While-drilling type formation water outlet plugging device and well wall stabilizing method
By utilizing in-situ melting of rock cuttings and high-pressure jetting technology, the drilling water-stopping device solves the problems of well kick, blowout, and wellbore instability during drilling, achieving a high-temperature, low-permeability plugging effect and reducing plugging costs.
Patent Information
- Application Number
- CN202511415103.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-30
- Publication Date
- 2025-11-21
AI Technical Summary
Existing plugging methods have poor temperature resistance, low timeliness, and high cost during drilling, and lack active plugging methods while drilling, leading to frequent accidents such as well kicks, blowouts, and wellbore instability.
The drilling-while-drilling formation water plugging device utilizes the gas compression channel and reverse cuttings heating channel in the drill bit lining to melt the cuttings in situ and form a dense mud cake through high-pressure directional injection, thereby stabilizing the wellbore and plugging the water-producing layer.
It enables real-time plugging during drilling, forming a solidified mud cake that is resistant to high temperatures and has low permeability, thus preventing well kicks and blowouts, reducing plugging costs, improving wellbore stability, and reducing the occurrence of accidents.
Smart Images
Figure CN120990524A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of oil drilling engineering technology, specifically a drilling device and method that utilizes in-situ rock cuttings melting to generate composite dense mud cake during drilling, thereby achieving rapid sealing of water-producing layers and wellbore stability. Background Technology
[0002] As oil and gas exploration and development continues to advance into deeper and more complex formations, the proportion of drilling in formations prone to water production, such as shale gas wells and high-temperature geothermal wells, is increasing. These formations have diverse pore types and well-developed natural and induced fractures. Under the influence of formation pressure differences, formation water can easily infiltrate the wellbore along pores and fractures, posing numerous challenges to safe and efficient drilling operations. Once in the wellbore, formation water mixes with the drilling fluid, diluting solid weighting particles such as barite, causing a rapid decrease in drilling fluid density. It also disrupts the colloidal stability of the drilling fluid, leading to deviations in properties such as viscosity and shear stress from design values. Drilling fluid density is crucial for balancing wellbore and formation pressures; insufficient density can trigger a well kick. If not controlled in time, formation pressure can exceed the drilling fluid column pressure and blowout preventer sealing pressure, potentially escalating into a blowout. Simultaneously, the interaction between formation water and the wellbore rock exacerbates wellbore instability. In water-sensitive formations like shale, ions in formation water react with clay minerals, causing clay to expand and the rock structure to loosen, ultimately leading to wellbore collapse. Formation water at high temperatures accelerates rock erosion, widening fractures and also increasing the risk of wellbore collapse. Wellbore collapse results in irregular wellbore diameters, increasing friction between the drill string and the wellbore, potentially causing stuck pipe. Accumulated rock debris at the bottom of the well can also cause drill bit burial. These incidents halt drilling, require significant manpower and resources for repairs, extend the project timeline, and increase costs.
[0003] Existing plugging methods mainly include chemical plugging and physical plugging, but they have shortcomings such as poor temperature resistance, low timeliness, and high cost. Moreover, they are mostly post-operative remedial measures and lack active plugging methods while drilling. Summary of the Invention
[0004] In response to the shortcomings of existing technologies and adhering to the concept of "turning waste into treasure", this invention provides a drilling-based formation water plugging device that can effectively solve the problems of poor temperature resistance, low timeliness, and high plugging cost.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a drilling-based formation water plugging device, comprising: a drill bit body with a conversion joint at its upper part for connection to the drill pipe; an outer shell for improving the strength of the drill bit body; and an inner liner for isolating internal cuttings channels. A gas compression channel is provided in the middle of the inner liner, and a vertical nozzle and three oblique nozzles are provided at the bottom of the inner wall of the gas compression channel. The vertical nozzles are conical, and the oblique nozzles are straight, both increasing the gas flow rate to assist in rock breaking and wellbore cleaning. The bottom ends of the oblique nozzles penetrate the outer shell of the drill bit body. Three reverse cuttings heating channels are uniformly provided inside the inner liner. The three reverse cuttings heating channels surround the outside of the gas compression channel. The bottom end of each reverse cuttings heating channel is fixedly connected to a cuttings intake port for guiding cuttings from the bottom of the well into the channel and melting them at high temperature. The bottom end of the cuttings intake port penetrates the bottom end of the drill bit housing. The top end of each reverse cuttings heating channel is fixedly connected to a melt cuttings ejection port, and the top end of the melt cuttings ejection port penetrates the outer wall of the drill bit housing. Reverse nozzles are fixedly connected between each of the three reverse cuttings heating channels and the gas compression channel for ejecting high-pressure gas to provide recoil power, creating a pressure difference at the bottom cuttings intake port to provide power for cuttings intake, and directionally ejecting the melted cuttings through the melt cuttings ejection port to the well wall.
