Patent Publication Number: US-2022235616-A1

Title: Operating Tool For an Artificial Lift System

Description:
BACKGROUND 
     Field 
     Embodiments of the present disclosure generally relate to an operating tool for an artificial lift system. 
     Description of the Related Art 
     A conventional oil well includes a cased wellbore with at least one string of tubing extending downwardly through the casing into the oil or other petroleum fluid contained in the subsurface mineral formation to be produced. The casing is perforated at the level of the production zone to permit fluid flow from the formation into the casing, and the lower end of the tubing string is generally open to provide entry for the fluid in the tubing. 
     Many hydrocarbon wells are unable to produce at commercially viable levels without assistance in lifting the formation fluids to the earth&#39;s surface. In some instances, high fluid viscosity inhibits fluid flow to the surface. More commonly, formation pressure is inadequate to drive fluids upward in the wellbore. In the case of deeper wells, the hydrostatic head that acts downwardly against the formation inhibits the unassisted flow of production fluid to the surface. 
     In many instances, artificial lift may be required to raise the produced fluids to the surface. A common approach for urging production fluids to the surface uses a mechanically actuated, positive displacement pump driven from the surface by a pumping unit, such as a pump jack connected to the pump by a sucker rod string. Reciprocal movement of the sucker rod string induces reciprocal movement of the pump for lifting production fluid to the surface. 
     For example, an artificial lift system  20  is shown in  FIG. 1A  to produce production fluid from a wellbore  10 . The surface casing  12  hangs from the surface and has a liner casing  14  hung therefrom by a liner hanger  16 . Production fluid F from the formation  11  outside the cement  13  can enter the liner  14  through perforations  17 . To convey the fluid, production tubing  26  extends from a wellhead  28  downhole, and a packer  15  seals the annulus between the production tubing  26  and the liner  14 . At the surface, the wellhead  28  receives production fluid and diverts it to a flow line  29 . 
     The production fluid F may not produce naturally to reach the surface so operators use the artificial lift system  20  to lift the fluid F. The artificial lift system  20  has a surface pumping unit  22 , a sucker rod string  24 , and a downhole pump  30 . The surface pumping unit  22  reciprocates the sucker rod string  24 , and the reciprocating sucker rod string  24  operates the downhole pump  30 . The pump  30  has internal components attached to the sucker rod string  24  and has external components positioned in a pump-seating nipple  31  near the producing zone and the perforations  17 . 
     As best shown in the detail of  FIG. 1B , the pump  30  has a barrel  40  with a plunger  32  movably disposed therein. The plunger  32  has a plunger rod  33  attached to it, which connects to the sucker rod string  24  of the artificial lift system  20 . The plunger rod  33  is of sufficient length so that the plunger rod  33  will extend through the upper end of the barrel  40  even at the bottom of the plunger&#39;s stroke. 
     The barrel  40  has a standing valve  42 , and the plunger  32  has a traveling valve  34 . For example, the standing valve  42  disposed in the barrel  40  can be a check valve having a ball  44  and seat  46 . Similarly, the traveling valve  34  can also be a check valve (e.g., one-way valve) having a ball  36  and seat  38 . 
     As the surface pumping unit  22  reciprocates, the sucker rod string  24  reciprocates in the production tubing  26  and moves the plunger  32 . The plunger  32  moves the traveling valve  34  in reciprocating upstrokes and downstroke. During an upstroke, the traveling valve  34  is closed (i.e., the upper ball  36  seats on upper seat  38 ). In some instances, the hydraulic force acting on the plunger  32  during the upstroke may exceed 30,000 pounds 
     Movement of the closed traveling valve  34  upward reduces the static pressure within the pump chamber  45   b  (the volume between the standing valve  42  and the traveling valve  34  that serves as a path of fluid transfer during the pumping operation). This, in turn, causes the standing valve  42  to unseat so that the lower ball  44  lifts off the lower seat  46 . Production fluid F is then drawn upward into the chamber  45   b.    
     Ultimately, the produced fluid F is delivered by positive displacement of the plunger  32 , out passages  45   a  in the barrel  40 . The moved fluid then moves up the wellbore  10  through the production tubing  26  to the wellhead  28 . The production fluid is diverted from the wellbore via the flow line  29 . 
     On the following downstroke, the plunger  32  moves downward in barrel  40  by the reciprocation applied by the pumping unit  22  via the sucker rod string  24 . The weight of the sucker rod string  24  pushes the plunger  32  through the fluid in the barrel  40 . The standing valve  42  closes as the standing ball  44  seats upon the lower seat  46 . At the same time, the traveling valve  34  opens so fluids previously residing in the chamber  45   b  can pass through the valve  34  and into the plunger  32 . The upstroke and down stroke cycles are repeated, causing fluids to be lifted upward through the wellbore  10  and ultimately to the earth&#39;s surface. 
