Abstract:
The present invention generally relates to an abrasive jet drilling assembly. In one aspect, a resettable circulation tool for use in an abrasive jet drilling assembly is provided. The resettable circulation tool includes an inner body having a first port in fluid communication with a bore. The resettable circulation tool further includes an outer body having a second port. Additionally, the resettable circulation tool includes a cam member configured to move along one or more slots, wherein the bodies move relative to each other to selectively align and misalign the first port and the second port as the cam member moves along the slots. In another aspect, a method of using a resettable circulation tool disposed in an abrasive jet drilling assembly includes moving the first and second ports into and out of alignment.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims benefit of U.S. Provisional Application No. 61/427,549, filed Dec. 28, 2010, the contents of which are herein incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    Embodiments of the present invention generally relate to an abrasive jet drilling assembly. More particularly, embodiments of the present invention relate to a resettable circulation tool for use in the abrasive jet drilling assembly. 
         [0004]    2. Description of the Related Art 
         [0005]    In the oil and gas industry, a wellbore may be formed by using an abrasive jet drilling assembly. The abrasive jet drilling assembly typically includes a jetting drill device disposed on a drill string. The jetting drill device ejects a high velocity stream of drilling fluid which includes abrasive particles. The high velocity stream of drilling fluid erodes the rock adjacent the jetting drill device to form the wellbore. If the abrasive jet drilling assembly encounters a gas cake (e.g. gas pocket) while forming the wellbore, it is oftentimes necessary to circulate back through a circulation port of a circulation tool. There are circulation tools commercially available that enable a downhole circulation port to be opened from the surface. Current designs of such circulation tools are limited in their number of operation and function by dropping a ball, shearing a pin, or other method that precludes utilizing the circulating function for another event. Many tools function by dropping a ball or plug that impedes further flow as the circulation function is not reversible or resettable. Additionally, these circulation tools stay open without the ability to utilize the flow through the body of the circulation tool as per the initial (pre-deployed) condition. Therefore, there is a need for a resettable circulation tool for use in the abrasive jet drilling assembly. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention generally relate to an abrasive jet drilling assembly. In one aspect, a resettable circulation tool for use in an abrasive jet drilling assembly includes an inner body having a first port in fluid communication with a bore; an outer body having a second port; and a cam member configured to move along one or more slots, wherein the bodies move relative to each other to selectively align and misalign the first port and the second port as the cam member moves along the slots. 
         [0007]    In another aspect, a resettable circulation tool for use in an abrasive jet drilling assembly is provided. The resettable circulation tool includes an inner body having a first port in fluid communication with a bore. The resettable circulation tool further includes an outer body having slots formed on an inner surface, wherein the outer body includes a second port. Additionally, the resettable circulation tool includes a cam member configured to move along the slots of the outer body, wherein the bodies move relative to each other to selectively align and misalign the first port and the second port as the cam member moves along the slots. 
         [0008]    In another aspect, a method of using a resettable circulation tool disposed in an abrasive jet drilling assembly is provided. The method includes the step of positioning a jetting drill device in the abrasive jet drilling assembly into contact with a portion of a wellbore. The method further includes the step of applying a first axial force and a first rotational force on the drilling assembly, thereby causing a first port and a second port in the resettable circulation tool to align. The method also includes the step of pumping fluid through the ports of the resettable circulation tool. The method further includes the step of applying a second axial force and a second rotational force on the drilling assembly, thereby causing the first port and the second port to misalign. Additionally, the method includes the step of pumping fluid through the resettable circulation tool and into the jetting drill device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
           [0010]      FIG. 1  is a view illustrating a resettable circulation tool in an abrasive jet drilling assembly. 
           [0011]      FIG. 2  is a cross-section view illustrating the resettable circulation tool in the abrasive jet drilling assembly. 
           [0012]      FIG. 3  is a cross-section view illustrating the resettable circulation tool. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    The present invention generally relates to a resettable circulation tool for use in the abrasive jet drilling assembly. To better understand the novelty of the resettable circulation tool of the present invention and the methods of use thereof, reference is hereafter made to the accompanying drawings. 
         [0014]      FIG. 1  is a view illustrating a resettable circulation tool  100  in an abrasive jet drilling assembly  200 . Generally, the abrasive jet drilling assembly  200  is used to form a wellbore by ejecting a high velocity stream of drilling fluid which includes abrasive particles. The abrasive jet drilling assembly  200  includes a jetting drill device  205  for ejecting the high velocity stream of drilling fluid. The abrasive jet drilling assembly  200  is connected to a drill string (not shown). The abrasive jet drilling assembly  200  further includes the resettable circulation tool  100 . 