[0006] Preferably, the drill bit liner is further provided with a transmission cable and a resistance heating rod. The transmission cable is electrically connected to the resistance heating rod to provide electrical energy. The resistance heating rod is set on the outer wall of the reverse cuttings heating channel to heat it at high temperature. The reverse nozzle is located at one-third of the upper half of the resistance heating rod.
[0007] Preferably, the resistance heating rod is fixed inside the drill bit liner by a conductive limiting sleeve. The middle part of the conductive limiting sleeve has a hollow structure, and its corners are rounded to reduce the resistance to rock cuttings flow and facilitate ejection.
[0008] Preferably, a high-pressure gas channel is provided at the top of the drill bit liner, which is connected to a gas compression channel. Three oblique nozzles are provided at the bottom of the gas compression channel. The oblique nozzles and the cuttings inlet are not intersecting in position and are arranged at a certain angle, ranging from 10 degrees to 40 degrees. The oblique nozzles 24 and the cuttings inlet 26 are distributed in a ring at equal intervals inside the drill bit liner 21 to avoid fluid interference. A set of cutting teeth is evenly distributed on the bottom and sides of the drill bit shell to improve the strength of the drill bit shell for cutting rocks. The angle between the oblique nozzle and the horizontal plane is 60 degrees, the angle between the outlet direction of the oblique nozzle and the horizontal plane is 60 degrees, and the angle between the outlet direction of the melted cuttings outlet and the horizontal plane is 30 degrees.
[0009] Preferably, the present invention also discloses a method for stabilizing the wellbore by sealing formation water while drilling, specifically including the following steps: 1. During normal drilling, the device operates as a conventional drilling tool; 2. When formation water is detected on the surface, the drilling speed is reduced, and the resistance heating rod is activated to heat to 400–600°C; 3. Rock cuttings enter the reverse rock cuttings heating channel through the rock cuttings inlet and melt at high temperature; 4. High-pressure gas is released through the gas compression channel and ejected through the reverse nozzle, carrying the molten rock cuttings and directionally sprayed onto the wellbore from the melted rock cuttings outlet to form a low-permeability, dense, solidified mud cake to seal the water-producing layer; 5. After drilling through the water-producing layer, heating is stopped, and the normal drilling speed is restored.
[0010] Preferably, the solidified mud cake is composed of in-situ melted rock fragments, has high temperature resistance and low permeability, and is suitable for high-temperature complex strata.
[0011] Preferably, the adapter has a threaded structure on its upper part for connection with the internal thread of the drill pipe.
[0012] Beneficial effects
[0013] This invention provides a drilling-while-drilling formation water plugging device and a wellbore stabilization method. Compared with the prior art, it has the following advantages:
[0014] (1) The drilling-while-drilling formation water plugging device is designed with the innovative design of "in-situ melting of rock cuttings-high pressure directional injection" to achieve "drilling and plugging at the same time" without stopping or starting drilling. The solidified mud cake has high temperature resistance and low permeability, which can effectively block formation water intrusion to avoid well kick and blowout, and can also isolate formation water from the reaction with the well wall to suppress collapse, thus solving the pain points of traditional plugging such as poor real-time performance, insufficient temperature resistance, and easy to cause safety accidents.
