PDC drill bit tooth simulation cutting experimental device

Abstract

The present invention discloses a PDC drill bit tooth simulation cutting experimental device, including: a main structure, which includes: a loading cylinder barrel, a confining pressure cavity is formed therein, and a confining pressure injection interface is sealed at the bottom end; a peripheral sleeve is provided with a heating sleeve; a pressure-bearing straightening cylinder, which is sealed and arranged at the top of the loading cylinder barrel, an axial pressure loading mechanism, including an axial pressure loading cavity sealed and fixed in the pressure-bearing straightening cylinder, a PDC piston loading rod in sealing contact with the axial pressure loading cavity and relatively movable, a detection component and a test tool for connecting the test tool are arranged at one end of the PDC piston loading rod, and the detection component includes a uniaxial load sensor and a temperature sensor; a bearing frame, which is used to protect and fix the main structure; a cylinder lifting mechanism, which is installed and fixed by the bearing frame and is used to drive the confining pressure cavity to move axially; a sample clamping tool, which is arranged in the confining pressure cavity for installing a core sample; and a data acquisition and processing system, which is used to be electrically connected to the detection component. The present invention has various and rich functions.

Description

Technical Field

[0001] The invention relates to the technical field of PDC drill bit tooth rock breaking research, and in particular to a PDC drill bit tooth simulation cutting experimental device. Background Art

[0002] The description in this section merely provides background information related to the present disclosure and does not constitute prior art.

[0003] Reducing drilling costs and increasing drilling speed is one of the eternal themes of the development of the oil and gas well industry. PDC drill bits have been increasingly widely used in the oil and gas well industry due to their high drilling speed, long life, good stability, low unit footage cost, and flexible drill bit design. However, with the discovery of deeper reservoirs and the drilling of deeper wells, the rock is often harder, and the pressure and temperature conditions become more extreme. Therefore, a better understanding of the interaction between the drill bit and the rock in deep and ultra-deep well environments is of great significance for responding to the increase in the speed and efficiency of PDC drill bits.

[0004] PDC drill bits are a key link in increasing drilling speed and efficiency, and are one of the core technologies for achieving "one-trip drilling" in oil and gas well engineering. The performance of the drill bit will directly affect the drilling cycle, drilling quality and drilling costs. PDC drill bit teeth are an important component of the PDC drill bit, and its rock breaking efficiency directly affects the overall rock breaking effect of the drill bit.

[0005] Indoor experimental research on PDC drill teeth will help analyze its rock breaking mechanism. However, the current indoor experiments on PDC drill teeth can only provide atmospheric environmental pressure, resulting in a serious lack of simulation experiments on PDC drill teeth cutting under confining pressure. In addition, the main problem of the current indoor experiments on PDC drill teeth is the lack of machines that can meet the requirements of PDC drill teeth cutting under confining pressure. Compared with simulation, experimental research is more consistent with the field situation and more convincing. Therefore, it is urgent to design a mechanical device that can meet the requirements of PDC drill teeth cutting tests under confining pressure.

[0006] In view of the above problems, it is necessary to propose a PDC drill bit tooth cutting experimental device that can provide a confining pressure environment under the premise of fully considering the industrial manufacturing level. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a PDC drill bit tooth simulation cutting experimental device which can simulate and collect the mechanical behaviors of the tangential, radial and axial forces exerted on the PDC drill bit teeth when cutting rocks under a simulated confining pressure environment, and the experimental device has various and rich functions.

[0008] The embodiment of the present application discloses a PDC drill bit tooth simulation cutting experimental device, comprising: a main structure, which comprises: a hollow loading cylinder body, a confining pressure cavity is formed in the loading cylinder body, and the loading cylinder body has a top end and a bottom end opposite to each other; the bottom end is sealed with a confining pressure injection interface; the outer sleeve of the loading cylinder body is provided with a heating sleeve; a hollow pressure-bearing straightening cylinder, which is sealed and arranged at the top end of the loading cylinder body and extends upward away from the bottom end; an axial pressure loading mechanism, comprising an axial pressure loading cavity sealed and fixed in the pressure-bearing straightening cylinder, a sealing contact with the axial pressure loading cavity and A relatively movable PDC piston loading rod, and a detection assembly, wherein the end of the PDC piston loading rod close to the confining pressure injection interface is provided with a detection assembly and a tool for connecting an experimental tool, wherein the detection assembly includes a uniaxial load sensor and a temperature sensor; a bearing frame, which is arranged on the periphery of the main structure and is used to protect and fix the main structure; a cylinder lifting mechanism, which is installed and fixed by the bearing frame and is used to drive the axial movement of the confining pressure chamber; a sample clamping tool, which is arranged in the confining pressure chamber and is used to install a core sample; and a data acquisition and processing system, which is used to be electrically connected to the detection assembly.

[0009] In a preferred embodiment, the axial pressure loading mechanism further comprises: a magnetostrictive displacement sensor capable of detecting the axial movement distance of the PDC piston loading rod.

