While-drilling leaking stoppage tool and using method

Abstract

The invention discloses a while-drilling leaking stoppage tool and a using method. The while-drilling leaking stoppage tool comprises an upper connector and a lower connector which are in threaded connection, a leaking stoppage hole is formed in the outer wall of the upper connector, a sliding sleeve ball seat is installed in the upper connector, a spring is installed in the lower connector, the spring makes contact with the sliding sleeve ball seat, and a pressure relief hole is formed in the outer wall of the lower connector. The plugging agent can be applied to plugging of formation fracture leakage in the drilling process of sidetrack drilling of a vertical well, a directional well, a horizontal well and an old well, drilling fluid is prevented from continuously leaking to formation fractures, the drilling fluid can normally circulate, and normal drilling is achieved; the operation process is simple, the plugging agent can smoothly flow to the annulus of the leakage position from the interior of the drill rod, the plugging effect is good, and the well drilling plugging period is shortened.

Description

Technical Field

[0001] This invention relates to the field of drilling technology in petroleum engineering, and in particular to a leak-stopping tool and its usage method while drilling. Background Technology

[0002] Liaohe Oilfield is a typical sandstone reservoir, primarily composed of heavy oil. In recent years, due to the depletion of formation pressure, the reservoir pressure has continuously decreased during the extraction process. Well leakage is the most common and serious problem during drilling of many older wells and later infill wells, resulting in significant losses. Addressing well leakage should prioritize prevention. Only effective surface leakage prevention can minimize or even eliminate leakage. Truly effective leakage prevention primarily focuses on preventing induced leakage. A crucial aspect of leakage prevention is controlling the fluid column pressure within the well. Many factors contribute to excessively high fluid column pressure, depending not only on drilling fluid density, wellbore structural parameters, and drilling operations, but also on the properties of the drilling fluid, particularly its rheological properties. Common methods for preventing well leakage focus on the following aspects.

[0003] 1. The design adopts a reasonable wellbore structure. Based on the formation conditions, gas and water shows, changes in formation pressure coefficient, and leakage, and considering the drilling methods and objectives, a reasonable casing program is designed to maximize the isolation of fractured and cavernous formations, active gas and water layers, and high-low transition zones to prevent high pressure differentials from occurring in low-pressure formations during drilling.

[0004] 2. Based on the predicted formation pressure, design a reasonable drilling fluid density and, in conjunction with actual drilling conditions, adjust and maintain the drilling fluid density in a timely and appropriate manner to achieve near-equilibrium drilling, thereby minimizing the drilling fluid column pressure. For low-pressure sections without gas, water or polymer drilling fluid is preferred. During drilling, solids control should be implemented to maintain the relative stability of the drilling fluid density.

[0005] 3. Optimize drilling fluid rheological properties. While ensuring good wellbore cleanliness, the viscosity shear stress, especially the static shear stress, of the drilling fluid should be reduced as much as possible to minimize the annular circulation equivalent density and reduce pressure surges. Preventing induced lost circulation in weak gel drilling fluids is particularly important. Generally, regardless of the drilling fluid density, a funnel viscosity of 30–50 seconds, an initial shear stress of 1–5 Pa, a final shear stress of less than 2.5–12.5 Pa, and a dynamic shear stress of less than 10 Pa are recommended.

[0006] 4. Gas formation drilling is prone to blowouts and lost circulation. Blowout prevention and well control are crucial to preventing lost circulation. Proper fluid level monitoring and strict control of drilling fluid density are essential. When tripping out the drill string, drilling fluid must be filled completely according to regulations. Balanced drilling should be prioritized to prevent blowouts. If a blowout occurs and well control is necessary, the kill fluid density must also be strictly controlled to prevent lost circulation.

[0007] 5. Strictly adhere to drilling operation procedures to avoid excessive pressure surges. Especially in drilling through easily leaky sections and gas-bearing zones, select an appropriate displacement rate, avoid excessive annular return speed, control tripping speed, operate smoothly, and after drilling to the bottom, rotate the drill string for 5-15 minutes to disrupt the drilling fluid structure before slowly starting the pump. In ultra-deep well sections, if necessary, low-displacement, low-pump-pressure circulation can be performed in stages.

