Curve continuous coring drilling tool and method

Abstract

The invention discloses a curve continuous coring drilling tool and method, and relates to the technical field of geotechnical engineering.The curve continuous coring drilling tool comprises a drilling rod, a hollow screw drilling tool, a guide track control device and a coring drill bit, and the hollow screw drilling tool is connected between the drilling rod and the coring drill bit; the guide track control device comprises a plurality of control supporting components and a guide support, the control supporting components are distributed on the peripheral side of the coring drill bit, and the guide support is arranged on the outer sides of the hollow screw drill and the control supporting components; when the control supporting component is in an extending state, the guide support can be expanded outwards to form a lateral supporting effect on the hole wall, and when the control supporting component is in a retracting state, the guide support is separated from the hole wall. According to the invention, guide track control can be carried out, long-distance rapid coring, curve coring and continuous coring are realized, and the drilling precision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of geotechnical engineering, and particularly relates to a curved continuous coring drill tool and method. Background Technique

[0002] The statements in this part only provide background technical information related to the present invention, and do not necessarily constitute prior art.

[0003] Geological drilling is one of the most direct and effective means of geological information acquisition, and is an important prerequisite for ensuring the safe construction of linear projects such as traffic tunnels and water diversion tunnels. For construction areas with relatively complex geological conditions, due to restrictions such as terrain, traffic, and environment, it is very difficult to implement drilling operations. Especially when conducting drilling at a depth of thousands of meters, the construction process often encounters complex geological environments such as high stress and alternating hard and soft rocks, making it difficult to control the trajectory of the long-distance drilling process, resulting in problems such as low rock-breaking efficiency and slow coring speed.

[0004] In order to improve the coring efficiency, there are some improvement schemes in the prior art. For example, a hollow screw drill tool assembly increases the drill bit rotation speed by setting a hollow screw motor, and installs a wireline coring drill tool in the internal space to save coring time. However, when the above drill tool is used for long-distance drilling, there are still problems such as difficult adjustment of the drilling trajectory and certain drilling errors. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a curved continuous coring drill tool and method, which can perform guiding trajectory control, realize long-distance rapid coring, curved coring and continuous coring, and improve the drilling accuracy.

[0006] In order to achieve the above purpose, the present invention is realized by the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a curved continuous coring drill tool, including a drill pipe, a hollow screw drill tool, a guiding trajectory control device and a coring drill bit, and the hollow screw drill tool is connected between the drill pipe and the coring drill bit;

[0008] The guiding trajectory control device includes a control support member and a guiding support. A plurality of control support members are distributed on the periphery of the coring drill bit, and the guiding support is arranged outside the hollow screw drill tool and the control support member; when the control support member is in the extended state, the guiding support can be expanded outward to form a lateral support on the hole wall, and when the control support member is in the retracted state, the guiding support is separated from the hole wall.

[0009] As a further implementation manner, one outer wall of the guiding support has a plurality of convex portions, and the other outer wall is a smooth structure.

[0010] As a further implementation, multiple columns of the control and support members are evenly distributed on the circumferential side of one end of the coring bit close to the downhole motor.

[0011] The control and support members are connected to the driving device, and the control and support members are perpendicular to the axis direction of the coring bit.

[0012] As a further implementation, the downhole motor includes an eccentrically installed stator and a rotor, and the rotor is connected to the hollow screw.

[0013] Second, the embodiment of the present invention further provides a drilling method for a curved continuous coring tool, using the curved continuous coring device, including:

[0014] Obtain drilling parameters and rock mechanics parameters, and construct a drilling theoretical model based on mechanical specific energy;

[0015] Combined with the energy consumption during drilling, obtain a drilling model based on mechanical specific energy according to the drilling theoretical model based on mechanical specific energy;

[0016] Based on the fact that the minimum value of the mechanical specific energy for rock breaking during drilling is equal to the equivalent rock compressive strength under confining pressure, construct a drilling rate model;

[0017] Use the least squares method to determine the undetermined coefficients to obtain a drilling parameter optimization model;

[0018] According to the drilling parameter optimization model, form a drilling plan.