     At some point, it may become necessary to disconnect or connect the sucker rod string  24  with the pump  30 , such as in an oversize tubing pump installation where the pump plunger  32  is installed separately from the sucker rod string  24 . In an insert pump or a standard tubing pump  30 , the plunger  32  or other portions of the pump  30  may become sanded in, corroded, or otherwise difficult to remove from the wellbore  10 . Typically, the sucker rod string  24  is not robust enough to transmit the necessary force required to remove stuck components without damaging the sucker rod string  24  for later use. In other instances, it may be desirable the remove only the sucker rod string  24  simply to adjust and maintain the sucker rod string  24  without removing either the plunger  32  or the barrel  40 . 
     For these reasons, it may be desirable to use an on-off tool  50  on the sucker rod string  24 , as shown in  FIGS. 1A-1B . The on-off tool  50  must be able to disconnect the sucker rod string  24 , but must also be able to be reconnected as desired by the operators. Usually, the on-off tool  50  is installed on the sucker rod string  24  close to the plunger  32 . 
     To connect the sucker rod string  24  to the pump  30  disposed downhole, the on-off tool  50  connects automatically to the pump  30  as the sucker rod string  24  is lowered. The on-off tool  50  is rotated to the correct alignment position and uses the sucker rod string&#39;s weight to complete the connection. To disconnect the sucker rod string  24  from the pump  30 , the on-off tool  50  is unlocked and disconnected by setting the pump  30  at the bottom of its stroke and turning the sucker rod string  24  in the release direction of the tool  50  while slowly picking up the sucker rod string  24 . The on-off tool  50  can have either right-release or left-release direction based on the application and other equipment used. 
       FIG. 2A-2D  illustrates a prior art on-off tool  50 .  FIG. 2A  illustrates the tool  50  with the key  70  disconnected from the housing  52 . The tool  50  includes a housing  52  having a top fitting  54  with a pin connector for attaching to a sucker rod string  24  with a coupling  25 . The housing  52  includes a key slot  60  and a seat  62 . The tool  50  further includes a cam  58  disposed inside the housing  52 . The cam  58  can move axially/longitudinally against the bias of one or more springs  56 . Fixed pins  59  on the housing  52  can ride in slots of the cam  58  to keep the cam  58  from rotating within the housing  52  as the cam  58  moves longitudinally. The tool  50  further includes a key  70  having a head  72  at one end and a connector  71 , such as a box, at the other end to connect the key  70  to the plunger rod  33  of the pump  30 . 
     The housing  52  includes a clutch tab  53  and an end shoulder  57 . The key  70  includes a tab  73  and a shoulder  75 . The engagement of the clutch tab  53  with the tab  73  limits the rotation of the housing  52  relative to the key  70  to align the key  70  relative to the housing  52 . During a disconnecting operation of the tool  50 , the engagement of the clutch tab  53  with the tab  73  aligns the oblong head  72  with the slot  60  such that the key  70  may be withdrawn from the housing  52 . 
     The on-off tool  50  incorporates a cam-type system using the internal cam  58  under the spring&#39;s  56  force and being actuated (in a longitudinal direction) by rotating the cam  58  and the housing  52  relative to the key  70 . This imparts torque, which requires the guide pins  59  to counteract the torque and to keep the cam  58  from rotating in the housing  52 . 
     When connecting the key  70  to the housing  52  downhole, the housing  52  may be lowered onto the key  70  so that the housing  52  interfits and interlocks with the key  70 . The connection is accomplished by the weight of the sucker rod string  24  above the housing  52 , by a rotation of the sucker rod string  24  that causes relative rotary motion between the housing  52  and the key  70  to misalign the key head  72  with the slot  60 , and by the locking action of the key&#39;s head  72  to the internal mechanism of the tool  50 . 
     In particular, the key  70  inserts in a key slot  60  in the housing  52  so the key  70  in a locked position can engage a seat  62  and transmit the tensile forces exerted by the pumping unit  22  on the up stroke. The shoulder  75  of the key cooperates with the shoulder  57  of the housing  52  to transmit any compressive forces of the tool  50  to the plunger rod  33  and ultimately the plunger  32 . 
