Casing friction resistance detection device and detection method for casing in casing

Abstract

The present invention discloses a device and method for detecting friction resistance of casing during casing-in-casing. The device comprises a first pipe body, a second pipe body, a third pipe body, a fourth pipe body, a weighted pipe, a fifth pipe body and a drill bit mechanism connected in sequence; the second pipe body and the third pipe body are rotationally connected by a first meshing rotating assembly that drives the third pipe body to rotate circumferentially; the third pipe body and the fourth pipe body are rotationally connected by a second meshing rotating assembly that drives the fourth pipe body to rotate circumferentially; the second pipe body and the third pipe body are both provided with friction resistance detection assemblies of the same structure, which are used to detect the friction resistance between the casing and the wellbore during the process of advancing against the wall. The friction resistance detection assembly provided in the present invention can simulate the friction resistance of different casing lowering conditions during the casing-in-casing process, and the simulated working conditions are more in line with the actual situation, providing a decision-making basis for the safe lowering of the casing in the later stage, and can clean the wellbore of the old well to ensure the safe lowering of the casing in the later stage.

Description

Technical Field

[0001] The present invention belongs to the technical field of drilling and completion friction resistance detection, and in particular relates to a casing-in-casing fixed casing friction resistance detection device and a detection method. Background Art

[0002] In recent years, my country's dependence on foreign oil and natural gas has steadily increased. As a major manufacturing nation, energy-related technologies are crucial for China's development of its real economy. Drawing on the successful experience of the US shale oil and gas revolution, large-scale volumetric fracturing technology has been rapidly applied to the development of low-permeability oil and gas reservoirs since the beginning of this century, enabling the establishment and expansion of production in many of my country's major oil and gas basins and major oil companies. For example, the Changqing Oilfield has produced over 60 million tons for many consecutive years, and the Yanchang Oilfield has successfully exceeded 20 million tons of oil and gas equivalent.

[0003] However, a prominent development challenge facing these oil and gas basins is the rapid decline in production from oil and gas wells. This has resulted in a large number of low-yield, low-efficiency, and older, highly deviated and horizontal wells becoming "dormant wells." With the rapid advancement of fracturing technology, the scale of fracturing has grown, the methods employed have become more diverse, and the volume of reservoirs being transformed has also increased. However, due to the early construction of these "dormant wells," many reservoir sections have not been fully transformed due to the limitations of existing technology, and thus hold significant potential for recovery. Therefore, re-fracture of these under-reformed sections of these older wells to restore production has become a crucial production-boosting measure for oil and gas fields.

[0004] A new approach in current refracturing techniques involves running a small casing within the existing casing, performing a "casing-in-casing" method to rebuild the wellbore before conducting a larger fracturing operation. Field trials have demonstrated that this method offers the best scalability and effectiveness in refracturing, significantly increasing stimulation volume and production. To maximize the scale of stimulation, the casing required for this "casing-in-casing" method must be sufficiently large. However, in low-permeability reservoirs, many older wells are highly deviated or horizontal, and already have existing casing with a small inner diameter. The annular clearance is extremely small (for example, running a 4.5-inch casing within an 8.5-inch casing, the annular clearance is one-tenth that of a conventional one). This makes running casing in this "casing-in-casing" method extremely challenging and risky. Therefore, the key to the success of this type of refracturing lies in determining whether the casing can be safely run. If the casing cannot be fully lowered, its lowering limit cannot be predicted, making it crucial to predict or test the friction resistance during casing running. There are some existing algorithms for calculating and predicting the friction resistance of casing installation, but these are all based on conventional operating conditions, where the annular clearance generally exceeds 19mm. Other tests are not applicable to the new ultra-small clearance technology of casing-in-casing. The main difficulties and requirements for repeating fracturing and inserting casing in such old wells are as follows: First, due to years of production, the wellbore of the old well has a large amount of scale, sand, etc. on the wellbore, which needs to be cleaned; second, due to the influence of the original wellbore trajectory and years of production, there are many wide and narrow sections, twisted sections, and deformed sections in the wellbore, which makes it difficult to predict and test the friction resistance; third, some sections of the original wellbore may have casing wear or wall thickness changes, and whether they can continue to serve subsequent fracturing or production (whether new casing needs to be inserted into the entire wellbore) needs to be evaluated. Summary of the Invention

[0005] In response to the defects of the existing technology, the present invention provides a casing friction resistance detection device and detection method for casing lowering during the casing-in-casing process, which can simulate the friction resistance of different casing lowering conditions during the casing-in-casing process. The simulated working conditions are more in line with the actual situation, and the old wellbore can be cleaned, providing a decision-making basis for the safe lowering of the subsequent casing, thereby ensuring the safe lowering of the subsequent casing.