[0019] As a further implementation, the drilling theoretical model based on mechanical specific energy is:

[0020]

[0021] where v is the axial impact velocity, m is the mass of the drill pipe, f ac is the axial impact frequency, F is the drilling pressure, v t is the drilling speed, T is the torque, ω is the rotational speed, I is the moment of inertia of the drill pipe, ω im is the torsional impact velocity, f rac is the torsional impact frequency, and A is the cross-sectional area of the borehole.

[0022] As a further implementation, the drilling model based on mechanical specific energy is:

[0023]

[0024] where η1, η2, η3, and η4 are energy wear coefficients.

[0025] As a further implementation manner, the drilling parameter optimization model is a multi-objective optimization model for drilling with the drilling speed and power as the objectives, maximizing the drilling speed under the condition of constant power:

[0026]

[0027] where v t is the drilling speed, P is the output power of the drilling rig, and C is the maximum output power of the drilling rig.

[0028] As a further implementation manner, the rock mechanical parameters include the uniaxial compressive strength and density of the rock.

[0029] As a further implementation manner, during the drilling process, the drilling data is updated and iterated based on the multi-objective particle swarm optimization algorithm optimization model.

[0030] The beneficial effects of the present invention are as follows:

[0031] (1) The curve continuous coring drill of the present invention is provided with a guiding trajectory control device. The guiding trajectory control device includes a control support member and a guiding support. When the control support member is in the retracted state, the guiding support does not act on the hole wall and the entire drill can drill smoothly. When the control support member is in the extended state, the guiding support forms a lateral support on the hole wall, thereby generating a guiding reaction force on the entire drill to realize the guiding trajectory control and achieve the purpose of guiding drilling.

[0032] (2) The present invention combines the energy consumption during the drilling process to obtain a drilling model based on the mechanical specific energy; based on the fact that the minimum value of the mechanical specific energy for rock breaking during the drilling process is equal to the equivalent uniaxial compressive strength of the rock under confining pressure, a drilling speed model is constructed; the least squares method is used to determine the undetermined coefficients to obtain a drilling parameter optimization model; according to the drilling parameter optimization model, a drilling plan is formed; for complex working conditions such as long-distance high in-situ stress and alternating hard and soft strata, the optimal drilling parameters and optimization effects can be given to achieve precise drilling.

[0033] (3) The drilling model of the present invention based on the mechanical specific energy simultaneously considers the comprehensive influence of six parameters, namely the axial static pressure, axial impact velocity, torsional impact velocity, rotational speed, axial impact frequency, and torsional impact frequency. Compared with the existing drilling models, more and more comprehensive factors are considered; on the other hand, the actual construction working conditions are also considered, and the power and various limit construction parameters are used as constraint conditions to optimize the drilling speed on the premise of constant power. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The specification drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0035] Figure 1Schematic diagram of the curved continuous coring drill tool according to one or more embodiments of the present invention;

[0036] Figure 2 Partial schematic diagram of the curved continuous coring drill tool according to one or more embodiments of the present invention;

[0037] Figure 3 Schematic diagram of the guiding trajectory control device according to one or more embodiments of the present invention;

[0038] Figure 4 Schematic diagram of the hollow screw drill tool according to one or more embodiments of the present invention;

[0039] Figure 5 Schematic diagram of the curved continuous coring drill tool during drilling according to one or more embodiments of the present invention;

[0040] Figure 6 Flowchart of the curved continuous coring method according to one or more embodiments of the present invention.

[0041] Wherein, 1, drill pipe; 2, wireline retrievable tool; 3, core; 4, connecting device; 5, hollow screw drill tool; 6, guiding trajectory control device; 7, coring bit; 8, guiding support; 9, control support member; 10, stator; 11, rubber layer; 12, rotor; 13, cavity. Detailed implementation manners

[0042] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0043] Example 1:

[0044] This example provides a curved continuous coring drill tool. Compared with the existing drill tools, the guiding trajectory control device 6 is added in this example to realize the control of the drilling direction of the drill tool.

