A multi-frequency motor direct drive top drive drilling device and its driving method

Abstract

The present invention relates to the technical field of oil drilling and geological exploration, and in particular to a multi-frequency motor direct drive top drive drilling device and its driving method. Its transmission mechanism is not easily failed, has high energy utilization rate, and is relatively compact in volume and weight. The top drive device is rotated by a multi-frequency motor to carry out drilling work. The motor adopts a multi-winding structure. By switching the connection mode of the windings, the number of parallel branches of the windings is changed, and thus the motor frequency is changed, and multiple sets of different speeds and torques are output, which not only realizes high efficiency, high power factor and high energy utilization rate, but also reduces the power and greatly reduces the cost. It includes a top drive main shaft and a multi-frequency drive motor. The motor main shaft of the multi-frequency drive motor is sleeved outside the top drive main shaft. A sling hanger is fixedly connected to the lower end of the top drive main shaft where the multi-frequency drive motor is located. The lower end of the top drive main shaft is connected to the drill string through a protection joint. An inlet water device is installed at the upper end of the top drive main shaft. The multi-frequency drive motor adopts a multi-winding structure.

Description

Technical Field

[0001] The present invention relates to the technical field of oil drilling and geological drilling, and particularly relates to a multi-frequency motor direct drive top drive drilling device and a driving method thereof. Background Art

[0002] The top drive drilling device is a cutting-edge technical equipment for oil and geological drilling. It is a device that can directly drive the drill string to rotate at the upper part of the derrick, and feed the drill downward along the special top drive guide rail on the derrick to complete drilling operations such as drill string rotation, circulating drilling fluid, connecting single joints, connecting stands, making up and breaking out tool joints, and reaming. Most of the top drive transmission devices are driven by asynchronous motors plus speed-changing mechanisms. In recent years, there have been very few energy-saving electric direct drive top drives; however, the motors used in the top drive system are all single-frequency (single-speed) motors. The drilling rig system needs to select a driving motor with an overload capacity of 2-3 times the torque required under normal working conditions based on the accident handling ability, and the power of the motor cannot be too small.

[0003] Although the use of the existing single-frequency (single-speed) motor-driven top drive device meets the usage requirements for handling accidents at low speeds and high torques, the motor is still selected according to the maximum rotational speed during normal drilling when selecting the motor. Due to the absence of a mechanical speed-changing system, it cannot meet the requirements of the drilling rig for a wide range of speed reduction and torque increase; if the requirements of the maximum torque and maximum speed of the drilling rig are met simultaneously, the selected motor power will be very large, its variable frequency control system will be very expensive, and its energy-saving effect will be weakened.

[0004] For the existing non-direct drive type top drive transmission device, which uses gear reduction in the gearbox to achieve the transmission of the top drive, it has the following disadvantages: ① The gearbox needs to be sealed, and the seal is prone to failure, resulting in oil leakage of the lubricating oil and causing the failure of the gearbox; ② The iron filings worn during the operation of the gearbox are prone to cause the failure of the lubricating oil, affecting heat dissipation and causing the failure of the gearbox; ③ Existing top drives are all driven by single-speed AC machines, requiring a large power, and having too large a speed regulation range, making it difficult to control within a large range. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a multi-frequency motor direct drive top drive drilling device and a driving method thereof, which have a transmission mechanism not easily failing, high energy utilization rate, and relatively compact volume and weight. The main shaft of the multi-frequency motor directly drives the main shaft of the top drive device to rotate, and the rotation speed and torque of the top drive device are controlled by adjusting the rotation speed and torque of the multi-frequency motor.

[0006] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0007] A multi-frequency motor direct drive top drive drilling device, comprising a top drive main shaft and a multi-frequency drive motor. The top drive main shaft is a hollow main shaft, and the motor main shaft of the multi-frequency drive motor is sleeved outside the top drive main shaft. The inner side surface of the motor main shaft matches the outer side surface of the top drive main shaft. A lifting ring hanger is fixedly connected to the lower end of the top drive main shaft where the multi-frequency drive motor is located. The lower end of the top drive main shaft is connected to a drill string through a protection joint. An inlet water device is installed at the upper end of the top drive main shaft. The multi-frequency drive motor adopts a multi-winding structure.

[0008] In a possible technical solution, the inner side surface of the motor main shaft is an internal hexagon or an internal multi-sided shape, and the outer side surface of the top drive main shaft is an external hexagon or an external multi-sided shape.

[0009] In a possible technical solution, the multi-frequency drive motor is provided with a motor winding switching cabinet and an inverter for switching the connection mode of the windings.

