Test well torque load simulation pipe string

Abstract

The test well torque load simulation pipe string comprises a drill string, and the lower end of the drill string is connected with a test tool; the screw drill is connected to the lower end of the testing tool; and the torque load simulator is connected to the lower end of the screw drill, and the torque load simulator generates torque and simulates the torque generated by rock breaking of the drill bit. When in use, the drill string, the test tool, the screw drill and the torque load simulator are combined into a torque load simulation pipe string. The torque load simulation pipe string is put down into the test well, the torque load simulator is started, the torque load simulator rotates to generate torque, the generated torque is transmitted to the test tool, and therefore a test is carried out. According to the invention, the functions of testing under various underground loads and avoiding actual drilling are realized.

Description

Technical Field

[0001] The present invention relates to a test well torque load simulation string, belonging to the field of oil and gas drilling simulation tests. Background Art

[0002] Due to the complex downhole environment during drilling, affected by multiple factors such as temperature, pressure and vibration, the reliability requirements for downhole tools are relatively high. When newly developed downhole tools are tested in the well, complex situations such as functional failure, structural failure, and even fracture often occur, causing huge losses to the test well, and in severe cases, even leading to the abandonment of the wellbore. To solve the problem of high risk of new tools entering the well, an experimental device that can simulate the complex downhole environment needs to be designed.

[0003] Chinese Patent Document CN201910847803.3 discloses a near-horizontal directional drilling actual drilling simulation and drilling parameter testing device and method, which includes six parts: a simulated geological body, a drilling drive system, a drilling pump, a solids control system, a pipe string system, and a monitoring and control system. The actual drilling geological body is simulated by a horizontally placed concrete cylinder. This test bench can provide a site and platform for the development of directional drilling technology, instrument testing, and basic research on near-horizontal directional drilling. The main problem is that using a concrete cylinder to simulate the formation can only perform drilling for a very short distance. When the drill bit drills a longer footage, the drill bit is likely to penetrate through the concrete block, and there are environmental pollution risks such as drilling fluid leakage. The ground simulation test cannot simulate the vibration and mechanical properties of a drill string thousands of meters long.

[0004] Chinese Patent Document CN201010143674.9 mainly consists of a drilling system, a autoclave system, a rock sample heating and pressurizing system, a detection system, and a data acquisition system. The rock sample is placed on the experimental bench, the resistance wire heats the rock sample, the rock sample clamping and pressurizing mechanism pressurizes the rock sample, and the drilling system drills the rock sample. In fact, it only provides a rock sample that simulates the downhole temperature and pressure, and cannot simulate the actual drilling working conditions, and the ground simulation test cannot simulate the vibration and mechanical properties of a drill string thousands of meters long.

[0005] The prior art can perform tests under various downhole loads and avoid the effects of actual drilling. Summary of the Invention

[0006] Aiming at the above technical problems existing in the prior art, the present invention proposes a test well torque load simulation string, which realizes the function of being able to perform tests under various downhole loads and avoid actual drilling.

[0007] The present invention proposes a test well torque load simulation string, including:

[0008] A drill string, the lower end of the drill string is connected to a test tool;

[0009] A positive displacement motor, connected to the lower end of the test tool; and

[0010] A torque load simulator connected to the lower end of the positive displacement motor, the torque load simulator generating torque to simulate the torque generated by the bit breaking rock.

[0011] A further improvement of the present invention is that the torque load simulator includes a high-speed turbodrill and a liquid agitator.

[0012] A further improvement of the present invention is that the liquid agitator includes an agitator body, and a fluid passage for flowing fluid is provided inside the agitator body;

[0013] A plurality of stirring blades are provided on the side wall of the agitator body.

[0014] A further improvement of the present invention is that a limiting ring or a limiting protrusion is provided at the lower part of the agitator body to form a cavity communicating with the fluid passage, and a ball is provided in the cavity;

[0015] A plurality of liquid return holes are provided on the outer wall of the cavity, and the diameter of the liquid return holes is smaller than the diameter of the ball, so that the ball is limited in the cavity.