[0010] In a preferred embodiment, the experimental tool includes: a single-tooth cutting tool, a drillable tool, and the detection component further includes: a three-dimensional force sensor or a torque sensor connected between the uniaxial load sensor and the single-tooth cutting tool or the drillable tool.

[0011] In a preferred embodiment, the cylinder lifting mechanism includes a cylinder lifting track fixed on the supporting frame and connected to the confining pressure chamber, and a lifting cylinder connected to the cylinder lifting track and used to provide driving force. The confining pressure chamber can be driven by the lifting cylinder to move axially along the cylinder lifting track.

[0012] In a preferred embodiment, the supporting frame includes: a top cover, a bottom cover and a surrounding frame arranged between the top cover and the bottom cover connected by fastening bolts, and the lifting cylinder is fixed on the top cover.

[0013] In a preferred embodiment, the main structure also includes a pressure-bearing chassis arranged at the bottom end of the loading cylinder barrel, the pressure-bearing chassis is in sealed contact with the confining pressure chamber, and a sample rotation mechanism is installed on the pressure-bearing chassis. The sample rotation mechanism is fixed to the sample clamping tool and is used to drive the core sample to rotate.

[0014] In a preferred embodiment, the sample rotating mechanism comprises: a sample rotating disk fixed to the sample clamping tool, a rotating disk power assembly for driving the sample rotating disk to rotate, and a high-speed bearing installed between the sample rotating disk and the pressure chassis.

[0015] In a preferred embodiment, the PDC drill bit tooth simulation cutting experimental device further comprises a guide rail bracket, and the pressure-bearing chassis is placed on the guide rail bracket.

[0016] In a preferred embodiment, the pressure-bearing chassis, the sample clamping tool, the high-speed bearing, and the rotating disk power assembly can move as a whole relative to the guide rail bracket.

[0017] In a preferred embodiment, two windows are installed on the loading cylinder body, which are connected to the confining pressure chamber and are horizontally oriented at 90° to each other; one of the windows is used as a light source window, and the other is used as an observation window.

[0018] In a preferred embodiment, a sealing adjustment mechanism is arranged between the pressure-bearing straightening cylinder and the axial pressure loading mechanism, and an eccentric adjustment portion is arranged on the inner wall of the pressure-bearing straightening cylinder. The sealing adjustment mechanism can cooperate with the pressure-bearing straightening cylinder to change the radial position of the axial pressure loading mechanism. When the sealing adjustment mechanism is in a first position relative to the eccentric adjustment portion, the axis of the axial pressure loading mechanism can be directly opposite to the center of the core sample. When the sealing adjustment mechanism is in a second position relative to the eccentric adjustment portion, the axis of the axial pressure loading mechanism is staggered from the center of the core sample.

[0019] The characteristics and advantages of the present invention are:

[0020] The present invention comprehensively considers the actual situation of on-site drilling and can provide better feedback for theoretical research. The device can provide a confining pressure environment of a specified pressure to the confining pressure chamber through the confining pressure injection interface, and the flexible temperature sensor mounted on the pressure-bearing straightening cylinder can monitor the temperature of the liquid in the confining pressure chamber in real time, and can also exchange information with the external flexible heating sleeve to maintain the liquid temperature in the confining pressure chamber at the set temperature value. In terms of cutting mode, it can meet the traditional PDC drill bit cutting at a specified fixed depth. In addition, the axial pressure loading chamber can perform PDC drill bit cutting under fixed axial pressure conditions similar to on-site drilling.

[0021] The device can also be used for rock drillability experiments, by comparing the time it takes for PDC drill teeth to cut a certain depth under fixed axial pressure conditions to determine the drillability of the rock. It can also be used to study the impact of the holding effect on the rock crushing mechanism, and to compare the three-dimensional force changes of the data acquisition system before and after laying cuttings to determine whether to lay cuttings on the cutting trajectory.

[0022] It is worth noting that the PDC drill bit tooth simulation cutting test device provided in this application is different from the general single test machine. The PDC drill bit tooth simulation cutting test device can be used not only for single tooth cutting experiments, but also for drillability experiments. There are also multiple options for cutting modes. A constant depth can be set for cutting, a constant feed speed can be used for cutting, and a constant axial pressure cutting method that is consistent with the actual situation on site can be used. The core sample rotates quickly and efficiently, can quickly reach the set speed, and is stable. At the same time, the core sample can also be set to stop at a certain angle. The equipment has diverse and rich functions.

[0023] With reference to the following description and drawings, the specific embodiments of the present application are disclosed in detail, indicating the manner in which the principles of the present application can be adopted. It should be understood that the embodiments of the present application are not limited in scope.