[0010] In a possible technical solution, the multi-frequency drive motor is provided with a multi-frequency motor outgoing line box, and the windings of the multi-frequency motor outgoing line box are a1, a2, … a m , where m is the number of coil groups per phase of the motor.

[0011] A top direct drive method for a drilling device, implemented according to any of the above multi-frequency motor direct drive top drive drilling devices. Under normal working conditions, the windings are connected in series, and a state of 1 times torque and 1 times speed is used, with electrical parameters of rated power f and rated torque T. The inverter is controlled using the above electrical parameters. When dealing with stuck pipe accidents, the motor windings are switched to parallel, and a state of n times torque and 1 / n times speed is used, with electrical parameters of rated power f / n and rated torque n*T. The inverter is controlled using the above electrical parameters. n is a multiple of the number of parallel branches of the motor windings, and the value range of n is determined based on the back electromotive force of the motor and the winding form.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The top drive device is rotated by a multi-frequency motor to perform drilling work. The motor adopts a multi-winding structure. By switching the connection mode of the windings, the number of parallel branches of the windings is changed, thereby changing the motor frequency, and multiple groups of different speeds and torques are output, improving the working efficiency of the drilling top drive. The structure of the present invention is simple. The direct drive method in the structure makes the maintenance of the drilling rig system convenient. There is no configuration of a speed reducer and a lubrication device. In terms of performance, while meeting the usage requirements of the drilling rig and ensuring a high safety factor for accident handling ability, it not only achieves high efficiency, high power factor, and high energy utilization rate, but also reduces power, resulting in a significant reduction in cost. It is suitable for promotion in exploration drilling equipment, including the top drive devices of geological drilling rigs, oil drilling rigs, and water well drilling rigs, with remarkable economic effects. Description of the Drawings

[0013] Figure 1 It is a schematic structural diagram of the present invention;

[0014] Figure 2 It is a schematic sectional structural diagram of the cooperation between the motor main shaft and the top drive main shaft;

[0015] Figure 3 It is an enlarged schematic structural diagram of the outgoing line box part of the multi-frequency motor.

[0016] Reference numerals: 1 - water inlet device; 2 - top drive main shaft; 3 - multi-frequency drive motor; 4 - motor main shaft; 5 - sling hanger; 6 - lock nut; 7 - protection joint; 8 - multi-frequency motor outgoing line box. Specific embodiments

[0017] The following will further describe in detail the specific embodiments of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0018] As Figure 1 shown, the multi-frequency motor of the present invention directly drives the top drive drilling device, which includes a top drive main shaft 2 and a multi-frequency drive motor 3. The top drive main shaft 2 is a hollow main shaft, and the motor main shaft 4 of the multi-frequency drive motor 3 is sleeved outside the top drive main shaft 2. The inner side surface of the motor main shaft 4 matches the outer side surface of the top drive main shaft 2; a sling hanger 5 is fixedly connected to the lower end of the top drive main shaft 2 where the multi-frequency drive motor 3 is located. In this embodiment, the sling hanger 5 is locked by a lock nut 6 at its lower end, so that the multi-frequency drive motor 3 and the top drive main shaft 2 become an integral body. The lower end of the top drive main shaft 2 is connected to the drill string through a protection joint 7, and a water inlet device 1 is installed at the upper end of the top drive main shaft 2. The multi-frequency drive motor 3 adopts a multi-winding structure; the multi-frequency drive motor 3 drives the top drive main shaft 2 to rotate, so as to drive the drill string to drill through the protection joint 7. During the drilling process, the drilling fluid passes through the channel formed by the water inlet device 1 and the top drive main shaft 2, passes through the protection joint 7, and enters the drill string for circulation.

[0019] When selecting a drive motor for a top drive device, the motor power cannot be too small. The top drive device is designed with the maximum working load to determine the maximum power (rated power). During the process of drilling a well from shallow to deep by a drilling rig, the actual applied load is only 20%-30% of the maximum load. The ratio of the actual output power to the rated power is the load rate. If an induction motor is used, the power factor and motor efficiency will drop sharply at a low load rate, only about 20%, resulting in serious energy waste. If a single-speed motor is used, although the energy utilization rate of the motor is high, the power-to-volume ratio cannot be reduced. If the motor power is only selected according to normal working conditions, although it can provide a 2-fold overload torque, the time for handling stuck pipe accidents at the drilling site ranges from several minutes to several consecutive days. Long-term overload will cause the motor to overheat seriously and the stuck pipe releasing ability will be insufficient. This application uses a multi-frequency motor as the drive motor for the top drive drilling device. The multi-frequency motor is a new type of drive motor. This motor adopts a multi-winding structure. By switching the connection mode of the windings, the number of parallel branches of the windings is changed, and then the motor frequency is changed to output multiple groups of different speeds and torques. Under normal working conditions, it provides the rated speed and torque. When handling stuck pipe accidents, the connection mode of the windings is switched to provide a rated torque several times that of normal working conditions, meeting the requirements of the drilling rig system for low speed and high torque. Using a multi-frequency motor only by switching the connection mode of the windings, the motor power is only considered according to normal working conditions, which not only reduces the power during motor selection but also provides the drilling rig with the ability to continuously release stuck pipes.

