Patent ID: 12247447

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The present invention relates to a decoupling wrench for unlocking bits from a drill, a system for replacing drill bits and a method of replacing bits. More precisely, the decoupling wrench works in conjunction with a system to carry out the bit replacement method, which allows a worn bit to be replaced by a spare bit with low impact of interrupting the drilling operation, in addition to being carried out in a safely manner, through commands from the operating cabin.

Although the present device, system and method are presented in the use of a mobile drilling rig, this is only one of the embodiments within the scope of the present invention.

FIG.1shows an embodiment of the drill10, which includes a drilling derrick11, a drilling string12, a base13that supports the drilling derrick11, the operating cabin14coupled to the base13and a machine room15. The drill string12is configured to extend downwards vertically into a well and at its lower end is attached a percussion hammer, where a drill bit is installed.

FIG.2shows a decoupling wrench20, which will be used to break bit torque, which represents the function of unlocking a bit of percussion hammer50so that said bit can be replaced by another. The decoupling wrench20is fixed to the lower end of the drilling derrick11through tabs that extend outwards (21a,21b) from the actuation of hydraulic cylinders (54a,54b), being positioned posterior to the drill string12and immediately above the drill hole. The decoupling wrench20will move from a retracted position20ato an extended position20bupon a command from the operating cabin14. The lower end of the drill string12, which comprises the percussion hammer50, will be engaged in central slot22of the decoupling wrench20.

As can be seen inFIG.2a, which illustrates an exploded and bottom view of the decoupling wrench20, which comprises central slot22and a wide range of recesses23a,23b,23c,23d. From the engagement of the percussion hammer50into the central slot22of the decoupling wrench20, the wide range of recesses comprised23a,23b,23c,23din the lower part of the decoupling wrench20locks the bit from its protuberances, when a coupling wrench is engaged with the percussion hammer50and a force is applied in a first direction, it allows the bit to remain fixed and then it is unlocked from the decoupling wrench20. Once unlocked, the bit still remains connected to the percussion hammer.

In this way, there is an embodiment of a system for replacing drill bits, the drill comprising a pivotable drill string12with a percussion hammer50that receives bits at its end, the system comprising:a decoupling wrench20mounted on the percussion hammer50, the decoupling wrench20being movable between an extended position, in which the decoupling wrench20is aligned with a drill hole of the pivotable drill string12, and between a retracted position, in which the decoupling wrench20is spaced away from the pivotable drill string12, the decoupling wrench20comprising:a central slot to receive the bit coupled to the percussion hammer50, anda wide range of recesses23a,23b,23c,23dlocated on the inner surface of the central slot, wherein the recesses23a,23b,23c,23dare arranged to accommodate protrusions of the percussion hammer bit50and prevent rotational movement of the bit when the bit is accommodated in the decoupling wrench20;a coupling wrench51set up to apply torque to the percussion hammer50when the bit is positioned in the decoupling wrench20;a bit storage device30comprising:a bit cradle carriage34set up to move on rail36to align with the percussion hammer50;a bit housing31comprising a wide range of receptacles31a,31b,31c,31d,31e;a drill control device set up to send a command and hydraulically actuate the decoupling wrench20, the bit storage device30, the engagement wrench51and the percussion hammer50.

FIG.3illustrates the bit storage device30, which comprises the bit housing31with a wide range of receptacles31a,31b,31c,31d,31and connected by shaft32, with locks33a,33b,33cof recess and the bit cradle carriage34. The bit storage device30is arranged in longitudinal movement mechanism35from conveyor36, and can be electrically activated via a control from the operating cabin.

FIG.3arepresents an isometric view of the bit housing31, which comprises a wide range of receptacles31a,31b,31c,31d,31e. In the illustrated embodiment, there is the presence of five receptacles31a,31b,31c,31d,31e, having a cylindrical shape and which are connected through shaft32. The ends of the shaft32connecting receptacles31a,31b,31c,31d,31ewill fit into holes37a,37blocated at the ends of the bit cradle carriage34, which will allow receptacles31a,31b,31c,31d,31eare tilted from a command in the operating cabin14. The worn bits will be deposited in receptacles31a,31b,31c,31d,31eand the spare bits will be installed in the percussion hammer50.

FIG.3brepresents bit cradle carriage34, where the bit housing31will be coupled to its base38. Additionally, the ends of shaft32connecting receptacles31a,31b,31c,31d,31and bit housing31will be inserted into holes37a,37bof bit cradle carriage34, allowing receptacles31a,31b,31c,31d,31eare tilted to a replacement orientation hydraulically from a command in the operating cabin. The bit cradle carriage34is arranged in longitudinal movement mechanism35that allows the bit housing31to be aligned with the drill string12through position sensors to carry out the bit replacement process.

Referring toFIG.4, an alternative embodiment of the bit storage device is shown, wherein one of a wide range of receptacles is empty and spare bits are positioned in a wide range of receptacles31a,31b,31c,31d,31e.

With reference toFIG.5, a part of the drill string12is shown with the percussion hammer50coupled, together with the presence of a coupling wrench51and a decoupling wrench20in the retracted position. As illustrated inFIG.5, the drill string12is in a drilling orientation, extended vertically downward, in wellbore52. Therefore, from this set-up, it will be possible to start the method for replacing drill bits, which, as shown inFIG.5a, comprises the steps of:position S100the percussion hammer bit50on a decoupling wrench20for unlocking bits;unlock the percussion hammer bit S200by rotating the percussion hammer in a first direction;move the percussion hammer50with the bit unlocked S300to a receptacle, wherein the receptacle comprises means for locking the rotational movement of the bit;rotate (S400) the percussion hammer50in a second direction, opposite to the first direction, to disconnect the unlocked bit inside the receptacle.connect (S500) a spare bit to the percussion hammer.