[0045] As Figure 1 and Figure 2 and Figure 5As shown, the curved continuous coring drill of this embodiment includes a drill pipe 1, a downhole motor 5, a guiding trajectory control device 6, a coring bit 7, etc. One end of the drill pipe 1 is connected to the downhole motor 5 and the guiding trajectory control device 6 through a connecting device 4, and the other end of the downhole motor 5 is connected to the coring bit 7. Among them, the coring bit 7 is used to obtain the core 3 during drilling. The guiding trajectory control device 6 can achieve large-angle trajectory control during the coring process. The downhole motor 5 is used to provide bottom-hole power. The wireline fishing tool 2 in the drill pipe 1 is used to fish the bottom-hole core 3 to the ground. An impactor is also arranged between the downhole motor 5 and the coring bit 7, and the impactor provides impact force for the rock-breaking process during drilling.

[0046] In this embodiment, the trajectory of the coring process is controlled by the guiding trajectory control device 6. As Figure 3 shown, the guiding trajectory control device 6 includes a guiding support 8. The guiding support 8 is sleeved outside the coring bit 7 and the downhole motor 5. One end of the guiding support 8 is connected to the connecting device 4. The connecting device 4 is a conventional structure, for example, it can be a sleeve structure with internal threads. The guiding support 8 is a cylindrical structure as a whole. One side outer wall thereof has a plurality of protruding parts, and the other side outer wall is a smooth structure. Among them, the side part of the guiding support 8 where the protruding parts are arranged is set as a movable structure. This part uses a splicing plate to cooperate with other parts of the guiding support 8. The splicing plate is hinged to the connecting device 4, so that the splicing plate can move under the action of an external force.

[0047] The control support member 9 is installed on the coring bit 7, and the control support member 9 has an extended state and a retracted state. During the extension process of the control support member 9, the inner side of the guiding support 8 is pushed by the control support member 9, and the splicing plate of the guiding support 8 moves outward, which can contact the hole wall and form a lateral support force on the hole wall, so as to generate a reaction force for guiding the whole drill, achieving the purpose of directional drilling. When the control support member 9 is in the retracted state, it has no effect on the guiding support 8, and the guiding support 8 will not form a support force on the hole wall. At this time, the whole drill can drill smoothly. Therefore, the guiding trajectory control can be realized and the curved coring can be achieved under the combined action of the control support member 9 and the guiding support 8.

[0048] As Figure 3As shown in the figure, several control and support members 9 are evenly distributed on the circumferential side of one end of the coring bit 7 close to the downhole motor 5. The control and support members 9 are arranged in multiple columns along the circumferential direction of the coring bit 7, and each column has multiple control and support members 9 to form a stable pushing effect on the guiding support 8. The control and support members 9 are perpendicular to the axis direction of the coring bit 7. In the initial state, a certain length protrudes from the side wall of the coring bit 7, and this length does not produce a supporting effect on the guiding support 8. The control and support members 9 are connected to a driving device inside the coring bit 7, and the driving device can drive the control and support members 9 to move in a direction perpendicular to the coring bit 7. The driving device can provide linear motion power, and it can be an electric, pneumatic or hydraulic driving method. For example, each column of control and support members 9 is connected to the same push plate, and the push plate is connected to an electric push rod.

[0049] The downhole motor 5 is used to provide bottom-hole power, such as Figure 5 As shown in the figure, the downhole motor 5 includes an eccentrically installed stator 10 and a rotor 12. A rubber layer 11 is arranged between the stator 10 and the rotor 12. The rotor 12 is connected to a hollow screw, and the hollow screw has a cavity 13, which is used to store and transport the core 3.

[0050] The curved continuous coring tool of this embodiment provides bottom-hole power through the downhole motor 5 and is applicable to long-distance drilling; moreover, the tool has a guiding function and can perform long-distance directional coring; due to the setting of the wireline fishing tool 2, long-distance continuous coring can be carried out.

[0051] Therefore, the curved continuous coring tool of this embodiment can achieve long-distance rapid coring, curved coring and continuous coring.

