CN102536113B - Underground electric drill device and method capable of reducing torque borne by drill stem - Google Patents

Abstract

The invention provides a downhole electric drilling tool device and method capable of reducing the torque suffered by the drill string. The device is installed between the drill collar and the drill bit, and consists of two parts: a fixed power short and a rotating rock-breaking short. The upper end of the fixed power short is connected with the drill collar, and two motors are symmetrically installed on the metal cylinder wall, and each of the two motors is connected with a bevel gear. The lower end of the rotary rock breaking short is connected with the drill bit, and the upper end has gear teeth. The lower end of the fixed power short and the upper end of the rotary rock breaking short are connected by bearings. After the connection, the two bevel gears on the fixed power short and the upper end of the rotating rock breaking are meshed at the same time, and the fixed power short and the rotating rock breaking The short connection can be rotated relative to the axial direction. The device and method can greatly reduce the torque borne by the drill string during the drilling process, improve the safety of drilling operations, increase the service life of the drill string, and reduce the cost of oil and gas field exploitation, and are applicable to oil and natural gas deep wells and ultra-deep well drilling .

Description

A downhole electric drilling tool device and method capable of reducing the torque on the drill string

technical field

The invention relates to a design method and device of an electric downhole drilling tool which uses a double driving wheel bevel gear combination as a power transmission medium to reduce the torque on a drill string during oil and natural gas drilling.

Background technique

The deformation sign when the circular shaft is twisted is the relative rotation angle around the shaft between the two cross-sections, which is also the torsion angle. Calculated as follows:

—圆轴两个横截面间绕成的相对转角；in:

— the relative rotation angle formed between the two cross-sections of the circular axis;

T—torque between two sections;

l—the distance between two sections;

D为圆轴直径。I _p —polar moment of inertia of the section, and for the circular axis:

D is the diameter of the shaft.

与圆轴的长度l成正比。It can be seen from formula (1) that when T, G, and I _p are constant, the relative rotation angle formed between the two cross-sections of the circular axis

It is proportional to the length l of the circular axis.

It can be seen from the formula (1) that in the traditional rotary drilling process, due to the long length of the drill string, the torque generated at the wellhead and the bottom of the well causes a large torsional deformation of the drill string, and the rotation between the drill pipe and the well wall Friction, which is very damaging to the drill pipe, and the cost of making the drill pipe is also very high.

Downhole power drilling tools can reduce the torsional deformation of the drill string during drilling, and among the existing downhole power drilling tools, electric rotary tools have more unique advantages than turbo drilling tools and screw drilling tools:

1. The transmission of energy from the surface to the drill bit does not depend on the flow of drilling fluid;

2. Different drilling fluid media can be used;

3. Electric energy can be easily and efficiently converted into other types of energy;

4. By increasing the voltage, the energy loss in the transmission process can be reduced, so a constant high power can be maintained;

5. Using electric drilling tools, the relevant data of downhole rock performance can be explained by the operating characteristics of the drill bit. During the drilling process, the change of the drill bit resistance torque can be directly reflected on the current and power of the electric rotary tool engine. It controls the drilling process, allows the use of automation technology and remote control technology, and realizes the information management function in the drilling process.

The existing electric drilling tools still have many deficiencies, such as poor reliability and difficult repair after the armature winding fails. In particular, the longitudinal vibration of the tri-cone bit is severe, and the working condition of the electric drill is harsh.

Because the existing electric drilling tools are in the rock-breaking process, the resistance moment on the contact between the drill bit and the rock is in the vertical direction, and the counter torque will still be generated on a part of the drill string, so there are still some drill strings. The column will bear a certain torque and produce torsional deformation.

Contents of the invention

The object of the present invention is to provide a method and device for reducing the torque on the drill string during the drilling process. The method and device use the combination of double drive wheels and bevel gears as the power transmission medium, which can offset most of the torque at the downhole drill bit.