[0016] A further improvement of the present invention is that there are four liquid return holes, which are evenly arranged along the circumferential direction of the agitator body; the liquid return holes include a large hole with a larger diameter and three small holes with smaller diameters.

[0017] A further improvement of the present invention is that the ball is a metal ball.

[0018] A further improvement of the present invention is that a centralizer is provided at the end of the agitator body, and a centralizer bearing is provided on the centralizer.

[0019] A further improvement of the present invention is that an upper sub is provided at the upper end of the agitator body, which is connected to the high-speed turbodrill by a thread type.

[0020] A further improvement of the present invention is that the rotational speed of the high-speed turbodrill driving the liquid agitator to rotate is 200 - 400 r / min.

[0021] A further improvement of the present invention is that 10 - 20 groups of stirring blades are arranged axially on the agitator body;

[0022] Each group of stirring blades has 3 - 6 blades, and they are evenly arranged along the circumferential direction of the agitator body.

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] The test well torque load simulation string described in the present invention realizes the function of being able to conduct tests under various downhole loads and avoid actual drilling.

[0025] According to the test well torque load simulation string of the present invention, when the drilling pump of the test well is started, the drilling fluid flows through the downhole positive displacement motor, turbo drill and liquid agitator from the drill string. When the liquid agitator rotates at high speed, torque load is generated, and the torque is fluctuating. When the agitator rotates clockwise, the liquid generates a counterclockwise torque (reaction torque) on the agitator, turbo drill and the upper string including the test tool. At this time, the test tool is simultaneously subjected to downhole loads such as torque fluctuations and hydraulic pressure. The torque fluctuations act on the test tool and the drill string in contact with the wellbore for thousands of meters, generating complex loads and vibration amplitudes identical to those in the downhole. Under the condition of not requiring the bit to break rock to create a new wellbore, the performance of downhole tools can be tested by simulating the torque load. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings:

[0027] Figure 1 The structural schematic diagram of the test well torque load simulation string of an embodiment of the present invention is shown;

[0028] Figure 2 The structural schematic diagram of the liquid agitator of an embodiment of the present invention is shown;

[0029] Figure 3 is Figure 2 the A-A sectional view of

[0030] Figure 4 is Figure 2 the B-B sectional view of

[0031] The drawings are not drawn to actual scale.

[0032] The meanings of the reference numerals in the drawings are as follows:

[0033] 1, test wellbore; 2, drill string; 3, test tool; 4, positive displacement motor; 5, high-speed turbo drill; 6, liquid agitator; 61, upper sub; 62, fluid passage; 63, stirring vane; 64, liquid return hole; 65, centralizing bearing; 66, ball. DETAILED DESCRIPTION OF THE INVENTION

[0034] To make the technical solutions and advantages of the present invention clearer and more understandable, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than an exhaustive list of all embodiments. And without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0035] Due to the complex downhole environment during drilling, affected by various factors such as temperature, pressure, and vibration, the reliability requirements for downhole tools are relatively high. When newly developed downhole tools are tested in the well, complex situations such as functional failure, structural failure, and even fracture often occur, causing huge losses to the test well, and in severe cases, even leading to the abandonment of the wellbore. To solve the problem of high risk of new tools entering the well, an experimental device that can simulate the complex downhole environment needs to be designed.

[0036] In the Figure 1 embodiment shown in

[0037] the test well torque load simulation string includes:

[0038] a drill string 2, the lower end of the drill string 2 is connected to a test tool 3, the test tool 3 is the downhole tool to be tested, which is the test object of this test, and the torque load capacity is tested through the test;

[0039] and

[0040] a torque load simulator connected to the lower end of the positive displacement motor 4, the torque load simulator generates torque to simulate the torque generated by the bit breaking rock.

[0041] When using the test well torque load simulation string according to this embodiment to conduct a torque load test, the drill string 2, the test tool 3, the positive displacement motor 4, and the torque load simulator are combined into a torque load simulation string. The torque load simulation string is lowered into the test well.

[0042] Start the torque load simulator, the torque load simulator rotates to generate torque, and the generated torque is transmitted to the test tool 3, thereby conducting the test.

