Abstract:
A quick connection for coiled tubing run tools eases the assembly and disassembly while deploying such tools. The quick connection utilizes a locking collet and an inner mandrel with locking sleeve system. Such a quick connection does not require perfect alignment between mating pieces.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from U.S. Provisional Application Ser. No. 62/018,303, filed Jun. 27, 2014, the entire disclosure of which is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to devices and methods for connecting downhole tools. 
       BACKGROUND 
       [0003]    One of the activities associated with the completion of an oil or gas well is the perforation of a well casing. During this procedure, perforations, such as passages or holes, are formed in the casing of the well to enable fluid communication between the wellbore and the hydrocarbon producing formation that is intersected by the well. These perforations are usually made with a perforating gun loaded with shaped charges. The gun is lowered into the wellbore on coiled tubing until it is at a desired target depth; e.g., adjacent to a hydrocarbon producing formation. 
         [0004]    One drawback with running tooling on coiled tubing involves correct alignment between threads on the two mating parts. This requires the two parts to be manually handled when hanging in the vertical position. This process becomes difficult to position the two mating pieces due to the weight of the gun assembly and environmental conditions (e.g., high winds). Other issues include cross threading, and damaging the straight threads between the mating parts. This damage can occur due to misalignment of the threads. 
         [0005]    The present disclosure addresses these and other drawbacks of the prior art. 
       SUMMARY 
       [0006]    In aspects, the present disclosure provides a quick connection for coiled tubing run tools. These connections ease the assembly and disassembly while deploying such tools. In embodiments, the connection utilizes a locking collet and an inner mandrel with locking sleeve system. Such a connection does not require perfect alignment between mating pieces. 
         [0007]    It should be understood that examples of certain features of the disclosure have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the disclosure that will be described hereinafter and which will in some cases form the subject of the claims appended thereto. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    For detailed understanding of the present disclosure, references should be made to the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals and wherein: 
           [0009]      FIG. 1  schematically illustrates an elevation view of a surface facility adapted to perform one or more pre-defined tasks in a wellbore using one or more downhole tools; 
           [0010]      FIG. 2  illustrates a side sectional view of a quick connect and a time delay module according to one embodiment of the present disclosure; and 
           [0011]      FIG. 3  illustrates a side sectional view of the  FIG. 2  quick connect and time delay module in a locked state. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    In one aspect, the present disclosure relates to devices and methods for providing a quick connect housing that is structurally and functionally integrated into a time delay module. The present disclosure is susceptible to embodiments of different forms. For example, the quick connect housing can be adapted to other downhole tools such as packers, tubing cutters, wellbore patches, and other wellbore completion tools. There are shown in the drawings, and herein will be described in detail, specific embodiments of the present disclosure with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that illustrated and described herein. 
         [0013]    Referring initially to  FIG. 1 , there is shown a well construction and/or hydrocarbon production facility  30  positioned over subterranean formations of interest  32 ,  34  separated by a gap section  36 . The teachings of the present disclosure, however, may be applied to any type of subsurface formation. The facility  30  can be a land-based or offshore rig adapted to drill, complete, or service a wellbore  38 . The facility  30  can include known equipment and structures such as a platform  40  at the earth&#39;s surface  42 , a wellhead  44 , and casing  46 . A work string  48  suspended within the wellbore  38  is used to convey tooling into and out of the wellbore  38 . The work string  48  can include coiled tubing  50  injected by a coiled tubing injector  52  and a lubricator  53 . Other work strings  48  can include tubing, drill pipe, wire line, slick line, or any other known conveyance means. A surface control unit (e.g., a power source and/or firing panel)  54  can be used to monitor and/or operate tooling connected to the work string  48 . 
         [0014]    In one embodiment of the present disclosure, a perforating gun train  60  is coupled to an end of the work string  48 . An exemplary gun train  60  includes a plurality of guns or gun sets  62   a - b,  each of which includes perforating shaped charges  64   a - b,  and detonators or firing heads  66   a - b.  It should be understood that the perforating gun train  60  can include three or more guns. Also, while a ‘top-down’ firing sequence is described, it should be understood that a ‘bottom-up’ sequence may also be utilized. That is, instead of the top most gun being fired first with the lower guns sequentially firing, the bottom most gun may be fired with the upper guns sequentially firing. 
         [0015]    In some situations, it may be desirable to perforate one formation by firing a first gun and then move the gun train to another formation. An arrangement for accommodating such movement involves initiating the firing of a first gun and using the firing of the first gun to initiate the firing of a second gun. To provide the time necessary to move the guns between two formations, a time delay module  100  may be inserted between two guns. 