       FIGS. 2A-2C  illustrates a connection operation of the on-off tool  50 . Initially, the key  70  is coupled to the plunger rod  33  of the pump  30  disposed downhole in the production tubing  26 . The housing  52  is connected to the sucker rod string  24  using the coupling  25  and is lowered down the tubing string to the pump  30 . As shown in  FIG. 2A , the housing  52  is separated from the key  70 . 
     The housing  52  is lowered relative to the key  70 . The head  72  of the key  70  has an oblong cross-section. If the key  70  is not properly aligned with the opening for the slot  60 , then relative rotation between the housing  52  and key  70  can align the head  72  with the slot  60 . Eventually, the housing  52  inserts over the key  70 , which passes through the slot  60  in the housing  52 . Passing up through the housing  52 , the key  70  pushes the cam  58  against the bias of the spring  56 , as shown in  FIG. 2B . 
     To complete the connection, the sucker rod string  24  is rotated to rotate the housing  52  to misalign the head  72  with the slot  60 . As the housing  52  is rotated, the cam  58  cooperates with the oblong head  72  and the spring  56  push the cam  58  over the head  72 .  FIG. 2C  illustrate the tool  50  with the key  70  locked in the housing  52 . Reciprocating of the sucker rod string  24  can now operate the pump  30  while the on-off tool  50  holds the sucker rod string  24  to the plunger rod  33 . 
     To disconnect the tool  50 , sucker rod string  24  is rotated in a direction opposite of the direction of connecting the tool  50  to unlock the key  70  from the housing  52 . For example, the sucker rod string  24  is rotated in a clockwise direction to rotate the housing  52  relative to the key  70 . The cam  58  rotates with the housing  52 , and the profile of the cam  58  slides along the key head  72 . As the cam  58  slides along the key head  72 , the cam  58  is forced to travel longitudinally within the housing  52  and thus compresses the spring  56 . Rotation of the housing  52  relative to the key  70  is limited by the engagement of the clutch tab  53  with the tab  73 . When the clutch tab  53  and tab  73  are engaged, the head  72  is aligned with the slot  60 . The sucker rod string  24  can be lifted to withdraw the key  70  from the housing  52 . 
     During use, for example, the key  70  and housing  52  are subjected to deformation due to downstroke and upstroke impacts. The housing&#39;s seat  62  deforms due to broaching of the key head  72 , and the shoulder  75  and tab  73  of the key head  72  deforms from impact wear with the housing  52  as the pump  30  is stroked. Likewise, the shoulder  57  and clutch tab  53  is subjected to brinelling due to the impact with the key  70  as the pump  30  is stroked. 
     As wear progresses during use, the gap or play between the shoulder  57  and the shoulder  75  increases and produces a slide hammer effect as the play between the components progressively increases as wear occurs. The increased play between the housing  52  and the key  70  further beats the seat  62  against the head&#39;s bearing surface  75 . Eventually, the key head  72  can break off due to impacts. Further, the wear of the clutch tab  53  and tab  73  may reduce their effectiveness in aligning the key head  72  with the slot  60  when disconnecting the tool. During high stroke speeds, the on-off tool  50  can also become disconnected, or the key  70  becomes unlocked from the housing  52 , due to dynamic forces (axial loads and torque) imparted through the sucker rod string  24  coupled with low spring force on the cam  58 . 
     The coil spring  56  biases the cam  58  toward the key head  72  to complete the connecting sequence. However, the coil spring  56  may fail to provide enough axial load needed to keep the tool  50  connected in higher speed pumping applications where the dynamics of the sucker rod string  24  can cause the key  70  to overcome the rotational torque needed to compress the coil spring  56 , causing the tool  50  to disconnect. 
       FIGS. 3A-3C  illustrates another exemplary conventional on-off tool  50  similar to the on-off tool disclosed in U.S. Pat. No. 10,273,762, which is hereby incorporated by reference. A cam  58  in the housing  52  can move longitudinally against the bias of one or more springs  56 , such as a plurality of disk springs. Rather than using fixed pins, the tool  50  includes guide bearings  59  that correspond to a slot in the cam  58  to keep the cam  58  from rotating inside the housing  52 . The guide bearings  59  are elongate pins disposed longitudinally between the cam  58  and the interior of the housing  52 . Opposite the housing  52 , the tool  50  similarly includes a key  70  having a head  72 . The key  70  includes a connector  71  to facilitate the connection of the key  70  to the plunger rod  33  of a pump  30 . The tool  50  can be connected or disconnected in a similar manner to the tool shown in  FIGS. 2A-2D . 
