Stress measurement-while-drilling device based on vibration

Abstract

The utility model provides a stress measurement-while-drilling device based on vibration, and relates to the technical field of mining engineering and drilling parameter measurement. The device comprises a drilling machine and a measuring drill rod, a plurality of axial acceleration sensors, a plurality of radial acceleration sensors, a plurality of lateral acceleration sensors, a data collector, a power supply and a signal transmitting device are arranged on the measuring drill rod, glue is injected into a cavity of the measuring drill rod, and a computer receives monitoring signals transmitted by the signal transmitting device. The various acceleration sensors transmit acceleration signals generated by measuring axial, radial and lateral vibration of the drill rod to the collector, the computer processes and calculates vibration displacement signals according to signal data packets, drilling machine parameters are calculated through the vibration signals, coal stress is inversely calculated, drilling and measuring data can be analyzed and processed in real time, and drilling and measuring accuracy is improved. And the reliability of stress monitoring is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of mining engineering and drilling parameter measurement, in particular to a vibration-based stress while-drilling measurement device. Background Art

[0002] Measurement While Drilling (MWD) is a key technology in the oil drilling and coal mining fields, which allows real-time acquisition of downhole information during the drilling process.

[0003] In the field of oil drilling, MWD technology was originally used to provide basic drilling parameters, such as well depth, azimuth and inclination. The current MWD system can provide more complex measurement data, including physical properties, porosity, permeability and saturation of the formation. These data are crucial for geo-guided drilling and rotary steerable drilling, and support safe, efficient and high-yield drilling operations. In the field of coal mining, the application of MWD technology is mainly focused on improving drilling efficiency and safety. It can obtain parameters such as well inclination, azimuth, tool face near the drill bit in real time, which is crucial for directional drilling. With these data, the drilling trajectory can be accurately controlled to avoid deviation from the target area, reduce the blank zone of gas extraction, and thus improve the extraction efficiency of coalbed methane.

[0004] The existing measurement while drilling technology mainly measures the following parameters: well inclination, azimuth, tool face, resistivity, sound velocity, porosity, density, drilling pressure, torque, rotation speed, annular pressure, temperature, etc. However, the existing technology is lacking in vibration measurement and cannot measure the vibration response of the drill pipe during drilling. The current measurement while drilling instruments have four basic inherent problems: measurement (engineering parameters and geological parameters, etc.), power supply (high-power power supply downhole), transmission (high-speed real-time upload) and temperature (resistance to high, ultra-high and extremely high temperatures downhole).

[0005] In the prior art, most of the stress measurement devices for drilling stress measurement use multiple external sensors for measurement, and then use manual methods for analysis and calculation. Chinese patent CN117738639A discloses a drilling monitoring device for mining drills and a method for measuring coal body stress. The data monitoring system includes a pull-wire displacement sensor and a torque speed sensor. One end of the pull-wire sensor is connected to the bottom of the power head, and the other end is connected to the drill rig support. However, the actual drilling rig structure is compact and it is difficult to support redundant connection structures. The patent transmits the drilling rig parameters to the ground monitoring host, and then calculates the coal body stress through the calculation method. However, in practice, it is often necessary to monitor the stress of dozens of holes, and the amount of monitoring data is huge. The method of first transmitting and then manually calculating is inefficient.

[0006] In summary, the technical problems encountered by the current stress while drilling measurement device include: first, due to too many additional devices, the installation environment is harsh or difficult to install in the expected way; second, in the existing technology, the measured value needs to be further processed to obtain the stress monitoring value, and the calculation process is complicated and inefficient. Therefore, it is necessary to further improve the existing while drilling measurement device and measurement method. Utility Model Content

[0007] In order to simplify the measurement while drilling equipment and data processing, ensure the monitoring accuracy, and improve the reliability of stress monitoring, the utility model provides a stress measurement while drilling device based on vibration, and the specific technical scheme is as follows.