[0015] (2) The drilling-while-drilling formation water plugging device uses bottom rock cuttings as plugging material, eliminating the need for additional plugging agents and significantly reducing the cost of plugging a single well. At the same time, it avoids the handling costs and construction period losses of accidents such as stuck drill and buried drill. Moreover, the core components are highly reusable and have low long-term investment, comprehensively promoting cost reduction and efficiency improvement in drilling operations, and is suitable for large-scale application in complex formations. Attached Figure Description
[0016] Figure 1 This is a schematic cross-sectional view of the overall structure of the present invention;
[0017] Figure 2 This is a top view of the overall structure of the present invention;
[0018] Figure 3 This is a top view of the main structure of the present invention.
[0019] Explanation of reference numerals in the attached drawings: 11—Conversion connector; 12—Transmission cable; 13—High-pressure gas passage; 21—Drill bit liner; 22—Gas compression passage; 23—Vertical nozzle; 24—Angled nozzle; 25—Reverse nozzle; 26—Cutting material intake; 27—Reverse cutting material heating passage; 28—Melting cutting material outlet; 29—Resistance heating rod; 210—Conductive limiting sleeve; 31—Drill bit housing; 32—Cutting pin; Detailed Implementation
[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0021] The following description, in conjunction with the accompanying drawings and embodiments, provides a more detailed explanation of the drilling-based formation water plugging device and the wellbore stabilization method based on in-situ cuttings transformation of the present invention.
[0022] Example 1: Device Structure
[0023] This device includes: a drill bit body with a conversion connector 11 at its upper part for connection to the drill pipe; a drill bit shell 31 on its exterior to improve the strength of the drill bit body; a drill bit liner 21 inside the drill bit liner 21 to isolate the internal cuttings flow channel; a gas compression channel 22 is opened in the middle of the drill bit liner 21; a vertical nozzle 23 and three oblique nozzles 24 are opened at the bottom of the inner wall of the gas compression channel 22; the vertical nozzle 23 is conical and the oblique nozzles 24 are straight, which can increase the gas flow rate to assist rock breaking and well bottom cleaning, and the bottom end penetrates the drill bit shell 31; three reverse cuttings heating channels 27 are evenly opened inside the drill bit liner 21. A reverse cuttings heating channel 27 surrounds the outside of the gas compression channel 22. A cuttings intake port 26 is fixedly connected to the bottom of the reverse cuttings heating channel 27 to guide cuttings from the bottom of the well into the channel and melt them at high temperature. The bottom of the cuttings intake port 26 penetrates the bottom of the drill bit housing 31. A melted cuttings ejection port 28 is fixedly connected to the top of the reverse cuttings heating channel 27, and the top of the melted cuttings ejection port 28 penetrates the outer wall of the drill bit housing 31. Reverse nozzles 25 are fixedly connected between the three reverse cuttings heating channels 27 and the gas compression channel 22 to eject high-pressure gas to provide recoil power, directing the molten cuttings through the melted cuttings ejection port 28 to the well wall. The drill bit liner 21 also contains a transmission cable 12 and a resistance heating rod 29. The transmission cable 12 is electrically connected to the resistance heating rod 29 to provide electrical energy. The resistance heating rod 29 is located on the outer wall of the reverse cuttings heating channel 27 for high-temperature heating. The reverse nozzles 25 are located at the upper third of the resistance heating rod 29. The resistance heating rod 29 is fixed inside the drill bit liner 21 by the conductive limiting sleeve 210. The middle part of the conductive limiting sleeve 210 has a hollow structure, and its corners are rounded to reduce the resistance to rock cuttings flow and facilitate ejection.
[0024] The top of the drill bit liner 21 is provided with a high-pressure gas channel 13, which is connected to the gas compression channel 22. The bottom of the gas compression channel 22 is provided with three oblique nozzles 24. The oblique nozzles 24 and the cuttings inlet 26 are not intersecting in position and are arranged at a certain angle, ranging from 10 degrees to 40 degrees. The oblique nozzles 24 and the cuttings inlet 26 are distributed in a ring at equal intervals inside the drill bit liner 21 to avoid fluid interference. A set of cutting teeth 32 are evenly distributed on the bottom and sides of the drill bit shell 31 to improve the strength of the drill bit shell 31 for cutting rocks. The angle between the oblique nozzles 24 and the horizontal plane is 60 degrees. The angle between the outlet direction of the oblique nozzles 24 and the horizontal plane is 60 degrees, and the angle between the outlet direction of the melting cuttings outlet 28 and the horizontal plane is 30 degrees.
