A rigid conveyed, branching drilling completion tool and method of drilling

Abstract

The application discloses a rigid transmission branch drilling completion tool and a drilling completion method thereof, which is used for development of multi-thin-layer oil and gas reservoirs and can also be used for bedding drilling of a certain thin oil layer to increase oil drainage area and improve recovery ratio. The radial drilling completion system is composed of a diverter and a high-plasticity drilling pipe column, the high-plasticity drilling completion pipe column comprises a hinged short section string, a high-plasticity metal pipe and / or a high-pressure elastic metal outer pipe; the drilling completion tool further comprises a drill bit and / or a packer and / or a sliding sleeve and / or a spray gun, and the drilling completion tool can complete multi-oil-layer drilling completion in a main wellbore and / or can complete drilling completion of a certain thin oil layer in the main wellbore, so as to achieve the purpose of increasing the oil drainage area. In addition, by adopting a one-time drill bit and the high-plasticity drilling completion pipe column, support to a small wellbore is completed, and wellbore collapse is prevented.

Description

Technical Field

[0001] This invention relates to the field of lateral drilling technology, specifically a rigid-transfer branch drilling completion tool and its drilling method. Background Technology

[0002] Radial drilling technology is widely used in the stimulation of old wells and for improving oil recovery. It typically involves lowering a high-pressure hose with a jet sleeve and / or nozzle and / or screen module via a drive drill string. The jet sleeve and / or nozzle and / or screen module, along with the high-pressure hose, pass through a steering mechanism and enter the formation laterally into the borehole. In this technology, the turning radius of micro-branch wells is less than 1 meter, and the diameter of the sleeve and / or nozzle and / or screen module is generally between 0.75 and 3 inches, sometimes even within the casing. However, current radial drilling technologies, which rely on jet drilling, suffer from poor rock breaking, tortuous wellbore, and short penetration in micro-branch wells, making it difficult to achieve ultra-deep radial holes. Literature and experiments show that the wellbore formed by high-pressure water jet rock breaking is irregular, and the drilling efficiency of jet rock breaking is low. Furthermore, water jet radial drilling technology relies on high-pressure water jet drilling, therefore it can only be achieved by connecting a drive drill string suitable for conveying high-pressure fluid to a high-pressure hose for drilling, and can only achieve radial branch well drilling within a certain diameter, making it difficult to apply in highly deviated wells and horizontal wells. The biggest limitation of this technology is that the high-pressure hose inside the tiny branch orifice cannot rotate, thus the high-pressure hose in the tiny branch orifice is affected by axial frictional resistance and cannot advance. The aforementioned reasons further limit the efficiency of this technology and the wellbore footage.

[0003] Therefore, it is necessary to provide a rigid transmission branch drilling and completion tool and its drilling method to solve the problems mentioned in the background art. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A rigid-transmission branch drilling and completion tool, characterized in that it includes at least one section of radial drilling and completion system, the radial drilling and completion system consisting of a steering gear and a high-plasticity drilling string, the high-plasticity drilling string including a tandem articulated short section and a high-plasticity metal tube; wherein, the tandem articulated short section is formed by multiple drive sections connected in series through a torque transmission structure;

[0006] The high-plasticity metal tube is sleeved outside the articulated short section series; both ends of the high-plasticity metal tube can be connected and sealed to the articulated short section series by threads;

[0007] The plastic metal tube has a flow channel inside, and the two ends of the flow channel are connected to the internal flow channels of the drill bit and drive drill string or other downhole tools, which together form a channel for the flow of drilling circulating medium.

[0008] It should be noted that the lower end of the high-plasticity metal tube is connected to the drill bit via threads, and the drill bit and the drill bit connecting sleeve can be connected by a pin. The upper end of the high-plasticity metal tube is connected to the drive drill string or other downhole tools via the articulated short section tandem and the drive connecting sleeve. The drive drill string or other downhole tools can provide the drilling pressure required for drilling to the articulated short section tandem.

[0009] A gap is provided between the articulated short section series and the high-plasticity metal tube, the gap allowing the articulated short section series to bend together with the high-plasticity metal tube.