         [0015]    The resettable circulation tool  100  includes a plurality of circulation ports  105  that may be selectively opened during the drilling operation to circulate drilling fluid out of the drill string and then closed. The resettable circulation tool  100  could be operated multiple times during the drilling operation. The resettable circulation tool  100  is normally closed, and may optionally be provided with a shear pin safety system to prevent unwanted operation. The resettable circulation tool  100  is movable between a closed position (normal operation) and an opened position. In the opened position, fluid is circulated out from the resettable circulation tool  100  above the device  205  to eliminate a shot column. To move the resettable circulation tool  100  to the opened position from the closed position, a downward motion will allow the resettable circulation tool  100  to open and allow circulation, and remain in this position until a similar downward motion is utilized to close the resettable circulation tool  100  and resume the drilling operation. The resettable circulation tool  100  can be operated as often as required to accomplish the desired objectives during the drilling operation. 
         [0016]      FIG. 2  is a cross-section view illustrating the resettable circulation tool  100  in the abrasive jet drilling assembly  200 . As shown, a bore  210  of the jetting drill device  205  is in fluid communication with a bore  110  of the resettable circulation tool  100 . During the drilling operation, drill fluid is pumped through the drill string through the bores  110 ,  210  and then out of the jetting drill device  205 . The drill fluid includes abrasive particles that are configured to erode the rock to form the wellbore. The resettable circulation tool  100  in the closed position (e.g. normal operation) allows all of the drill fluid to flow though the bore  110  of the resettable circulation tool  100 . The resettable circulation tool  100  in the opened position allows substantially all of the drill fluid to flow though the circulation ports  105  of the resettable circulation tool  100 . 
         [0017]      FIG. 3  is a cross-section view illustrating the resettable circulation tool  100 . The resettable circulation tool  100  generally includes an inner sub  130  and an outer sub  125 . Each sub  125 ,  130  has the requisite connection member, such as a threaded connection, that is required to be placed above the jetting drill device  205 , and allows the subs  125 ,  130  to be an extension of the jetting drill device  205 . The inner sub  130  has the sector control profile, such as slots, that allows the “ratcheting” function of the sub&#39;s operation. As set forth herein, cams  140  are installed into the outer sub  125  to provide the control of the ports  105  to either the opened position or the closed position. In one embodiment, there are three sets of cams  140  and profiles to allow strength to support the resettable circulation tool  100  function. In addition, there may also be a lock collar  160  that adds additional shear strength in tension operations. The outer sub  125  may optionally include shear pins with total WOB (Weight on Bit) loads from 9,500 lbs. to 20,000 lbs. to actuate the circulation function of the resettable circulation tool  100  for the first time. 
         [0018]    The resettable circulation tool  100  is generally a two-position tool, which can be cycled from the closed position to the opened position and back again to the closed position any number of times. The resettable circulation tool  100  is cycled by a downward direction force, arrow  165 , with slight rotation in a first direction. In one embodiment, the first direction is toward the right. Re-pressurization (e.g. by restoring flow) pumps open the tool and open the circulating ports  105  of the resettable circulation tool  100 . In the event that this action needs to be reversed (e.g. moved to the closed position), the downward force  165  is once again applied with slight rotation in the first direction, and re-pressurizing to pump, the circulation ports  105  are closed. 
         [0019]    The resettable circulation tool  100  allows numerous cycles from opened position to closed position as required during the drilling operation. In addition, there is no obstruction to flow in the bore  110  of the resettable circulation tool  100  as compared to current designs of circulation tools which require a ball or a plug to operate. Further, there are minimum maintenance requirements in the resettable circulation tool  100  other than grease flush during cleaning. In one embodiment, shear pins may be included to ensure a minimum operating force (e.g. downward force  165 ) prior to operation; however this feature would be single use only. 
         [0020]    The resettable circulation tool  100  is installed in-line with the jetting drill device  205  (see  FIG. 2 ), with appropriate connections and crossovers as required. The inlet  170  is the fluid inlet for the resettable circulation tool  100  and directly provides a flow path to the jetting drill device  205  through a crossover at the bottom. The only other flow ports are ports  105 ,  155 . 
         [0021]    During the operation of the resettable circulation tool  100 , the flow ports  105  are either closed or open. The resettable circulation tool  100  is operated by pressure acting as a spring and forcing the outer sub  125  to travel downward and stop. In one embodiment, low pressure operation of around 100 to 300 PSI is used. 