         [0016]    Referring now to  FIG. 2 , there is shown further details of a time delay module  100  configured to provide a predetermined amount of time delay for moving a gun train  60  ( FIG. 1 ) between two formations. Advantageously, the time delay module  100  may be include features that enable a quick connection between the perforating guns  62   a  and  62   b  ( FIG. 1 ). In one non-limiting embodiment described below, the time delay module  100  includes a quick connect housing  110  and a time delay assembly  200 . 
         [0017]    The quick connect housing  110  may use a translating action to interconnect the guns  62   a,b  ( FIG. 1 ). In one arrangement, the housing  110  may include an upper section  112  and a lower section  114 . The upper section  112  has a gun end  116  that connects with a first perforating gun such as gun  62   a  ( FIG. 1 ) and a connector end  118 . The lower section  114  has a gun end  120  that connects with a second perforating gun such as gun  62   b  ( FIG. 1 ) and a connector end  122 . A connection is formed by mating the connector ends  118 ,  122  of the sections  112 ,  114 , respectively. 
         [0018]    In one embodiment, the upper section  112  includes a cylindrical base  130  and a collet  132 . The base  130  may include an opening  134  that provides communication between a chamber  133  formed proximate to the gun end  116  and a bore  138  that traverses the base  130 . The collet  132  may include a passage  140 , a ring  135  that seats within the bore  138 , and a plurality of fingers  136  that axially project from the ring  135 . Additionally, the upper section  112  may also include seals  142  that form a fluid barrier between the base  130  and the ring  135 . 
         [0019]    The fingers  136  are circumferentially distributed and formed of a flexible material such as spring steel. Thus, the fingers  136  may be forced to bend radially outward and return to an original shape when the force is removed. 
         [0020]    In one embodiment, the lower section  114  may include a mandrel  160  and a locking sleeve  162 . The mandrel  160  may be a generally cylindrical member that includes a chamber  164  proximate to the gun end  120  and in communication with an adjacent bore  166 . The mandrel  160  may have a pin section  168 , a locking section  170 , a sleeve support section  172 , and a base section  174 . The pin section  168  has an outer diameter sized to be received into the bore  140  of the collet  132 . The locking section  170  may have a projection  176  that are sized to axially engage the fingers  136 . By axial engagement, it is meant that engagement occurs between surfaces that are not parallel with the longitudinal axis of the upper and lower sections  112 ,  114 . For example, the engagement can occur along inclined surfaces such that a compressive loading can occur. The sleeve support section  172  may include a shoulder region  178  on which are formed external threads  180  and a reduced diameter landing  182 . 
         [0021]    The locking sleeve  162  may be disposed on and surround the sleeve support section  172 . The locking sleeve  162  may be a tubular body having a bore  163  defined by an inner surface on which are formed inner threads  184  that are complementary to the external threads  180 . The bore  163  has a first section through which the shoulder region  178  can slide without obstruction. Thus, the sleeve  162  can slide axially along the landing  182  without rotation and then rotationally engage the externals threads  180 . A lip  186  of the locking sleeve  162  is sized to receive and enclose the fingers  136  when they are not bent radially outward; i.e., the fingers  136  are in a radially relaxed state. The length of the first section is selected to allow the lip  186  to axially slide over and surround the fingers  136 / 
         [0022]    Advantageously, the quick connect housing  110  may be integrated with the time delay assembly  200  such that mating the quick connect upper and lower sections  112 ,  114  also completes assembly of the time delay assembly  200 . In one non-limiting embodiment, the time delay assembly  200  may include an initiator assembly  210  integrated into the upper section  112  and a fuse assembly  220  and a detonation transfer assembly  230  integrated into the lower section  114 . 
         [0023]    The initiator assembly  210  may include an explosive booster charge (not shown) that is energetically coupled to a detonator cord (not shown) associated with an immediately adjacent perforating gun. However, the initiator assembly  210  may also be energetically coupled to other sources for a detonation such as a firing pin, an igniter assembly, or another booster. The initiator assembly  210  may be positioned inside the chamber  133  of the base  130  of the upper section  112  and generate a high-order output when activated. A high-order output generally consists of shock waves (i.e., high-amplitude pressure waves) and thermal energy. Such detonations have a duration of no more than ten seconds and are more typically no greater than a second or no greater than a millisecond. This high order output travels to the bore  138  via the passage  134 . 
         [0024]    The fuse assembly  220  may include one or more time delay fuse(s) element  222  and a fuse support  224  positioned in the lower section  112 . For instance, the fuse assembly  220  may be positioned inside the bore  166  of the mandrel  160 . The fuse support  224  may be a tubular member secures the fuse element  222  within the bore  166 . When so positioned, the high-order output exiting the passage  134  can impinge and detonate the fuse element(s)  222 . 