[0008] 6. Avoid annular obstructions. Maintain excellent drilling fluid anti-collapse, anti-sticking, rheological, and fluid loss-forming properties to ensure wellbore stability, wellbore cleanliness, and effective annular hydraulic values, thereby avoiding well leakage caused by annular mud rings, sand bridges, drill bit mud packs, etc.

[0009] 7. Before drilling into known fractured, fractured, or easily leaking sections of the formation, or into areas where leakage is expected, add 2-4% of plugging material (bridging agent, single sealant, PCC, DTR plugging agent, etc.) to the drilling fluid to prevent leakage.

[0010] 8. When drilling into gas-bearing or easily leaky formations with high-density drilling fluid, the principles of "continuous, uniform, and stable" treatment must be strictly adhered to during maintenance and treatment to prevent excessively high local drilling fluid density from causing formation leakage. During mud treatment, the mud density fluctuation within the well should not exceed ±0.03 g / cm³. 3 .

[0011] 9. Pressure testing of the upper open hole section should be avoided as much as possible. If it cannot be avoided, pressure testing should be conducted using methods such as step-down drilling fluid density increase, weighting methods, or packer isolation. Avoid testing in weak formations within the wellbore to prevent well leakage during pressure testing.

[0012] The above measures all aim to prevent well leakage from an objective perspective. However, when well leakage actually occurs, there are no truly effective plugging tools available. Therefore, it is necessary to design and develop new plugging tools that can effectively solve the problem of well leakage during drilling. Summary of the Invention

[0013] This invention provides a leak-proof tool and its usage method for solving the leakage problem during drilling. It is easy to operate, enabling drilling work to proceed normally, shortening the drilling cycle, and reducing drilling costs.

[0014] To solve the above-mentioned technical problems, the technical solution of the present invention is: a drilling leak sealing tool, comprising an upper connector and a lower connector connected by threads, the outer wall of the upper connector having a leak sealing hole, a sliding ball seat installed inside the upper connector, a spring installed inside the lower connector, the spring contacting the sliding ball seat, and a pressure relief hole being provided on the outer wall of the lower connector.

[0015] Furthermore, four leak-sealing holes are evenly distributed on the outer wall of the upper connector.

[0016] Furthermore, the upper connector is provided with a sliding ball seat hole and a soluble sleeve hole in sequence.

[0017] Furthermore, a spring ring groove and a sliding ball seat ring groove are sequentially provided inside the lower connector.

[0018] Furthermore, the pressure relief hole is formed around the outer wall of the spring ring groove.

[0019] Furthermore, stepped holes and conical holes are sequentially opened inside the sliding ball seat.

[0020] Furthermore, the conical hole has a conical structure that is narrow inside and wide outside.

[0021] Furthermore, in the leak-sealing process, rubber balls are placed inside the stepped holes and conical holes.

[0022] Furthermore, after the leak is plugged, a soluble sleeve is placed inside the upper connector.

[0023] Furthermore, the soluble sleeve has a hollow cylindrical structure, and one end of the soluble sleeve has a limiting chamfer that matches the tapered hole.

[0024] Furthermore, the upper connector is threadedly connected to the upper drill rod.

[0025] Furthermore, the lower connector is threadedly connected to the lower drill rod.

[0026] Furthermore, the material of the sliding ball seat is cemented carbide.

[0027] Furthermore, the spring is made of an alloy.

[0028] Furthermore, the soluble sleeve is made of an alloy.

[0029] Furthermore, the soluble sleeve is made of MgAl alloy.

[0030] Furthermore, the outer diameters of the upper and lower connectors are equal.

[0031] A method for using a drilling leak sealing tool includes the following steps:

[0032] Step 1: Connect the leak sealing tool while drilling to the drill string;

[0033] Step 2: After discovering the leak, insert the rubber ball, and the rubber ball should reach the position of the sliding ball seat;

[0034] Step 3: Continue to pressurize. As the pressure increases, the sliding ball seat moves downward under the pressure, opening the flow channel.

[0035] Step 4: The plugging material enters the leakage point in the open hole formation through the flow channel. After the leakage is plugged, a soluble sleeve is then inserted, which will block the flow channel.

[0036] Step 5: Continue applying pressure to increase the pressure. Under the pressure, the rubber ball will shrink in diameter and fall through the stepped hole into the drill bit.