In order to achieve the above object, the present invention adopts the following technical solutions: the device of the present invention is installed between the drill collar and the drill bit, and the device of the present invention is composed of a fixed power short and a rotating rock-breaking short. The upper end of the fixed power short is connected to the drill collar through the female thread. Two motors are symmetrically installed on the metal cylinder wall of the fixed power short. The bottom end covers of the two motors are opposite to each other. Each of the two motors is connected to a bevel gear. During the power input process, the two motors simultaneously drive the respective connected bevel gears to rotate, and the rotation directions of the two bevel gears are opposite, so the torque on the two motors is in the horizontal direction. The two torques are equal in magnitude and opposite in direction, and the two torques cancel each other out. The lower end of the rotary rock-breaking short is connected to the drill bit through the female thread, and the upper end of the rotary rock-breaking short has gear teeth, and the teeth are designed and processed on the conical surface, similar to the teeth of the bevel gear. The two bevel gears on the fixed power short mesh. The lower end of the fixed power short-circuit and the upper end of the rotary rock-breaking short are connected through bearings. After the connection, the fixed power short-circuit and the rotating rock-breaking short-circuit are coaxial, and the two conical gears on the fixed power short-circuit are simultaneously connected with the rotating rock-breaking short. The gear teeth at the upper end mesh, and the fixed power short and the rotary rock-breaking short can rotate relatively along the axial direction.

The specific method of fixed power short-circuiting input power and counteracting torque is: the rock-breaking power is provided by two motors, and the two motors are powered by the ground through the wires fixed on the drill pipe to deliver current. The two motors are symmetrically installed on the metal cylinder wall of the fixed power short circuit, the bottom end covers of the two motors are opposite, the rotors are coaxial and the rotating shaft is in the horizontal direction. The installation method of the two motors ensures that when the two motors are connected to the same direction of current and rotate, since the bottom end covers of the two motors are opposite, the rotation directions of the rotors of the two motors in the horizontal direction are opposite, for example: from Looking from right to left, if the rotor of one motor is rotating clockwise, the rotor of the other motor must be rotating counterclockwise. In this way, the respective torques of the two motors are on a horizontal straight line, equal in magnitude and opposite in direction, and can cancel each other out. Each of the two motors is connected to a bevel gear. During the power input process, the two motors simultaneously drive the respective connected bevel gears to rotate, and the rotation directions of the two bevel gears are opposite, so the torque borne by the two motors is at a level They are equal in magnitude and opposite in direction, and the two torques cancel each other out.

The specific method for the rotary rock-breaking short to drive the drill bit to rotate and break the rock is: the upper end of the rotary rock-breaking short has gear teeth, and the teeth are designed and processed on the conical surface, similar to the teeth of the bevel gear, the teeth are used It meshes with two bevel gears on the fixed power short. The upper end of the rotary rock-breaking short is connected to the fixed power short through the bearing. The bevel gear meshes, the fixed power short-circuit and the rotary rock-breaking short-circuit can rotate relatively along the axial direction. When the two bevel gears with fixed power are rotating, the two bevel gears are the driving wheels, and the rotating rock-breaking short is the driven wheel. The final effect of the two bevel gears working together is to drive the rotating rock-breaking short to rotate in one direction , the rotation axes of the two bevel gears are in the horizontal direction, and the rotation direction of the rock-breaking short-circuit is in the vertical direction. The lower end of the rotary rock-breaking short is connected to the drill bit through a female thread, which can drive the drill bit to rotate and break rock.

The two motors are high-power, high-torque AC motors to ensure the power required for rock breaking.

The fixed power short circuit, the rotating rock breaking short circuit and the two bevel gears are all made of high-strength metal materials to ensure that the two motors are in the process of offsetting the torque on the metal cylinder wall of the fixed power short circuit. The strength of all aspects of the wall can meet the requirements, and the strength of the meshing parts of each gear tooth can meet the requirements during the short-circuit transmission power process of the bevel gear to the rotary rock breaking.

There is an umbrella-shaped protective structure on the upper part of the fixed power short circuit, which is used to prevent the large cuttings generated during rock breaking from causing jamming or other damage to the bevel gear.

The specific dimensions and parameters of each part of the device of the present invention should be designed according to parameters such as the size of the borehole to be drilled, the lithology encountered, the power of the motor, and the maximum torque of the motor.

The invention has the advantages of greatly reducing the torque borne by the drill string in the drilling process, lowering the requirement on the torsional strength of the drill rod, and reducing the material cost required for making the drill rod!

Description of drawings

Figure 1 is a front view (section) of a bevel gear meshing diagram that is widely used now.

Fig. 2 is a right side view of Fig. 1 .

Fig. 3 is a meshing diagram of a combination structure of double driving wheels and bevel gears, which is the main principle diagram of the present invention.