     The cam  58  has two forks  58   f  each having a cam profile. The cam profile is a helical progression with a gradual slope that corresponds to the profile of the key head  72 . The key head  72  interfits with the cam  58  when the key  70  is locked within the housing  52 . During the insertion of the key  70  into the housing  52 , the profile of the head  72  engages of profile of the cam  58 , which causes the cam  58  to travel within the housing  52  and compress the springs  56 . 
     As shown in  FIGS. 3A-3C , the tool  50  does not include an external clutch, in that the housing  52  and key  70  do not have corresponding clutch tabs. Instead, the key  70  has a uniform shoulder  75  that corresponds to a uniform shoulder  57  of the housing  52 . By omitting the clutch tabs, the area of contact between the shoulders  57 ,  75  is increased, which increases the longevity of the tool by decreasing the progression of the wear that occurs during the use of the tool  50 . 
     To disconnect the tool  50  shown in  FIGS. 3A-3B , the sucker rod string  24  is rotated in the release direction while slowly picking up on the sucker rod string  24 . For example, the housing  52  may need to be rotated 90 degrees to align the key head  72  with the slot  60  to unlock the tool  50 . When the key head  72  is aligned with the slot  60 , the key head  72  may be withdrawn from the slot  60 . As a person of ordinary skill in the art understands, each revolution of the sucker rod string  24  at the surface does not necessarily translate to a full revolution of the sucker rod string  24  at depth due to the twisting of the sucker rod string  24 . For example, about four or more revolutions at the surface may be necessary to rotate the housing  52  about 90 degrees when the tool  50  is deployed downhole. As the sucker rod string  24  is rotated in the release direction to disconnect the tool  50 , the sucker rod string  24  may be over rotated. Over rotation of the housing  52  will cause the key head  72  to misalign with the slot  60  and will further cause the key  70  to ratchet within the housing  52 . Ratcheting occurs when the end of the forks  58   f  rides over the top of the head  72 , which allow the springs  56  to force the cam  58  back over the head  72  which prevents the head  72  from exiting the slot  60 . Thus, the tool  50  may unlock and relock multiple times without the key head  72  exiting the slot  60 . If the tool is over rotated, then the sucker rod string  24  will need further rotation to aligned the key head  72  with the slot  60  such that the upward force on the sucker rod string  24  is sufficient to begin the travel of the key head  72  within the slot  60 . While the tool  50  shown in  FIGS. 3A-3C  has increased wear endurance by omitting the external clutch, multiple attempts may be necessary to unlock the tool  50  due to the ratcheting of the key  70  in the housing  52 . 
     Thus, there exists a need in the art for a tool that can be reliably disconnected and reconnected downhole while having increased wear resistance. 
     SUMMARY 
     In one embodiment, an operating tool includes a housing including a key slot. The operating tool further includes at least one biasing member disposed in the housing. The operating tool further includes a key including a key head having a key profile, wherein the key head is remove from the slot when aligned with the key slot. The operating tool further includes a cam including a cam profile, wherein the cam is disposed in the housing and biased toward the slot by the at least one biasing member, wherein the cam profile is configured to engage the key profile to align the key head with the key slot. 
     In one embodiment, an operating tool includes a housing including a slot and a seat. The operating tool further includes at least one biasing member disposed in the housing. The operating tool further includes a key including a key head and a shoulder. The operating tool further includes a cam including a pocket, a first clutch profile, and a second clutch profile, wherein the cam is disposed in the housing and biased toward the slot by the at least one biasing member. When operating tool is in a locked configuration, the key head is misaligned with the slot and the key head is disposed in the pocket of the cam, wherein the shoulder is configured to engage the seat when the key head is misaligned with the slot. When the operating tool is in an unlocked configuration, the first clutch profile and the second clutch profile are engaged with the key head and the key head is aligned with the slot. 
     In one embodiment, a method of using an operating tool, comprising disconnecting the operating tool. Disconnecting the operating tool includes unlocking the operating tool by rotating a housing of the operating tool relative to a key of the operating tool, wherein the rotation of the housing relative to the key is limited by the engagement of a clutch profile of a cam disposed within the housing with a key head of the key, wherein the key head is aligned with a slot of the housing when the clutch profile is engaged with the key head. Disconnecting the operating tool further includes moving the housing relative to the key to withdraw the key head from the slot. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, 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 exemplary embodiments and are therefore not to be considered limiting of its scope, may admit to other equally effective embodiments. 
         FIG. 1A-1B  illustrates an artificial lift system.  FIG. 1B  illustrates an exemplary pump. 
         FIGS. 2A-2D  illustrate a conventional on-off tool with an external clutch disposed in a wellbore. 