[0008] A vibration-based stress while-drilling measurement device comprises a drilling rig and a measuring drill rod. The drilling rig is connected to and drives a plurality of measuring drill rods to rotate. A plurality of axial acceleration sensors, a plurality of radial acceleration sensors, a plurality of lateral acceleration sensors, a data collector, a power supply and a signal transmitting device are fixedly arranged in the cavity of the measuring drill rod. The power supply is configured to supply power in this section of the measuring drill rod. The cavity of the measuring drill rod is sealed by glue injection. The signal transmitting device and a computer transmit interactive information via wireless signals.

[0009] Preferably, the computer is connected to a signal receiver via a USB interface, and the signal receiver receives signals from various signal transmitting devices.

[0010] Preferably, a plurality of sensor slots are provided inside the measuring drill rod, the axial acceleration sensor is arranged in the middle of the length direction of the measuring drill rod, the radial acceleration sensor is arranged adjacent to the axial acceleration sensor, and the lateral acceleration sensor is configured at the end inside the measuring drill rod.

[0011] Preferably, when there are two or more axial acceleration sensors, the algebraic mean of the monitoring values ​​of the axial acceleration sensors is used as the acceleration monitoring value of the group of axial acceleration sensors.

[0012] Preferably, when there are two or more radial acceleration sensors, an algebraic mean of the monitoring values ​​of the radial acceleration sensors is used as the acceleration monitoring value of the group of radial acceleration sensors.

[0013] Preferably, when there are two or more lateral acceleration sensors, the algebraic mean of the monitoring values ​​of the lateral acceleration sensors is used as the acceleration monitoring value of the group of lateral acceleration sensors.

[0014] It is also preferred that after drilling begins, the data collector collects acceleration at intervals of 1 second and converts the measured axial acceleration a into z , radial acceleration a y , lateral acceleration ax The data are packaged with the current timestamp into data packets and transmitted to the signal transmitting device.

[0015] It is also preferred that the signal transmitting device modulates the data packet into a wireless signal and transmits it to the signal receiving device via a wireless connection. The signal receiving device demodulates the wireless signal and restores it into a data packet and reads the timestamp, and transmits each received data packet in sequence to the computer for processing in the order of the timestamps.

[0016] The beneficial effects of the vibration-based stress while drilling measurement device provided by the utility model are:

[0017] The device and measurement method use a single measuring drill rod for measurement and connect to a matching computer via a wireless connection. When in use, the measuring drill rod only needs to be installed on the drilling rig as a section of drill rod, without the need for complicated connections and wiring. The algorithm uses a three-axis acceleration measurement method to measure the vibration generated during the drilling process, transmits the acceleration signal to the computer via a wireless signal transmitter / receiver, and solves the vibration displacement signal. The drilling rig parameters are calculated through the vibration signal and the coal body stress is inversely calculated. The drilling measurement data can be analyzed and processed in real time, thereby improving the reliability of stress monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the measuring drill pipe structure;

[0019] Figure 2 It is a schematic diagram of the signal receiver and computer;

[0020] Figure 3 is a schematic diagram of a wireless signal transmission system;

[0021] Figure 4 It is a schematic diagram of the algorithm flow;

[0022] In the figure: 1- axial acceleration sensor, 2- radial acceleration sensor, 3- lateral acceleration sensor, 4- collector, 5- signal transmitting device, 6- power module, 21- signal receiving device, 22- computer. DETAILED DESCRIPTION

[0023] Combination Figures 1 to 4 As shown, a specific implementation of a vibration-based stress while drilling measurement device provided by the utility model is described.