[0024] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0025] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of a PDC drill bit tooth simulation cutting experimental device provided in an embodiment of the present application;

[0027] Figure 2 It is a schematic diagram of the pressure-bearing frame and its main structure of the PDC drill bit tooth simulation cutting experimental device in the single-tooth cutting experimental state in the implementation manner of the present application;

[0028] Figure 3 for Figure 2 A local enlarged schematic diagram of the middle A;

[0029] Figure 4 It is a schematic diagram of the pressure-bearing frame and its main structure of the PDC drill bit tooth simulation cutting experimental device in the drillability experimental state in the implementation mode of the present application;

[0030] Figure 5 for Figure 4 A partial enlarged schematic diagram of point B in the middle;

[0031] Figure 6 It is a structural schematic diagram of the axial pressure loading mechanism provided in the embodiment of the present application;

[0032] Figure 7 for Figure 2 Sectional view at CC.

[0033] Description of reference numerals:

[0034] 1. Load-bearing frame;

[0035] 2. Aluminum alloy single door;

[0036] 3. Pressure-bearing straightening cylinder;

[0037] 4. Magnetotropic displacement sensor;

[0038] 5. Sensor bracket;

[0039] 6. Axial pressure loading cavity;

[0040] 7. Confining pressure cavity;

[0041] 8. Observation window;

[0042] 9. Guide rail bracket;

[0043] 10. Servo motor;

[0044] 11. Lifting cylinder;

[0045] 12. Tighten the bolts;

[0046] 13. Cylinder lifting track;

[0047] 14. Reversing slot;

[0048] 15. Sealing assembly;

[0049] 16. Loading cylinder barrel;

[0050] 17. Single axis load sensor;

[0051] 18. Three-dimensional force sensor;

[0052] 19. Core samples;

[0053] 20. Sample clamping tools;

[0054] 21. High-speed bearings;

[0055] 22. Transmission mechanism;

[0056] 23. Observation window connector;

[0057] 24. Sapphire mirror;

[0058] 25. Pressure cap;

[0059] 26. Single tooth cutting tool;

[0060] 27. Drillable tools;

[0061] 28. Confining pressure injection interface;

[0062] 29. Torque sensor;

[0063] 30. Temperature sensor;

[0064] 31. Heating jacket;

[0065] 32. PDC piston loading rod;

[0066] 33. Sealing adjustment mechanism;

[0067] 34. Pressure-bearing chassis. DETAILED DESCRIPTION

[0068] The details of the present invention can be more clearly understood by combining the accompanying drawings and the description of the specific embodiments of the present invention. However, the specific embodiments of the present invention described herein are only used for the purpose of explaining the present invention and cannot be understood as limiting the present invention in any way. Under the guidance of the present invention, technicians can conceive of any possible variations based on the present invention, which should be regarded as belonging to the scope of the present invention. It should be noted that when an element is referred to as "arranged on" another element, it can be directly on another element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there may be a central element at the same time. The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the communication between the two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method.

[0069] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0070] At present, the research on rock breaking by PDC drill teeth mainly relies on obtaining a simulated cutting experimental device by modifying a lathe or planer to meet the rock cutting conditions as much as possible. The simulated cutting experimental device includes a lathe, a rock sample chuck, a three-axis dynamometer, an adjustment device, a locking device, a PDC drill bit tooth and a rock sample, which are completely exposed to the air. The rock sample chuck rotates or moves linearly to complete the process of PDC drill bit teeth cutting rocks.

[0071] During actual on-site drilling, the PDC drill bit is always in the drilling fluid. At the same time, the properties and parameters of most rocks will change after the confining pressure reaches a certain value. However, the above-mentioned simulated cutting experimental device can only realize rock cutting work in an atmospheric environment, and cannot provide a confining pressure environment. The cutting mechanism and rock cuttings accumulation of PDC drill bit teeth in a liquid environment or even in a confining pressure environment cannot be realized through experiments. It cannot provide experimental support for the high temperature and high pressure formations commonly encountered in deep wells and ultra-deep wells in current drilling development, which has a certain impact on the understanding of the cutting mechanism in a high temperature and high pressure environment.

[0072] In another experimental study on the cutting mechanism of PDC drill bit teeth, a rock cutting experimental device in a confining pressure environment was provided, which can provide three independent pressures to the rock: the confining pressure acting on the side of the cylindrical core sample, the pore pressure acting inside the rock pores and controlled by the bottom surface of the sample, and the pressure acting on the upper surface of the rock due to the drilling.

[0073] In use, the core sample is mounted in a sample holder and placed in the high pressure chamber. The high pressure chamber is filled with the required fluid and closed. The pressure pump then pressurizes the rock and once the required pressure conditions are reached, the variable speed drive rotates the rock sample inside the pressure cell. As the rock rotates at a given rotational speed under pressurized conditions, the cutter drive system pushes the cutter downward, pressing the single cutter into the rock and producing the cut in a single round of cutting. The current design of the device is to perform almost one round of cutting at a fixed cutting depth.

[0074] The device can only conduct rock cutting experiments at room temperature. The rubber ring that separates the pressure at high temperature may be deformed by heat and cannot effectively isolate the pressure of various parts. In actual on-site drilling conditions, there is a temperature gradient in the formation, and most underground wells will have a high temperature and high pressure environment. In addition, the cutting mode can use the pneumatic piston drive system to make the PDC drill bit teeth reach the specified depth and cut the rock at a fixed cutting depth, which is somewhat different from the fixed drilling pressure used in actual on-site drilling.