[0006] A casing friction resistance detection device for casing-in-casing, comprising a first pipe body, a second pipe body, a third pipe body, a fourth pipe body, a weighted pipe, a fifth pipe body and a drill bit mechanism connected in sequence;

[0007] The second tube body and the third tube body are rotationally connected via a first meshing rotation assembly that drives the third tube body to rotate circumferentially; the third tube body and the fourth tube body are rotationally connected via a second meshing rotation assembly that drives the fourth tube body to rotate circumferentially;

[0008] The second pipe body and the third pipe body are both provided with friction resistance detection components with the same structure, which are used to detect the friction resistance between the casing and the wellbore during the process of advancing against the wall.

[0009] Preferably, the friction resistance detection assembly includes a mounting ring, a pressure sensor connected to the mounting ring, a second movable ring and a first movable ring; the mounting rings are respectively fixed on the corresponding tube bodies, and the first movable ring and the second movable ring are slidably arranged on the corresponding tube bodies; the pressure sensor and the second movable ring, and the second movable ring and the first movable ring are all connected by a spring; the mounting ring and the second movable ring, and the second movable ring and the first movable ring are all connected by a number of connecting rod assemblies distributed along the circumference of the second movable ring, and the connecting rod assembly is located outside the spring; the connecting rod assembly includes a first connecting rod and a second connecting rod, and the two ends of the first connecting rod and the second connecting rod that are close to each other are hingedly connected to the same contact wheel, and the two ends of the first connecting rod and the second connecting rod that are far away from each other are respectively hingedly connected to the mounting ring and the second movable ring, or the two ends of the first connecting rod and the second connecting rod that are far away from each other are respectively hingedly connected to the second movable ring and the first movable ring.

[0010] Preferably, the first meshing rotation assembly includes a first connecting sleeve fixedly connected to the second tube body, a first external gear ring rotatably mounted on the end of the first connecting sleeve, connected to the end of the third tube body, and a first motor mounted on the outer wall of the first connecting sleeve. The output shaft of the first motor is connected to a first gear meshing with the first external gear ring and coplanar with the first external gear ring. The meshing transmission of the first gear and the first external gear ring drives the friction resistance detection assembly on the third tube body to rotate circumferentially, thereby adapting to the working conditions of rotating the lower casing.

[0011] Preferably, the second meshing rotation assembly includes a second connecting sleeve fixedly connected to the third pipe body. A second externally toothed ring, rotatably mounted on the end of the second connecting sleeve and connected to the end of the fourth pipe body, is provided. A second motor is also mounted on the outer wall of the second connecting sleeve. The output shaft of the second motor is connected to a second gear meshing with the second externally toothed ring and coplanar with the second externally toothed ring. The meshing transmission of the second gear and the second externally toothed ring drives the fourth pipe body and the weighted pipe member to rotate circumferentially, thereby driving the drill bit for composite drilling, improving horizontal section dirt removal efficiency and preventing tool sticking, thus adapting to the exploration environment of horizontal wells.

[0012] Preferably, the drill bit mechanism includes a connecting shaft and a mounting seat which are sequentially connected to the fifth tube body; the outer wall of the mounting seat is evenly distributed with a number of rectangular grooves in the circumference; both ends of the rectangular groove are respectively provided with transmission shafts connected through a conveyor belt; the outer wall of the conveyor belt is evenly provided with excavation heads; the mounting seat is also provided with a number of third motors corresponding to the number of rectangular grooves, and the output shaft of each third motor is connected to one of the transmission shafts in the rectangular groove; the transmission direction of the conveyor belt is parallel to the forward direction of the drill bit.

[0013] Preferably, four groups of tunneling heads are evenly arranged on the outer wall of the conveyor belt along the circumference of the mounting seat, and the excavation parts of the two middle groups of tunneling heads face the connecting shaft, while the excavation parts of the two edge groups of tunneling heads face away from the connecting shaft.

[0014] Preferably, the mounting seat is also provided with a number of grooves corresponding to the number of rectangular grooves, and a digging roller is provided in each of the grooves. The digging roller is connected to the transmission shaft connected to the third motor through the mounting shaft, and the digging direction of the digging roller is consistent with the transmission direction of the conveyor belt.

[0015] Preferably, two electromagnetic flaw detection modules are symmetrically arranged on the first tube body, the second tube body, the third tube body, the fourth tube body and the fifth tube body.

[0016] Preferably, the casing friction resistance detection device is a hollow structure, and a one-way valve is provided at the hollow structure of the drill bit mechanism. The one-way valve can control the one-way flow of fluid from the first tube body to the drill bit mechanism and out of the drill bit mechanism.

[0017] A method for detecting friction resistance of casing during casing-in-casing operation, using the detection device of the present invention, comprises the following steps:

[0018] S1: A casing friction resistance detection device is lowered into the existing wellbore to detect the wellbore. The detection device moves along the wall. During the lowering process, the drill bit mechanism cleans the dirt on the wellbore wall. In the horizontal section, the fourth pipe body and the weighted pipe are driven to rotate by the second meshing rotation assembly, thereby driving the drill bit to perform composite drilling, thereby improving the wellbore cleaning efficiency.