[0024] A vibration-based stress while drilling measurement device and a measurement method, which only requires a measuring drill rod and a wirelessly connected computer, does not require other external devices, and directly and automatically calculates stress data during data processing. The device includes a drilling rig and a measuring drill rod, the drilling rig is connected to and drives a plurality of measuring drill rods to rotate, the plurality of measuring drill rods are fixed by plugging, and the drilling rig drives the measuring drill rods to drill along the direction of the borehole. A plurality of axial acceleration sensors, a plurality of radial acceleration sensors, a plurality of lateral acceleration sensors, a data collector, a power supply and a signal transmitting device are fixedly configured in the cavity of the measuring drill rod, wherein the number of axial acceleration sensors, radial acceleration sensors and lateral acceleration sensors is selected according to the length of the measuring drill rod, and the longer the length of the measuring drill rod, the more acceleration sensors need to be arranged, and the power supply is configured in this section of the measuring drill rod to supply power to each acceleration sensor, the data collector and the signal transmitting device, etc., and each acceleration sensor and the data collector and other structures are connected by wires. The cavity of the measuring drill pipe is sealed by injection, and the sensor is sealed in the cavity and fixed in position. The signal transmitter and the computer transmit interactive information through wireless signals, and the effective transmission of data is ensured by wireless transmission of data. A group of axial acceleration sensors, radial acceleration sensors, and lateral acceleration sensors are set respectively. If any group of sensors has more than one, the algebraic mean of the monitoring values ​​of the group of sensors is used as the acceleration monitoring value of the group.

[0025] If there are more than or equal to two axial acceleration sensors, the algebraic mean of the monitoring values ​​of each axial acceleration sensor is used as the acceleration monitoring value of the group of axial acceleration sensors; if there are more than or equal to two radial acceleration sensors, the algebraic mean of the monitoring values ​​of each radial acceleration sensor is used as the acceleration monitoring value of the group of radial acceleration sensors; if there are more than or equal to two lateral acceleration sensors, the algebraic mean of the monitoring values ​​of each lateral acceleration sensor is used as the acceleration monitoring value of the group of lateral acceleration sensors.

[0026] The computer is connected to the signal receiver via a USB interface, and the signal receiver receives signals from various signal transmitting devices.

[0027] Among them, the measuring drill pipe is provided with a plurality of sensor slots inside, and the slots match the size of the acceleration sensor, and the sensors are stuck in the slots to avoid axial or radial movement. Among them, the axial acceleration sensor is arranged in the middle of the length direction of the measuring drill pipe, the radial acceleration sensor is arranged adjacent to the axial acceleration sensor, and the lateral acceleration sensor is arranged at the end inside the measuring drill pipe, so as to achieve accurate measurement of axial, radial and lateral acceleration. Furthermore, a limit pressing plate can be arranged around the slot, and the limit pressing plate limits the axial movement of the axial acceleration sensor, the radial movement of the radial acceleration sensor, and the lateral movement of the lateral acceleration sensor, and the limit pressing plate is made of stainless steel.

[0028] In addition, the components in the measuring drill pipe may not be arranged in the internal cavity, such as reducing the diameter of the measuring drill pipe, and setting the axial and lateral acceleration sensors on the outer surface of the measuring drill pipe, and connecting them to the power module and signal transmitter arranged on the drilling rig frame through long wires. The number, range, and graduation value of the axial and lateral acceleration sensors can be the same or different, and the shape, structure, and size of each acceleration sensor can be exactly the same, or each can have an appropriate structure and size.

[0029] When the device is in use, the non-contact switch of the power module on the measuring drill rod is turned on, the power module supplies power to each component of the measuring drill rod, the computer is turned on and a reliable wireless connection is established between the signal receiver and the signal transmitter on the measuring drill rod, and the measuring drill rod is connected to the drilling rig through a joint in the form of a drill rod. After drilling begins, the acceleration sensor transmits the acceleration signal generated by the axial, radial and lateral vibration of the measuring drill rod to the collector, and the collector collects the acceleration at intervals of 1s. If the number of acceleration sensors in a group is more than 1, the arithmetic average operation is performed to obtain the acceleration monitoring value, and the three accelerations and the current timestamp are packaged into a data packet and transmitted to the signal transmitting device. The signal transmitting device modulates the data packet into a wireless signal and transmits it to the signal receiving device through a wireless connection. The signal receiving device demodulates the wireless signal and restores it into a data packet and reads the timestamp. The received data packets are sequentially transmitted to the computer for processing in the order of the timestamps. After the computer receives the data packet, it processes the data packet in the order of the timestamps, specifically converting the acceleration signal into a vibration signal through the above algorithm and finally processing it into stress data, and writing the stress data and the corresponding timestamp sequence number into the table file in sequence.