[0010] Furthermore, it also includes a steering device and an anchor, wherein the steering device enables the high-plasticity drilling string to complete a very short-radius steering within the main wellbore;

[0011] Furthermore, the high-plasticity metal tube is fixedly connected to the lower end of the drill bit by a thread. When the drill string is driven downward, the articulated short section can compress the driving high-plasticity metal tube, causing it to move forward in the steering gear and the formation.

[0012] Furthermore, the high-plasticity metal tube is connected to the upper end of the articulated short section series via a shear pin. When the articulated short section series presses against the driving high-plasticity metal tube to move forward, the shear pin is not subjected to shearing force.

[0013] Furthermore, the shear pin between the drill bit and the drill bit connecting sleeve is not subjected to shear force during drilling, and the drilling pressure during drilling is transmitted through the shoulder between the drill bit and the drill bit connecting sleeve.

[0014] Furthermore, the anti-retrograde structure can be any type such as a spring clip or an expansion ring to prevent the highly ductile metal tube from exiting the formation structure. During the descent or advance, the anti-retrograde structure should not generate additional resistance.

[0015] After the designed drilling footage is completed, the drive drill string pulls the articulated short section tandem out of the wellbore. At this point, the anti-retrograde structure can be locked into the formation, creating significant resistance. In particular, the anti-retrograde structure located at the main wellbore casing position can be completely locked outside the casing to prevent the high-plasticity metal tube from exiting the formation. Under the pulling force, the shear pins between the high-plasticity metal tube and the upper end of the articulated short section tandem, as well as the shear pins between the drill bit and the drill bit connecting sleeve, are all sheared by the shearing force. The drive drill string pulls the articulated short section tandem out of the formation, while the high-plasticity metal tube, along with the drill bit, remains in the bottom layer, providing support for the small wellbore and preventing wellbore collapse.

[0016] Furthermore, the completion module includes a spray gun module and / or a sliding sleeve module and / or a screen pipe module. The completion module is connected in series in the high-plasticity metal pipe. The completion module can be integrally formed with the high-plasticity metal pipe or it can be made into a separate structure. The screen pipe structure and / or screen pipe module should be regarded as any structure with screening, filtering and drainage functions, such as slots, grooves, holes, etc.

[0017] Furthermore, the length of the high-plasticity metal tube should be equal to the designed advance length and less than the total length of the articulated stubs. When the designed advance is reached, the high-plasticity metal tube should be fully inserted into the formation or at least completely pass through the pre-drilled window sleeve.

[0018] Furthermore, a throttling cap (10) is fixedly connected to the end of the high-plasticity metal tube (2a). The throttling cap (10) is a hollow cylindrical structure with internal threads. The two ends of the high-plasticity metal tube (2a) are provided with external threads. When the high-plasticity metal tube (2a) is sleeved outside the articulated short section, its two ends are pressed and fixed by the throttling cap (10).

[0019] Specifically, when the drilling fluid reaches the radial drilling and completion system through the drive drill string (4), the fluid velocity changes under the action of the choke cap (10). At this time, the upper surface N of the choke cap (10) becomes the pressure-bearing surface of the hydraulic piston, and under the action of the high-pressure fluid, the drill string is further propelled forward. During the forward movement, hydraulic energy is ejected from the water inlet (11) to break up the formation.

[0020] Furthermore, the torque transmission structure (31) is a universal joint.

[0021] Furthermore, the torque transmission structure (31) is a hinged universal joint.

[0022] Furthermore, the outer diameter of the drill bit (1) is 15-150 mm, the outer diameter of the high-plasticity metal tube (2) is 14-140 mm, and the outer diameter of the articulated short section series is 10-130 mm;

[0023] Furthermore, it may also include an attitude measurement module (5) for measuring the attitude near the drill bit (1).