[0075] As my country's drilling develops towards deeper layers, high temperature and high pressure formations are encountered during the drilling and mining process. However, the basic principles of PDC drill bit teeth cutting rocks under high temperature and high pressure environments are not yet clear, and there is an urgent need for a PDC drill bit tooth cutting device that can provide a high temperature and high pressure environment.

[0076] The present application specification provides a PDC drill bit tooth simulation cutting experimental device. In addition to helping to study the basic principle of PDC drill bit teeth cutting rocks under high temperature and high pressure environments, the device can also be used for rock drillability experiments by grading the time required to drill to a certain depth under fixed drilling pressure, and testing and analyzing the drillability characteristics of rocks; at the same time, in a confining pressure environment with liquid, rock cuttings will have a holding effect, and can also be used to study the influence of the holding effect on the rock crushing mechanism, etc., including but not limited to experimental research that can be carried out under these confining pressure environments.

[0077] Please refer to Figures 1 to 5 In the embodiment of the present application, a PDC drill bit tooth simulation cutting experimental device is provided, which can mainly include: a main structure, a load-bearing frame 1, a cylinder lifting mechanism, a sample clamping tool 20, a data acquisition and processing system, etc.

[0078] The main structure may include: a hollow loading cylinder barrel 16, a confining pressure cavity 7 is formed in the loading cylinder barrel 16, and the loading cylinder barrel 16 has a top and a bottom opposite to each other; the bottom end is sealed with a confining pressure injection interface 28; the outer sleeve of the loading cylinder barrel 16 is provided with a heating sleeve 31; a hollow pressure-bearing straightening cylinder 3, which is sealed and arranged at the top of the loading cylinder barrel 16 and extends upward away from the bottom end; an axial pressure loading mechanism, including an axial pressure loading cavity 6 sealed and fixed in the pressure-bearing straightening cylinder 3, and a heating sleeve 31 connected to the axial pressure loading cylinder 3; A PDC piston loading rod 32 is in sealing contact with the cavity 6 and can move relatively. The end of the PDC piston loading rod 32 close to the confining pressure injection interface 28 is provided with a detection component and a tool for connecting an experimental tool (for example, a single-tooth cutting tool 26, a drillability tool 27. Of course, the specific form of the experimental tool can be adapted to the specific experiment required. In the implementation mode of the present application, the single-tooth cutting tool 26 and the drillability tool 27 are mainly used as examples for illustration). The detection component includes a uniaxial load sensor 17 and a temperature sensor 30.

[0079] Please refer to Figure 6 The axial pressure loading mechanism provided in the embodiment of the present application may include an axial pressure loading chamber 6 sealed and fixed in the pressure-bearing straightening cylinder 3, a PDC piston loading rod 32 that is in sealing contact with the axial pressure loading chamber 6 and can move relatively, and a detection assembly. Among them, the axial pressure loading chamber 6 can specifically be a cavity structure with a stepped hole section formed inside, and a limited step is formed at the transition position of two hole sections with different inner diameters. The periphery of the PDC piston loading rod 32 is provided with a snap-fitting portion that cooperates with the limit step, and when the snap-fitting portion is snapped with the limit step, the PDC piston loading rod 32 is at the maximum displacement position relative to the position. The maximum displacement position can ensure that the lower end of the PDC piston loading rod 32 will not retract into the axial pressure loading chamber 6.

[0080] In addition, the axial pressure loading mechanism may further include: a magnetostrictive displacement sensor 4 that can be used to detect the axial movement distance of the PDC piston loading rod 32. Figure 6 As shown, the magnetostrictive displacement sensor 4 can be fixed on the axial pressure loading cavity 6 through the main body of the sensor bracket 5, and its measuring part can extend into the axial pressure loading cavity 6 and be inserted into the axial hole reserved for the PDC piston loading rod 32. When in use, the PDC piston loading rod 32 can move relative to the axial pressure loading cavity 6, while the magnetostrictive displacement sensor 4 is fixed relative to the axial pressure loading cavity 6, so as to measure the axial movement distance of the PDC piston loading rod 32.

[0081] The detection assembly may further include: a three-dimensional force sensor 18 and / or a torque sensor 29 connected between the uniaxial load sensor 17 and the single-tooth cutting tool 26 or the drillable tool 27. The above sensors may be installed and positioned by a sensor bracket 5.

[0082] Among them, the approximate installation positions of each sensor are as follows: the lower end of the PDC piston loading rod 32 is connected to the uniaxial load sensor 17; the lower end of the uniaxial load sensor 17 is connected to the three-dimensional force sensor 18 (or torque sensor 29); the lower end of the three-dimensional force sensor 18 (or torque sensor 29) is connected to the single-tooth cutting tool 26 (or drillable tool 27); the lower end of the high-pressure uniaxial load sensor 17 is installed with a temperature sensor 30.

