Abstract:
An electronics package of substantially monolithic configuration. The package is particularly adept at enhancing heat dissipation and avoiding secondary shock when placed in harsh application environments. Thus, the package may be particularly well suited for use in conjunction with high shock producing downhole application environments such as bridge plug setting.

Description:
FIELD 
     Embodiments described relate to electronics packaging. In particular, packaging that is to be exposed to significant amounts of heat and shock. More specifically, packaging that is employed in a high temperature downhole environment and subject to several hundred g&#39;s of shock is detailed herein. 
     BACKGROUND 
     Exploring, drilling and completing hydrocarbon and other wells are generally complicated, time consuming, and ultimately very expensive endeavors. As a result, over the years, a significant amount of added emphasis has been placed on overall well architecture, monitoring and follow on interventional maintenance. Indeed, perhaps even more emphasis has been directed at minimizing costs associated with applications in furtherance of well formation, monitoring and maintenance. All in all, careful attention to the cost effective and reliable execution of such applications may help maximize production and extend well life. Thus, a substantial return on the investment in the completed well may be better ensured. 
     Depending on the nature and architecture of the well, interventional maintenance may be a routine part of operations. For example, proper well management may require the periodic clean-out of debris or scale from certain downhole locations. This may require isolating the location at issue and halting production during the clean out. Indeed, such isolating may be required in the natural course of completions, for example, to allow for perforating and/or stimulating applications to proceed. That is, in certain instances, high pressure perforating and stimulating of well regions may be called for. In this case, the active perforating or stimulating intervention may be preceded by the added intervention of closing off and isolating the well regions with mechanisms capable of accommodating such high pressure applications. 
     Closing off of a well region for a subsequent high pressure application may be achieved by way of setting a mechanical plug. That is, a plug may be positioned at a downhole location and ‘set’ to seal off a downhole region adjacent thereto. The plug is configured to accommodate the high pressures associated with perforating or stimulating as noted. Thus, it is generally radially expandable in nature through the application of substantial compressible force. In this manner, slips of the radially expandable plug may be driven into engagement with a casing wall of the well so as to ensure its sufficient anchoring. By the same token, the radial responsiveness of elastomeric portions of the plug may help ensure adequate sealing for the high pressure application to be undertaken. 
     Unfortunately, the noted compression and overall setting application is generally achieved by way of an explosively powered setting tool that is coupled to the plug. Even setting aside the transport hazards and limited reliability associated with such explosively driven applications, the operator is unable to direct a controlled, monitored, or intelligent setting application when such is explosively driven. Thus, the setting application generally proceeds in an unintelligent manner without readily available data to ensure its effectiveness. 
     Alternatively, in the case of perforating or stimulating applications, electronics may be used to trigger the application. However, such electronics are relatively unsophisticated and limited to initiating a trigger, for example, for perforating. Thus, the cost of replacement due to heat or shock damage encountered in carrying out the application may be relatively low. To the contrary, substituting explosives with electronics for a setting application involves directing a motor drive unit over the period of the application (e.g. as opposed to merely initiating a perforating trigger). As such, the electronics involved may utilize digital signal processing and other sophisticated capacity, thereby driving up replacement cost where heat and/or shock damage are experienced over the course of the application. 
     Unfortunately, techniques for mitigating heat and shock damage to sophisticated electronics packaging generally run contrary to one another. In the particular circumstance of plug setting, the setting tool, packaging, and plug may be exposed to about 200 g&#39;s or more, not to mention temperatures in excess of 150° C. So, for example, if heat dissipation is addressed through a conventional technique including a heat sink in conjunction with spring compression directed at the electronics, secondary shocks in excess of 200 g&#39;s are likely imparted on the electronics. In other words, the heat dissipation technique may have amplified shock directed at the electronics. 