[0052] Embodiment 2:

[0053] This embodiment provides a drilling method for a curved continuous coring tool, which uses the curved continuous coring device described in Embodiment 1 and includes:

[0054] Obtain drilling parameters and rock mechanics parameters, and construct a drilling theoretical model based on mechanical specific energy;

[0055] Combined with the energy consumption during the drilling process, obtain a drilling model based on mechanical specific energy according to the drilling theoretical model based on mechanical specific energy;

[0056] Based on the fact that the minimum value of the rock-breaking mechanical specific energy during the drilling process is equal to the equivalent rock compressive strength under confining pressure, construct a drilling rate model;

[0057] Use the least squares method to determine the undetermined coefficients to obtain a drilling parameter optimization model;

[0058] According to the drilling parameter optimization model, form a drilling plan.

[0059] Specifically, such as Figure 6As shown, the drilling parameters include axial static pressure, axial impact velocity, axial impact frequency, rotational speed, torque, torsional impact velocity, and impact frequency, and the rock mechanics parameters include rock compressive strength and density.

[0060] Furthermore, the process of constructing the drilling theoretical model based on the mechanical specific energy is as follows:

[0061] The expression of mechanical specific energy (the energy required to break a unit volume of rock) is:

[0062]

[0063] In Equation (1), W is the energy required to break the rock, and V is the broken volume of the rock.

[0064] Among them, the rock-breaking energy W can be expressed as:

[0065] W = W a,i + W a,p + W r,i + W r,s (2)

[0066] In Equation (2), W a,i is the axial impact rock-breaking energy, W a,p is the axial static pressure rock-breaking energy, W r,i is the torsional impact rock-breaking energy, W r,s is the rotary cutting rock-breaking energy. The specific expressions are:

[0067]

[0068] W r,s = Tωt (6)

[0069] The drilling theoretical model based on the energy expression (drilling theoretical model based on mechanical specific energy) after sorting from Equation (1) to Equation (6) is:

[0070]

[0071] In Equation (7), v is the axial impact velocity, m is the mass of the drill pipe, f ac is the axial impact frequency, F is the drilling pressure, v t is the drilling speed, T is the torque, ω is the rotational speed, I is the moment of inertia of the drill pipe, ω im is the torsional impact velocity, f rac is the torsional impact frequency, and A is the cross-sectional area of the borehole.

[0072] Furthermore, considering the energy consumption generated by friction due to the drilling pressure, torque, and impact during the drilling process, the energy wear coefficients η1, η2, η3, and η4 are added based on Equation (7) to obtain the drilling model based on mechanical specific energy:

[0073]

[0074] During the actual drilling process, the ratio of the minimum mechanical specific energy for rock breaking to the actual mechanical specific energy for drilling is the rock breaking energy efficiency. The minimum value of the mechanical specific energy for rock breaking during the drilling process is equal to the equivalent rock compressive strength under confining pressure, that is:

[0075]

[0076] E min = S cc (10)

[0077] In Equations (9) and (10), E EFE is the rock breaking energy efficiency, E min is the minimum mechanical specific energy for rock breaking, E s is the actual mechanical specific energy for drilling, and S cc is the equivalent rock compressive strength considering confining pressure and water pressure conditions.

[0078]

[0079] The rock breaking energy efficiency is related to the rock compressive strength and rock density:

[0080] E EFE = (k1S cc + b1)(k2lnρ + b2) (13)

[0081] Therefore, the drilling rate model is obtained:

[0082]

[0083] In Equation (14), ρ is the density of the rock, and k1, k2, b1, and b2 are undetermined coefficients.

[0084] Furthermore, in this embodiment, with the goal of rapid drilling, the drilling speed is optimized and improved. However, if only the improvement of the drilling speed is considered, it is contrary to the actual engineering; this is because the drilling power is limited in actual engineering, and the power needs to be constrained.

[0085] Therefore, in this embodiment, a multi-objective optimization model for drilling with the drilling speed and power as the objectives maximizes the drilling speed under the condition of constant power.

[0086]

[0087] In Equation (15), C is the maximum output power of the drill, and P is the output power of the drill.

[0088] Furthermore, based on the drilling multi-objective optimization model, drilling data during the drilling process of the rig is obtained, and the mechanical parameters of the drilled rock are input. Moreover, as the drilling progresses, the optimization model is continuously updated and learned according to the multi-objective particle swarm optimization algorithm to improve the accuracy of the drilling results. By analyzing the drilling parameters in real time, the optimization results of the drilling parameters and the adjustment methods are given to guide the rapid core drilling in the project.