         FIGS. 3A-3C  illustrate a conventional on-off tool without an external clutch.  FIGS. 3A-3B  are cross-sectional views of the conventional on-off tool.  FIG. 3C  is a perspective view with a portion of the housing cut away to reveal internal features. 
         FIGS. 4A-4D  illustrate an operating tool according to the present disclosure in a locked configuration.  FIGS. 4A-4B  illustrate a cross-section of the tool.  FIGS. 4C-4B  are perspective views of the tool, with a portion of the housing cut away to reveal internal features. 
         FIGS. 5A-5C  illustrate a cam of the operating tool of the present disclosure.  FIGS. 5A-5B  are different perspective views of the cam.  FIG. 5C  is a close-up view of the circled region in  FIG. 5B . 
         FIGS. 6A-6C  are perspective views of a key of the operating tool of the present disclosure.  FIG. 6C  is a perspective view of the key head. 
         FIGS. 7A-7D  illustrate the key engaged with the clutch profile of the cam.  FIG. 7B  is a cross-sectional view of the operating tool.  FIGS. 7A, and 7C-7D  are perspective views of the tool, with a portion of the housing cut away to reveal internal features. 
         FIGS. 8A-8C  illustrate the unlocking of the operating tool of the present disclosure.  FIGS. 8A-8C  are perspective views of the tool, with a portion of the housing cut away to reveal internal features.  FIG. 8A  illustrates the on-off tool in the locked configuration.  FIG. 8B  illustrates the tool in the unlocked configuration.  FIG. 8C  illustrates a disconnected tool, with the key separated from the housing. 
     
    
    
     To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. 
     DETAILED DESCRIPTION 
       FIGS. 4A-4D  illustrate an exemplary operating tool such as an on-off tool  100 , according to one embodiment. In this embodiment, the on-off tool  100  including a housing  110 , a cam  140 , and a key  170 . As will be described herein, the tool  100  has an internal clutch profile  152  that prevents over rotation during disconnection. As will be described herein, the tool  100  may also have a uniform shoulder contact area between the key  170  and housing  110  to improve the wear resistance and durability of the tool  100 . The tool  100  can be used for connecting a sucker rod string  24  to a plunger rod  33  of a pump  30  of an artificial lift system, such as the artificial lift system  20  previously discussed with reference to  FIGS. 1A-1B .  FIGS. 4A-4B  illustrate a cross-sectional view of the tool  100 .  FIGS. 4C and 4D  illustrate a perspective view of the tool  100  with a portion of the housing  110  omitted to better show the internal components of the tool  100 . 
     The tool  100  may include a fitting  102 , guide pins  104 , the housing  110 , the cam  140 , the key  170 , and one or more biasing members  190 . The biasing member  190  may be a plurality of disk springs as shown in  FIGS. 4A-4D . In some embodiments, the biasing member  190  is one or more coiled springs. 
     The housing  110  has first and seconds end portions  114 ,  116  and defines an interior  112 . The first end portion  114  connects to the fitting  102 . The interior  112  defines a key slot  120  at the second end portion  116  of the housing  110 . The key slot  120  terminates at a seat  122  within the housing  110 . The second end portion  116  also includes an end shoulder  117 . 
       FIGS. 5A-5C  also illustrate the cam  140 . The cam  140  is disposed in the interior  112  of the housing  110 . The cam  140  may be machined. In some embodiments the cam  140  includes two forks  144 . The cam  140  may also include a slot  142  on opposing sides corresponding to the guide pins  104 . The cam  140  further includes a pocket  146  between the forks  144  to receive a head  172  of the key  170 . The cam  140  is longitudinally moveable within the housing  110 . The biasing member  190  biases the cam  140  towards the second end portion  116 . As the cam  140  moves longitudinally within the housing, a guide pin  104  rides in a respective slot  142 . The travel of the cam  140  towards the second end portion  116  is limited by the abutment of the guide pins  104  with the end of the slots  142 . The cam  140  is rotationally locked to the housing  110  by the interaction of the slots  142  with the guide pins  104 . 