[0030] After drilling is completed, the signal transmitter sends a termination signal, the power module of the measuring drill pipe is turned off, and the measuring drill pipe stops working; when the signal receiving device receives the termination signal or does not receive a signal for 60 consecutive seconds, it sends all received data packets and sends a completion signal to the computer. When the computer receives the completion signal, it processes all received data packets, verifies and saves the table file. Verification means traversing the timestamps in the table file. The time should be arranged in sequence every 1 second from the first timestamp until the last timestamp. If a reverse order occurs, the corresponding data will be exchanged until there is no reverse order, and the error will be written to the log file. If a missing occurs, the data before the missing time 1 second is copied to fill the missing, and the error is written to the log file. When calling stress monitoring data, open the saved table file on the computer or copy the table file to other devices and open it to read the corresponding stress data.

[0031] A vibration-based stress while drilling measurement method, using the above-mentioned vibration-based stress while drilling measurement device, comprises the following steps:

[0032] S1. Real-time monitoring of axial acceleration a during drilling z , radial acceleration a y , lateral acceleration a x ;

[0033] S2. The data logger records the axial acceleration a at fixed time intervals z , radial acceleration a y , lateral acceleration a x and transmitted to the computer via a signal transmitting device;

[0034] The collector records the axial acceleration a of the i-th group at a fixed interval of time Δt. z , radial acceleration a y and lateral acceleration a x Numeric value, i.e. a zi 、a yi 、a xi , transmitted to the computer through the signal transmitting device and the signal receiving device on the computer.

[0035] S3. The lateral acceleration eliminates the influence of the centripetal acceleration to obtain the lateral vibration acceleration, and calculates the rotational velocity;

[0036] The lateral acceleration excludes the centripetal acceleration a n The influence of lateral vibration acceleration a xREAL :

[0037] a xi =a xiREAL +a n

[0038] The drill bit radius is r, and the drill rod radius R is not much different from r. Assume that R = r;

[0039] Then the lateral vibration acceleration a of the i-th group is xiREAL for:

[0040] a xiREAL =a xi -v yi 2 / r

[0041] The radial velocity is:

[0042] v yi =a yi Δt

[0043] S4. Filter the drilling displacement from the axial vibration displacement signal and perform first-order inertial filtering to obtain the drilling displacement;

[0044] x zi Perform first-order inertial filtering to obtain the drilling displacement x ziDRIL The calculation formula is:

[0045] x ziDRIL =αx zi-1DRIL +(1-α)x zi

[0046] Where α is the filter coefficient, the value is 0.1, x zi-1DRIL To perform iterative calculation using the drilling displacement of the previous set of time.

[0047] S5. Determine the vibration displacement;

[0048] At the initial moment, the ordinal number j=0; the monitoring vibration displacement value x i , when x i-2 <x i-1 And x i <x i-1 Time i-1 For the maximum displacement, let j increase by 1 and record i j =i-1, when j=2, the recording period is T 2 =Δt(i 2 -i 1 ), frequency f 2 for:

[0049]

[0050] j=3, continue recording i j , the update cycle is:

[0051]

[0052] Update frequency is:

[0053]

[0054] S6. Calculate and determine the axial vibration frequency and the lateral vibration frequency;