[0019] S2: Calculate the friction resistance of the casing in the casing using the value tested by the friction resistance detection component. For different working conditions, the calculation is as follows:

[0020] 1. For conventional casing running conditions, the following formula (1) is used to calculate the friction resistance of casing running:

[0021] (1),

[0022] in, F h The casing is fixed in the casing during the normal casing running process. h The friction resistance at , in KN;

[0023] h is the test well depth, in m;

[0024] i The depth of the contact point of the friction resistance detection component during the detection process is 1 to h , unit is m;

[0025] v c The casing lowering speed when the casing is fixed in the casing, the unit is m / s;

[0026] r c The outer diameter of the casing when the casing is fixed in the casing, in mm;

[0027] M i Well depth tested for the friction resistance detection assembly installed on the second pipe body i The value of the force at , in KN;

[0028] v 1 is the lowering speed of the friction resistance detection device, in m / s;

[0029] r 1 is the outer diameter of the friction resistance detection assembly provided on the second tube body in its natural state, in mm;

[0030] k is the well inclination gravity coefficient, dimensionless; when the well inclination angle is 0 k The value is 1; when the well inclination is not 0 k The value is ,in G c It is the linear weight of the casing during the casing-in-casing construction. G 1 is the linear weight of the casing friction resistance detection device, both units are kg / m;

[0031] Second, for the rotating casing working condition, the third tube body is driven to rotate circumferentially by the first meshing rotating assembly, thereby driving the friction resistance detection assembly thereon to rotate. The following formula (2) is used to calculate the friction resistance of the casing in the fixed sleeve:

[0032] (2),

[0033] in, N h The casing is lowered to the well depth when the casing is fixed in the casing under the condition of rotating casing. h The friction resistance at , in KN;

[0034] n c The casing speed during casing-in-casing construction is r / min.

[0035] n 1 is the rotation speed of the friction resistance detection assembly provided on the third tube body, in r / min;

[0036] r 2 is the outer diameter of the friction resistance detection assembly provided on the third tube body in its natural state, in mm;

[0037] P i Well depth tested for the friction resistance detection assembly installed on the third pipe body i The value of the force at is in KN.

[0038] Advantages of the present invention:

[0039] (1) The present invention provides a friction resistance detection component, which can test the friction resistance of the new process of running new casing into the old well casing during the process of advancing along the wall. It fully considers different working conditions such as conventional casing running and rotary casing running, highly simulates the actual working conditions of later casing running, tests and obtains the friction resistance of casing running, and provides technical support for later casing running. The test method is simple and the test accuracy is high, which meets the technical requirements of the new technology of casing in casing;

[0040] (2) Through the setting of the drill bit mechanism and the further setting of the second meshing rotating assembly, on the one hand, high-efficiency drilling of the drill bit mechanism can be achieved, and on the other hand, the drill bit mechanism can be rotated to prevent the drill tool from sticking, thereby adapting to the cleaning of dirt in the old wellbore of the vertical well section and the horizontal well section, and facilitating the safe lowering of the casing in the later stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a structural schematic diagram of the present invention;

[0042] Figure 2 for Figure 1 Schematic diagram of a local enlarged structure;

[0043] Figure 3 This is a partially enlarged structural diagram of the friction resistance detection assembly of the present invention;

[0044] Figure 4 It is a partially enlarged structural diagram of the drill bit mechanism of the present invention;

[0045] Figure 5 Test data diagram of the device of the present invention under conventional casing running conditions;

[0046] Figure 6 Comparison diagram of the conventional casing running condition of the present invention and the actual situation on site;

[0047] Figure 7 Test data diagram of the device of the present invention under the condition of rotating casing;

[0048] Figure 8 Comparison diagram of the present invention under the rotating casing working condition and the actual situation on site;

[0049] Among them, 1. first tube body; 2. second tube body; 3. third tube body; 4. fourth tube body; 5. fifth tube body; 611. connecting shaft; 612. mounting seat; 613. conveyor belt; 614. tunneling head; 615. tunneling roller; 616. transmission shaft; 617. third motor; 7. electromagnetic flaw detection module; 81. friction resistance detection assembly; 811. first movable ring; 812. first connecting rod; 813. second connecting rod; 814. second movable ring; 815. mounting ring; 816. spring; 817. contact wheel; 818. pressure sensor; 911. first motor; 912. first connecting sleeve; 913. first gear; 914. first outer gear ring; 10. weighted pipe; 111. second motor; 112. second connecting sleeve; 113. second outer gear ring; 114. second gear. DETAILED DESCRIPTION