[0024] Furthermore, the following usage steps are included:

[0025] 1) Drill the main wellbore (9) using conventional drilling tools to complete the evaluation of each layer;

[0026] 2) The cementing casing string is run in layers to complete the cementing of the main wellbore (9);

[0027] 3) Insert the steering gear (6) and anchor (7) to complete the orientation and mounting;

[0028] 4) The pre-opened window sleeve (16) is a conventional sleeve with a pre-opened window on the outside.

[0029] 5) Run the radial drilling and completion system tools;

[0030] 6) Lift the articulated short sections in series.

[0031] Assuming the target layer (17) reservoir thickness limit is L3 from the bottom of the reservoir to the top of the reservoir, then the distance L2 from the designed radial drilling hole to the top of the reservoir and the distance L1 from the sliding sleeve insertion point to the top of the reservoir must both be less than L3. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0033] Figures 2-4 This is a schematic diagram of the structure of Example 1;

[0034] In the diagram: 1. Drill bit; 2. Conventional drilling tools; 2a. High-ductility metal tubing; 2b. Flow channel; 3. Drive joint; 31. Torque transmission structure; 4. Drive drill string; 41. Clearance; 5. Attitude measurement module; 6. Steering gear; 7. Anchor; 8. Logging instrument; 9. Main borehole; 10. Tail connection thread; 11. Water eye; 12. Casing external centralizer; 13. Casing; 14. Drive connection sleeve; 15. Drill bit connection sleeve; 16. Pre-opened window casing; 17. Target layer; 23. Shear pin; 24. Shoulder; 25. Anti-reverse structure; 26. Screen structure and / or screen module. Detailed Implementation

[0035] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention. Specific Implementation Example 1:

[0037] like Figures 1-4As shown in this embodiment, a rigid transmission branch drilling and completion tool and its drilling method are described. First, the main wellbore (9) is drilled by conventional drilling tools. During this process, logging instruments (8) are brought into the drill assembly to evaluate each layer. After the main wellbore (9) is drilled to the designed depth, the drill string is taken out and cementing casing string is run in according to the layered development to complete the cementing of the main wellbore (9). In this process, the cementing casing string also includes a cementing function module. The cementing function module is composed of packers, sliding sleeves and / or pre-opened casing (16), which can complete the sealing and completion of multiple oil layers and / or a thin oil layer in the main wellbore. At least one packer is set between the pre-layered development layers, and at least one controllable sliding sleeve is included between any two packers. The controllable sliding sleeve can be switched by a switching tool run through the tubing, switched by an electric control actuator, or switched by a hydraulic actuator.

[0038] After cementing the main wellbore (9), the steering gear (6) and anchor (7) can be run in to complete orientation and mounting, and then the radial drilling and completion system tools can be run in.

[0039] As a preferred embodiment, the radial drilling and completion system of this embodiment consists of a steering gear (6) and a high-plasticity drilling string. The high-plasticity drilling string includes a tandem articulated short section and a high-plasticity metal tube (2a). The tandem articulated short section is formed by connecting multiple drive sections (3) in series through a torque transmission structure (31). The high-plasticity metal tube (2a) is sleeved on the outside of the tandem articulated short section. In addition, the high-plasticity metal tube (2a) is provided with anti-retrograde structure (25) and screen structure and / or screen module (26) at intervals on the outside. Its lower end is connected to the drill bit (1) by threads. The drill bit (1) and the drill bit connecting sleeve (15) can be connected by a pin. The drive drill string (4) or other downhole tools are then connected through the tandem articulated short section and the drive connecting sleeve (14). The drive drill string (4) or other downhole tools can provide the drilling pressure required for drilling of the tandem articulated short section. The high-plasticity metal tube (2a) is connected to the drive drill string (4) via a tail connection thread (10).

[0040] During descent, turning, or forward movement, a gap (41) exists between the articulated short section tandem and the high-plasticity metal tube (2a), allowing the articulated short section tandem to turn within the high-plasticity metal tube (2a). Furthermore, since the high-plasticity metal tube (2a) is threadedly connected to the lower end of the drill bit (1), when the drill bit (1) and the drive drill string (4) are driven downwards, the articulated short section tandem can compress the drive high-plasticity metal tube (2a), causing it to move forward within the steering mechanism (6) and the formation.