[0055] Apply the above analysis to the axial vibration displacement and lateral vibration displacement to obtain the axial vibration frequency f z , lateral vibration frequency f x For the i-th group of time, there is an axial vibration frequency f zi , lateral vibration frequency f xi . Reference frequency method to measure cable force principle, take vibration as first order, drilling pressure F = 4ρf z 2 L s 2 , where L s is the total length of the drill pipe (initial L 0 To measure the length of the drill rod, let s be the current number of drill rods. Each time a drill rod is added, the length of a single drill rod is increased by L, i.e. L s =L 0 +sL), ρ = m / L is the (average) linear density of the drill pipe; correspondingly, there is a torque M = 4ζf x 2 r 2 , where ζ = m s / 2π is the average angular density of the drill pipe, m s =m 0 +sm is the total mass of the drill pipe. In the measurement while drilling, the drilling pressure F is:

[0056]

[0057] Stress value σ 0 for:

[0058]

[0059] S7. Calculate the stress monitoring value σ of the i-th group 0i for:

[0060]

[0061] Where c is the cohesive force in the coal body, b is the drill bit blade width, and θ is the blade angle. is the anti-cutting angle, δ is the friction angle in the coal body, ξ 1 ,ξ 2 is a constant coefficient.

[0062] ξ 1 ,ξ 2 The calculation method is:

[0063]

[0064] Where c is the cohesive force of the coal body, b is the drill bit blade width, θ is the blade angle, φ is the anti-cutting angle, and δ is the friction angle inside the coal body.

[0065] The axial velocity ν of the i-th group xi , axial displacement x xi , radial velocity ν yi , radial displacement x yi , lateral velocity v zi and lateral displacement x zi The expression is:

[0066]

[0067] The lateral velocity v zi is the drilling speed, n i is the rotation speed.

[0068] When in use, the power module supplies power, establishes a wireless connection between the signal receiver and the signal transmitter on the measuring drill rod, and connects the measuring drill rod to the drilling rig through a joint; after drilling begins, the acceleration sensor transmits the acceleration signal generated by the axial, radial, and lateral vibrations of the measuring drill rod to the data collector, which collects acceleration at intervals of 1 second. If there are more than one acceleration sensors measuring the same parameter, an arithmetic average operation is performed to obtain the acceleration monitoring value, and the axial acceleration a is calculated. z , radial acceleration a y , lateral acceleration a x The data are packaged with the current timestamp into data packets and transmitted to the signal transmitting device.

[0069] The signal transmitting device modulates the data packet into a wireless signal and transmits it to the signal receiving device via a wireless connection. The signal receiving device demodulates the wireless signal and restores it into a data packet and reads the timestamp, and transmits each received data packet in sequence to the computer for processing in the order of the timestamps.

[0070] After drilling is completed, when the computer receives the completion signal, it processes all received data packets, verifies and saves the table file; when calling stress monitoring data, it opens the saved table file on the computer or copies the table file to other devices and opens it to read the corresponding stress data. The computer is loaded with calculation algorithms to process the monitoring data and obtain the calculation results.

[0071] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A vibration-based stress while drilling measurement device, comprising a drilling rig and a measuring drill rod, wherein the drilling rig is connected to and drives a plurality of measuring drill rods to rotate, and is characterized in that: Several axial acceleration sensors, several radial acceleration sensors, several lateral acceleration sensors, a data collector, a power supply and a signal transmitting device are fixedly configured in the cavity of the measuring drill rod. The power supply is configured to supply power in this section of the measuring drill rod. The cavity of the measuring drill rod is sealed by glue injection. The signal transmitting device and the computer transmit interactive information via wireless signals.

2. A vibration-based stress while drilling measurement device according to claim 1, characterized in that: The computer is connected to a signal receiver via a USB interface, and the signal receiver receives signals from various signal transmitting devices.

3. The vibration-based stress while drilling measurement device according to claim 2, characterized in that: The measuring drill rod is provided with a plurality of sensor slots inside. The axial acceleration sensor is arranged in the middle of the measuring drill rod in the length direction. The radial acceleration sensor is arranged adjacent to the axial acceleration sensor. The lateral acceleration sensor is arranged at the end inside the measuring drill rod.

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