[0037] Step Six: The downward force on the sliding ball seat disappears, and it moves upward under the elastic force of the spring, thereby closing the flow channel;

[0038] Step 7: The soluble casing dissolves and disappears under the action of drilling fluid.

[0039] Furthermore, the sealing material is Diesel sealant.

[0040] The beneficial effects of this invention are: it can be applied to plugging formation fractures during drilling processes in vertical wells, directional wells, horizontal wells, and sidetracking of old wells, preventing drilling fluid from continuing to leak into formation fractures, allowing the drilling fluid to circulate normally and enabling normal drilling; the operation process is simple, enabling the plugging agent to flow smoothly from the drill pipe to the annulus at the leakage site, with a strong plugging effect and saving drilling plugging cycle. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in this invention or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a diagram showing the leak sealing port in the open position;

[0043] Figure 2 yes Figure 1 AA section view;

[0044] Figure 3 This is a diagram showing the leak plug in the closed state;

[0045] Figure 4 yes Figure 3 BB section view;

[0046] Figure 5 This is a schematic diagram of the upper connector structure;

[0047] Figure 6 This is a schematic diagram of the lower connector structure;

[0048] Figure 7 This is a schematic diagram of the sliding ball seat structure;

[0049] Figure 8 This is a schematic diagram of a soluble sleeve structure;

[0050] Figure 9 It is a dissolution curve of KCl solution at 25℃;

[0051] Figure 10 It is a dissolution curve of KCl solution at 90℃;

[0052] Figure 11 It is a dissolution curve of KCl solution at 120℃.

[0053] Among them: 1-upper connector, 2-lower connector, 3-spring, 4-sliding sleeve ball seat, 5-soluble sleeve, 6-rubber ball, 7-leakage plugging hole, 8-sliding sleeve ball seat hole, 9-soluble sleeve hole, 10-spring ring groove, 11-sliding sleeve ball seat ring groove, 12-pressure relief hole, 13-stepped hole, 14-conical hole, 15-limiting chamfer. Detailed Implementation

[0054] The following will be combined with the appendix Figure 1-11 The technical solutions of the present invention have been clearly and completely described. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0055] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0056] In the description of this invention, it should be noted that the terms "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used only for distinction and should not be construed as indicating or implying relative importance.

[0057] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0058] A drilling leak sealing tool includes an upper connector 1 and a lower connector 2 connected by threads. The outer diameters of the upper connector 1 and the lower connector 2 are equal. The upper connector 1 is threaded to the upper drill pipe, and the lower connector 2 is threaded to the lower drill pipe. Four leak sealing holes 7 are evenly distributed on the outer wall of the upper connector 1. A sliding ball seat hole 8 and a soluble sleeve hole 9 are sequentially formed inside the upper connector 1. A sliding ball seat 4 is installed inside the upper connector 1 and can slide up and down under pressure and the action of a spring 3 to close and open the channel. A stepped hole 13 and a conical hole 14 are sequentially formed inside the sliding ball seat 4. The conical hole 14 has a conical structure that is narrow inside and wide outside. A spring ring groove 10 and a sliding ball seat ring groove 11 are sequentially formed inside the lower connector 2. A spring 3 is installed inside the lower connector 2 and contacts the sliding ball seat 4. A pressure relief hole 12 is formed on the outer wall of the lower connector 2, surrounding the outer wall of the spring ring groove 10. In the leak-sealing state, rubber balls 6 are placed inside the stepped hole 13 and the conical hole 14. After the leak is sealed, a soluble sleeve 5 is placed inside the upper connector 1. The soluble sleeve 5 has a hollow cylindrical structure, and a limiting chamfer 15 is provided at one end of the soluble sleeve 5, which matches the conical hole 14. The sliding ball seat 4 is made of hard alloy, and the spring 3 is made of alloy.

[0059] The soluble sleeve 5 is made of MgAl alloy, which has high specific strength, specific stiffness, specific elastic modulus, and good castability and machinability. The strength of the soluble sleeve 5 is increased by adding Zn, Ca, and porous ceramics, while the corrosion rate is increased by adding metals such as Ni and Cu. Magnesium's high reactivity makes it easy for it to form corrosion cells with other structures, leading to galvanic corrosion. The cathode of galvanic corrosion can be an internal metal structure or an external metal in contact with it. If impurity phases such as Ni and Cu are present in the alloy, due to the potential difference between the metals, magnesium acts as the anode, and other metals act as the cathode, causing severe galvanic corrosion. Internal galvanic corrosion can also occur between normal phase structures formed in magnesium alloys, with the lower potential phase acting as the anode and experiencing limited corrosion (such as the α and β phases in magnesium-aluminum alloys).