     Alternatively, where electronics are tightly accommodated through a conventional o-ring or centralizer mounting technique to enhance shock tolerance, thermal contact between the electronics and heat sink, or other thermal dissipating structure, is compromised. Ultimately, due to such counterintuitive options available for dealing with heat and shock, explosively driven setting is generally utilized in lieu of superior, but costly electronics that would allow for a controlled, monitored, and/or intelligent setting application. 
     SUMMARY 
     An electronics package is provided with a housing having a channel therethrough. The channel is configured to accommodate first and second electronics chassis adjacent one another. Each chassis includes an inclined surface for interfacing one another. An activation force mechanism is also disposed in the channel adjacent one of the chassis. The mechanism may be configured for axially directing this chassis toward the other such that radial expansion of the chassis toward the housing takes place via interfacing of the inclined surfaces. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially sectional view of an embodiment of a shock tolerant heat dissipating electronics package incorporated into a bridge plug setting tool. 
         FIG. 2  is an exploded view of adjacent chassis of the electronics package of  FIG. 1 . 
         FIG. 3A  is a side cross sectional view of the electronics package of  FIG. 1  with the adjacent chassis of  FIG. 2  in an unexpanded pre-set position. 
         FIG. 3B  is a side cross sectional view of the package of  FIG. 3A  with the chassis in a radially expanded set position. 
         FIG. 4  is an overview of an oilfield with a well accommodating a bridge plug and setting tool employing the electronics package of  FIGS. 1, 2, 3A and 3B . 
         FIG. 5A  is an enlarged side view of the bridge plug and setting tool of  FIG. 4  positioned at a targeted isolation location in the well. 
         FIG. 5B  is an enlarged side view of the bridge plug of  FIG. 5A  upon setting thereof at the targeted isolation location. 
         FIG. 6A  is a schematic view of an alternate embodiment of a shock tolerant heat dissipating electronics package with chassis in an unexpanded pre-set position. 
         FIG. 6B  is a cross-sectional view taken from  6 - 6  of  FIG. 6A  with the chassis in a radially expanded set position. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments herein are described with reference to certain shock tolerant heat dissipating electronics packaging types. For example, these embodiments focus on sophisticated electronics packages utilized in conjunction with setting a downhole bridge plug or other type of well isolation mechanism. However, a variety of applications utilized at, or outside of, the oilfield environment may take advantage of the unique combination of shock and heat dissipating features of electronics packaging as detailed herein. Indeed, such packaging may be beneficial wherever electronics are subject to both extreme temperature and shock environments. Regardless, embodiments of the electronics packaging detailed herein include multiple chassis with interfacing inclined surfaces, such that application of an activation force leads to a radial expansion of the chassis toward a housing thereabout. As a result, a near monolithic structure is formed that is substantially enhanced in terms of heat and shock resistance. 
     Referring now to  FIG. 1 , a partially sectional view of a shock tolerant heat dissipating electronics package  100  is shown. The package  100  is incorporated into a downhole tool, such as a bridge plug setting tool  101  for placement of a bridge plug  400  at a target location in a well  480  (see  FIG. 4 ). However, embodiments of the package  100  may be advantageously utilized in conjunction with a host of wellbore applications including other high temperature and/or high shock exposure applications. Such applications may include setting of well isolation mechanisms other than bridge plugs, such as mechanical packers. Further, as indicated above, applications outside of the oilfield environment may also take advantage of such electronics packaging embodiments. 
     In the embodiment of  FIG. 1 , the package  100  is depicted with a housing  175  defining a channel  130  for accommodating electronic chassis  160 ,  165 . In  FIG. 1 , these chassis  160 ,  165  are depicted in a roughly schematic form, each having inclined surfaces  262 ,  267  oriented toward the interior of the housing  175 . Indeed, each chassis  160 ,  165  takes on an appearance similar to a wedge type door stop. As detailed herein below, the resulting wedging, as axial force is applied to either of the chassis  160 ,  165 , allows for a radial expansion of the chassis  160 ,  165  relative one another. Thus, from one side of the housing  175 , across its radius (r), from chassis  160  to chassis  165 , and to the other side of the housing  175 , the package  100  takes on the character of a near monolithic structure. Thus, internal movement is virtually eliminated and thermal contact maximized. As a result, heat dissipation and shock tolerance of the chassis  160 ,  165  are enhanced as also described further below. 