     Each fork  144  includes an interior surface  145  and a cam profile  150  having a helical progression along the fork  144 . The cam profile  150  includes a lock profile  151  and a clutch profile  152 . In some embodiments, and as shown in  FIG. 5A-5C , the clutch profile  152  includes a curved surface adjacent a clutch shoulder  153 . The clutch shoulder  153  may be a flat face. The clutch shoulder  153  is configured to engage a profile  180  of the key  170  to align the key  170  with the slot  120  during an unlocking operation of the tool  100 . Additionally, the clutch shoulder  153  is configured to prevent the key  170  from ratcheting within the housing  110  due to an over rotation of either the housing  110  or the key  170  relative to one another. The lock profile  151  may have two or more pitches such that the profile  180  of the head  172  travels longitudinally relative to the housing at a different rate per unit of rotation. The lock profile  151  cooperates with the profile  180  when the tool  100  is connected to reduce the instances of unintended unlocking of the tool  100  when in use downhole. To disconnect the tool  100 , sufficient torque applied to the housing  110  or key  170  to cause the cam  140  to slide along the profile  180  against the biasing force of the biasing member  190  as the key head  172  is aligned with the slot  120 . An increased slope of the lock profile  151 , such as a steep slope of the pitch, increases the amount of torque necessary to disconnect the tool  100 . Therefore, the lock profile  151  is configured to lock the key  170  to the housing  110  until sufficient torque is applied to disconnect the tool  100 . The differing pitches of the lock profile  151  may correspond to differing torque thresholds of the tool  100 , such as a torque necessary to disconnect the tool  100 . In some embodiments, the two or more pitches of the lock profile  151  may accommodate the insertion and locking of the key head  172  within the spatial constraints of the housing  110  and the longitudinal range of movement of the cam  140  within the housing  110 . 
     The key  170  is shown in  FIGS. 6A-6C . The key  170  includes a stem  171 , a head  172 , and a base  178 . The stem  171  is disposed between the head  172  and the base  178 . The head  172  includes the profile  180  on opposing sides of the head  172 . The end of the head  172  may be rounded as shown in the figures. The head also includes shoulder  175  corresponding to the seat  122 . The head  172  has an oblong cross-section that corresponds to the slot  120 . The base  178  may include a shoulder  177  that corresponds to the shoulder  117  of the housing  110 . The base  178  may further include a connector, such as a box connector  178   c , to facilitate the connection of the key  170  to the plunger rod  33 . 
     The head  172  is configured to be inserted or removed the housing  110  once aligned with the slot  120 . When the head  172  is inserted into the housing  110  past the slot  120 , either the housing  110  or the key  170  may be rotated, such as clockwise by 90 degrees, to misalign the head  172  with the slot  120  to lock the key  170  to the housing  110 . When the key  170  is locked to the housing  110 , the shoulder  175  may engage the seat  122 . The engagement of the seat  122  with the shoulder  175  transfers tensile forces during operation of the tool  100 . Additionally, the shoulders  117  and  177  may be engaged when the tool  100  is in the connected. The shoulders  117  and  177  may have uniform surface areas. The cooperation of the shoulders  117 ,  177  may reduce wear of the shoulders  117 ,  177  as they contact one another during use of the tool  100  to improve the wear resistance and durability of the tool  110 . 
       FIG. 6C  illustrates a perspective view of the key head  172  which includes the profile  180 . The profile  180  may have a first profile portion  182  and a second portion  184 . As shown, the first profile portion  182  is the outer surface of the key head  172  near the tip of the key head  172 . The first profile portion  182  is configured to engage the cam profile  150 . The cam profile  150  and the first profile portion  182  interact to guide the head  172  into the pocket  146  during the locking of the key  170  to the housing  110 . The second portion  184 , such as a face, is configured to engage the interior surface  145  of a fork  144 . 
       FIGS. 4A-4D  illustrate the tool  100  in a locked configuration. When the key  170  is locked to the housing  110 , the tool  100  is connected. Prior to disconnecting the tool  100  (i.e., separating the key  170  from the housing  110 ), the tool  100  is unlocked. To unlock the tool, either the housing  110  or key  170  is rotated to align the key head  172  with the slot  160  such that the key head  172  may be withdrawn from the slot  160  to disconnect the tool  100 . 
       FIGS. 7A-7D  illustrate the engagement of the clutch profile  152  with the first profile portion  182  of the profile  180 . This engagement of the clutch profile  152  occurs during the insertion of the key  170  into the housing  110 . The clutch profile  152  is the first point of contact of the head  172  with the cam  140  when the head  172  is initially inserted into the slot  120 . Continued insertion of the head into the slot  120  will overcome the biasing force of the biasing member  190 , causing the cam  140  to travel longitudinally within the housing  110  to accommodate the insertion of the key head  172 . When unlocking the tool  100 , the tool will return to this position. Thus,  FIGS. 7A-7D  also show the tool  100  in an unlocked configuration. As the tool  100  is unlocked, the key head  72  will reengage the clutch profile  152  to align the key head  172  with the slot  120 . 