[0083] like Figure 3 As shown, in one embodiment, two windows are installed on the loading cylinder body 16, which are connected to the confining pressure chamber 7 and are horizontally 90 degrees to each other; one of the windows is used as a light source window, and the other is used as an observation window 8. Taking the observation window 8 as an example, it may include: an opening opened on the loading cylinder body 16, an observation window connector 23 is arranged in the opening, a sapphire mirror 24 is arranged in the connector, and an observation window pressure cap 25 is arranged on the outer periphery of the sapphire mirror 24.

[0084] The PDC drill bit tooth simulation cutting experimental device provided in the present application can be used for both single tooth cutting experiments and drillability experiments.

[0085] Since the single-tooth cutting experiment and the drillability experiment have different relative position relationships of the axial pressure loading mechanism with respect to the core sample 19, in order to achieve switching between the two, a sealing adjustment mechanism 33 is arranged between the pressure-bearing straightening cylinder 3 and the axial pressure loading mechanism, and an eccentric adjustment portion is arranged on the inner wall of the pressure-bearing straightening cylinder 3. The sealing adjustment mechanism 33 can cooperate with the pressure-bearing straightening cylinder 3 to change the radial position of the axial pressure loading mechanism. When the sealing adjustment mechanism 33 is in a first position relative to the eccentric adjustment portion, the axis of the axial pressure loading mechanism can be directly opposite to the center of the core sample 19. When the sealing adjustment mechanism 33 is in a second position relative to the eccentric adjustment portion, the axis of the axial pressure loading mechanism is staggered with the center of the core sample 19.

[0086] Specifically, the eccentric adjustment portion on the pressure-bearing straightening cylinder 3 can be an axial step limit hole opened on the inner wall of the pressure-bearing straightening cylinder 3, and the center of the axial step limit hole has different radial distances from the axis of the pressure-bearing straightening cylinder 3. Figure 7 As shown, the sealing adjustment mechanism 33 may be an annular structure as a whole, and the centers of the inner circle and the outer circle may not coincide.

[0087] When the sealing adjustment mechanism 33 is in the first position relative to the axial step limit hole, it can ensure that the axis of the axial pressure loading mechanism can be directly opposite to the center of the core sample 19 to facilitate drillability experiments. When the sealing adjustment mechanism 33 is in the second position relative to the axial step limit hole, the axis of the axial pressure loading mechanism is offset from the center of the core sample 19 to facilitate single-tooth cutting experiments.

[0088] In the middle of the pressure-bearing straightening cylinder 3, in order to ensure that the axial pressure loading mechanism does not interfere when switching to different experimental positions, a reversing groove 14 is provided in the pressure-bearing straightening cylinder 3. Specifically, in addition to providing a space for the pressure-bearing straightening cylinder 3 to switch positions, the reversing groove 14 can also be provided with two limiting parts (a first limiting part and a second limiting part) corresponding to the axial pressure loading mechanism. When the sealing adjustment mechanism 33 is in the first position relative to the axial step limiting hole, the axial pressure loading mechanism can be inserted into the first limiting part to limit it radially; when the sealing adjustment mechanism 33 is in the second position relative to the axial step limiting hole, the axial pressure loading mechanism can be inserted into the second limiting part to limit it radially.

[0089] Of course, the sealing adjustment mechanism 33 cooperates with the pressure-bearing straightening cylinder 3 to achieve a structure for changing the radial position of the axial pressure loading mechanism and is not limited to the above examples. Technical personnel in the relevant field may make other changes inspired by the technical essence of this application. However, as long as the functions and effects achieved are the same or similar to those of this application, they should be covered within the scope of protection of this application.

[0090] In this embodiment, the pressure-bearing centralizing cylinder 3 and the loading cylinder barrel 16 can be sealed by a sealing assembly 15. Specifically, the sealing assembly 15 can be a component that is resistant to high pressure and high temperature.

[0091] In this embodiment, the load-bearing frame 1 can be arranged outside the main structure to protect and fix the main structure. The load-bearing frame 1 can include: a top cover, a bottom cover connected by fastening bolts 12, and a surrounding frame arranged between the top cover and the bottom cover. Figure 1 As shown, an aluminum alloy single-opening door 2 may be provided on the enclosure frame, through which the supporting frame 1 can be opened to install or overhaul the internal components.

[0092] In this embodiment, the cylinder lifting mechanism is installed and fixed by the supporting frame 1 and is used to drive the confining pressure chamber 7 to move axially.

[0093] Specifically, the cylinder lifting mechanism includes a cylinder lifting track 13 fixed on the bearing frame 1 and connected to the confining pressure chamber 7, and a lifting cylinder 11 connected to the cylinder lifting track 13 and used to provide a driving force, and the confining pressure chamber 7 can be driven by the lifting cylinder 11 to move axially along the cylinder lifting track 13. The lifting cylinder 11 can be fixed on the top cover of the bearing frame 1.