[0043] In one embodiment, the torque load simulator includes a high-speed turbine drill 5 and a liquid agitator 6.

[0044] The upper end of the high-speed turbine drill 5 is connected to the positive displacement motor 4, and the lower end is connected to the liquid agitator 6.

[0045] The high-speed turbodrill 5 rotates, driving the liquid stirrer 6 to rotate. The liquid stirrer 6 stirs the liquid in the test wellbore 1 and generates resistance with the fluid, thereby simulating the torque generated by the drill bit breaking rock.

[0046] In one embodiment, as Figure 2 shown, the liquid stirrer 6 includes a tubular stirrer body. A fluid passage 62 is provided inside the stirrer body for circulating the fluid.

[0047] As Figure 3 shown, a number of stirring blades 63 are provided on the side wall of the stirrer body. When the stirrer body rotates, resistance is generated between the stirring blades 63 and the fluid, simulating the friction generated by the drill bit breaking rock.

[0048] In one embodiment, as Figure 4 shown, a cavity communicating with the fluid passage 62 is provided at the lower part of the stirrer body. A ball 66 is provided in the cavity, and a number of liquid return holes 64 are provided on the outer wall of the cavity. The diameter of the liquid return holes 64 is smaller than the diameter of the ball 66, so that the ball 66 is confined in the cavity.

[0049] When simulating the torque load of the pipe string in the test well according to this embodiment, a limiting ring or a number of limiting protrusions are provided on the inner wall at the lower part of the stirrer body. There is a certain distance between the limiting ring or the limiting protrusions and the end of the stirrer body, forming a cavity between the limiting ring or the limiting protrusions and the stirrer body.

[0050] The liquid return holes 64 are used to return the fluid in the pipe.

[0051] The limiting ring or the limiting protrusions confine the ball in the cavity. The diameter of the liquid return holes 64 on the outer wall of the cavity is smaller than the diameter of the ball, ensuring that the ball cannot slide out from the liquid return holes 64.

[0052] In a preferred embodiment, the ball 66 is a metal ball, preferably a copper ball. The metal ball has a relatively large weight compared to other lighter materials, and can ensure that it remains on the lower side (here, the lower side is the distance towards the center of the earth, which is different from the lower side of the device. In this embodiment, when describing the device, the lower part of the component is the direction towards the well bottom, and the upper part is the direction towards the wellhead. In the horizontal well section, the lower part of the device is not the direction towards the center of the earth) of the cavity under the action of gravity most of the time when the stirrer body rotates, and can block each hole, thereby generating torque fluctuations, which is more in line with the actual drilling load.

[0053] The surface of the metal ball is smooth and is less affected by friction, ensuring that it will not rotate with the rotation of the stirrer body.

[0054] In one embodiment, there are four liquid return holes 64 which are evenly arranged along the circumference of the agitator body; the liquid return holes 64 include a large hole with a larger diameter and three small holes with smaller diameters.

[0055] In the test well torque load simulation pipe string according to the present embodiment, the liquid return hole 64 at the bottom of the liquid agitator 6 is composed of four holes, one hole has a diameter larger than the other three holes, and the outer diameter of the metal ball is slightly larger than the diameter of the large hole to ensure that the metal ball will not slip out of the hole.

[0056] When the liquid agitator 6 rotates, the metal ball always blocks the return hole on the low gravity side under the action of gravity. When the copper ball blocks the large hole, the fluid resistance generated by the three small holes is large, and the liquid flow rate will decrease; when the copper ball blocks the small hole, the fluid resistance generated by the other two small holes and one large hole is small, and the liquid flow rate will increase; from the perspective of the pulsating pressure and flow generated when the agitator body rotates at high speed, the flow rate will affect the turbine speed, and the turbine speed will affect the torque, thus generating torque fluctuations, which is more in line with the actual drilling load.

[0057] In one embodiment, a centralizer is provided at the end of the agitator body, and a centralizer bearing is provided on the centralizer.

[0058] The centralizer is provided with an outer ring on the outside, and the outer diameter of the outer ring matches the inner diameter of the wellbore. The centralizer bearing is arranged on the inner side of the outer ring.