     The tool  100  may be connected at its fitting  102  to a sucker rod string  24  with a coupling  25  and may be connected at its key  170  to the plunger rod  33  of a pump  30 . For example, fitting  102  may be connected to the coupling  25  by a pin connector  102   c  and the key  170  may be connected to the plunger rod  33  via the box connector  178   c . In some embodiments, the key  170  will be connected to the sucker rod string  24  and the fitting  102  may be connected to the plunger rod  33 . As will be detailed below, locking and unlocking of the tool  100  is achieved through the interaction of the key  170  with the housing  110  and cam  140  biased by the biasing members  190 . 
     To connect the tool  100 , the key  170  is inserted into the housing  110  via the slot  120 . As the key  170  is inserted into the housing  110  via the slot  120 , the head  172  will engage the cam  140 . The first profile portion  182  contacts the cam profile  150 , such as contacting the clutch profile  152  as shown in  FIGS. 7A-7D . Continued insertion of the key  170  will overcome the biasing force of the biasing member  190 , causing the cam  140  to travel longitudinally within the housing  110  to accommodate the insertion of the key head  72 . Once the head  172  is fully inserted into the housing  110 , either the key  170  or the housing  110  may be rotated a number of degrees, such as clockwise 90 degrees, to misaligned the head  172  with the slot  120 . Misalignment of the head  172  with the slot  120  also facilitates the expansion of the biasing member  190  to slide the cam  140  over the key head  172 . As either the housing  110  or key  170  is rotated, the cam profile  150  will slide along the profile  180  as the expansion of the biasing member  190  causes the cam  140  to travel within the housing  110 . The key head  172  will be guided along the cam profile  150  such that the key head  172  is housed within the pocket  146  of the cam  140  when the tool  100  is in the locked configuration as shown in  FIGS. 4A-4D . The biasing force of the biasing member  190  and the weight of the string  24  may be sufficient to slide the cam  140  over the key head  172  which applies torque sufficient to rotate the key  170  into misalignment with the slot  120 . For example, as the housing  110  is rotated, the biasing force and weight may cause the key head  172  to rotate into misalignment with the slot  120 . In some embodiments, upon insertion of the key head  172  into the slot  120 , the biasing member  190  expands and the cam  140  slides over the key head  172  causing the key  170 , and the plunger rod  33 , to rotate into misalignment of the slot  120  without rotating the sucker rod string  24  at the surface. 
     The key  170  is locked within the housing  110  because it cannot be withdrawn from the slot  120  due to the engagement of the shoulder  175  and the seat  122 . The cam  140 , the key head  172 , and the biasing member  190  interact to maintain the misalignment of the key  170  with the slot  120  until an unlocking operation is performed. 
       FIGS. 8A-8C  illustrate an unlocking operation. As shown in  FIG. 8A , the tool  100  is in the locked configuration. To unlock the tool  100 , the key head  172  needs to be aligned with the slot  120 . The pump  30  may be set on the bottom of the stroke prior to the beginning of the unlocking operation. Either the housing  110  or the key  170  is rotated relative to the other to unlock the tool  100 . To rotate the housing  110  or key  170 , the sucker rod string  24  may be rotated in the release direction. The sucker rod string  24  may be slowly picked up as it is rotated. In some embodiments, the housing  110  may be rotated 90 degrees counterclockwise relative to the key  170  to align the key head  172  with the slot  120 . A torque is applied to overcome the locking force of the biasing member  190  and the lock profile  151 . As the housing  110  rotates, the cam profile  150  slides along the profile  180  of the key head  172  which causes the cam  140  to move longitudinally and compresses the biasing member  190 . The rotation of the housing  110  is limited by the engagement of the clutch profile  152  with the first profile portion  182 . The abutment of the clutch profile  152  with the first profile portion  182  prevents further travel of the profile  180  along the cam profile  150 .  FIG. 8B  illustrates the tool  100  in the unlocked configuration, with the profile  180  engaged with the clutch profile  152 . The abutment of the clutch shoulder  153  with the first profile portion  182  transfers torque applied to the housing  110  to the key head  172 . Thus, the abutment of the clutch shoulder  153  with the profile prevents the key  170  from over-rotating in the housing  110  and aligns the key head  172  with the slot  120  allowing for ease of tool  100  disconnection. 
     Once the tool  100  is unlocked, the tool  100  may be disconnected as shown in  FIG. 8C . For example, the sucker rod string  24  may be raised to lift the housing  110  off the key  170 . The housing  110  may be raised to the surface. 