[0020] In this embodiment, as Figure 2 shown, the inner side of the motor spindle 4 is internal hexagon or internal multi-sided, and the outer side of the top drive spindle 2 is external hexagon or external multi-sided; the motor spindle 4 of the multi-frequency drive motor 3 directly drives the top drive spindle 2 to rotate without an intermediate link.

[0021] The winding switching of the multi-frequency drive motor 3 can be achieved by using a motor winding switching cabinet or manually connecting at the motor terminal box, and it can be flexibly used according to the requirements of switch size, on-site layout and switching response speed. In this embodiment, the multi-frequency drive motor 3 is provided with a motor winding switching cabinet and an inverter for switching the connection mode of the windings; the multi-frequency drive motor 3 is provided with a multi-frequency motor outlet box 8, as Figure 3 shown, the windings of the multi-frequency motor outlet box 8 are a1, a2,... a m , where m is the number of coil groups under each phase of the motor; the input power is connected to the multi-frequency drive motor 3 through the multi-frequency motor winding outlet box 8. According to the number of parallel branches of the motor, the windings a1, a2,... am form different series-parallel combinations. By switching the connection mode of the windings, the number of parallel branches of the windings is changed, and then the motor frequency is changed to output multiple groups of different speeds and torques.

[0022] The top direct drive method of the drilling device in this embodiment uses series winding under normal working conditions, with electrical parameters of 1 times torque and 1 times speed, rated power of f, and rated torque of T. The frequency converter is controlled with the above electrical parameters. When dealing with stuck pipe release accidents, the motor windings are switched to parallel, using n times torque and 1 / n times speed, with electrical parameters of rated power of f / n and rated torque of n*T. The frequency converter is controlled with the above electrical parameters. n is a multiple of the number of parallel branches of the motor, and the value range of n is determined according to the motor back electromotive force and winding form.

[0023] The top direct drive method of this application not only meets the requirements of the drilling rig under accident handling and heavy load working conditions, but also meets the requirements of the drilling rig for rapid pipe hoisting and lowering under normal drilling and light load working conditions. It realizes torque doubling and speed doubling of the top drive of the drilling rig only by the electric control system without gear transmission under the condition of constant motor power. It can still meet the requirements of the drilling rig for large torque and high speed under the condition of very small total power of the drilling rig motors, greatly improving the energy utilization efficiency.

[0024] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A top direct drive method for a drilling device, characterized in that, It is realized according to a multi-frequency motor directly driving a top drive drilling device. The drilling device includes a top drive main shaft (2) and a multi-frequency drive motor (3). The top drive main shaft (2) is a hollow main shaft. The motor main shaft (4) of the multi-frequency drive motor (3) is sleeved outside the top drive main shaft (2), and the inner side surface of the motor main shaft (4) matches the outer side surface of the top drive main shaft (2). A sling hanger (5) is fixedly connected to the lower end of the top drive main shaft (2) where the multi-frequency drive motor (3) is located. The lower end of the top drive main shaft (2) is connected to a drill string through a protection joint (7). An inlet device (1) is installed at the upper end of the top drive main shaft (2). The multi-frequency drive motor (3) adopts a multi-winding structure. The multi-frequency drive motor (3) is provided with a motor winding switching cabinet and a frequency converter for switching the connection mode of windings. The multi-frequency drive motor (3) is provided with a multi-frequency motor outlet box (8). The windings of the multi-frequency motor outlet box (8) are a1, a2, … am, where m is the number of coil groups per phase of the motor. The method for directly driving the top of the drilling device is as follows: Under normal working conditions, the windings are connected in series, and a state of 1 times torque and 1 times speed is used, with electrical parameters of rated power f and rated torque T. The frequency converter is controlled with the above electrical parameters. When dealing with stuck pipe release accidents, the motor windings are switched to parallel, and a state of n times torque and 1 / n times speed is used, with electrical parameters of rated power f / n and rated torque n*T. The frequency converter is controlled with the above electrical parameters. n is a multiple of the number of parallel branches of the motor, and the value range of n is determined according to the back electromotive force of the motor and the winding form. The inner side surface of the motor main shaft (4) is in the form of an internal hexagon, and the outer side surface of the top drive main shaft (2) is in the form of an external hexagon.

Images