[0059] The outer diameter of the stabilizing bearing 65 at the bottom is equal to the inner diameter of the wellbore, which is used to center the liquid agitator 6 and prevent the stirring blades 63 from contacting the wellbore and causing wear.

[0060] In one embodiment, the high-speed turbodrill 5 drives the liquid agitator 6 to rotate at a speed of 200-400 r / min.

[0061] The stirring blades 63 are arranged in 10-20 groups in the axial direction of the stirrer body;

[0062] The number of stirring blades 63 in each group is 3 to 6 and they are evenly arranged along the circumference of the agitator body.

[0063] According to the test well torque load simulation pipe string described in this embodiment, when the drilling pump of the test well is started, the drilling fluid flows from the drill string 2 through the lower screw drill 4, turbine drill and liquid agitator 6. When the liquid agitator 6 rotates at high speed, a torque load is generated, and the torque is fluctuating.

[0064] When the agitator rotates clockwise, the liquid generates a counterclockwise torque (reaction torque) on the agitator, the turbodrill, and the upper pipe string including the test tool. At this time, the test tool is simultaneously subjected to downhole loads such as torque fluctuations and hydraulic pressure. The torque fluctuations act on the test tool and the drill string 2 in contact with the wellbore for thousands of meters, generating complex loads and vibration amplitudes identical to those downhole. Under the condition that there is no need for the drill bit to break rock to create a new wellbore, the performance of downhole tools can be tested by simulating the torque load.

[0065] Embodiment 1

[0066] The test well torque load simulation pipe string includes:

[0067] A drill string 2, with a test tool 3 connected to the lower end of the drill string 2. The test tool 3 is the downhole tool to be tested and is the test target of this test. The torque load capacity is tested through the test.

[0068] A positive displacement motor 4 provided at the lower end of the test tool 3. Depending on the test items of the test tool 3, the positive displacement motor 4 is a commonly used downhole drill in the current actual drilling assembly and has a built-in bend angle. Adding the positive displacement motor 4 to the pipe string can better simulate the downhole working conditions.

[0069] A torque load simulator connected to the lower end of the positive displacement motor 4. The torque load simulator generates torque to simulate the torque generated by the drill bit breaking rock.

[0070] The torque load simulator includes a high-speed turbodrill 5 and a liquid agitator 6.

[0071] The upper end of the high-speed turbodrill 5 is connected to the positive displacement motor 4, and the lower end is connected to the liquid agitator 6.

[0072] The high-speed turbodrill 5 rotates, driving the liquid agitator 6 to rotate. The liquid agitator 6 stirs the liquid in the test wellbore 1 and generates resistance with the fluid, thereby simulating the torque generated by the drill bit breaking rock.

[0073] The liquid agitator 6 includes a tubular agitator body, and a fluid passage 62 is provided inside the agitator body for fluid circulation.

[0074] A number of stirring vanes 63 are provided on the side wall of the agitator body. When the agitator body rotates, the stirring vanes 63 generate resistance with the fluid, simulating the friction generated by the drill bit breaking rock.

[0075] A cavity communicating with the fluid passage 62 is provided at the lower part of the agitator body. A ball is provided in the cavity, and a number of liquid return holes 64 are provided on the outer wall of the cavity. The diameter of the liquid return holes 64 is smaller than the diameter of the ball, so that the ball is confined in the cavity.

[0076] When simulating the torque load of the pipe string in the test well according to this embodiment, a limiting ring or a plurality of limiting protrusions are provided on the inner wall of the lower part of the stirrer body. There is a certain distance between the limiting ring or the limiting protrusions and the end of the stirrer body, and a cavity is formed between the limiting ring or the limiting protrusions and the stirrer body.

[0077] The liquid return hole 64 is used to return the fluid in the pipe.

[0078] The limiting ring or the limiting protrusions limit the ball in the cavity. The diameter of the liquid return hole 64 on the outer wall of the cavity is smaller than the diameter of the ball, ensuring that the ball cannot slide out from the liquid return hole 64.