[0060] Magnesium is a naturally passivated metal, especially when it contains Cl. - This can reduce the likelihood of passivation film formation in magnesium or magnesium-aluminum alloys or accelerate the destruction of the passivation film, thereby promoting localized corrosion. - It has the characteristics of small radius, strong penetrating power, and strong adsorption by metal surfaces. Cl - The higher the concentration, the stronger the conductivity of the aqueous solution, and the lower the resistance of the electrolyte. - This allows it to easily reach the metal surface, accelerating the process of localized corrosion. Therefore, Cl -The main mechanisms of metal corrosion are the formation of corrosion cells and depolarization. This not only promotes corrosion cells on the metal surface but also accelerates their operation. The inhibition of the anodic process is usually called anodic polarization, while the acceleration of anodic polarization is called depolarization. Cl - It is precisely because it plays a role in deanodic polarization and conductivity that Cl - The presence of ions enhances the reduction of resistance between the anode and cathode, thus improving the electrochemical corrosion process. The overall reaction equation for magnesium in aqueous solution is:

[0061] Mg + 2H₂O → Mg(OH)₂ + H₂ (Overall reaction)

[0062] This reaction can be expressed as the sum of the following partial reactions, namely:

[0063] Mg→Mg 2+ +2e (anodic reaction)

[0064] 2H₂O + 2e⁻ → H₂ + OH⁻ - (Anodic reaction)

[0065] Mg 2 +2OH - →Mg(OH)2

[0066] The preparation of soluble composite materials employs hydrogen reduction coating technology. The principle involves using high-pressure hydrogen gas to reduce metal ions in a metal salt solution and precipitate them onto the surface of suspended particles. Traditional electroless particle plating suffers from drawbacks such as difficulty in quantitative coating, easy decomposition of the plating bath, high levels of free metal, and the introduction of boron and phosphorus impurities. Electrodeposition production requires very demanding operating conditions, necessitating rolling electrolysis equipment, and is generally not used for powder coatings. In contrast, high-pressure hydrogen reduction technology can yield a uniform metal layer with high density and low impurity content. The process is easy to implement, and the component ratios are easily adjusted and precisely controlled, with high accuracy in metal content control. This paper employs hydrogen reduction technology to coat the surface of alloy particles with a metal layer.

[0067] 100g of soluble composite powder was compressed into cylindrical samples with a diameter of 25mm. The compression pressure was controlled at 40MPa for 6 minutes. Following compression, the samples underwent inert gas heat treatment to improve strength. The compressed samples were then placed in prepared potassium chloride solutions with concentrations of 1% and 3% at test temperatures of 25℃, 90℃, and 120℃. The 120℃ test was conducted in an autoclave. The solubility of the compressed samples under different experimental conditions is shown below. Figure 9-11 As shown.

[0068] Depend on Figure 9-11It can be seen that when the KCl solution concentration remains constant, the dissolution time decreases with increasing temperature; when the solution temperature remains constant, the dissolution time decreases with increasing KCl concentration, and the selected formula satisfies the solubility requirement.

[0069] A method for using a drilling leak sealing tool includes the following steps:

[0070] Step 1: Connect the leak sealing tool while drilling to the drill string;

[0071] Step 2: After discovering the leak, insert rubber ball 6, and place rubber ball 6 at the position of sliding ball seat 4;

[0072] Step 3: Continue to pressurize. As the pressure increases, the sliding ball seat 4 moves downward under the pressure, opening the flow channel.

[0073] Step 4: The leak-sealing material, Diesel leak-sealing agent, enters the leakage point in the open hole formation through the flow channel. After the leakage is blocked, the soluble sleeve 5 is then added. At this time, the soluble sleeve 5 will block the flow channel.

[0074] Step 5: Continue to pressurize, increasing the pressure. The rubber ball 6 will shrink in diameter under the pressure, thus passing through the stepped hole 13 and falling into the drill bit.