[0050] Example 1

[0051] A casing friction resistance detection device for casing-in-casing, comprising a first pipe body 1, a second pipe body 2, a third pipe body 3, a fourth pipe body 4, a weighted pipe 10, a fifth pipe body 5, and a drill bit mechanism connected in sequence; the weighted pipe 10 is used to pressurize the drill bit mechanism;

[0052] The second tube body 2 and the third tube body 3 are rotationally connected via a first meshing rotation assembly that drives the third tube body 3 to rotate circumferentially; the third tube body 3 and the fourth tube body 4 are rotationally connected via a second meshing rotation assembly that drives the fourth tube body 4 to rotate circumferentially;

[0053] The second tube body 2 and the third tube body 3 are both provided with a friction resistance detection assembly 81 of the same structure, which is used to detect the friction resistance between the casing and the wellbore during the process of advancing against the wall.

[0054] As the detection device advances and the drill bit mechanism itself performs drilling action, it drives the detection device deeper to perform wellbore detection work. Through the friction resistance detection component 81 provided, the friction resistance between the casing and the wellbore can be tested during the process of advancing against the wall, providing a decision-making basis for the safe lowering of the casing in the later stage, thereby ensuring the safe lowering of the casing in the later stage.

[0055] Example 2

[0056] On the basis of the above embodiment 1, the friction resistance detection assembly 81 includes a mounting ring 815, a pressure sensor 818 connected to the mounting ring 815, a second movable ring 814 and a first movable ring 811; the mounting ring 815 is fixed on the corresponding tube body, the first movable ring 811 and the second movable ring 814 are slidably arranged on the corresponding tube body; the pressure sensor 818 and the second movable ring 814, the second movable ring 814 and the first movable ring 811 are connected by a spring 816; the mounting ring 815 and the second movable ring 814, the second movable ring 814 and the first movable ring The rings 811 are all connected by a number of connecting rod assemblies distributed circumferentially along the second movable ring 814, and the connecting rod assemblies are located outside the spring 816; the connecting rod assemblies include a first connecting rod 812 and a second connecting rod 813, and the two ends of the first connecting rod 812 and the second connecting rod 813 that are close to each other are hingedly connected to the same contact wheel 817, and the two ends of the first connecting rod 812 and the second connecting rod 813 that are far away from each other are hingedly connected to the mounting ring 815 and the second movable ring 814 respectively, or the two ends of the first connecting rod 812 and the second connecting rod 813 that are far away from each other are hingedly connected to the second movable ring 814 and the first movable ring 811 respectively.

[0057] In this embodiment, a friction resistance detection assembly 81 is provided, the mounting ring 815 is fixed, and the second movable ring 814 and the first movable ring 811 are both slidingly provided. When the detection device advances in the casing under different environments, a certain friction resistance is generated when the contact wheel 817 simulates moving forward and sticks to the wall, pushing the first connecting rod 812 and the second connecting rod 813 connected to the contact wheel 817 to slide backward along the axial direction of the device, driving the second movable ring 814 and the first movable ring 811 to slide in the direction close to the mounting ring 815, the length of the spring 816 is compressed, and the corresponding pressure sensor 818 reading changes. The force value tested by the friction resistance detection assembly 81 provided on the corresponding tube body can be obtained through the degree of change in the reading of the pressure sensor 818.

[0058] Furthermore, the contact wheel 817 is of rotating or fixed type, simulating the working conditions with a roller centralizer or a rigid centralizer respectively.

[0059] Example 3

[0060] Based on the above-mentioned embodiment 2, the first meshing rotation assembly includes a first connecting sleeve 912 fixedly connected to the second tubular body 2. The end of the first connecting sleeve 912 is rotatably provided with a first external gear ring 914 connected to the end of the third tubular body 3. A first motor 911 is also provided on the outer wall of the first connecting sleeve 912. The output shaft of the first motor 911 is connected to a first gear 913 that meshes and transmits with the first external gear ring 914 and is located on the same plane. The first external gear ring 914 is rotatably arranged relative to the first connecting sleeve 912, and the two can rotate. When the first motor 911 is in operation, it drives the first gear 913 to mesh and transmit with the first external gear ring 914, thereby driving the connected third tubular body 3 to rotate 360 ​​degrees, thereby driving the friction resistance detection assembly 81 on the third tubular body 3 to rotate, simulating the working condition of rotating casing and detecting the friction resistance between the casing and the wellbore.

[0061] Furthermore, the second meshing rotation assembly includes a second connecting sleeve 112 fixedly connected to the third pipe body 3. The end of the second connecting sleeve is rotatably provided with a second external gear ring 113 connected to the end of the fourth pipe body 4. A second motor 111 is also provided on the outer wall of the second connecting sleeve 112. The output shaft of the second motor 111 is connected to a second gear 114 that meshes and drives with the second external gear ring 113 and is coplanar with the second external gear ring 113. When the second motor 111 is in operation, it drives the second gear 114 to mesh and drive with the second external gear ring 113, driving the fourth pipe body 4 to rotate along the end of the second connecting sleeve 112, thereby driving the weighted pipe 10, the fifth pipe body 5, and the drill bit mechanism to rotate, improving the dirt cleaning efficiency of the horizontal section and the tool anti-jamming effect, so as to adapt to the exploration environment of horizontal wells.