Fig. 4 is a front view (sectional view) of a structural schematic diagram of a fixed power short circuit.

Fig. 5 is a right side view of Fig. 4 .

Fig. 6 is a front view (sectional view) of a structural schematic diagram of a rotary rock-breaking short circuit.

Fig. 7 is a right side view of Fig. 6 .

Fig. 8 is a front view (sectional view) of a meshing diagram of a single bevel gear and a short-circuited rotary rock breaker.

Fig. 9 is a right side view of Fig. 8 .

Fig. 10 is a front view (section) of a schematic diagram of an assembly structure of the present invention.

Fig. 11 is a right side view of Fig. 10 .

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1 and Figure 2, the bevel gear combination is mainly used for the transmission between two intersecting shafts, the left bevel gear 1 is the driving wheel, and the lower bevel gear 2 is the driven wheel. If a right bevel gear 3 is installed as a driving wheel on the right side of the structure in Fig. 1, then a double driving wheel bevel gear combination structure as shown in Fig. 3 is formed.

As shown in Figure 3, in the combined structure of double driving wheel bevel gears, the left bevel gear 1 and the right bevel gear 3 are both driving wheels, the lower bevel gear 2 is the driven wheel, and the left bevel gear 1 and the right bevel gear 3 are rotating axes The direction is in the horizontal direction, and the rotation directions of the left bevel gear 1 and the right bevel gear 3 are opposite. The direction of the axis of rotation of the lower bevel gear 2 is in the vertical direction. For example: the right bevel gear 3 rotates clockwise when viewed from right to left, the left bevel gear 1 rotates counterclockwise when viewed from right to left, and the lower bevel gear 2 rotates clockwise when viewed from top to bottom. Thus, the torques on the left bevel gear 1 and the right bevel gear 3 are equal in magnitude in the horizontal direction and opposite in direction, which can cancel each other out.

As shown in Fig. 4 and Fig. 5, the structure schematic diagram of the fixed power short-circuit 17, motor M1 and motor M2 are installed on the metal cylinder wall of the fixed power short-circuit 17, the motor M1 is connected with the bevel gear-4, and the motor M2 is connected with the bevel gear Two 5. In this structure, bevel gear one 4 is equivalent to the left bevel gear 1 in the structure of FIG. 3 , and bevel gear two 5 is equivalent to the right bevel gear 3 in the structure of FIG. 3 . The upper end of the fixed power short connection 17 is connected with the drill collar through the female thread 8 . The umbrella structure 7 protects the bevel gear 1 4 and the bevel gear 2 5, preventing the bevel gears from being stuck or otherwise damaged by larger cuttings produced when drilling and breaking rocks. The crescent-shaped structure 9 is used to make the drilling fluid flow smoothly from the fixed power short-circuit 17 to the rotary rock-breaking short-circuit 18, which can prevent the drilling fluid from flowing into the joint gap between the fixed power short-circuit 17 and the rotary rock-breaking short-circuit 18 .

As shown in Fig. 6 and Fig. 7, the structural diagram of the rotary rock-breaking short-connection 18, the upper end of the rotary rock-breaking short-connection 18 has gear teeth 6, and the gear teeth 6 are designed and processed on the conical surface, and the gear teeth 6 are similar to The gear tooth of lower bevel gear 2 in Fig. 1. The gear teeth 6 are used to mesh with the bevel gear one 4 and the bevel gear two 5 on the fixed power short circuit 17 simultaneously. The lower end of the rotary rock breaking short joint 18 is connected with the drill bit through the female thread 10 .

As shown in Figure 8 and Figure 9, use conical gear-4 to mesh with the gear teeth 6 on the upper end of the rotary rock-breaking short 18, then this structure is similar to the structure shown in Figure 1, and bevel gear-4 is equivalent to the structure in Figure 1 The left bevel gear 1 in the middle, the rotary rock-breaking short-circuit 18 is just equivalent to the lower bevel gear 2 in the structure of Fig. 1.