     Continuing with reference to  FIG. 1 , the bridge plug setting tool  101  is also equipped with a power housing  185  as well as sensor  190  and valve  195  housings. These features of the tool  101  may be important in allowing a controlled deployment and setting of the bridge plug  400  as shown in  FIG. 4 . The power housing  185  in particular, may accommodate an axial piston pump driven by a sophisticated motor. In one embodiment, a brushless DC motor is utilized. As such, the motor drive electronics accommodated at the chassis  160 ,  165 , may include a digital signal processor and other fairly sophisticated components for driving a controlled setting application. 
     The bridge plug setting tool  101  is equipped with a housing sleeve  110  which may be hydraulically driven by the above noted pump via an extension  115 . Thus, as detailed below with added reference to  FIG. 4 , a bridge plug  400  coupled to the sleeve  110  may be compressed and radially set at a location in a well  480  for isolation thereat. Further, the tool  101  is shown with its head  150  coupled to a line  140  for deployment into the well  480 . In one embodiment, this line  140  may be a conventional wireline cable to allow for powering of the setting application as well as for real-time telemetry over electronics of the line  140 . Thus, parameters of the setting application may be changed in real-time based on data obtained during the setting application (e.g. from the sensor  190 ). That is to say, electronics of the package  100  may be utilized to alter the setting application in process. 
     In an embodiment, the line  140  may be a slickline or other non-powered line. In such an embodiment, powering of the application may be achieved by way of a suitably sized downhole power source (e.g. a lithium-based battery) coupled to the tool  101 . Nevertheless, downhole conditions and other data relating to the application may be recorded and stored by electronics of the package  100 . Thus, subsequent analysis at surface may be available to help determine effectiveness and other details of the application. 
     Referring now to  FIG. 2 , an exploded view of the adjacent chassis  160 ,  165  of the electronics package  100  of  FIG. 1  is shown. In this view, a less schematic, and more realistic depiction of the chassis  160 ,  165  is provided. Nevertheless, the inclined surfaces  262 ,  267  of each are apparent. More specifically, each chassis  160 ,  165  includes a platform  260 ,  265  defined by the respective surfaces  262 ,  267  for interfacing one another. In fact, in the embodiment shown, the inclined surfaces  262 ,  267  are staggered and repeating, taking the appearance of inclined stair steps. Indeed, while each platform  260 ,  265  is shown with two such staggered and repeating surfaces  262 ,  267 , any practical number, say 1-5 or more, may be employed. The number of such inclines may be selected based on factors such as, but not limited to, the overall length of the package  100  of  FIG. 1  and the angles utilized for the surfaces  262 ,  267 . 
     Continuing with reference to  FIG. 2 , each platform  260 ,  265  serves as a structural substrate to which an electronics board  275  may be secured. In the embodiment shown, the board  275  may be a conventional printed circuit board with electronics  280  electronically and physically secured thereto. Further, the board  275  may be mounted in place through the aid of a cover plate  250 . Thus, sophisticated electronics are provided at each chassis  160 ,  165  in much the same manner as other conventional electronics packaging. However, as detailed below, the shape, manner of interfacing, and overall configuration of the chassis  160 ,  165  enhance shock tolerance and heat dissipation in a unique manner for electronics packaging. 
     Referring now to  FIGS. 3A and 3B , side cross sectional views of the electronics package  100  of  FIG. 1  are shown. More specifically,  FIG. 3A  reveals the adjacent chassis  160 ,  165  of  FIG. 2  in an unexpanded pre-set position whereas  FIG. 3B  reveals the chassis  160 ,  165  in a radially expanded set position. That is to say, in  FIG. 3A , the chassis  160 ,  165  are disposed in the housing  175  with a degree of movement or play (note the available space  300  present between one of the chassis  165  and the housing  175 ). However, in  FIG. 3B , an axial force has been applied to at least one of the chassis  160 ,  165  such that sliding along the interface  360  is induced. Thus, the available space  300  is eliminated and a substantially monolithic structure of housing  175  and chassis  160 ,  165  is formed. 