[0062] Example 4

[0063] On the basis of the above-mentioned embodiment 3, the drill mechanism includes a connecting shaft 611 and a mounting seat 612 which are sequentially connected to the fifth tube body 5. The outer wall of the mounting seat 612 is evenly distributed with a number of rectangular grooves. The two ends of the rectangular grooves are respectively provided with transmission shafts 616 which are connected by a conveyor belt 613. The outer wall of the conveyor belt 613 is evenly provided with a boring head 614. The mounting seat 612 is also provided with a number of third motors 617 corresponding to the number of rectangular grooves. The output shaft of each third motor 617 is connected to one of the transmission shafts 616 in the rectangular groove. The transmission direction of the conveyor belt 613 is parallel to the forward direction of the drill bit. Figure 4 As shown, the third motor 617 works, driving the transmission shaft 616 to rotate and the conveyor belt 613 to transmit, thereby driving the tunneling head 614 to drill parallel to the forward direction of the casing, so as to carry out the in-depth work of cleaning the wellbore.

[0064] Furthermore, four sets of boring heads 614 are evenly distributed along the outer wall of the conveyor belt 613, circumferentially around the mounting base 612. The digging sections of the two central sets of boring heads 614 face the connecting shaft 611, while the digging sections of the two peripheral sets of boring heads 614 face away from the connecting shaft 611. When the conveyor belt 613 encounters difficulties in advancing, a third motor 617 controls the forward and reverse movement of the conveyor belt 613, enabling the back-and-forth movement of the conveyor belt 613 and switching the digging heads 614's digging direction. This facilitates the removal of surrounding debris and dirt, effectively improving the wellbore cleaning process.

[0065] Furthermore, the mounting base 612 is provided with a number of grooves corresponding to the number of rectangular slots. Each groove houses a driving roller 615. The driving roller 615 is connected to a drive shaft 616 connected to a third motor 617 via a mounting shaft. The driving direction of the driving roller 615 aligns with the conveying direction of the conveyor belt 613. With the driving roller 615, when the driving head 614 is operating, the driving shaft 616 rotates, driving the driving roller 615 to perform rotary cleaning operations. The driving head 614 assists in this, further improving the drilling efficiency.

[0066] Example 5

[0067] Based on the above-mentioned embodiment 4, two electromagnetic flaw detection modules 7 are symmetrically installed on each of the first, second, third, fourth, and fifth pipe bodies 5. These electromagnetic flaw detection modules 7 utilize established technology (EMDS / MDT or DS-WC series) and fall within the scope of magnetic well logging. The law of electromagnetic induction serves as the theoretical basis for their application. They transmit DC pulses to the transmitting coil, which induces changes in the electromotive force at different points in time in the receiving coil and records the relevant information in real time. Changes in casing thickness or design flaws will cause corresponding changes in the induced electromotive force. Using analysis and calculation methods, the presence of cracks, holes, and other quality issues in single- and double-casing string structures can be accurately identified, thereby determining the actual wall thickness of the string. The symmetrical and linear distribution of the two electromagnetic flaw detection modules 7 across different sections of the detection device effectively improves detection efficiency and accuracy.

[0068] More preferably, the casing-in-casing friction resistance detection device has a hollow structure, and a one-way valve is provided in the hollow structure of the drill bit mechanism. The one-way valve can control the unidirectional flow of fluid from the first pipe body 1 to the drill bit mechanism and out of the drill bit mechanism, so that the fluid can remove impurities generated during the drilling process and then be discharged from the well, thereby preventing excessive impurities from contaminating the device.

[0069] Example 6

[0070] A method for detecting friction resistance of casing during casing-in-casing operation, using the detection device of the present invention, comprises the following steps:

[0071] S1: A casing friction resistance detection device is lowered into the existing wellbore to detect the wellbore. The detection device moves along the wall. During the lowering process, the drill bit mechanism cleans the dirt on the wellbore wall. In the horizontal section, the fourth pipe body 4 and the weighted pipe 10 are driven to rotate by the second meshing rotation assembly, thereby driving the drill bit to perform composite drilling, thereby improving the wellbore cleaning efficiency.