As shown in Figure 10 and Figure 11, the fixed power short-circuit 17 and the rotating rock-breaking short-circuit 18 are assembled, and the power transmission principle of the whole structure is just like the double drive wheel bevel gear combination structure shown in Figure 3, and the bevel gear-4 is Be equivalent to the left bevel gear 1 in the structure of Fig. 3, bevel gear 2 5 is just equivalent to the right bevel gear 3 in the structure of Fig. 3, and the rotary rock-breaking short-circuit 18 is just equivalent to the lower bevel gear 2 in Fig. 3, bevel gear 1 4 and the conical gear 2 5 mesh with the gear teeth 6 on the upper end of the rotating rock-breaking short-connect 18 at the same time, and the fixed power short-connect 17 and the rotating rock-breaking short-connect 18 are connected by bearings, wherein: bearing one 11, bearing two 12, bearing Three 13, bearing four 14 and bearing five 15 are all deep groove ball bearings, and the effect of these five bearings is to ensure that the fixed power short-connect 17 and the rotating rock-breaking short-connect 18 can relatively rotate coaxially in the vertical direction. Bearing 16 is a thrust ball bearing, and its effect is to be used to bear the drilling pressure on the vertical direction, prevents the drilling pressure from damaging the above five deep groove ball bearings and prevents the drilling pressure from bevel gear one 4, bevel gear two 5 and wheel Damage caused by tooth 6 meshing. The whole structure is connected with the drill collar through the female thread 8, and connected with the drill bit through the female thread 10. When drilling, the motor M1 and the motor M2 are fed with the same direction current, and at the same time, the bevel gear 1 4 and the bevel gear 2 5 are respectively driven to rotate, then in the horizontal direction, the rotation directions of the bevel gear 1 4 and the bevel gear 2 5 are opposite of. For example: looking from right to left, if bevel gear 2 5 rotates clockwise, then bevel gear 1 4 must rotate counterclockwise. clockwise rotation. Since the respective torques of the motor M1 and the motor M2 are equal in magnitude and opposite in direction in the horizontal direction during this process, they cancel each other out on the metal cylinder wall of the fixed power short circuit 17 . The crescent-shaped structure 9 is used to block the thrust ball bearing 16 to prevent damage to it by the drilling fluid. At the same time, the crescent-shaped structure 9 can make the drilling fluid flow smoothly from the fixed power short-circuit 17 to the rotary rock-breaking short-circuit 18 .

In the present invention, a double driving wheel bevel gear combination structure is mainly designed. The torques that the two driving wheels in this structure bear are equal in magnitude and opposite in direction, so they can cancel each other out. Applying the principle of double drive wheel bevel gear combination structure to this electric drilling tool, the torque on the drill string during drilling can be greatly reduced.

Claims (5)

1. the downhole electric drilling rig that can reduce the suffered moment of torsion of drill string, it is characterized in that: stationary power short circuit (17) is installed in drill collar lower end, the broken rock short circuit (18) of rotation is installed in drill bit upper end, and the broken rock short circuit (18) of stationary power short circuit (17) and rotation connects by deep groove ball bearing one (11), deep groove ball bearing two (12), deep groove ball bearing three (13), deep groove ball bearing four (14), deep groove ball bearing five (15) and bearing (16), on the metal barrel of stationary power short circuit (17), symmetry is equipped with two motor M 1 and M2, motor M 1 is relative with the bottom head covers of motor M 2, rotor coaxial and rotating shaft are in the horizontal direction, motor M 1 and conical gear one (4) connect, conical gear one (4) is for the gear teeth (6) engagement with the broken rock short circuit (18) of rotation upper end, motor M 2 and conical gear two (5) connect, conical gear two (5) is also for the gear teeth (6) engagement with the broken rock short circuit (18) of rotation upper end, in power input process, motor M 1 and motor M 2 drive the conical gear that connected separately to rotate simultaneously, on stationary power short circuit (17) top, have a umbrella shape protection structure (7), the larger drilling cuttings producing when preventing brokenly rock causes blocked portion or other destruction to conical gear one (4) and conical gear two (5), in stationary power short circuit (17) bottom, there is a crescent structure (9), be used for making drilling fluid successfully from stationary power short circuit (17) transition, to flow into the broken rock short circuit (18) of rotation, can prevent that drilling fluid from flowing in the connection gap of stationary power short circuit (17) and the broken rock short circuit (18) of rotation, stationary power short circuit (17) upper end connects with drill collar by box thread (8), and during broken rock, stationary power short circuit (17) drives conical gear one (4) and conical gear two (5) to provide power for rotating broken rock short circuit (18) by motor M 1 and motor M 2, the upper end of the broken rock short circuit (18) of rotation has the gear teeth (6), and the gear teeth (6) design processing on taper seat, the gear teeth of similar conical gear, the gear teeth (6) for stationary power short circuit (17) on conical gear one (4) and conical gear two (5) engagement, the broken rock short circuit (18) of rotation lower end connects with drill bit by box thread (10), and the transmission of power that stationary power short circuit (17) is provided is to drill bit, the broken rock short circuit (18) of stationary power short circuit (17) and rotation connects by deep groove ball bearing one (11), deep groove ball bearing two (12), deep groove ball bearing three (13), deep groove ball bearing four (14), deep groove ball bearing five (15) and bearing (16), wherein, deep groove ball bearing one (11), deep groove ball bearing two (12), deep groove ball bearing three (13), deep groove ball bearing four (14), deep groove ball bearing five (15) can coaxially relatively rotate by the vertical direction for guaranteeing the broken rock short circuit (18) of stationary power short circuit (17) and rotation, bearing (16) is for bearing the axial load on vertical direction, after connection, broken rock short circuit (18) in the vertical direction of stationary power short circuit (17) and rotation is coaxial, and conical gear one (4) and conical gear two (5) simultaneously and the gear teeth (6) engagement of the broken rock short circuit (18) of rotation upper end, stationary power short circuit (17) and rotation are broken rock short circuit (18) and can be prolonged on axis direction and relatively rotate.