     In the particular embodiment of  FIGS. 3A and 3B , axial force is imparted on the chassis  160 ,  165  through the combination of a screw  350  at one end and a structural stop  375  at the other. More specifically, a screw  350 , may be threadably disposed in the housing  175  adjacent one of the chassis  165  for exerting an axial force thereon (downwardly in the depictions of  FIGS. 3A and 3B ). By the same token, a stop  375 , structurally integral with the housing  175  may be located immediately adjacent the other chassis  160 , opposite the screw  350 . Indeed, this chassis  160  may even be immobilized by securing to the stop  375  or other structural portion of the housing  175 . 
     As the screw  350  is turned to threadably apply axial downward force on the adjacent chassis  165 , this chassis  165  slides along the interface  360 . In one embodiment, skids, perhaps of beryllium copper, are provided to each chassis  160 ,  165  for interfacing and stably aiding such sliding. Once more, an end of the sliding chassis  165  may enter a stop space  301  adjacent the stop  375 . More importantly, however, this movement eliminates the available space  300  adjacent the chassis  165  as noted above. Thus, the entire interior radius (r) of the housing  175  is occupied by chassis structure, forming a substantially monolithic package  100 . As such, the possibility of secondary shock induction is largely eliminated, while at the same time near complete thermal contact between the chassis  160 ,  165  and housing  175 . 
     In the embodiment shown, the angle of interface  360 , via surfaces  262 ,  267  (see  FIG. 2 ), exceeds about 45°. As such, the amount of radial force by the chassis  160 ,  165  toward the interior wall of the housing  175 , exponentially exceeds the amount of axial force applied by the screw  350 . For example, no more than about 2,000 lbs. of axial force may translate to more than about 15,000 lbs. of radial force in such an embodiment. Thus, the chassis  160 ,  165  are now firmly immobilized by the indicated tightening of the screw  350 . 
     In the embodiment of  FIGS. 3A and 3B , the axial force of the screw  350  is translated through a spring  325  and screw sleeve  380  in reaching the noted chassis  165 . In this manner, the spring  325  may allow for dimensional changes in the housing and/or chassis  160 ,  165 . So, for example, where exposure to extreme temperatures is prone to induce such dimensional changes, the axial force imparted through the screw  350  may remain substantially unaffected. Indeed, in one embodiment where temperatures well in excess of 100° C. are to be encountered, the platforms  260 ,  265  of the chassis  160 ,  165  may be aluminum-based whereas the housing  175  is of a stainless steel composition. Thus, the presence of the intervening spring  325  may help to ensure a more consistent axial force, in spite of likely slight dimensional changes in the chassis  160 ,  165 . Of course in other embodiments, an intervening spring  325  may not be utilized. Indeed, an axial force inducing mechanisms other than a screw  350  may also be employed. 
     Referring now to  FIG. 4 , an overview of an oilfield  401  is depicted accommodating a well  480 . The well  480  in turn accommodates a bridge plug  400  and the setting tool  101  detailed above, with the electronics package  100  of  FIGS. 1, 2, 3A and 3B . 
     The well  480  traverses various formation layers  490 ,  495  and may expose the electronics package  100  to a variety of extreme pressures and temperatures as alluded to above. The well  480  is also defined by a casing  485  that is configured for sealing and anchored engagement with the plug  400  upon a high shock inducing setting application as also described above (and further below). In the embodiment shown, the plug  400  is equipped with upper  440  and lower  460  slips to achieve anchored engagement with the casing  485  upon the setting. Similarly, a generally elastomeric, sealing element  475  is disposed between the slips  440 ,  460  to provide sealing of the plug  400  relative the casing  485  by way of the setting application. 
