Collapsible multi-sized drill bit and method of use

Abstract

The present invention relates to a collapsible drill bit for use in formation drilling and a method of formation drilling. The drill bit includes a main body having a first cutting diameter and includes a front end with a cutting face supporting one or more cutting elements and a rear end configured to operatively connect to a drill string. The drill bit also includes a retractable portion between the front end and the rear end, the retractable portion including at least one cutting face supporting one or more cutting elements, the retractable portion configured to move between an expanded position in which the retractable portion has a second cutting diameter and a collapsed position in which the retractable portion has a diameter less than or equal to the first cutting diameter. Wherein the retractable portion is caused to move into the collapsed position upon an application of a sufficient force.

1 . A collapsible drill bit for use in formation drilling comprises:
 a main body having a first cutting diameter and includes a front end with a cutting face supporting one or more cutting elements and a rear end configured to operatively connect to a drill string;   a retractable portion between the front end and the rear end, the retractable portion including at least one cutting face supporting one or more cutting elements, the retractable portion configured to move between an expanded position in which the retractable portion has a second cutting diameter and a collapsed position in which the retractable portion has a diameter less than or equal to the first cutting diameter;   wherein the retractable portion is caused to move into the collapsed position upon an application of a sufficient force.   
     
     
         2 . The bit of  claim 1  wherein the retractable portion is configured such that when the body is rotated in one direction, the rotational force will keep the retractable portion in the expanded position and when the body is rotated in the opposite direction, the rotational force which will urge the retractable portion into the collapsed position. 
     
     
         3 . The bit of  claim 1  wherein the body comprises a channel formed therein; and an actuation member disposed within the channel, the actuation member moveable between a first position and a second position relative to the body to operably move the retractable portion between the expanded position and the collapsed position, respectively, upon the application of the sufficient force. 
     
     
         4 . The bit of  claim 3  wherein the movement from the first position to the second position causes the retractable portion to move into the collapsed position. 
     
     
         5 . The bit of  claim 4  wherein the retractable position is maintained in the expanded position by one of more retainers, and upon the application of the sufficient force, the retainers become released, and the retractable portion is moved from the expanded position into the collapsed position. 
     
     
         6 . The bit of  claim 5  wherein the retainers are shear pins and the movement of the member causes the retainers become released when the shear pins to be sheared off 
     
     
         7 . The bit of  claim 4  wherein the member comprises threads and is configured to matingly engage corresponding thread on a torque ring, such that upon the application of the sufficient force, the member forces torque transfer to move the retractable portion between the expanded position and the collapsed position. 
     
     
         8 . The bit of  claim 3  wherein the movement is driven by the application of mechanical force from impact of a plugging means selected from among ball, dart and plug on the actuation member. 
     
     
         9 . The bit of  claim 3  wherein the movement is driven by the application of hydraulic or pneumatic force acting on the member. 
     
     
         10 . The bit of  claim 1  further comprising one or more drill arms operatively connected to the body between the retractable portion and the rear end, supporting one or more cutting elements, the drill arms configured to move between a resting position wherein the arms are closed to the body and an activated position wherein the one or more arms extend away from the body, upon an application of another sufficient force. 
     
     
         11 . The bit of  claim 10  further comprises a second actuation member disposed within the channel and operatively connected to the drill arms, wherein upon the application of the sufficient force, the second actuation member moves between a first position and a second position relative to the body to push the drill arms outwards from the body. 
     
     
         12 . The bit of  claim 11  wherein the outer wall of the second actuation member comprises one or more shoulders defining a diameter greater than a diameter on either side of the shoulder, wherein when the shoulder is displaced upon the application of the sufficient force, the shoulder is moved into contact with the one or more drill arms and the one or more drill arms extend away from the body. 
     
     
         13 . The bit of  claim 10  wherein the retraction of the retractable portion and the actuation of the drill arms are independently actuable. 
     
     
         14 . The bit of  claim 10  wherein the force sufficient to cause the retraction of the retractable portion is less than the force sufficient to cause the actuation of the drill arms. 
     
     
         15 . The bit of  claim 10  wherein the drill arms are reamers defining a preselected diameter, in the activated position. 
     
     
         16 . An extendible bit for use in formation drilling, the bit comprising
 a hollow body defining a first cutting diameter and includes a front end with a cutting face supporting one or more cutting elements and a rear end adapted configured to operatively connect to a drill string;   one or more drill arms, supporting one or more cutting elements, the drill arms configured to move between a resting position wherein the arms are closed to the body and an activated position wherein the arms extend away from the body, upon an application of a sufficient force; and   an actuation member disposed within the body configured to receive the sufficient force and operatively connected to a portion of the one or more drill arms, the actuation member comprises one or more shoulders defining a diameter greater than a diameter on either side of the shoulder, wherein when the shoulder is displaced upon the application of the sufficient force, the shoulder is moved into contact with the portion of the one or more drill arms and the one or more drill arms extend away from the body.   
     
     
         17 . A method of formation drilling using a multi-sized drill bit configured to operatively connect to a drill string, the bit defining a cutting diameter, a front end with a cutting face, and a rear end configured to connect to the drill string, a retractable cutting blade defining a cutting profile greater than the cutting diameter of the bit and configured to retract into the body and an extendible cutting blade configured to extend out of the body defining another cutting profile when extended from a rest position, the method comprising:
 drilling a bore using the retractable cutting blade, wherein the drilled bore has a diameter defined by the cutting profile;   applying a first force sufficient to retract the retractable cutting blade, wherein the applying the first force is insufficient for extending the extendible cutting blade from the rest position, when a first desired depth is reached;   applying a second force sufficient to extend the extendible cutting blade to the another cutting profile from the rest position after the retractable cutting blade is retracted; and   withdrawing the drill bit.   
     
     
         18 . The method of  claim 17  further comprising, after the first depth is reached, drilling deeper into the bore, wherein the drilled bore has a diameter substantially equal to the cutting diameter of the bit, and withdrawing the drill bit after a second desired depth is reached, wherein during the withdrawing, the drilled bore having the diameter substantially equal to the cutting diameter of the bit is enlarged by the extended extendible cutting blade to the another cutting profile. 
     
     
         19 . The method of  claim 17  further comprising applying a third force sufficient to retract the extended extendible cutting blade. 
     
     
         20 . The method of  claim 17  wherein the cutting profile is larger or smaller than the another cutting profile. 
     
     
         21 . The method of  claim 17  wherein the bit comprises a body having a channel formed therein; a first actuation member disposed within the channel, the first actuation member moveable between a first position and a second position relative to the body to retract the retractable cutting blade into the body upon the application of the first force; and a second actuation member disposed within the channel, wherein upon the application of the second force, the second actuation member moves between a first position and a second position relative to the body to push the extendible cutting blade outwards from the body.