[0094] Furthermore, the main structure may also include a pressure chassis 34 arranged at the bottom end of the loading cylinder barrel 16, the pressure chassis 34 is in sealing contact with the confining pressure chamber 7, and a sample rotation mechanism is installed on the pressure chassis 34, and the sample rotation mechanism is fixed to the sample clamping tool 20, and is used to drive the core sample 19 to rotate.

[0095] In one embodiment, the sample rotating mechanism includes: a sample rotating disk fixed to the sample clamping tool 20, a rotating disk power assembly for driving the sample rotating disk to rotate, and a high-speed bearing 21 installed between the sample rotating disk and the pressure-bearing chassis 34. The high-speed bearing 21 can be used to control the rapid and accurate rotation of the sample rotating disk. Among them, the sample rotating disk installed on the pressure-bearing chassis 34 can be driven to rotate by the rotating disk power assembly through a transmission mechanism 22. Specifically, the transmission mechanism 22 can be in the form of a synchronous belt. Of course, the transmission mechanism 22 can also be in the form of other structures, and this application does not make specific limitations here.

[0096] In one embodiment, the PDC drill bit tooth simulation cutting experimental device further includes a guide rail bracket 9, and the pressure-bearing chassis 34 is placed on the guide rail bracket 9. Further, the pressure-bearing chassis 34, the sample clamping tool 20, the high-speed bearing 21, and the rotating disk power assembly can move as a whole relative to the guide rail bracket 9. Specifically, the pressure-bearing chassis 34, the sample clamping tool 20, the high-speed bearing 21, and the rotating disk power assembly can be integrated into an integrated structure. During subsequent use, they can be moved as a whole.

[0097] The rotating disk power assembly may include: a high-power servo motor 10. Of course, the specific form of the rotating disk power assembly is not limited to the above examples, and the present application does not make any specific limitation here.

[0098] The present invention comprehensively considers the actual situation of on-site drilling and can provide better feedback for theoretical research. The device can provide a confining pressure environment of a specified pressure to the confining pressure chamber 7 through the confining pressure injection interface 28, and the flexible temperature sensor 30 mounted on the pressure-bearing straightening cylinder 3 can monitor the temperature of the liquid in the confining pressure chamber 7 in real time, and can also exchange information with the external flexible heating sleeve 31 to maintain the temperature of the liquid in the confining pressure chamber 7 at a set temperature value. In terms of cutting mode, it can meet the traditional PDC drill bit cutting at a specified fixed depth, and can also perform PDC drill bit cutting under fixed axial pressure conditions similar to on-site drilling through the axial pressure loading chamber 6.

[0099] The device can also be used for rock drillability experiments, by comparing the time it takes for PDC drill teeth to cut a certain depth under fixed axial pressure conditions to determine the drillability of the rock. It can also be used to study the impact of the holding effect on the rock crushing mechanism, and to compare the three-dimensional force changes of the data acquisition system before and after laying cuttings to determine whether to lay cuttings on the cutting trajectory.

[0100] The present invention will be described in detail below in conjunction with specific experiments.

[0101] At least the following experiments can be performed using the PDC drill bit tooth simulation cutting experimental device provided in this application.

[0102] (I) Single tooth cutting experiment

[0103] 1. Single tooth cutting test with and without confining pressure

[0104] ①Under no confining pressure conditions: Figure 1As shown, first, by driving the sample clamping tool 20, the clamping plate on the sample clamping tool 20 clamps the four sides of the core sample 19, and the core sample 19 is pushed to the bottom of the single-tooth cutting tool 26 through the track bracket (the sample clamping tool 20, high-speed bearing 21, transmission mechanism 22, high-power servo motor 10 and other parts above the track bracket are integrated and can move smoothly on the track bracket); the single-tooth cutting tool 26 is switched to the planned PDC tooth, and the confining pressure chamber 7 is lowered to the position as shown in the figure through the cylinder lifting track 13. Figure 2 As shown, the PDC piston loading rod 32 is controlled to rise and fall through the axial pressure loading chamber 6, so that the single-tooth cutting tool 26 contacts the upper surface of the core sample 19; wait for the program to start.

[0105] ② Under confining pressure conditions: Figure 1 As shown, first, by driving the sample clamping tool 20, the clamping plate on the sample clamping tool 20 clamps the four sides of the core sample 19, and the core sample 19 is pushed to the bottom of the single-tooth cutting tool 26 through the track bracket (the sample clamping tool 20, high-speed bearing 21, transmission mechanism 22, high-power servo motor 10 and other parts above the track bracket are integrated and can move smoothly on the track bracket); the single-tooth cutting tool 26 is switched to the planned PDC tooth, and the confining pressure chamber 7 is lowered to the position as shown in the figure through the cylinder lifting track 13. Figure 2 As shown, the lifting and lowering of the PDC piston loading rod 32 is controlled by the axial pressure loading chamber 6, so that the single-tooth cutting tool 26 contacts the upper surface of the core sample 19; the confining pressure oil is injected into the loading cylinder barrel 16 through the confining pressure injection interface 28, and it is filled and pressurized to the set pressure; wait for the program to start.