     The assembly of the setting tool  101  and plug  400  also includes a platform  420  at its downhole end. This platform  420  is coupled internally to the extension  115  of the tool  101  (see  FIG. 1 ). Thus, the plug  400  is compressed between this platform  420  and the housing sleeve  110 , as this sleeve  110  is forced against a plug sleeve  410  of the plug  400 . In this way, the setting application ultimately radially expands plug components into place once the plug  400  is positioned in a targeted location. 
     In the embodiment shown, the targeted location for placement and setting of the plug  400  is immediately uphole of a production region  497  with defined perforations  498 . So, for example, the plug  400  may be utilized to isolate the region  497  for subsequent high pressure perforating or stimulating applications in other regions of the well  480 . 
     Continuing with reference to  FIG. 4 , the wireline delivery of the assembly means that even though a relatively high powered setting application is undertaken, it may be done so with relatively small mobile surface equipment  425 . Indeed, the entire assembly traverses the well head  550  and is tethered to a spool  427  of a wireline truck  426  without any other substantial deployment equipment requirements. In the embodiment shown, a control unit  429  for directing the deployment and setting is also shown. The control unit  429  may ultimately be electrically coupled to the electronics packaging  100  so as to monitor and intelligently control the setting of the plug  400 . That is to say, the unit  429  may initiate setting and also modify the application in real time, depending on monitored pressure and other application data as described above. 
     Referring now to  FIGS. 5A and 5B , enlarged side views of the bridge plug  400  and lower portion of the setting tool  101  of  FIG. 4  are depicted positioned at the noted targeted location in the well  480  for isolation. More specifically,  FIG. 5A  depicts the initiation of the setting application as the plug  400  is compressed between the housing sleeve  110  and the platform  420 .  FIG. 5A  depicts the plug  400  following setting with the housing sleeve  110  removed and the slips  440 ,  460  and seal  475  in a complete radially expanded state. 
     Continuing with reference to  FIGS. 5A and 5B  mechanics of the noted compression and setting are described. In the embodiment shown, the platform  420  is ultimately physically coupled to the extension  115  by way of a central mandrel  575 , plug head  550 , and tool coupling  525 . Yet, at the same time, the platform  420  serves as a backstop to downward movement of non-central plug components such as the slips  440 ,  460 , seal  475 , sleeve  410 , etc. Thus, the depicted movement  501  of the housing sleeve  110  tends to compress plug components therebetween until the plug  400  is set against the casing  485 . 
     With specific reference to  FIG. 5A , the plug  400  is compressed upon initial setting of lower slip rings  460  by the downward movement  501  of the housing sleeve  110 . That is, as the force of the downward movement  501  is translated through the plug sleeve  410  and other plug components, the radially expandable component closest the platform  420  begins its expansion. Thus, in  FIG. 5A , teeth of the lower slips  460  are shown engaging and biting into the casing  485  defining the well  480 . As a result, anchoring of the plug  400  has begun. At the same time, however, the seal  475  and upper slips  440  have yet to be substantially compressed. Therefore, interfacing spaces  501 ,  502  remain between these components and the casing  485 . 
     Referring to  FIG. 5B , however, as the housing sleeve  110  continues to move in the downward direction, the indicated spaces  501 ,  502  disappear. This disappearance takes place as the seal  475  engages the casing  485  and the upper slips  440  radially expand and bitingly set into the casing  485 . Thus, the anchoring of the plug  400  and the sealing isolation of the well  480  takes hold. It is worth noting that in compressing the plug  400  in this manner, its general location within the well  480  is unaffected. That is to say, the downward movement  501  of the sleeve  110  acts against the platform  420  to achieve the noted compression as opposed to having any significant affect on the plug  400  depth in the well  480 . 