[0041] Furthermore, the articulated short section tandem is provided with a flow channel (2b), and both ends of the high-plasticity metal tube (2a) are connected to the internal flow channels of the drill bit (1) and the drive drill string (4) or other downhole tools, forming a channel for the flow of drilling circulating medium. Since the end of the high-plasticity metal tube (2a) is provided with a threaded choke cap (10), the choke cap (10) is a hollow cylindrical structure with internal threads, and the end of the high-plasticity metal tube (2a) is provided with external threads, when the high-plasticity metal tube (2a) is sleeved on the outside of the articulated short section tandem, its two ends are pressed and fixed by the choke cap (10). When the drilling fluid reaches the radial drilling and completion system through the drive drill string (4), the fluid velocity changes under the action of the choke cap (10). At this time, the upper surface N of the choke cap (10) becomes the bearing surface of the hydraulic piston, and under the action of the high-pressure fluid, the tubing is further pushed forward. During the forward movement, hydraulic energy is ejected from the water eye (11) and breaks up the strata.

[0042] Preferably, in this embodiment, during the running-in process, the high-plasticity metal tube (2a) and the drill bit (1) of the radial drilling and completion system are suspended on the articulated sub-unit tandem by shear pins. Specifically, this includes the shear pins (23) at the upper ends of the high-plasticity metal tube (2a) and the articulated sub-unit tandem, as well as the shear pins (23) between the drill bit (1) and the drill bit connecting sleeve (15). When the articulated sub-unit tandem compresses the driving high-plasticity metal tube (2a) to move forward, the shear pins (23) are not subjected to shear force, and the drilling pressure is transmitted through the shoulder (24) between the drill bit (1) and the drill bit connecting sleeve (15).

[0043] As a preferred option, the anti-retraction structure (25) spaced out on the outside of the high-plasticity metal tube (2a) is a spring. During the downward or forward movement of the spring, since its tangential direction is opposite to the forward direction, the anti-retraction structure (25) should not generate additional forward resistance. However, when the designed drilling footage is completed, and the drive drill string (4) pulls the articulated short section to exit the wellbore, the anti-retraction structure (25) can be stuck into the formation to form a great resistance. In particular, the anti-retraction structure (25) located at the main wellbore casing position can be completely stuck on the outside of the casing to prevent the high-plasticity metal tube (2a) from exiting the formation. At this time, under the action of the pulling force, the shear pins (23) between the high-plasticity metal tube (2a) and the upper end of the articulated short section, as well as the shear pins (23) between the drill bit (1) and the drill bit connecting sleeve (15), are all sheared by the shearing force. The drive drill string (4) pulls the articulated short section out of the formation, while the high-plasticity metal tube (2a) together with the drill bit (1) remains in the bottom layer to support the small wellbore and prevent the wellbore from collapsing. Since the outer surface of the high-plasticity metal tube (2a) is processed with the screen structure and / or screen module (26) and remains in the formation, it can play the functions of screening, filtering and draining, thereby stabilizing the wellbore and increasing the oil drainage area.

[0044] During radial drilling, the length of the high-plasticity metal tube (2a) should be equal to the designed drilling length and less than the total length of the articulated short sections. When the designed drilling length is reached, the high-plasticity metal tube (2a) should be fully inserted into the formation or at least completely pass through the pre-opened casing. Simultaneously, the attitude measurement module (5) located at the drill bit (1) can measure the attitude near the drill bit (1) to determine whether drilling is proceeding along the designed trajectory.

Claims

1. A rigid conveyed, branched drilling completion tool, characterized in that, At least one radial drilling completion system, which is composed of a deflector (6) and a high plasticity drilling pipe string, the high plasticity drilling pipe string includes a hinged short section string, a high plasticity metal pipe (2a); wherein the hinged short section string is connected by a torque transmission structure (31) through a plurality of driving sections (3); the high plasticity metal pipe (2a) is sleeved outside the hinged short section string; a driving drill string (4) or other downhole tools can provide the hinged short section string with the drilling pressure required for drilling; The high plasticity metal pipe (2a) is internally provided with a flow channel (2b), the flow channel (2b) is communicated with the internal flow channels of a drill bit (1) and the driving drill string (4) or other downhole tools at both ends, and together forms a channel for the flow of drilling circulating medium.

2. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, The deflector (6) and an anchor (7) are further included, the deflector can make the high plasticity drilling pipe string complete a very short radius deflection in the main borehole.

3. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, The high plasticity metal pipe (2a) is fixedly connected with the lower end of the drill bit (1) through threads, when the drill bit (1) and the driving drill string (4) are sent downward, the hinged short section string can compress the high plasticity metal pipe (2a) to make it advance in the deflector (6) and the formation.

4. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, The high plasticity metal pipe (2a) is connected with the upper end of the hinged short section string through a shear pin (23), when the hinged short section string compresses the high plasticity metal pipe (2a) to advance, the shear pin (23) is not affected by shear force; The shear pin (23) between the drill bit (1) and a drill bit connecting sleeve (15) is also not affected by shear force in the drilling process, and the drilling pressure in the drilling process is transmitted through a shoulder (24) between the drill bit (1) and the drill bit connecting sleeve (15).

5. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, The high plasticity metal pipe (2a) is externally and intermittently provided with a retreat prevention structure (25), the retreat prevention structure (25) can be any one of a spring sheet and an expansion ring, which can prevent the high plasticity metal pipe (2a) from exiting the formation structure, and the retreat prevention structure (25) should not generate additional resistance in the downward or advancing process; When the designed footage is completed, the driving drill string (4) pulls the hinged short section string out of the borehole, at this time, the retreat prevention structure (25) can be clamped into the formation to form a great resistance, in particular, the retreat prevention structure (25) located at the position of the main borehole casing can be completely clamped outside the casing to prevent the high plasticity metal pipe (2a) from exiting the formation; at this time, under the action of the lifting force, the shear pins (23) between the high plasticity metal pipe (2a) and the upper end of the hinged short section string and the shear pins (23) between the drill bit (1) and the drill bit connecting sleeve (15) are all sheared off under the action of shear force, the driving drill string (4) pulls the hinged short section string out of the formation, while the high plasticity metal pipe (2a) stays in the bottom layer together with the drill bit (1) to complete the support of the small borehole and prevent the borehole from collapsing.

6. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, The high plasticity metal pipe (2a) is connected in series with a completion module, the completion module includes a gun module and / or a sliding sleeve module and / or a screen module (26).

7. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, The length of the high plasticity metal pipe (2a) should be equal to the designed footage length and less than the total length of the articulated short section string; when the designed footage is reached, the high plasticity metal pipe (2a) should all enter the formation or at least completely pass through the pre-windowed casing (16).

8. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, A choke nipple (10) is fixedly connected to the end of the high plasticity metal pipe (2a).

9. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, The torque transmission structure (31) is a universal joint.

10. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, The torque transmission structure (31) is a hinged universal joint.

11. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, The outer diameter of the drill bit (1) is 15-150 mm, the outer diameter of the high plasticity metal pipe (2a) is 14-140 mm, and the outer diameter of the articulated short section string is 10-130 mm.

12. A rigid conveyed, branched drilling completion tool according to claim 1, characterized in that, A posture measurement module (5) can also be included for measuring the posture near the drill bit (1).

13. A method of drilling a borehole using a rigid conveyed diverging completion tool according to any one of claims 1-12, characterized in that: The method includes the following steps: 1) A conventional drilling tool drills a main wellbore (9), and evaluation of each layer system is completed; 2) A cementing casing string is run in accordance with separate layer development, and cementing of the main wellbore (9) is completed; 3) A diverter (6) and an anchor (7) are run in to complete orientation and seat carding; 4) The pre-windowed casing (16) has a window pre-opened on the outside of the conventional casing, 5) A radial drilling completion system tool is run in; 6) The articulated short section string is pulled up.

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