RU2806985C1 - Rotor controlled system with rotating case and bending central shaft - Google Patents

Abstract

FIELD: drilling equipment.

SUBSTANCE: invention can be used as part of bottom drill string assemblies when drilling directional, horizontal and multilateral wells using the rotary method. The rotary controlled system contains a drill bit, a central shaft connected to the drill bit, a cage made on top of the central shaft, forming a sealed volume underneath, a hinge element that ensures rotation of the axis of the central shaft relative to the axis of the cage, and at least one pusher installed in a sealed chamber. volume. Moreover, the cage is rigidly fixed on the central shaft from the side of the drill bit, and on the opposite side the cage has a hinge element.

EFFECT: improves the reliability, performance and durability of the system.

6 cl, 5 dwg

Description

The invention relates to drilling equipment and can be used as part of bottom drill string assemblies when drilling directional, horizontal and multilateral wells using the rotary method.

Various rotary steerable systems are known. The closest in technical essence to the present invention is the rotary controlled system described in US patent 9,752,386 B2 [1]. The known rotary steerable system is a device in which the rotor and bit are rigidly connected to each other. The bias plates are mounted on the stator and the motor is tilted relative to the wellbore by the bias plates while forming a deviated wellbore. The actuators used to move the plates between their retracted and extended positions are in the form of pistons to which fluid is supplied under pressure at appropriate times through a valve system controlled by a control unit. Piston actuators are designed to move the bias plates between their extended and retracted positions. Each actuator contains a piston sliding inside a corresponding cylinder. The first end of each piston engages a corresponding deflector plate, while the second end of each piston forms a chamber with a corresponding cylinder. The chambers communicate through appropriate channels with the valve block.

The disadvantage of this immediate technical solution is the presence of idle movement of the bias plates to the well wall, which wastes time. Also

The disadvantage of this immediate technical solution is the possibility of fragments of destroyed rock getting into the gap between the bias plate and the stator and, as a consequence, the impossibility of controlling the rotor controlled system.

Also close in technical essence to the present invention is the rotary controlled system described in US patent 7,188,685 B2 [2]. A known rotary steerable system is the lowermost component of a BHA and includes an upper section, which typically houses the electronics and other devices needed to control the rotary steerable system, and a steering section. The upper stabilizer 26 is attached to one of the pipes, preferably the one

which is adjacent to the rotary steerable system, the lower stabilizer is attached to the upper section. The guide section also includes a drill bit. The drill bit is tilted around a swivel (usually a universal joint) mounted in the steering section. The swivel itself can transmit torque from the drill string to the drill bit, or the torque can be transmitted separately through other devices. Suitable torque transmission devices include many well known devices such as spline couplings, gear drives, universal joints and ball recirculating devices. These devices can either be integrated with the top section or steering section, or they can be attached separately to facilitate repair and/or replacement. However, an important function of the swivel is to provide a 360-degree pivot point for the steering section. The guide section is periodically driven by one or more motors around the swivel in relation to the top section to actively hold the bit axis in a particular direction while the entire assembly rotates at the rotational speed of the drill string. The term "actively tilted" is intended to distinguish how a rotary steerable system is dynamically oriented compared to known fixed displacement installations. "Actively tilted" means that the rotary steerable system does not have a specified fixed angular or linear displacement with offset. Conversely, both the angular displacement and the offset displacement change dynamically as the rotary steerable system operates.

The disadvantage of this immediate technical solution is the presence of a universal joint assembly; the performance of the entire rotary steerable system depends on the reliability and durability, as well as the creation of a sealed channel for the flow of drilling fluid between the upper section and the steering section.

The technical challenge is to create a rotary steerable system with the ability to bend the central shaft to deflect the bit during drilling.

The proposed technical solution allows us to solve a technical problem.

The problem was solved by installing a bending mechanism on the central shaft of the rotary controlled system, which allows bending the shaft

connected to the bit at the required angle relative to the outer body of the rotary steerable system.

The ability to bend the central shaft of the rotary steerable system to deflect the bit while drilling is a distinctive feature of the prior art described above.

The technical result consists in increasing the reliability of the system, reducing time and labor costs during drilling, increasing the performance and durability of the system.

Figure 1 depicts a known rotary steerable system [1], according to the prior art;

Figure 2 depicts the mechanism for opening the deflection plates of a known rotary steerable system [1], according to the prior art;

Figure 3 depicts a known rotary steerable system [2], according to the prior art;

FIG. 4 depicts the rotary steerable system in its initial state, according to the invention;

FIG. 5 shows a rotary steerable system in a bent state according to the invention.

Figure 1 shows a well-known rotary steerable system [1], which is a device in which the rotor 16 and the bit 12 are rigidly connected to each other. The bias plates 34 are fixed to the stator 18, the motor 10 is tilted relative to the wellbore by the bias plates 34 during the formation of a curved wellbore. The actuators used to move the plates 34 between their retracted and extended positions are in the form of pistons to which fluid is supplied under pressure at appropriate times through a valve system controlled by a control unit. The piston actuators (see FIG. 2) are designed to move the bias plates 34 between their extended and retracted positions. Each actuator includes a piston 28 sliding within a corresponding cylinder 30. The first end 32 of each piston 28 engages a corresponding deflector plate 34, while the second end 40 of each piston 28 forms a chamber 41 with the corresponding cylinder 30. The chambers 41 communicate through respective channels 42, with valve block.