         [0025]    The time delay fuse element  222  may provide a specified time delay (e.g., 6 minutes, 9 minutes, etc.) for adjusting or controlling the time needed for the gun train  60  to travel to the depth of the next formation to be perforated. Burn times less than one minute are generally not considered adequate to move a perforating gun. Thus, the burn time of the fuse element  222  may be at least one minute, at least five minutes, or at least eight minutes. By adjustable or controllable, it is meant that the time delay mechanism can be configured to increase or decrease the time between the firing of the first gun  62   a  and the eventual firing of the gun  62   b.  In one embodiment, the time delay mechanism includes a combination of energetic materials, each of which exhibit different burn characteristics, e.g., the type or rate of energy released by that material. By appropriately configuring the chemistry, volume, and positioning of these energetic materials, a desired or predetermined time delay can be in the firing sequence. Generally, the energetic materials can include materials such as RDX, HMX that provides a high order detonation and a second energetic material that provides a low order detonation. Also, the number of fuses may be varied to control the duration of the time delay. 
         [0026]    The detonator transfer assembly  230  may include one or more boosters that are detonated by the time delay fuse element  224 . The detonator transfer assembly  230  may be positioned inside the chamber  164  of the mandrel  160 . When detonated by the fuse assembly  220  in the adjacent bore  166 , the detonator transfer assembly  230  generates a high-order output that initiates the firing of the lower gun  62   b  ( FIG. 1 ). The duration of the detonation of the detonation transfer assembly  230  may be no more than ten seconds and are more typically no greater than a second or no greater than a millisecond. 
         [0027]    One illustrative use of the time delay module  100  will be discussed in connection with  FIGS. 1-3 . For clarity, the time delay module  100  will be discussed with reference to perforating guns  62   a - b.  It should be appreciated, however, that certain aspects of the time delay module  100  is not limited to such use. For instance, the quick connect housing  110  may be adapted for use with other well tools. 
         [0028]    In preparation for deployment, the upper section  112  of the quick connect housing  110  is fixed to the upper perforating gun  62   a  and lower section  114  of the housing  110  is fixed to the lower perforating gun  62   b.  The several components making up the time delay assembly  100  have already been installed in the upper and lower sections  112 ,  114 . It should be noted that at this time the time delay assembly  100  is not functional, i.e., cannot transfer a detonation from the upper section  112  to the lower section  114 . 
         [0029]    At the rig floor, the coiled tubing string  50  is unspooled and positioned over the wellhead  44  using the lubricator  53 . Thereafter, a work string  48  is conformed in a sequential manner. First, the upper perforating gun  62   a  is attached to the coiled tubing string  50 . Next, the lower perforating gun  66   b  is positioned below the upper perforating gun  62   a.    
         [0030]    In order to have quick connection, the coiled tubing string  50  is lowered, which allows the connector end  118  of the upper section  112  to slide over the connector end  122  of the lower section  114 . This movement causes the pin section  168  to enter the bore  140  of the collet  132 . Also during this movement, the rib  176  contacts and bends the fingers  136  outward. Thereafter, the fingers  136  snap back to their nominal relaxed or un-flexed condition. Now, the locking sleeve  162  may be axially slid into to contact with the threaded shoulder region  178 . Upon such contact, the locking sleeve  162  may be rotated such that the external threads  180  engage with the inner threads  184 . The locking sleeve  162  is rotated until the lip  186  encloses the fingers  136 , thereby preventing radial flexing of the fingers  136 . In some embodiments, a screw (not shown) may be used to fix the locking sleeve  162  to the locking section  170 . 
         [0031]    Referring to  FIG. 3 , the housing  110  is shown in a locked state. In this locked state, a locking engagement is established between the upper section  112  and the lower section  114  by the fingers  136 . Specifically, a head portion  190  of the collets  136  is axially disposed between the rib  176  and a landing  192  formed on an inner surface of the locking sleeve  162 . The landing  192  may be a ramped or angled surface relative to the longitudinal axis of the lower section  114 . The head portion  190  provides surfaces that are transverse to a longitudinal axis of the lower section  114 . Thus, the lower section  112  cannot slide in a downhole direction  232  because the rib  176  interferingly engages the head portion  190 . Also, the lower section  112  cannot slide in an uphole direction  234  because the landing  192  interferingly engages the head portion  190 . Further, the fingers  136  cannot flex radially outward because they are surrounded and enclosed by the lip  186 . 
         [0032]    It should be appreciated that rotational movement is limited only to locking the upper section  112  to the lower section  114 . That is, a sliding action is the primarily mode to connect the upper section  112  and the lower section  114 . It should also be noted that upon entering the locked state, the initiator assembly  210 , the fuse assembly  220 , and the detonation transfer assembly  230  are energetically coupled or connected to one another. By “energetically coupled or connected,” it is meant that energy released by one device will initiate the detonation of an adjacent device. 