[0106] 2. Single tooth cutting experiment with constant feed speed, constant axial pressure and constant depth

[0107] ①Constant feed speed:

[0108] After selecting whether there is a confining pressure condition or not, start the high-power servo motor 10, which drives the core sample 19 to rotate on the high-speed bearing 21 through the transmission mechanism 22. After the core sample 19 starts to rotate, the PDC piston loading rod 32 will move downward at a constant speed to reach the set depth (the moving speed and the descending depth are measured and controlled by the magnetostrictive displacement sensor 4).

[0109] ②Constant axial pressure:

[0110] After selecting whether there is a confining pressure condition or not, start the high-power servo motor 10, which drives the core sample 19 to rotate on the high-speed bearing 21 through the transmission mechanism 22. After the core sample 19 starts to rotate, the PDC piston loading rod 32 will move downward at a constant axial pressure to reach the set depth (the constant axial pressure is measured and controlled by the high-pressure uniaxial load sensor 17, and the descending depth is measured and controlled by the magnetostrictive displacement sensor 4).

[0111] ③ Constant depth:

[0112] After selecting whether there is a confining pressure condition or not, the high-power servo motor 10 is started. The high-power servo motor 10 drives the core sample 19 to rotate on the high-speed bearing 21 through the transmission mechanism 22. The core sample 19 starts to rotate, and the PDC piston loading rod 32 does not move (the movement depth is measured by the magnetostrictive displacement sensor 4).

[0113] It should be noted that the main difference between the single-tooth cutting experiment at constant depth and the single-tooth cutting experiment at constant feed speed and the single-tooth cutting experiment at constant axial pressure is that before the core sample 19 rotates, a groove of a certain depth (the depth is greater than the cutting depth) needs to be opened under the PDC cutter, the PDC piston loading rod 32 will drop to the set depth, the rock starts to rotate, and the PDC piston loading rod 32 will not move.

[0114] (II) Drillability test

[0115] 1. Switch from single-tooth cutting mode to drillability mode: Figure 1 , Figure 2 , Figure 3 In the single-tooth cutting mode, the confining pressure chamber 7 is raised to the upper end through the cylinder lifting track 13 to contact the high-strength bearing frame 1; the screws fixing the sealing adjustment mechanism 33 are loosened, and the sealing adjustment mechanism 33 is rotated to change its radial position relative to the pressure-bearing straightening cylinder 3, so that the whole composed of the magnetic displacement sensor 4, the axial pressure loading chamber 6, the PDC piston loading rod 32, the uniaxial load sensor 17 and other parts reaches the position as shown in the figure. Figure 4 As shown, tighten the screws that fix the sealing adjustment mechanism 33; remove Figure 2 The three-dimensional force sensor 18 shown in the figure is equipped with a torque sensor 29 and a drillable tool 27 to achieve the following Figure 5 The installation effect is shown.

[0116] It is worth noting that the PDC drill bit tooth simulation cutting test device provided in this application is different from a general single test machine. The PDC drill bit tooth simulation cutting test device can be used not only for single tooth cutting experiments, but also for drillability experiments. There are also multiple options for cutting modes. A constant depth can be set for cutting, a constant feed speed can be used for cutting, and a constant axial pressure cutting method that is consistent with the actual situation on site can be used. The core sample 19 rotates quickly and efficiently, can quickly reach the set speed, and is stable. At the same time, the core sample 19 can also be set to stop at a certain angle, and the equipment has various and rich functions.

[0117] Any numerical value cited herein includes all values ​​of lower and upper values ​​that increase by one unit from the lower limit to the upper limit, and there is at least a two-unit interval between any lower value and any higher value. For example, if the value of the quantity of a component or a process variable (such as temperature, pressure, time, etc.) is stated to be from 1 to 90, preferably from 20 to 80, and more preferably from 30 to 70, the purpose is to illustrate that values ​​such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also explicitly listed in this specification. For values ​​less than 1, one unit is appropriately considered to be 0.0001, 0.001, 0.01, 0.1. These are merely examples that are intended to be clearly expressed, and it can be considered that all possible combinations of numerical values ​​listed between the lowest value and the highest value are clearly stated in this specification in a similar manner.

[0118] Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. "About" or "approximately" used with a range applies to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", including at least the specified endpoints.

[0119] All articles and references disclosed, including patent applications and publications, are incorporated herein by reference for all purposes. The term "consisting essentially of..." to describe a combination should include the identified elements, ingredients, parts or steps and other elements, ingredients, parts or steps that do not substantially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe a combination of elements, ingredients, parts or steps herein also contemplates embodiments that consist essentially of these elements, ingredients, parts or steps. By using the term "may", it is intended to indicate that any attribute described that "may" include is optional.