[0025] The middle and lower parts of the adapter (11) are provided with external threads, and the upper part of the drill bit liner (21) and the upper part of the drill bit shell (31) are provided with internal threads. The external thread of the lower part of the adapter (11) is first threaded to the internal thread of the drill bit liner (21), and then threaded to the internal thread of the drill bit shell (31).
[0026] Example 2: Usage Method
[0027] 1. Normal drilling stage: The device operates as a conventional drilling tool, and drilling fluid is sprayed out through vertical nozzle 23 and directional nozzle 24 to assist in rock breaking and bottom cleaning.
[0028] 2. Water-bearing layer identification and response: After detecting water in the formation, reduce the drilling speed and start the heating system.
[0029] 3. Rock cuttings melting: Under the action of hydraulic jet, rock cuttings at the bottom of the well enter the reverse rock cuttings heating channel 27 through the rock cuttings suction port 26, and are heated to a high temperature and melted under the action of the resistance heating rod 29.
[0030] 4. High-pressure jet sealing: At this time, the high-pressure gas released from the gas compression channel 22 generates recoil force through the reverse nozzle 25, carrying the molten rock fragments and injecting them directionally onto the well wall through the molten rock fragment ejection outlet 28. The molten rock fragments cool and solidify on the well wall surface, forming a low-permeability, dense solidified mud cake, thereby sealing the water-producing layer.
[0031] Example 3: Application Effect
[0032] Through simulation and experimental verification, this invention can achieve real-time plugging while drilling without the need for drilling out; the formed solidified layer is dense, has low permeability, and is resistant to temperatures above 400℃, effectively improving the plugging efficiency compared to traditional methods.
[0033] When the drill bit encounters a water-bearing formation, the resistance heating rod 29 inside the drill bit is activated. Its working principle is as follows: Under the action of the hydraulic jet, rock cuttings from the bottom of the well enter the reverse rock cuttings heating channel 27 through the rock cuttings intake 26, and are heated to a high temperature and melted by the resistance heating rod 29. At this time, the high-pressure gas released from the gas compression channel 22 forms a recoil force through the reverse nozzle 25, carrying the molten rock cuttings and directionally spraying them onto the well wall through the melted rock cuttings ejection outlet 28. The molten rock cuttings cool and solidify on the well wall surface, forming a low-permeability, dense solidified mud cake, thereby sealing the water-bearing formation.
[0034] To address the problems of water inflow in complex formations, wellbore instability, and the lag and low efficiency of traditional water shut-off methods during drilling, this invention proposes a drilling-while-drilling formation water shut-off device and a wellbore stabilization method based on in-situ cuttings transformation.
[0035] The device consists of a drill bit body, a conversion connector 11, a cuttings intake port 26, a reverse cuttings heating channel 27, a resistance heating rod 29, a conductive limiting sleeve 210, a transmission cable 12, a high-pressure gas channel 13, a gas compression channel 22, a reverse nozzle 25, a vertical nozzle 23, an oblique nozzle 24, and a melting cuttings ejection port 28. After entering the reverse cuttings heating channel 27, the cuttings are melted at high temperature by the resistance heating rod 29. Driven by the high-pressure gas released from the gas compression channel 22, they are ejected from the reverse nozzle 25 onto the well wall, forming a dense solidified layer, thus achieving active sealing while drilling.
[0036] Compared with traditional chemical plugging agents, this invention uses in-situ rock cuttings as the plugging material, which has the advantages of high temperature resistance (>400℃), low cost and high plugging efficiency.