2. a kind of downhole electric drilling rig that reduces the suffered moment of torsion of drill string according to claim 1, it is characterized in that: the broken rock short circuit (18) of rotation upper end has the gear teeth (6), and the gear teeth (6) design processing on taper seat, the gear teeth of similar conical gear, the gear teeth (6) mesh for while and conical gear one (4) and conical gear two (5) on stationary power short circuit (17), the broken rock short circuit (18) of rotation upper end is by deep groove ball bearing one (11), deep groove ball bearing two (12), deep groove ball bearing three (13), deep groove ball bearing four (14), deep groove ball bearing five (15) and bearing (16) connect with stationary power short circuit (17), after connection, the broken rock short circuit (18) of stationary power short circuit (17) and rotation is coaxial, and the gear teeth (6) while of the broken rock short circuit (18) of rotation upper end meshes with conical gear one (4) and conical gear two (5) on stationary power short circuit (17), stationary power short circuit (17) and the broken rock short circuit (18) of rotation can prolong on axis direction and relatively rotate, when conical gear one (4) and conical gear two (5) rotate simultaneously, conical gear one (4) and conical gear two (5) are driving wheels, the broken rock short circuit (18) of rotation is driven pulley, conical gear one (4) and conical gear two (5) coefficient final effects are that the broken rock short circuit (18) of driven rotary is toward a direction rotation, in the horizontal direction, the direction of rotation in the vertical direction of rock short circuit (18) is broken in rotation to the rotation direction of conical gear one (4) and conical gear two (5), the broken rock short circuit (18) of rotation lower end connects with drill bit by box thread (10), can drive bit to break rock.

3. a kind of downhole electric drilling rig that reduces the suffered moment of torsion of drill string according to claim 1, it is characterized in that: after described conical gear one (4), conical gear two (5) and the gear teeth (6) engagement, three forms a two driving wheel conical gear combining structure jointly.

4. a kind of downhole electric drilling rig that reduces the suffered moment of torsion of drill string according to claim 1, is characterized in that: bearing (16) is thrust ball bearing.

5. a kind of method that reduces the suffered moment of torsion of drill string of utilizing device as claimed in claim 1 to realize, it is characterized in that: broken rock power is provided by motor M 1 and motor M 2, motor M 1 and motor M 2 symmetries are arranged on the metal barrel of stationary power short circuit (17), motor M 1 is relative with the bottom head covers of motor M 2, and rotor coaxial and rotating shaft are in the horizontal direction; When such mounting means has guaranteed that motor M 1 and motor M 2 pass into same direction current rotation, because motor M 1 is relative with the bottom head covers of motor M 2, the rotor of motor M 1 and motor M 2 rotation direction is in the horizontal direction contrary, thus, the moment of torsion that motor M 1 and motor M 2 are born is separately all on a horizontal linear, and equal and opposite in direction, opposite direction, can cancel out each other.

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