[0079] The ball is a copper ball. The metal copper ball has a relatively large weight compared to other lighter materials, and can ensure that most of the time it remains on the lower side of the cavity under the action of gravity when the stirrer body rotates (here, the lower side is the direction towards the center of the earth, which is different from the lower side of the device. In this embodiment, when describing the device, the lower side of the component is the direction towards the wellbore, and the upper side is the direction towards the wellhead. In the horizontal well section, the lower side of the device is not the direction towards the center of the earth). It can block each hole, thereby generating torque fluctuations, which are more in line with the actual drilling load.

[0080] The surface of the metal copper ball is smooth and is less affected by friction, ensuring that it will not rotate with the rotation of the stirrer body.

[0081] There are four liquid return holes 64, which are evenly arranged along the circumference of the stirrer body; the liquid return hole 64 includes a large hole with a larger diameter and three small holes with smaller diameters.

[0082] In the test well torque load simulation pipe string according to this embodiment, the liquid return holes 64 at the lower part of the liquid stirrer 6 are composed of 4 holes. The diameter of one hole is larger than the diameters of the other three holes, and the outer diameter of the metal ball is slightly larger than the diameter of the large hole, ensuring that the metal ball will not slide out from the hole.

[0083] When the liquid stirrer 6 rotates, the metal ball is always blocked in the return hole at the low side of gravity under the action of gravity. When the copper ball blocks the large hole, the fluid resistance generated by the three small holes is relatively large, and the liquid flow rate will decrease; when the copper ball blocks the small hole, the fluid resistance generated by the other two small holes and one large hole is relatively small, and the liquid flow rate will increase; from the aspects of generating pulsating pressure and flow rate when the stirrer body rotates at a high speed, the flow rate affects the turbine speed, and the turbine speed affects the torque, so torque fluctuations are generated, which are more in line with the actual drilling load.

[0084] A centralizer is provided at the end of the stirrer body, and a centralizer bearing is provided on the centralizer.

[0085] The centralizer is provided with an outer ring on the outside, and the outer diameter of the outer ring matches the inner diameter of the wellbore. The centralizer bearing is arranged on the inner side of the outer ring.

[0086] The outer diameter of the stabilizing bearing 65 at the bottom is equal to the inner diameter of the wellbore, which is used to center the liquid agitator 6 and prevent the stirring blades 63 from contacting the wellbore and causing wear.

[0087] The high-speed turbodrill 5 drives the liquid agitator 6 to rotate at a speed of 200 r / min.

[0088] The stirring blades 63 are arranged in 20 groups in the axial direction of the stirrer body;

[0089] The number of stirring blades 63 in each group is four and they are evenly arranged along the circumference of the agitator body.

[0090] Example 2

[0091] Test well torque load simulation pipe string, including:

[0092] Drill string 2, the lower end of drill string 2 is connected to test tool 3, test tool 3 is a downhole tool to be tested, which is the test target of this test, and the torque load capacity is tested by the test;

[0093] The screw drill 4 arranged at the lower end of the test tool 3 is determined according to the test items of the test tool 3. The screw drill 4 is a downhole drill commonly used in actual drilling assemblies and has a curved corner. Adding the screw drill 4 to the pipe string can better simulate downhole working conditions.

[0094] The torque load simulator connected to the lower end of the screw drill 4 generates torque to simulate the torque generated by the drill bit breaking the rock.

[0095] The torque load simulator includes a high-speed turbodrill 5 and a liquid agitator 6 .

[0096] The upper end of the high-speed turbodrill 5 is connected to the screw drill 4 , and the lower end is connected to the liquid agitator 6 .

[0097] The high-speed turbodrill 5 rotates, driving the liquid agitator 6 to rotate. The liquid agitator 6 stirs the liquid in the test wellbore 1 and generates resistance with the fluid, thereby simulating the torque generated by the drill bit breaking the rock.

[0098] The liquid agitator 6 includes a tubular agitator body, and a fluid channel 62 is provided inside the agitator body for circulating the fluid.

[0099] A plurality of stirring blades 63 are arranged on the side wall of the stirrer body. When the stirrer body rotates, resistance is generated between the stirring blades 63 and the fluid, simulating the friction generated by the drill bit breaking the rock.