         [0033]    It should be understood that the quick connection described above does not depend on orientation. The lower section  114  may be fixed to the upper gun  62   a  and the upper section  112  may be fixed to the lower gun  62   b.  In such an arrangement, the mandrel  160  of the lower section  114  can be lowered into position into the collet  132  of the upper section  112 . 
         [0034]    Once the perforating gun train  60  is positioned at the desired target depth, a firing signal is transmitted into the wellbore  38 . The firing signal initiates a sequence of detonation events causes the firing of the upper gun  62   a.  This detonation sequence also leads to the activation of the initiator assembly  210  after the upper gun  62  fires. The initiator assembly  210  generates a high-order output that detonates the fuse element(s)  222 . At this time, the perforation gun train  60  can be moved to another desired target depth. After burning for the prescribed time period, the fuse element(s)  222  detonate the detonator transfer assembly  230 , which then generates a high-order output to fire the lower gun  62   b.    
         [0035]    From the above, it should be appreciated that what has been described includes an apparatus for perforating a subsurface formation using at least a first perforating gun and a second perforating gun. The apparatus may include an upper section configured to connect to the first perforating gun. The upper section may include a base having a bore and a collet disposed in the bore. The collet may include a passage and a ring having a plurality of axially projecting fingers. The apparatus may also include a lower section configured to connect to the second perforating gun. The lower section may include a mandrel having a pin section received into the passage of the collet, a locking section having a projection sized to axially engage the fingers, and a sleeve support section having a reduced diameter landing and an adjacent shoulder region on which are formed external threads. The apparatus may further include a tubular locking sleeve disposed on and surrounding the sleeve support section. The locking sleeve may include inner threads that are complementary to the external threads on the shoulder region and a lip configured to at least partially enclose the plurality of fingers. 
         [0036]    In variants, the locking sleeve may include a landing formed on an inner surface and the fingers may each include a head portion axially engaging the projection of the mandrel locking section and the landing of the locking sleeve. The upper section and lower section may have an unlocked state defined by the fingers being disengaged from the pin section and a locked state defined by the head portions of the fingers being enclosed by the lip and interposed between the projection and the landing. 
         [0037]    In further variants, the locking sleeve may include a bore having a first section through which the shoulder region can slide without obstruction, wherein a length of the first section is selected to allow the lip to enclose the fingers. Also, the external threads of the shoulder region may be positioned to engage the internal threads of the locking sleeve after the lip encloses the fingers. 
         [0038]    In still further variants, the base may further include a chamber in communication with the bore via a passage, and the mandrel may further includes a chamber in communication with an adjacent bore. The apparatus may also include a time delay module having an initiator assembly disposed in the base chamber, a fuse assembly disposed in mandrel bore, and detonation transfer assembly disposed in the mandrel chamber. 
         [0039]    In variants, the initiator assembly may be only energetically coupled to the fuse assembly during the locked state. In still further variants, the initiator assembly generates a high-order output when activated by the firing of the first perforating gun, the fuse assembly is detonated by the high-order output, and the detonator assembly initiates the firing of the second gun when activated by the fuse assembly. 
         [0040]    For the above, it should also be appreciated that what has been described includes an apparatus for perforating a subsurface formation. The apparatus may include a first perforating gun; a second perforating gun axially spaced apart from the first perforating gun; and a quick connect assembly selectively connecting the first perforating gun and the second perforating gun. The quick connect assembly may include an upper section configured to connect to the first perforating gun, the upper section including a base having a chamber in communication with a bore via a passage, a collet disposed in the bore, the collet including a passage and a ring having a plurality of axially projecting fingers, wherein each finger includes a head portion, and a lower section configured to connect to the second perforating gun, the lower section including: a mandrel having: a chamber in communication with an adjacent bore, a pin section received into the passage of the collet, a locking section having a projection sized to axially engage the fingers, and a sleeve support section having a reduced diameter landing and an adjacent shoulder region on which are formed external threads, and a tubular locking sleeve disposed on and surrounding the sleeve support section, the locking sleeve including inner threads that are complementary to the external threads of the shoulder region, a lip configured to at least partially enclose the fingers, and a landing formed on an inner surface that axially engages the head portions of the fingers, wherein the upper section and lower section have an unlocked state defined by the fingers being disengaged from the pin section and a locked state defined by the head portions of the fingers being enclosed by the lip and axially interposed between the projection and the landing. 
         [0041]    The foregoing description is directed to particular embodiments of the present disclosure for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible without departing from the scope of the disclosure. It is intended that the following claims be interpreted to embrace all such modifications and changes.