FIG.6shows the beginning of the S100method of unlocking a worn bit54of the percussion hammer50, where upon a command from the operating cabin14, the drilling process will be stopped. After stopping the drilling process, the lower end of the drill string12, comprising the percussion hammer50will be removed from the drill hole53.

Then, upon a command from a communication device in the operating cabin14, the position of the decoupling switch20, which is mounted on a pair of hydraulic cylinders54a,54b, will be changed from retracted to extended by sliding and then the percussion hammer50of the drill string12will be connected to the decoupling wrench20. In this way, as further shown inFIG.6, the protrusions of the worn bit54will be fixed in the recesses23a,23b,23c,23dof the central slot22of the decoupling wrench20. Subsequently, coupling wrench51will engage the percussion hammer50and then the coupling wrench51will apply a force to unlock the percussion hammer bit S200through rotational movement of the percussion hammer in a first direction. In this way, the percussion hammer50will be rotated while the worn bit54will remain attached to the decoupling wrench20, allowing the bit to be unlocked but remain connected to the percussion hammer50.

In this way, as shown inFIG.7, the coupling wrench51and decoupling wrench20will be disconnected from the percussion hammer50. The worn bit54, although unlocked, remains attached to the percussion hammer50and outside the drill hole53.

InFIG.8, it is possible to view the bit storage device30in a waiting position, where the first receptacle31athat is empty will receive the worn bit54. A second receptacle31bwith the spare bit55will replace the worn bit54in the percussion hammer50. Still inFIG.8, it is possible to see anti-rotation locks33a,33b,33cin the receptacles31a,31b, which prevent the bit54,55from being rotated inside the receptacle when the percussion hammer50is rotated.

Then,FIG.9shows the drilling derrick11positioned in a replacement orientation, allowing the drill string12to be extended S202with the worn bit54in a replacement orientation. Still inFIG.9, the bit storage device30is shown, which comprises the bit cradle carriage34, where in its wide range of receptacles31a,31b,31c,31d,31e, there is the presence of at least one empty receptacle31a, which will be used to deposit the worn bit54and at least one receptacle31bcontaining the spare bit55.

InFIG.10, the bit housing31, through an electrical drive, will be tilted into a replacement orientation and, a wide range of receptacles31athat is empty, will be aligned with the drill string12. Next, the step of moving the percussion hammer50with the unlocked bit to the receptacle S300will be carried out, wherein the receptacle comprises means for locking the rotational movement of the bit. The worn bit54will be secured by the anti-rotation locks33a,33b,33cof the receptacle31a, and the drill string12will perform the step of rotating the percussion hammer50in a second direction, opposite to the first direction, to disconnect the unlocked bit inside the receptacle31a.

In this way, it is shown inFIG.11that only the worn bit54was deposited in the receptacle31aand the percussion hammer50remained in the drill string12. Then, still inFIG.11, the drill string12without the worn bit54is retracted and the bit storage device30is moved to align the receptacle31b, through position sensors, with the spare bit55with the string. drill bit in its retracted position.

As perFIG.11a, the steps of repositioning S301the drill string in a replacement orientation and extending S302the drill string toward the receptacle31bwill be initiated.

FIG.12displays the steps of the flowchart ofFIG.12a, of tilting S303the bit housing to a replacement orientation and aligning S304an empty bit housing receptacle with the drill string, via position sensors, in its replacement orientation. Additionally,FIG.12also shows the steps of the flowchart ofFIG.12b, in which the steps of rotating S400the percussion hammer50in a second direction, opposite to the first direction, will be performed to disconnect the unlocked bit inside the receptacle, where the bit will be positioned S401in the anti-rotation locks on the receptacles to prevent bit54,55from being rotated within the receptacle when the percussion hammer50is rotated.

FIG.13shows that after the worn bit54is disconnected from the percussion hammer50, the drill string12is extended towards the receptacle31bcomprising the spare bit55which has been positioned S401in the anti-rotation locks of the receptacle to prevent bit55from being rotated within the receptacle when the percussion hammer50is rotated. In this way, still as illustrated inFIG.13and the flowchart inFIG.13a, the step of rotating the percussion hammer S500in a second direction, opposite to the first direction in the receptacle comprising the spare bit for installing the spare bit into the percussion hammer.

FIG.14shows the spare bit55installed and the receptacle31bwhere said bit55was stored, empty.

FIG.15shows that after changing the worn bit54, the drill string12returns to its drilling orientation and, in this way, restarts the drilling process from a command from a communication device in the operating cabin13.

CONCLUSION

The benefit of using the decoupling wrench to unlock bits, the bit replacement system and the aforementioned method are directly related to reducing the interruption time of the drilling operation, since only the bit will be replaced and the percussion hammer will remain in the drilling derrick, adding to the cost reduction, since the use of the percussion hammer will be optimized, covering the entire useful life of the equipment. Another positive point with installing the device is the increased safety in operations, since the activity is carried out safely in the operator's cabin, with no exposure of people to the risks of limbs being pinched and crushed and falls from different levels. The electrical drive of the bit storage device provides greater reliability, safety and eliminates the possibility of hydraulic leaks, in addition to eliminating human-machine contact.

In this way, the use of the present decoupling wrench for unlocking bits, system and method of replacing bits is not limited to just one embodiment and can be applied to a wide range of drilling equipment, bringing numerous benefits of gaining productivity.