[0072] S2: Calculate the friction resistance of the casing during the casing-in-casing process using the value measured by the friction resistance detection component 81. For different working conditions, the calculation is as follows:

[0073] 1. For conventional casing running conditions, the following formula (1) is used to calculate the friction resistance of casing running:

[0074] (1),

[0075] in, F h The casing is fixed in the casing during the normal casing running process. h The friction resistance at , in KN;

[0076] h is the test well depth, in m;

[0077] i The depth of the contact point of the friction resistance detection component 81 during the detection process is 1 to h , unit is m;

[0078] v c The casing lowering speed when the casing is fixed in the casing, the unit is m / s;

[0079] r c The outer diameter of the casing when the casing is fixed in the casing, in mm;

[0080] M i The well depth tested by the friction resistance detection assembly 81 provided on the second pipe body 2 i The value of the force at , in KN;

[0081] v 1 is the lowering speed of the friction resistance detection device, in m / s;

[0082] r 1 is the outer diameter of the friction resistance detection assembly 81 provided on the second tube body 2 in the natural state, in mm;

[0083] k is the well inclination gravity coefficient, dimensionless; when the well inclination angle is 0 k The value is 1; when the well inclination is not 0 k The value is ,in G c It is the linear weight of the casing during the casing-in-casing construction. G 1 is the linear weight of the casing friction resistance detection device, both units are kg / m;

[0084] Second, for the rotating casing operation, the third tube body 3 is driven to rotate circumferentially by the first meshing rotating assembly, thereby driving the friction resistance detection assembly 81 thereon to rotate. The following formula (2) is used to calculate the friction resistance of the casing in the fixed sleeve:

[0085] (2)

[0086] Where:

[0087] N h The casing is lowered to the well depth when the casing is fixed in the casing under the condition of rotating casing. h The friction resistance at , in KN;

[0088] n c The casing speed during casing-in-casing construction is r / min.

[0089] n 1 is the rotation speed of the friction resistance detection assembly 81 provided on the third tube body 3, in r / min;

[0090] r 2 is the outer diameter of the friction resistance detection assembly 81 provided on the third tube body 3 in the natural state, in mm;

[0091] P i It is the force value at the well depth tested by the friction resistance detection assembly 81 provided on the third pipe body 3, in KN.

[0092] Example 7

[0093] A horizontal well, WYJ-3, from a low-permeability oilfield in western China was selected to test the conventional casing running conditions of the device described in Example 5 of the present invention, and to conduct a comparative experiment with the casing running conditions under actual conditions. The test run depth was 600 m (including a 120 m horizontal section), the well inclination point was 210 m (i.e., the well inclination angle is 0 when the well depth is less than or equal to 210 m, and the well inclination angle is not 0 when the well depth is greater than 210 m), and the density of the liquid in the well before casing running was 1.05 g / cm3 The inner diameter of the production casing of this well is 124.26mm. The casing used in actual working conditions is 101.6mm uncoupled casing (i.e. r c =101.6mm), line weight ( G c ) is 16.38kg / m.

[0094] The friction resistance test of the casing in the well is conducted by using the device described in Example 5 of the present invention, which mainly relies on the friction resistance detection component 81 on the second pipe body 2. G 1) 9.24kg / m, outer diameter in natural state r 1 is 101.6 mm, the accuracy of the pressure sensor 818 is 1 N, the motor on the device uses a turbine motor, the data acquisition method adopts downhole storage, and the contact wheel 817 on the friction resistance detection assembly 81 is fixed. The test condition is conventional casing running, so the friction resistance detection assembly 81 on the third pipe body 3 remains stationary, as follows:

[0095] S1: Connect the device of the present invention to the oil pipe and lower it into the bottom of the well from the wellhead (test well depth h 600m), string running speed v 1 is the actual running speed of the uncoupled casing during the later stage, 0.3 m / s (i.e. v c 、 v 1 are both 0.3m / s). During the process of the detection device moving forward and lowering into the wellbore, the drill bit mechanism cleans the dirt on the wellbore wall. In the horizontal section, the fourth pipe body 4 and the weighted pipe 10 are driven by the second meshing rotation assembly to rotate circumferentially, thereby driving the drill bit to perform composite drilling. The maximum speed of the drill bit mechanism is controlled at 30r / min.

[0096] S2: The friction resistance of the casing in the casing is calculated by formula (1). The force values ​​tested by the friction resistance detection assembly 81 set on the second pipe body 2 corresponding to each contact point at different well depths are shown in Figure 5 According to formula (1), the friction resistance of casing running under conventional casing running conditions can be calculated; when the well depth is less than or equal to 210m (deflection point), k The value is 1, when the well depth is greater than 210m k The values ​​are: k = =16.38 / 9.24=1.77, the calculation result is shown in Figure 6 ; Collect the friction resistance of each section during the casing running process under actual working conditions, and compare the results. Figure 6 .Depend on Figure 6As can be seen from the results, the device of the present invention can test friction resistance under conventional operating conditions with minimal error compared to actual conditions. The technology of the present invention closely matches actual field conditions, offers high accuracy, and can meet field needs. Furthermore, the successful running of casing also demonstrates that the device can simultaneously clean dirt from existing wellbores while testing, ensuring the safe running of subsequent casing.