     Ultimately, as the sequential setting of plug components is completed a fully anchored plug  400  and sealingly isolated well  480  are provided at the targeted location. The application is completed with the breaking of a tension stud within the plug mandrel  575 . This may induce a large shock of over about 200 g&#39;s and lead to a release of the housing sleeve  110  of  FIG. 5A . Indeed, as depicted in  FIG. 5B , the setting tool  101  of  FIG. 1  is completely withdrawn from the well  480  with a pull out of the engaged housing  110  and plug  410  sleeves along with the engaged extension  115  and tool coupling  525 . However, in other embodiments, the particular interfacing components of the tool  101  and plug  400  which are left or withdrawn may vary. Further, a follow-on pressure-based application such as bore stimulation may subsequently proceed. 
     Regardless, a setting of a plug  400  has now been fully completed in a manner driven by relatively sophisticated electronics without undue concern over shock damage to the electronics packaging  100 . In fact, due to the substantially monolithic nature of this packaging  100 , exposure to secondary shock is virtually eliminated (see  FIG. 1 ). 
     Referring now to  FIGS. 6A and 6B , schematic views of an alternate embodiment of a shock tolerant heat dissipating electronics package  100  are shown. In such an embodiment, more than two chassis  600 ,  660 ,  665  are utilized for wedgingly interfacing to eventually form a shock and heat resistant near-monolithic electronics packaging structure. More specifically,  FIG. 6A  shows the package  100  with three chassis  600 ,  660 ,  665  in an unexpanded pre-set position relative to one another.  FIG. 6B  on the other hand is a cross-sectional view taken of these chassis  600 ,  660 ,  665  in a radially expanded set position (taken from  6 - 6  of  FIG. 6A ). 
     In the unexpanded pre-set position of  FIG. 6A , the chassis  600 ,  660 ,  665  are shown with some degree of play. For example, note the unoccupied free space  602  between one of the chassis  665  and the housing  175 . Nevertheless, a force inducing mechanism  680  (such as a screw or the like) may be driven in a direction  625  through the channel  130  of the housing  175  so as to wedgingly interface a chassis  600  into engagement with the others  660 ,  665 . As shown in  FIG. 6A , structural stops  675 ,  677  are provided to prevent movement of these other chassis  660 ,  665  in the direction  625  in response to the force inducing mechanism  680 . Indeed, in the embodiment shown, the driven chassis  600  may even extend to a degree into a space  601  beyond the other chassis  660 ,  665  and stops  675 ,  677  if need be. 
     Ultimately, the free space  602  is eliminated and the near-monolithic packaging structure of  FIG. 6B  is achieved in a manner similar to that detailed hereinabove with respect to  FIGS. 3A and 3B . The embodiment of  FIGS. 3A and 3B  focus on the utilization of two chassis  160 ,  165  and three  600 ,  660 ,  665  are shown in  FIGS. 6A and 6B . However, any practical number of two or more chassis may be employed so long as wedgingly interfacing surfaces between the chassis are accommodated by the design. Indeed, an embodiment utilizing four interlocking chassis may be utilized. Further, as the number of chassis utilized is increased, the chassis may be configured such that one set of finger-like chassis extending from a common base is directed for interlocking engagement with another set of finger-like chassis from another common base. So long as angled interfacing is provided for, a force inducing mechanism may be utilized to axially drive the chassis sets toward one another until a near-monolithic packaging structure is attained, thereby substantially enhancing temperature and shock resistance. 
     Embodiments described hereinabove utilize techniques for mitigating both heat and shock damage to sophisticated electronics packaging. Thus, such comparatively higher cost packaging may be reliably utilized even upon repeated exposure to shock in excess of 200 g&#39;s and temperatures in excess of 100° C. in downhole operations. Such packaging is configured in a manner that avoids significant secondary shock through compression springs disposed in the load path while also avoiding o-ring or centralizer mounting techniques that tend to adversely affect heat dissipation. 
     The preceding description has been presented with reference to presently preferred embodiments. Persons skilled in the art and technology to which these embodiments pertain will appreciate that alterations and changes in the described structures and methods of operation may be practiced without meaningfully departing from the principle, and scope of these embodiments. Furthermore, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.