     In some embodiments, the key  170  is connected to the sucker rod string  24  while the housing  110  is connected to the pump plunger  33 . In some embodiments, the key  170  may be rotated by the sucker rod string  24  relative to the housing  110  to unlock or lock the tool  100 . 
     In some embodiments, the on-off tool  100  may be used to connect and disconnect with a downhole tool that is not a pump. 
     In one embodiment, an operating tool includes a housing including a key slot. The operating tool further includes at least one biasing member disposed in the housing. The operating tool further includes a key including a key head having a key profile, wherein the key head is remove from the slot when aligned with the key slot. The operating tool further includes a cam including a cam profile, wherein the cam is disposed in the housing and biased toward the slot by the at least one biasing member, wherein the cam profile is configured to engage the key profile to align the key head with the key slot. 
     In some embodiments of the operating tool, the cam profile includes a clutch shoulder, wherein the clutch shoulder is configured to engage the key profile to align the key head with the key slot. 
     In some embodiments of the operating tool, the cam profile includes a lock profile. 
     In some embodiments of the operating tool, the lock profile has two or more pitches. 
     In some embodiments of the operating tool, the key profile includes a first profile portion and a second profile portion, wherein the clutch shoulder is configured to engage the first profile portion to align the key head with the key slot. 
     In some embodiments of the operating tool, the at least one biasing member is a plurality of disk springs. 
     In some embodiments of the operating tool, the housing includes a uniform shoulder configured to engage a uniform shoulder of the key. 
     In some embodiments of the operating tool, the cam includes a first fork and a second fork, wherein the cam profile is a first cam profile of the first fork, wherein the second fork includes a second cam profile. 
     In some embodiments of the operating tool, the operating tool further comprising at least one guide pin disposed in a corresponding slot of the cam. 
     In one embodiment, an operating tool includes a housing including a slot and a seat. The operating tool further includes at least one biasing member disposed in the housing. The operating tool further includes a key including a key head and a shoulder. The operating tool further includes a cam including a pocket, a first clutch profile, and a second clutch profile, wherein the cam is disposed in the housing and biased toward the slot by the at least one biasing member. When operating tool is in a locked configuration, the key head is misaligned with the slot and the key head is disposed in the pocket of the cam, wherein the shoulder is configured to engage the seat when the key head is misaligned with the slot. When the operating tool is in an unlocked configuration, the first clutch profile and the second clutch profile are engaged with the key head and the key head is aligned with the slot. 
     In some embodiments of the operating tool, the first clutch profile includes a first clutch shoulder and the second clutch profile includes a second clutch shoulder, wherein the first clutch shoulder and the second clutch shoulder are engaged with the key head in the unlocked configuration of the operating tool. 
     In some embodiments of the operating tool, the cam includes a first lock profile and a second lock profile. 
     In some embodiments of the operating tool, the first lock profile and the second lock profile have two or more pitches. 
     In some embodiments of the operating tool, the at least one biasing member is a plurality of disk springs. 
     In some embodiments of the operating tool, the housing includes a uniform shoulder configured to engage a uniform shoulder of the key. 
     In some embodiments of the operating tool, the operating tool further comprising at least one guide pin disposed in a corresponding slot of the cam. 
     In some embodiments of the operating tool, the housing is connectable to a sucker rod string and the key is connectable to a pump. 
     In one embodiment, a method of using an operating tool, comprising disconnecting the operating tool. Disconnecting the operating tool includes unlocking the operating tool by rotating a housing of the operating tool relative to a key of the operating tool, wherein the rotation of the housing relative to the key is limited by the engagement of a clutch profile of a cam disposed within the housing with a key head of the key, wherein the key head is aligned with a slot of the housing when the clutch profile is engaged with the key head. Disconnecting the operating tool further includes moving the housing relative to the key to withdraw the key head from the slot. 
     In some embodiments, the method of using the operating tool further includes connecting the operating tool after disconnecting the operating tool. Connecting of the operating tool includes inserting the key head into the slot, wherein the key head engages the clutch profile and the cam moves longitudinally relative to the housing away from the slot against the biasing force of at least one biasing member. Connecting the operating tool further includes rotating the housing to lock the key to the housing, wherein the biasing member causes the cam to travel longitudinally toward the slot as the housing is rotated until the key head is disposed in a pocket of the cam and misaligned with the slot, wherein a shoulder of the key head is engageable with a seat of the housing when the key is locked to the housing. 
     In some embodiments of the method of using the operating tool, the cam profile includes a clutch shoulder, wherein the rotation of the housing relative to the key is limited by the engagement the clutch shoulder with the key head. 
     While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.