity of the adjustable bend housing, and characterized in that: The adjustable bending shell includes an upper bending shell, a double male bending joint, a sliding locking sleeve and a lower bending shell. The male thread at the upper end of the upper bending shell is connected to the motor shell of the single-bend screw drill, and the thread axes at both ends of the double male bending joint have an angle of 1.5°. The upper end of the double male bending joint is screwed into the female thread at the lower end of the upper bending shell. The sliding locking sleeve is sleeved on the outer periphery of the middle section of the double male bending joint and is radially positioned by a flat key. The lower end of the double male bending joint is screwed into the female thread at the upper end of the lower bending shell. The female thread axes at the upper and lower ends of the lower bending shell also have an angle of 1.5°; the outer walls of the sliding locking sleeve and the lower bending shell are respectively welded with reaming cutting teeth.

2. The casing window sidetracking drilling assembly according to claim 1, characterized in that: The outer wall of the lower end of the bending adjustment upper shell is welded with hole expansion cutting teeth.

3. The casing window sidetracking drilling assembly according to claim 2, characterized in that: The reaming cutting teeth are cylindrical tungsten steel sheets with a diameter of 9 mm and a height of 10-13 mm.

4. The casing window sidetracking drilling assembly according to claim 1, characterized in that: The outer diameter of the non-magnetic drill collar is 102 mm, the inner diameter is 60 mm, and both the upper and lower ends are female buckles. The lower end of the non-magnetic drill collar is screwed to the upper end of the directional joint through a double male joint.

5. The casing window sidetracking drilling assembly according to claim 4, characterized in that: The upper and lower ends of the non-magnetic drill collar are both 210-type female buckles, and the double male connector is a 211×211 double male connector.

6. The casing window sidetracking drilling assembly according to claim 4, characterized in that: The outer diameter of the wireless MWD direction finder is 48 mm, the outer diameter of the weighted rod is 89 mm, and the inner diameter is 54.6 mm.

7. The casing window sidetracking drilling assembly according to claim 1, characterized in that: When unclamping said control button, under the effect of the compression spring and the bubble holding vessel internal pressure that shaves, combine closely in the interior edge of valve gap and sealing load chamber, and burble goes out control valve thereby control is shaved.

8. The casing window sidetracking drilling assembly according to claim 7, characterized in that: The lower end of the bypass valve outer cylinder is screwed onto an anti-drop outer cylinder, and the lower end of the anti-drop outer cylinder is screwed onto a motor outer cylinder, and the inner cavity of the motor outer cylinder is provided with a motor rotor; the middle section of the inner cavity of the anti-drop outer cylinder is provided with an anti-drop outer cylinder reducing section, and the middle section of the anti-drop shaft passes through the center hole of the anti-drop outer cylinder reducing section, and the lower end of the anti-drop shaft is provided with an anti-drop shaft expanding section and is screwed onto the upper end of the motor rotor, and the upper end of the anti-drop shaft is screwed onto a mushroom head nut, and the outer diameters of the mushroom head nut and the anti-drop shaft expanding section are larger than the inner diameter of the anti-drop outer cylinder reducing section.

9. The casing window sidetracking drilling assembly according to claim 1, characterized in that: The PDC drill bit includes a coaxial drill head and a center hole passing through the drill head upper body and a drill head lower body. The upper part of the drill head lower body is provided with a drill head lower body boss, and the drill head lower body boss is embedded in the countersunk hole of the drill head upper body. A pulse generator is embedded in the center hole of the drill head upper body, and a pulse oscillation cavity is provided along the axis of the pulse generator. The pulse oscillation cavity includes a conical bell mouth, a water inlet throat, an expanded diameter resonance cavity and a pulse outflow channel from top to bottom. The upper end of the expanded diameter resonance cavity is connected to the lower end of the water inlet throat through a chamfer, and the lower end of the expanded diameter resonance cavity is connected to the upper end of the pulse outflow channel through a chamfer. The water inlet throat and the pulse outflow channel are both cylindrical; the lower part of the center hole of the drill head lower body is provided with a diversion cavity with a downward conical expansion, and the lower part of the drill head lower body is provided with a blade, and water holes are respectively provided between adjacent blades. The inner end of each water hole is respectively communicated with the diversion cavity, and a nozzle is respectively installed in each water hole.

10. The casing window sidetracking drilling assembly according to claim 9, characterized in that: The middle section of the pulse generator is provided with a pulse generator outer boss, the upper shoulder of the pulse generator outer boss abuts against the inner step under the center hole of the upper body of the drill bit, the lower shoulder of the pulse generator outer boss abuts against the top of the lower body boss of the drill bit, and the lower part of the pulse generator is inserted into the center hole of the lower body of the drill bit.

11. The casing window sidetracking drilling assembly according to claim 9, characterized in that: The diameter of the water inlet throat is the same as the diameter of the pulse outflow channel, the aspect ratio of the pulse outflow channel is (1.8-2):1, and the diameter of the expanded resonant cavity is 1.78 times the diameter of the water inlet throat.

12. The casing window sidetracking drilling assembly according to claim 9, characterized in that: The distance between the bottom of the blade and the water eye outlet is greater than 10 mm.

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