[0037] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0038] Although embodiments of the 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 invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A drilling-while-drilling formation water plugging device, characterized in that, include: The drill bit body has a conversion connector (11) on its upper part for connection with the drill pipe; a drill bit shell (31) is provided on its exterior to improve the strength of the drill bit body; a drill bit liner (21) is provided inside to isolate the internal cuttings flow channel; a gas compression channel (22) is provided in the middle of the drill bit liner (21); a vertical nozzle (23) and an oblique nozzle (24) are provided at the bottom of the inner wall of the gas compression channel (22); the vertical nozzle (23) is conical and the oblique nozzle (24) is straight; both can increase the gas flow rate to assist in rock breaking and well bottom cleaning, and the bottom ends penetrate the drill bit shell (31); three reverse cuttings heating channels (27) are evenly provided inside the drill bit liner (21); the three reverse cuttings heating channels... A hot channel (27) surrounds the outside of the gas compression channel (22). The bottom end of the reverse cuttings heating channel (27) is fixedly connected to a cuttings intake port (26) for introducing the cuttings from the bottom of the well into the channel and melting them at high temperature. The bottom end of the cuttings intake port (26) penetrates the bottom end of the drill bit housing (31). The top end of the reverse cuttings heating channel (27) is fixedly connected to a melting cuttings ejection port (28). The top end of the melting cuttings ejection port (28) penetrates the outer wall of the drill bit housing (31). Reverse nozzles (25) are fixedly connected between the three reverse cuttings heating channels (27) and the gas compression channel (22) for ejecting high-pressure gas to provide recoil power and directionally spraying the molten cuttings onto the well wall through the melting cuttings ejection port (28).
2. The apparatus according to claim 1, characterized in that, The drill bit liner (21) is also equipped with a transmission cable (12) and a resistance heating rod (29). The transmission cable (12) is electrically connected to the resistance heating rod (29) to provide electrical energy. The resistance heating rod (29) is set on the outer wall of the reverse rock cuttings heating channel (27) to heat it at high temperature. The reverse nozzle (25) is located at one-third of the upper half of the resistance heating rod (29).
3. The apparatus according to claim 1, characterized in that, The resistance heating rod (29) is fixed inside the drill bit liner (21) by a conductive limiting sleeve (210). The middle part of the conductive limiting sleeve (210) is a hollow structure, and its corners are rounded to reduce the resistance of rock cuttings flow and facilitate ejection.
4. The apparatus according to claim 1, characterized in that, A high-pressure gas channel (13) is provided at the top of the drill bit liner (21), which is connected to a gas compression channel (22). Three oblique nozzles (24) are provided at the bottom of the gas compression channel (22). The oblique nozzles (24) and the cuttings intake (26) are not intersecting in position and are arranged at a certain angle, ranging from 10 degrees to 40 degrees. The oblique nozzles (24) and the cuttings intake (26) are located within the drill bit... The inner liner (21) is arranged in a ring with equal spacing to avoid fluid interference. A set of cutting teeth (32) is evenly distributed on the bottom and sides of the drill bit shell (31) to improve the strength of the drill bit shell (31) for cutting rocks. The angle between the inclined nozzle (24) and the horizontal plane is 60 degrees. The outlet direction of the molten rock cuttings outlet (28) is 30 degrees from the horizontal plane.
5. A method for stabilizing the wellbore during drilling to seal out formation water, employing the drilling-while-drilling formation water sealing device as described in any one of claims 1 to 4, characterized in that, Includes the following steps: (1) During normal drilling, the equipment is operated as a regular drilling tool; (2) When water is detected in the formation at the ground, the drilling speed is reduced and the resistance heating rod (3) is started to heat to 400–600℃; (3) Rock cuttings enter the reverse rock cuttings heating channel (27) through the rock cuttings intake port (26) and melt at high temperature; (4) High pressure gas is released through the gas compression channel (22) and ejected through the reverse nozzle (25), carrying the molten rock cuttings from the melted rock cuttings ejection port (28) and directed to the well wall to form a low-permeability dense solidified mud cake to seal the water-bearing layer; (5) After drilling through the water-bearing layer, heating is stopped and the normal drilling speed is restored.
6. The method according to claim 5, characterized in that, The solidified mud cake is composed of in-situ melted rock fragments, and has high temperature resistance and low permeability, making it suitable for high-temperature and complex formations.
7. The apparatus according to claim 1, characterized in that, The adapter (11) has a threaded structure on its upper part for connection with the internal thread of the drill pipe.
8. The apparatus according to claim 1, characterized in that... The middle and lower parts of the adapter (11) are provided with external threads, and the upper part of the drill bit liner (21) and the upper part of the drill bit shell (31) are provided with internal threads.