[0100] A cavity communicating with the fluid passage 62 is provided at the lower part of the stirrer body. A ball is provided in the cavity, and a plurality of liquid return holes 64 are provided on the outer wall of the cavity. The diameter of the liquid return hole 64 is smaller than the diameter of the ball, so that the ball is confined in the cavity.

[0101] When simulating the torque load string of the test well according to this embodiment, a limiting ring or a plurality of limiting protrusions are provided on the inner wall of the lower part of the stirrer body. There is a certain distance between the limiting ring or the limiting protrusions and the end of the stirrer body, and a cavity is formed between the limiting ring or the limiting protrusions and the stirrer body.

[0102] The liquid return hole 64 is used to return the fluid in the pipe.

[0103] The limiting ring or the limiting protrusions confine the ball in the cavity. The diameter of the liquid return hole 64 on the outer wall of the cavity is smaller than the diameter of the ball, ensuring that the ball cannot slide out of the liquid return hole 64.

[0104] The ball is a copper ball. The metal copper ball is relatively heavier than other lighter materials, and can ensure that it stays on the lower side of the cavity under the action of gravity most of the time when the stirrer body rotates (here, the lower side is the distance towards the center of the earth, which is different from the lower side of the device. In this embodiment, when describing the device, the lower part of the component is the direction towards the wellbore, and the upper part is the direction towards the wellhead. In the horizontal well section, the lower side of the device is not the direction towards the center of the earth). It can block each hole, thus generating torque fluctuations, which more conforms to the actual drilling load.

[0105] The surface of the metal copper ball is smooth and is less affected by friction, ensuring that it will not rotate with the rotation of the stirrer body.

[0106] There are four liquid return holes 64, which are evenly arranged along the circumferential direction of the stirrer body; the liquid return hole 64 includes a large hole with a larger diameter and three small holes with smaller diameters.

[0107] In the test well torque load simulation pipe string according to the present embodiment, the liquid return hole 64 at the bottom of the liquid agitator 6 consists of 4 holes, one of which has a diameter larger than the other three holes, and the outer diameter of the metal ball is slightly larger than the diameter of the large hole, so as to ensure that the metal ball will not slip out of the hole. When the liquid agitator 6 rotates, the metal ball always blocks the return hole on the low side of gravity under the action of gravity. When the copper ball blocks the large hole, the fluid resistance generated by the three small holes is large, and the liquid flow rate will decrease; when the copper ball blocks the small hole, the fluid resistance generated by the other two small holes and one large hole is small, and the liquid flow rate will increase; from the perspective of the pressure and flow rate generated when the agitator body rotates at high speed, the flow rate will affect the turbine speed, and the turbine speed will affect the torque, so the torque fluctuation is generated, which is more in line with the actual drilling load.

[0108] A centralizer is arranged at the end of the agitator body, and a centralizer bearing is arranged on the centralizer.

[0109] The centralizer is provided with an outer ring on the outside, and the outer diameter of the outer ring matches the inner diameter of the wellbore. The centralizer bearing is arranged on the inner side of the outer ring.

[0110] The outer diameter of the stabilizing bearing 65 at the bottom is equal to the inner diameter of the wellbore, which is used to center the liquid agitator 6 and prevent the stirring blades 63 from contacting the wellbore and causing wear.

[0111] The high-speed turbodrill 5 drives the liquid agitator 6 to rotate at a speed of 400 r / min.

[0112] The stirring blades 63 are arranged in 10 groups in the axial direction of the stirrer body;

[0113] There are six stirring blades 63 in each group, and they are evenly arranged along the circumference of the agitator body.

[0114] Example 3

[0115] Test well torque load simulation pipe string, including:

[0116] Drill string 2, the lower end of drill string 2 is connected to test tool 3, test tool 3 is a downhole tool to be tested, which is the test target of this test, and the torque load capacity is tested by the test;

[0117] The screw drill 4 arranged at the lower end of the test tool 3 is determined according to the test items of the test tool 3. The screw drill 4 is a downhole drill commonly used in actual drilling assemblies and has a curved corner. Adding the screw drill 4 to the pipe string can better simulate downhole working conditions.