[0075] Step Six: The downward force on the sliding ball seat 4 disappears, and it moves upward under the elastic force of the spring 3, thereby closing the flow channel;

[0076] Step 7: The soluble sleeve 5 dissolves and disappears under the action of drilling fluid.

[0077] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. For those skilled in the art, any obvious modifications made without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims. Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no technical conflict, the features in the embodiments disclosed in the present invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A lost circulation while drilling tool, characterized in that, The application relates to a leak-stopping tool for drilling, which comprises a screw-connected upper joint (1) and lower joint (2), the outer wall of the upper joint (1) is provided with leak-stopping holes (7), a sliding sleeve ball seat (4) is arranged in the upper joint (1), a spring (3) is arranged in the lower joint (2), the spring (3) is in contact with the sliding sleeve ball seat (4), and the outer wall of the lower joint (2) is provided with a pressure relief hole (12).

2. The drift plug tool of claim 1, wherein, Four leak-stopping holes (7) are uniformly arranged on the outer wall of the upper joint (1).

3. The drift plug tool of claim 1, wherein, A sliding sleeve ball seat hole (8) and a soluble sleeve hole (9) are sequentially arranged in the upper joint (1).

4. The drift plug tool of claim 1, wherein, A spring ring groove (10) and a sliding sleeve ball seat ring groove (11) are sequentially arranged in the lower joint (2).

5. The drift plug tool of claim 4, wherein, The pressure relief hole (12) is arranged on the outer wall of the spring ring groove (10).

6. The drift plug tool of claim 1, wherein, A stepped hole (13) and a tapered hole (14) are sequentially arranged in the sliding sleeve ball seat (4).

7. The drift plug tool of claim 6, wherein, The tapered hole (14) is a conical structure with a narrow inner part and a wide outer part.

8. The drift plug tool of claim 6, wherein, In the leak-stopping state, the stepped hole (13) and the tapered hole (14) are arranged with a rubber ball (6).

9. The drift plug tool of claim 6, wherein, After the leak-stopping state, the upper joint (1) is arranged with a soluble sleeve (5).

10. The lost circulation tool of claim 9, wherein, The soluble sleeve (5) is a hollow cylindrical structure, one end of the soluble sleeve (5) is provided with a limiting chamfer (15), and the limiting chamfer (15) is matched with the tapered hole (14).

11. The drift plug tool of claim 1, wherein, The upper joint (1) is screw-connected with an upper drill rod.

12. The drift plug tool of claim 1, wherein, The lower joint (2) is screw-connected with a lower drill rod.

13. The drift plug tool of claim 1, wherein, The material of the sliding sleeve ball seat (4) is hard alloy.

14. The drift plug tool of claim 1, wherein, The material of the spring (3) is alloy.

15. The drift plug tool of claim 9, wherein, The material of the soluble sleeve (5) is alloy.

16. The drift plug tool of claim 15, wherein, The material of the soluble sleeve (5) is MgAl alloy.

17. The drift plug tool of claim 1, wherein, The outer diameters of the upper joint (1) and the lower joint (2) are equal.

18. A method of using a lost circulation while drilling tool, the method comprising: The leak-stopping tool for drilling has the steps of any one of claims 1-17. Step one: connecting the leak-stopping tool for drilling with a drill string; Step two: after finding the leakage, putting in the rubber ball (6), and the rubber ball (6) is arranged at the position of the sliding sleeve ball seat (4); Step three: continuing to press, and with the rising of the pressure, the sliding sleeve ball seat (4) moves downwards, and the flow channel is opened; Step four: the leak-stopping material passes through the flow channel and enters the leakage position of the open hole formation, and after the leakage is stopped, the soluble sleeve (5) is put in, and at this time, the soluble sleeve (5) blocks the flow channel; Step five: continuing to press, so that the pressure rises, the rubber ball (6) is reduced in diameter under the action of the pressure, thereby passing through the stepped hole (13) and falling to the drill bit; Step six: the force of the sliding sleeve ball seat (4) moving downwards disappears, and the sliding sleeve ball seat (4) moves upwards under the elastic force of the spring (3), thereby closing the flow channel; Step seven: the soluble sleeve (5) is dissolved and disappears under the action of the drilling fluid.

19. The method of using the lost circulation tool while drilling of claim 18, wherein, The leak-stopping material is diesel leak-stopping agent.

Images