[0097] Example 8

[0098] Another horizontal well, KL-7, in a low-permeability oil field in western China was selected to test the rotary casing running conditions of the device of the present invention and conduct a comparative experiment with the actual casing running conditions. The test running depth was 600m (including the 101m horizontal section), the well inclination point was 260m (i.e., the well inclination angle is 0 when the well depth is less than or equal to 260m, and the well inclination angle is not 0 when the well depth is greater than 260m). The density of the liquid in the well before casing running was 1.07g / cm 3 The inner diameter of the production casing of this well is 124.26mm. The casing used in actual working conditions is the uncoupled casing with an outer diameter of 114.3mm (i.e. r c =114.3mm), line weight ( G c ) is 17.26kg / m, and the speed is 12r / min ( n c ).

[0099] The friction resistance test of the rotating casing in the well was conducted by using the device described in Example 5 of the present invention. The test was mainly carried out by the friction resistance detection component 81 on the third pipe body 3. The rotation speed was 10 r / min ( n 1), its line weight ( G 1) 9.24kg / m, outer diameter in natural state r 2 is 101.6 mm, the accuracy of the pressure sensor 818 is 1 N, the motor on the device adopts a turbine motor, the data acquisition method adopts downhole storage, and the contact wheel 817 on the friction resistance detection component 81 is fixed, as follows:

[0100] S1: Connect the device of the present invention to the oil pipe and lower it into the bottom of the well from the wellhead (test well depth h 600m), string running speed v 1 is the actual running speed of the uncoupled casing during the later stage, 0.3 m / s (i.e. v c 、 v1 are both 0.3m / s). During the process of the detection device moving forward and lowering into the wellbore, the drill bit mechanism cleans the dirt on the wellbore wall. In the horizontal section, the fourth pipe body 4 and the weighted pipe 10 are driven by the second meshing rotation assembly to rotate circumferentially, thereby driving the drill bit to perform composite drilling. The maximum speed of the drill bit mechanism is controlled at 30r / min.

[0101] S2: The third pipe body 3 is driven to rotate circumferentially by the first meshing rotating assembly, thereby driving the friction resistance detection assembly 81 thereon to rotate. The rotation speed is 10 r / min. The force values ​​tested by the friction resistance detection assembly 81 set on the third pipe body 3 corresponding to each contact point at different well depths are shown in FIG. Figure 7 , according to formula (2), the friction resistance of casing in casing under rotating casing condition is calculated. When the well depth is less than or equal to 260m, k The value is 1, when the well depth is greater than 260m k The values ​​are: k = =17.26 / 9.24=1.87, calculation results are shown in Figure 8 ; Collect the friction resistance of each section during the running of the rotating casing under actual working conditions, and compare the results. Figure 8 .Depend on Figure 8 It can be seen that the device of the present invention can test the friction resistance under the condition of rotating casing, and the error is small compared with the actual situation. The technology of the present invention is close to the actual situation on site, has good accuracy, and can meet the needs of the site.

Claims

1. A device for detecting friction resistance of casing during casing-in-casing operation, characterized in that: It includes a first tube body, a second tube body, a third tube body, a fourth tube body, a weighted tube, a fifth tube body and a drill bit mechanism that are connected in sequence; The second tube body and the third tube body are rotationally connected via a first meshing rotation assembly that drives the third tube body to rotate circumferentially; the third tube body and the fourth tube body are rotationally connected via a second meshing rotation assembly that drives the fourth tube body to rotate circumferentially; The second and third pipe bodies are both provided with friction resistance detection components of the same structure, which are used to detect the friction resistance between the casing and the wellbore during the process of advancing against the wall; The friction resistance detection assembly includes a mounting ring, a pressure sensor connected to the mounting ring, a second movable ring and a first movable ring; the mounting rings are respectively fixed on the corresponding tube bodies, and the first movable ring and the second movable ring are slidably arranged on the corresponding tube bodies; the pressure sensor and the second movable ring, the second movable ring and the first movable ring are all connected by a spring; the mounting ring and the second movable ring, the second movable ring and the first movable ring are all connected by a plurality of connecting rod assemblies distributed along the circumference of the second movable ring, and the connecting rod assemblies are located outside the spring; the connecting rod assembly includes a first connecting rod and a second connecting rod, the two ends of the first connecting rod and the second connecting rod that are close to each other are hingedly connected to the same contact wheel, the two ends of the first connecting rod and the second connecting rod that are far away from each other are respectively hingedly connected to the mounting ring and the second movable ring, or the two ends of the first connecting rod and the second connecting rod that are far away from each other are respectively hingedly connected to the second movable ring and the first movable ring; The drill head mechanism includes a connecting shaft and a mounting seat connected in sequence to the fifth tube body. The outer wall of the mounting seat is evenly distributed with a plurality of rectangular grooves. Transmission shafts connected by a conveyor belt are respectively provided at both ends of the rectangular grooves. The outer wall of the conveyor belt is evenly provided with drilling heads. The mounting seat is also provided with a plurality of third motors corresponding to the number of rectangular grooves. The output shaft of each third motor is connected to one of the transmission shafts in the rectangular groove. The transmission direction of the conveyor belt is parallel to the forward direction of the drill head. The mounting seat is also provided with a number of grooves corresponding to the number of rectangular grooves, and a digging roller is provided in each of the grooves. The digging roller is connected to the transmission shaft connected to the third motor through the mounting shaft, and the digging direction of the digging roller is consistent with the transmission direction of the conveyor belt.