[0118] The torque load simulator connected to the lower end of the screw drill 4 generates torque to simulate the torque generated by the drill bit breaking the rock.

[0119] The torque load simulator includes a high-speed turbine drill 5 and a liquid agitator 6.

[0120] The upper end of the high-speed turbine drill 5 is connected to the positive displacement motor 4, and the lower end is connected to the liquid agitator 6.

[0121] The high-speed turbine drill 5 rotates to drive the liquid agitator 6 to rotate. The liquid agitator 6 stirs the liquid in the test wellbore 1 and generates resistance with the fluid, thereby simulating the torque generated by the bit breaking rock.

[0122] The liquid agitator 6 includes a tubular agitator body. A fluid passage 62 is provided inside the agitator body for the fluid to flow through.

[0123] A number of stirring blades 63 are provided on the side wall of the agitator body. When the agitator body rotates, resistance is generated between the stirring blades 63 and the fluid, simulating the friction generated by the bit breaking rock.

[0124] A cavity communicating with the fluid passage 62 is provided at the lower part of the agitator body. A ball is provided in the cavity, and a number of liquid return holes 64 are provided on the outer wall of the cavity. The diameter of the liquid return holes 64 is smaller than the diameter of the ball, so that the ball is confined in the cavity.

[0125] When simulating the torque load simulation string in the test well according to this embodiment, a limiting ring or a number of limiting protrusions are provided on the inner wall of the lower part of the agitator body. The limiting ring or the limiting protrusions have a certain distance from the end of the agitator body, and a cavity is formed between the limiting ring or the limiting protrusions and the agitator body.

[0126] The liquid return holes 64 are used to return the fluid in the pipe.

[0127] The limiting ring or the limiting protrusions confine the ball in the cavity. The diameter of the liquid return holes 64 on the outer wall of the cavity is smaller than the diameter of the ball, ensuring that the ball cannot slide out of the liquid return holes 64.

[0128] The ball is a steel ball. The metal steel ball is relatively heavy compared to other lighter materials, and can ensure that it stays on the lower side of the cavity under the action of gravity most of the time when the agitator body rotates (here, the lower side is the distance towards the center of the earth, which is different from the lower side of the device. In this embodiment, when describing the device, the lower part of the component is the direction towards the wellbore, and the upper part is the direction towards the wellhead. In the horizontal well section, the lower side of the device is not the direction towards the center of the earth). It can block each hole, thereby generating torque fluctuations, which is more in line with the actual drilling load.

[0129] The surface of the metal steel ball is smooth and is less affected by friction, ensuring that it will not rotate with the rotation of the agitator body.

[0130] There are four liquid return holes 64, which are evenly arranged along the circumference of the agitator body; the liquid return holes 64 include a large hole with a larger diameter and three small holes with smaller diameters.

[0131] In the test well torque load simulation string according to the present embodiment, the liquid return holes 64 below the liquid agitator 6 are composed of 4 holes, the diameter of one hole is larger than that of the other three holes, and the outer diameter of the metal ball is slightly larger than the diameter of the large hole to ensure that the metal ball will not slide out of the hole. When the liquid agitator 6 rotates, the metal ball is always blocked in the return hole on the low gravity side under the action of gravity. When the steel ball blocks the large hole, the fluid resistance generated by the three small holes is relatively large, and the liquid flow rate will decrease; when the steel ball blocks the small hole, the fluid resistance generated by the other two small holes and one large hole is relatively small, and the liquid flow rate will increase; from the aspects of generating pulsating pressure and flow rate when the agitator body rotates at a high speed, the flow rate affects the turbine speed, and the turbine speed affects the torque, so torque fluctuations are generated, which is more in line with the actual drilling load.

[0132] A centralizer is provided at the end of the agitator body, and a centralizer bearing is provided on the centralizer.

[0133] An outer ring is provided outside the centralizer, and the outer diameter of the outer ring matches the inner diameter of the wellbore. The centralizer bearing is provided inside the outer ring.