[0120] Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure "one" or "an" used to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0121] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but should be determined with reference to the appended claims and the full scope of equivalents possessed by such claims. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a waiver of the subject matter, nor should it be considered that the inventors did not consider the subject matter to be part of the disclosed inventive subject matter.

[0122] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0123] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A PDC drill bit tooth simulation cutting experimental device, characterized in that: include: The main structure comprises: a hollow loading cylinder body, a confining pressure cavity is formed in the loading cylinder body, and the loading cylinder body has a top end and a bottom end opposite to each other; the bottom end is sealed with a confining pressure injection interface; the outer sleeve of the loading cylinder body is provided with a heating sleeve; a hollow pressure-bearing straightening cylinder is sealed and arranged at the top end of the loading cylinder body and extends upward away from the bottom end; an axial pressure loading mechanism comprises an axial pressure loading cavity sealed and fixed in the pressure-bearing straightening cylinder, a PDC piston loading rod which is in sealing contact with the axial pressure loading cavity and can move relatively, a detection component and a device for connecting an experimental tool are arranged at one end of the PDC piston loading rod close to the confining pressure injection interface, and the detection component comprises a uniaxial load sensor and a temperature sensor; A load-bearing frame, arranged at the periphery of the main structure, and used for protecting and fixing the main structure; A cylinder lifting mechanism, which is fixed by the bearing frame and used to drive the confining pressure chamber to move axially; A sample clamping tool, arranged in the confining pressure chamber and used for installing the core sample; The data acquisition and processing system is used to be electrically connected to the detection component.

2. The PDC drill bit tooth simulation cutting experimental device according to claim 1, characterized in that: The axial pressure loading mechanism also includes: a magnetostrictive displacement sensor that can be used to detect the axial movement distance of the PDC piston loading rod.

3. The PDC drill bit tooth simulation cutting experimental device according to claim 2, characterized in that: The experimental tool comprises: a single-tooth cutting tool and a drillable tool, and the detection component further comprises: a three-dimensional force sensor or a torque sensor connected between the uniaxial load sensor and the single-tooth cutting tool or the drillable tool.

4. The PDC drill bit tooth simulation cutting experimental device according to claim 3, characterized in that: The cylinder lifting mechanism includes a cylinder lifting track fixed on the supporting frame and connected to the confining pressure chamber, and a lifting cylinder connected to the cylinder lifting track and used to provide driving force. The confining pressure chamber can be driven by the lifting cylinder to move axially along the cylinder lifting track.

5. The PDC drill bit tooth simulation cutting experimental device according to claim 4, characterized in that: The bearing frame comprises: a top cover, a bottom cover and a surrounding frame arranged between the top cover and the bottom cover which are connected by fastening bolts, and the lifting cylinder is fixed on the top cover.

6. The PDC drill bit tooth simulation cutting experimental device according to claim 4, characterized in that: The main structure also includes a pressure-bearing chassis arranged at the bottom end of the loading cylinder body, the pressure-bearing chassis is in sealing contact with the confining pressure chamber, a sample rotation mechanism is installed on the pressure-bearing chassis, and the sample rotation mechanism is fixed to the sample clamping tool to drive the core sample to rotate.

7. The PDC drill bit tooth simulation cutting experimental device according to claim 6, characterized in that: The sample rotating mechanism comprises: a sample rotating disk fixed to the sample clamping tool, a rotating disk power assembly for driving the sample rotating disk to rotate, and a high-speed bearing is installed between the sample rotating disk and the pressure-bearing chassis.

8. The PDC drill bit tooth simulation cutting experimental device according to claim 7, characterized in that: The PDC drill bit tooth simulation cutting experimental device also includes a guide rail bracket, and the pressure-bearing chassis is placed on the guide rail bracket.

9. The PDC drill bit tooth simulation cutting experimental device according to claim 8, characterized in that: The pressure-bearing chassis, the sample clamping tool, the high-speed bearing, and the rotating disk power assembly can move as a whole relative to the guide rail bracket.

10. The PDC drill bit tooth simulation cutting experimental device according to claim 1, characterized in that: Two windows are installed on the loading cylinder body, which are connected to the confining pressure chamber and are horizontally oriented at 90 degrees to each other; one of the windows is used as a light source window, and the other is used as an observation window.

11. The PDC drill bit tooth simulation cutting experimental device according to claim 3, characterized in that: A sealing adjustment mechanism is provided between the pressure-bearing straightening cylinder and the axial pressure loading mechanism, and an eccentric adjustment portion is provided on the inner wall of the pressure-bearing straightening cylinder. The sealing adjustment mechanism can cooperate with the pressure-bearing straightening cylinder to change the radial position of the axial pressure loading mechanism. When the sealing adjustment mechanism is in a first position relative to the eccentric adjustment portion, the axis of the axial pressure loading mechanism can be directly opposite to the center of the core sample. When the sealing adjustment mechanism is in a second position relative to the eccentric adjustment portion, the axis of the axial pressure loading mechanism is offset from the center of the core sample.

Images