         [0022]    The resettable circulation tool  100  includes cam  140  which drives the outer sub  125  through the slots  145  that control the positioning of the outer sub  125  relative to the inner sub  130 . In one embodiment, the slots  145  extend circumferentially around the inner sub  130  and axially along a substantial length thereof. In one embodiment, the slots  145  extend circumferentially around the outer sub  125  and axially along a substantial length thereof. The slots  145  include guides and shoulders (not shown) that are used to direct the cam  140  along a slot pathway. The slots  145  may include a plurality of longer length slots and a plurality of shorter length slots. In one embodiment, a shear pin  135  may be utilized to prevent the movement of the cam  140  in the slots  140  unless sufficient force, such as 10,000 lbs. to 35,000 lbs., is applied downward. 
         [0023]    The slots  145  have been arranged to have the resettable circulation tool  100  function with applied downward force (e.g.  165 ), but the resettable circulation tool  100  is recommended to have right-hand torque when setting down. The slots  145  provide up and down function but will resist rotating the outer sub  125  relative to the inner sub  120 . The slots  145  provide different slot lengths for open or closed positions. The open position is longer, providing the additional length to open the flow ports  105 ,  155  to the bore  110 . In one embodiment, the slot configuration has three dual function segments in the cam surfaces. 
         [0024]    In the closed position as shown in  FIG. 3 , flow cannot exit the resettable circulation tool  100 , and the flow is directed into the jetting drill device  205 . If outboard circulation is desired, the force  165  (e.g. WOB) is applied with a slight torque in the first direction. In turn, the cam  140  is reset into a longer length slot of the slots  145 , so that when the pressure is applied to the resettable circulation tool  100 , it will cycle to the opening of the flow ports  105 . The resultant area is  6  times the nozzle area with a corresponding pressure drop. In other words, to move the resettable circulation tool  100  to the opened position, the resettable circulation tool  100  is cycled by a downward direction force, arrow  165 , with slight rotation in a first direction, which causes the cam  140  to move along the guides of the slots  145  and stop at one of the shoulders. At this point, the inner port  155  of the inner sub  120  is aligned with the outer port  105  of the outer sub  125 , and fluid is allowed to exit the resettable circulation tool  100 . 
         [0025]    To move the resettable circulation tool  100  from the opened position to the closed position, substantially the same set down force  165  (e.g. WOB) is applied with a torque in the first direction which allows the outer sub  125  to rotate to a shorter length slot in the slots  145 , and when pressurized, the resettable circulation tool  100  will cycle to the closed position with the flow ports  105  closed again. In other words the inner port  155  of the inner sub  120  is misaligned with the outer port  105  of the outer sub  125 , and fluid is prevented from exiting the resettable circulation tool  100 . Repetition of the same downward action will reset the resettable circulation tool  100  to either the closed or open position as desired. The resettable circulation tool  100  alternatively either opens or closes during activation. 
         [0026]    The resettable circulation tool  100  includes a first seal  115  and a second seal  120  between the inner sub  120  and the outer sub  125 . The seals  115 ,  120  are configured to prevent the leakage of fluid between the subs  120 ,  125 . The seals  115 ,  120  also seal ports  105 ,  155  and provide the necessary seal and backup for 10,000 PSI operation for multiple cycles. 
         [0027]    In another embodiment, the threaded collar  160  may be used for tensile strength. Specifically, the threaded collar  160  is used at the bottom of the inner sub  120  to retain the integrity of the resettable circulation tool  100  if the cams malfunction. 
         [0028]    In addition to circulating fluid, the resettable circulation tool  100  may be used to allow for drill string drainage (after shot is circulated out) and subsequent (dry string) to aid in drill string servicing when coming out of the hole. This is enabled by opening the ports  105  in a similar manner, as described herein, for drainage of the drill string. 
         [0029]    The resettable circulation tool  100  may be furnished as a custom tool to match the threaded connections of the jetting drill device  205  and the desired upper connection, as well as larger sizes of jetting drill devices. 
         [0030]    The simplicity and ease of maintenance of the resettable circulation tool  100  are maintained by removing the threaded collar  160  and the three cam pins  140 . Larger resettable circulation tools may have more cam pins. Once removal of the cam pins  140  has been accomplished, the inner sub  120  is removed from the outer sub  125  for cleaning and seal replacement. 
         [0031]    While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.