[0134] The outer diameter of the centralizer bearing 65 at the bottom end is equal to the inner diameter of the wellbore, which centrally positions and straightens the liquid agitator 6 to prevent the stirring blade 63 from contacting the wellbore and causing wear.

[0135] The high-speed turbodrill 5 drives the liquid agitator 6 to rotate at a speed of 300 r / min.

[0136] 15 groups of stirring blades 63 are arranged axially on the agitator body;

[0137] There are 5 stirring blades 63 in each group, and they are evenly arranged along the circumference of the agitator body.

[0138] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should extend to equivalent alternatives of these features understood by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are only for the purpose of describing specific embodiments and do not mean to limit.

[0139] In the description of the present invention, unless otherwise specified, "a plurality of" means two or more; the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the present invention. In addition, terms such as "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0140] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0141] Certain terms are used throughout this application to refer to particular system components. As those skilled in the art will recognize, the same components may typically be referred to by different names, and thus this application is not intended to distinguish components that differ only in name and not in function. The phrase "one embodiment" or "an embodiment" as used in the specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the phrase "one embodiment" or "an embodiment" that appears throughout the specification does not necessarily refer to the same embodiment.

[0142] The embodiments of the present invention are given for purposes of illustration and description, and are not exhaustive or limiting of the invention to the disclosed form. Many modifications and variations will be obvious to those of ordinary skill in the art. The embodiments are chosen and described in order to better illustrate the principles of the present invention and its practical application, and to enable those of ordinary skill in the art to understand the present invention and design various embodiments with various modifications suitable for a particular purpose.

[0143] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and / or modifications that fall within the scope of the present invention. All changes and / or modifications made in accordance with the embodiments of the present invention should be covered within the protection scope of the present invention.

Claims

1. A test well torque load simulation pipe string, characterized in that Comprising: A drill string (2), the lower end of the drill string (2) being connected to a test tool (3); A positive displacement motor (4), connected to the lower end of the test tool (3); and A torque load simulator connected to the lower end of the positive displacement motor (4), the torque load simulator generating a torque to simulate the torque generated by the bit breaking rock.

2. The test well torque load simulation pipe string according to claim 1, characterized in that, The torque load simulator includes a high-speed turbodrill (5) and a liquid agitator (6).

3. The test well torque load simulation string according to claim 2, characterized in that, The liquid agitator (6) includes an agitator body, and a fluid passage (62) for flowing fluid is provided inside the agitator body; A plurality of stirring vanes (63) are provided on the side wall of the agitator body.

4. The test well torque load simulation string according to claim 3, wherein A limiting ring or a limiting protrusion is provided at the lower part of the agitator body to form a cavity communicating with the fluid passage (62), and a ball (66) is provided in the cavity; A plurality of liquid return holes (64) are provided on the outer wall of the cavity, and the diameter of the liquid return holes (64) is smaller than the diameter of the ball (66), so that the ball (66) is confined in the cavity.

5. The test well torque load simulation string according to claim 4, wherein There are four of the liquid return holes (64), which are evenly arranged along the circumference of the agitator body; the liquid return holes (64) include a large hole with a larger diameter and three small holes with smaller diameters.

6. The test well torque load simulation string according to claim 4, wherein, The ball (66) is a metal ball.

7. The test well torque load simulation string according to any one of claims 4 to 5, characterized in that, A centralizer is provided at the end of the agitator body, and a centralizer bearing is provided on the centralizer.

8. The test well torque load simulation pipe string according to claim 8, wherein, An upper joint (61) for snap connection with the high-speed turbodrill (5) is provided at the upper end of the agitator body.

9. The test well torque load simulation string according to claim 8, wherein, The high-speed turbodrill (5) drives the liquid agitator (6) to rotate at a speed of 200 - 400 r / min.

10. The test well torque load simulation string according to claim 9, wherein The stirring vanes (63) are arranged in 10 - 20 groups in the axial direction of the agitator body; There are 3 - 6 stirring vanes (63) in each group, and they are evenly arranged along the circumference of the agitator body.

Images