2. The device for detecting friction resistance of casing during casing-in-casing according to claim 1, characterized in that: The first meshing rotating assembly includes a first connecting sleeve fixedly connected to the second tube body, and the end of the first connecting sleeve is rotatably provided with a first external gear ring connected to the end of the third tube body. A first motor is also provided on the outer wall of the first connecting sleeve, and the output shaft of the first motor is connected to a first gear that meshes with the first external gear ring and is in the same plane.

3. The device for detecting friction resistance of casing during casing-in-casing according to claim 2, characterized in that: The second meshing rotation assembly includes a second connecting sleeve fixedly connected to the third tube body, and the end of the second connecting sleeve is rotatably provided with a second external gear ring connected to the end of the fourth tube body. A second motor is also provided on the outer wall of the second connecting sleeve, and the output shaft of the second motor is connected to a second gear that meshes with the second external gear ring and is in the same plane.

4. The device for detecting friction resistance of casing during casing-in-casing according to claim 1, characterized in that: Four groups of tunneling heads are evenly arranged on the outer wall of the conveyor belt along the circumference of the mounting seat, and the excavation parts of the two middle groups of tunneling heads face the connecting shaft, while the excavation parts of the two edge groups of tunneling heads face away from the connecting shaft.

5. The device for detecting friction resistance of casing during casing-in-casing according to claim 1, characterized in that: Two electromagnetic flaw detection modules are symmetrically arranged on the first tube body, the second tube body, the third tube body, the fourth tube body and the fifth tube body.

6. The device for detecting friction resistance of casing during casing-in-casing according to claim 1, characterized in that: The casing friction resistance detection device is a hollow structure, and a one-way valve is provided at the hollow structure of the drill bit mechanism.

7. A method for detecting friction resistance of casing during casing-in-casing operation, characterized in that: The method is carried out using the detection device according to any one of claims 1 to 6, comprising the following steps: S1: A casing friction resistance detection device is lowered into the existing wellbore to detect the wellbore. The detection device moves along the wall. During the lowering process, the drill bit mechanism cleans the dirt on the wellbore wall. In the horizontal section, the fourth pipe body and the weighted pipe are driven to rotate by the second meshing rotation assembly, thereby driving the drill bit to perform composite drilling. S2: Calculate the friction resistance of the casing in the casing using the value tested by the friction resistance detection component. For different working conditions, the calculation is as follows:

1. For conventional casing running conditions, the following formula is used to calculate the friction resistance of casing running in a fixed casing: ， in, F h The casing is lowered to the well depth during casing running. h The friction resistance at , in KN; h is the test well depth, in m; i The depth of the contact point of the friction resistance detection component during the detection process is 1 to h , unit is m; v c The casing lowering speed when the casing is fixed in the casing, the unit is m / s; r c The outer diameter of the casing when the casing is fixed in the casing, in mm; M i Well depth tested for the friction resistance detection assembly installed on the second pipe body i The value of the force at , in KN; v 1 is the lowering speed of the friction resistance detection device, in m / s; r 1 is the outer diameter of the friction resistance detection assembly provided on the second tube body in its natural state, in mm; k is the well inclination gravity coefficient, dimensionless; when the well inclination angle is 0 k The value is 1; when the well inclination is not 0 k The value is ,in G c It is the linear weight of the casing during the casing-in-casing construction. G 1 is the linear weight of the casing friction resistance detection device, both units are kg / m; Second, for the rotating casing operation, the first meshing rotating assembly drives the third tube to rotate circumferentially, thereby driving the friction resistance detection assembly thereon to rotate. The following formula is used to calculate the friction resistance of the casing in the fixed sleeve: ， in, N h The casing is lowered to the well depth when the casing is fixed in the casing under the condition of rotating casing. h The friction resistance at , in KN; n c The casing speed during casing-in-casing construction is r / min. n 1 is the rotation speed of the friction resistance detection assembly provided on the third tube body, in r / min; r 2 is the outer diameter of the friction resistance detection assembly provided on the third tube body in its natural state, in mm; P i Well depth tested for the friction resistance detection assembly installed on the third pipe body i The value of the force at is in KN.

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