The disadvantage is the presence of idle movement of the bias plates 34 to the well wall, which wastes time. Also, a disadvantage of this immediate technical solution is the possibility of fragments of destroyed rock getting into the gap between the bias plate 34 and the stator 18 and, as a consequence, the impossibility of controlling the rotor controlled system.

Figure 3 shows a known rotary steerable system [2], which is the lowest component of the BHA and includes an upper section 122, which typically houses the electronics and other devices needed to control the rotary steerable system, and a steering section 124. Upper stabilizer 126 is attached to one of the tubes 117, preferably the one adjacent to the rotary steerable system, the lower stabilizer 130 is attached to the upper section 122. The guide section 124 also includes a drill bit 128. The drill bit 128 is tilted around a swivel 131 (typically a universal joint 132 ) mounted in the steering section 124. The swivel 131 itself may transmit torque from the drill string to the drill bit 128, or the torque may be transmitted separately through other devices. Suitable torque transmission devices include many well known devices such as spline couplings, gear drives, universal joints and ball recirculating devices. These devices may either be integrated with the top section 122 or the steering section 124, or they may be attached separately to facilitate repair and/or replacement. However, an important function of the swivel 131 is to provide a 360 degree pivot point for the steering section 124. The guide section 124 is periodically driven by one or more motors 139 around the swivel 131 relative to the top section 122 to actively hold the bit axis 134 in a particular direction while the entire assembly rotates at the rotational speed of the drill string. The term "actively tilted" is intended to distinguish how a rotary steered

system 120 is dynamically oriented compared to prior art fixed displacement units. "Actively tilted" means that the rotary steerable system 120 does not have a predetermined fixed angular or linear displacement with offset. Conversely, both the angular displacement and the offset displacement change dynamically as the rotary steerable system 120 operates.

The disadvantage is that the presence of a universal joint assembly depends on the reliability and durability of the entire rotary steerable system, as well as the creation of a sealed channel for the flow of drilling fluid between the upper section 122 and the steering section 124.

Figure 4 shows a cross-section of the inventive rotary steerable system with the possibility of bending the central shaft of the rotary steerable system to deflect the bit while drilling a well. The rotary steerable system consists of a central shaft 201 which is directly connected to the drill bit 202, on the reverse side the central shaft 201 is connected to an upper section (not shown) which typically houses the electronics and other devices necessary to control the rotary steerable system. On top of the central shaft 201 there is a holder 203, under which sealed volumes 208 are formed; the tightness is ensured using sealing elements 207, for example rubber O-rings. The race 203 is rigidly clamped on the central shaft 201 from the side of the bit 202; on the opposite side, the race 203 has a sealed hinge element 206 that ensures rotation of the axis of the central shaft 201 relative to the axis of the race 203. The hinge element 206 can be made in many well-known ways, for example, a ball joint, ball recirculation device, splined coupling, etc. In the sealed volume 208 there is at least one pusher 204, which is driven by fluid passing through the channels 205. It is worth clarifying that the pusher 204 can be driven not only hydraulically, but also by other means (for example, pneumatic, mechanical, electrical and other ways). When applying pressure to the pusher 204, it rests against the holder 203, which leads to bending of the central shaft 201 (Fig. 5) and thereby to a displacement of the axis of the bit 202 relative to the axis of the well 209 and thereby curvature of the wellbore. It should also be noted that the cage 203 rotates at the same speed and in the same direction as the central shaft 201, which minimizes sticking in the well.

A rotary steerable system with a rotating body and a bending central shaft is installed in the bottom hole assembly and contains:

- the central shaft, which is directly connected to the drill bit, on the reverse side the central shaft is connected to the upper section, in which it is usually

electronics and other devices necessary to control the rotary steerable system are housed;

- a cage under which sealed volumes are formed;

- tightness is ensured using sealing elements;

- a hinge element providing rotation of the axis of the central shaft relative to the axis of the cage;

- at least one pusher located in a sealed volume.

The movement of a pusher or set of pushers is provided by hydraulic, pneumatic, mechanical, electrical or other action.

The level of impact on the pusher determines the bending angle of the central axis relative to the holder.

Claims (6)

1. A rotary controlled system, characterized in that it contains a drill bit, a central shaft connected to the drill bit, a cage made on top of the central shaft, forming a sealed volume underneath, a hinge element that ensures rotation of the axis of the central shaft relative to the axis of the cage, and at least at least one pusher installed in a sealed volume, and the cage is rigidly fixed to the central shaft on the side of the drill bit, and on the opposite side the cage has a hinged element. 2. Rotary controlled system according to claim 1, characterized in that the cage is designed to rotate at the same speed and in the same direction as the central shaft. 3. The rotary steerable system according to claim 1, characterized in that the central shaft, which is connected to the drill bit on one side, is connected on the reverse side to the upper section in which the rotary steerable system controls are located. 4. A rotary controlled system according to claim 1, characterized in that it additionally contains sealing elements that ensure tightness. 5. Rotary controlled system according to claim 1, characterized in that the movement of at least one pusher is carried out by means of hydraulic, or pneumatic, or mechanical, or electrical action. 6. Rotary controlled system according to claim 5, characterized in that the level of influence on the pusher determines the bending angle of the central axis relative to the holder.