[0089] In this embodiment, it is not necessary to adjust various construction parameters (torque, static pressure, impact velocity, impact frequency, etc.) to the maximum to achieve the fastest drilling speed. Instead, multiple parameters are coordinated to seek the optimal combination to achieve the optimal construction operation parameters. Based on the drilling model of mechanical specific energy, this embodiment simultaneously considers the comprehensive influence of six parameters, namely axial static pressure, axial impact velocity, torsional impact velocity, rotational speed, axial impact frequency, and torsional impact frequency. Compared with the existing drilling models, more and more comprehensive factors are considered. On the other hand, the actual construction conditions are also considered, and the power and various limit construction parameters are used as constraint conditions to optimize the drilling speed on the premise of constant power.

[0090] This embodiment can give the optimal drilling parameters and optimization effects for complex working conditions such as long-distance high in-situ stress and alternating hard and soft strata, and achieve precise drilling.

[0091] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A curve continuous coring drill tool, characterized in that, It includes a drill pipe, a downhole motor, a steering trajectory control device and a core bit, and the downhole motor is connected between the drill pipe and the core bit; The steering trajectory control device includes a control support member and a guiding support. A plurality of control support members are distributed around the core bit, and the guiding support is arranged outside the downhole motor and the control support members. When the control support members are in the extended state, the guiding support can be unfolded outwards to form a lateral supporting effect on the hole wall, and when the control support members are in the retracted state, the guiding support is separated from the hole wall.

2. The curve continuous coring drill tool according to claim 1, characterized in that, One outer wall of the guiding support has a plurality of protrusions, and the other outer wall is a smooth structure.

3. The curve continuous coring drill tool according to claim 1, characterized in that, The control support members are evenly distributed in multiple columns on the circumference of one end of the core bit close to the downhole motor; The control support members are connected to a driving device, and the control support members are perpendicular to the axis direction of the core bit.

4. A kind of curve continuous coring drill tool according to claim 1, characterized in that, The downhole motor includes an eccentrically installed stator and a rotor, and the rotor is connected to a hollow screw.

5. A drilling method for a curve continuous coring drill string according to any one of claims 1-4, characterized in that, It includes: Obtain drilling parameters and rock mechanics parameters, and construct a drilling theoretical model based on mechanical specific energy; Combined with the energy consumption during the drilling process, obtain a drilling model based on mechanical specific energy according to the drilling theoretical model based on mechanical specific energy; Based on the fact that the minimum value of the mechanical specific energy for rock breaking during the drilling process is equal to the equivalent rock compressive strength under confining pressure, construct a drilling rate model; Use the least squares method to determine the undetermined coefficients to obtain a drilling parameter optimization model; According to the drilling parameter optimization model, form a drilling plan.

6. A drilling method for a curve continuous coring drill tool according to claim 5, characterized in that, The drilling theoretical model based on mechanical specific energy is: v is the axial impact velocity, m is the mass of the drill pipe, and f ac is the axial impact frequency, and F is the drilling pressure. Among them, Force, v t is the drilling speed, T is the torque, ω is the rotational speed, I is the moment of inertia of the drill pipe, ω im is the torsional impact speed, f rac is the torsional impact frequency, A is the cross-sectional area of the borehole.

7. A drilling method for a curve continuous coring drill tool according to claim 6, characterized in that The drilling model based on mechanical specific energy is: Among them, η1, η2, η3, and η4 are energy wear coefficients.

8. A drilling method for a curve continuous coring drill tool according to claim 5, characterized in that, The drilling parameter optimization model is a multi-objective optimization model for drilling with drilling rate and power as the objectives, and maximizes the drilling speed under the condition of constant power: Among them, v t is the drilling speed, P is the output power of the drilling rig, and C is the maximum output power of the drilling rig.

9. The drilling method of a curve continuous coring drill tool according to claim 5, characterized in that The rock mechanics parameters include rock compressive strength and density.

10. The drilling method of a curve continuous coring drill tool according to claim 5, characterized in that During the drilling process, update and iterate the drilling data based on the multi-objective particle swarm optimization algorithm optimization model.

Images