Abstract:
A tubular closure assembly responsive to speed or velocity of an object. The tubular closure assembly includes at least one sensor in operable communication with an interior of a tubular. The at least one sensor sensing an object passing a first point and then a second point within the tubular. A processor receiving an output from the at least one sensor and calculating speed of the object from the first point to the second point. A control panel receiving information from the processor and a closure system movable between an open condition and a closed condition. Activatable to the closed condition by the control panel in response to the object moving from the first point to the second point at speed faster than a preset value or at a velocity outside a preset range. Also included is a method of closing a tubular of a borehole.

Description:
BACKGROUND 
       [0001]    In the drilling and completion industry, the formation of boreholes for the purpose of production or injection of fluid is common The boreholes are used for exploration or extraction of natural resources such as hydrocarbons, oil, gas, water, and CO2 sequestration. A riser pipe may be fitted at the top of the borehole as a guide for a drill stem or as a conductor for drilling fluid. As tools are taken out through the riser pipe or introduced into the borehole through the riser pipe, some oil field operators have experienced a loss of tools and other equipment downhole when the tools and equipment are accidentally dropped, resulting in a loss of time trying to retrieve such dropped objects. Additionally, considerable expense may be suffered if the dropped object cannot be retrieved. It has been previously proposed to extrapolate a speed of a cable dropped into a well by monitoring rotation of wheels that pass the cable into the well or by monitoring the cable tension, however this approach requires direct contact with the cable and is limited to spooled devices. 
         [0002]    Another extremely undesirable experience that needs to be prevented in the drilling and completion industry is a blowout. A blowout preventer (“BOP”) is a safety valve installed in a well which may be manipulated between open and closed positions by variation of hydraulic pressure contained within a line extending from the safety valve to a control panel at a surface of the well. BOPs come in various configurations, including rams and annular preventers, and are often used in stacks. The BOP can be triggered by an electrical control signal via a cable extending from the rig, a “deadman” switch designed to automatically trigger the BOP if connection between the rig and the BOP is severed, and an acoustic control signal sent to the BOP from a surface location. In any case, the BOP is triggered when well fluids are required to be confined to the borehole. It has been previously proposed to employ slip rams of a blowout preventer to assist in the prevention of lost tubulars and tools downhole during their removal process, however this approach requires contact with the tubular or tool, is not based on the speed of the tubulars, and is limited to use during removal as it does not allow introduction into the well. 
         [0003]    Accordingly, improvements for previous methodologies and configurations would be well received by the art. 
       BRIEF DESCRIPTION 
       [0004]    A tubular closure assembly responsive to speed or velocity of an object, the tubular closure assembly includes at least one sensor in operable communication with an interior of a tubular, the at least one sensor sensing an object passing a first point and then a second point within the tubular; a processor receiving an output from the at least one sensor and calculating speed of the object from the first point to the second point; a control panel receiving information from the processor; and, a closure system movable between an open condition and a closed condition, and activatable to the closed condition by the control panel in response to the object moving from the first point to the second point at speed faster than a preset value or at a velocity outside a preset range. 
         [0005]    A method of closing a tubular of a borehole, the method includes sensing an object location at a first point in the tubular; sensing the object location at a second point in the tubular; calculating a speed of the object from the first point to the second point; and activating a closure system from an open condition to a closed condition if the speed exceeds a selected value or if a velocity of the object is outside a selected range. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
           [0007]      FIG. 1  depicts a schematic and cross sectional view of an exemplary embodiment of a speed activated closure assembly; 
           [0008]      FIG. 2  depicts a schematic and cross sectional view of another exemplary embodiment of a speed activated closure assembly; 
           [0009]      FIG. 3  depicts a schematic and cross sectional view of yet another exemplary embodiment of a speed activated closure assembly; 
           [0010]      FIG. 4  depicts a top plan view of an exemplary embodiment of a pair of blind ram blocks for a closure system; 
           [0011]      FIG. 5  depicts a side cross-sectional view of an exemplary embodiment of a single blind ram block for a closure system; 
           [0012]      FIG. 6  depicts a top plan view of an exemplary embodiment of a pair of gripper blocks for a closure system; 
           [0013]      FIG. 7  depicts a side cross-sectional view of an exemplary embodiment of an elastomeric packing member for a closure system; 
           [0014]      FIG. 8  depicts a side cross-sectional view of an inflatable annular reverse annular bag for a closure system; and, 
           [0015]      FIG. 9  depicts a side cross-sectional view of a flapper valve for a closure system. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
         [0017]    As shown in  FIG. 1 , in one exemplary embodiment, a speed activated closure assembly  10  includes a tubular  12 . Although the closure assembly  10  may be incorporated with any tubular along the length of a borehole, the closure assembly  10  is most advantageously incorporated within a riser, at an uphole end of the borehole. Incorporation within a riser prevents a dropped object, such as object  14 , from traveling downhole further into the borehole, simplifying the retrieval of the dropped object  14 . However, the closure assembly  10  is also installable further downhole the borehole, i.e. downhole of a riser, to prevent an object  14 , such as a well tool that is in use, from falling further downhole into a casing, sleeve, or other tubular. A plurality of the closure assemblies  10  may be provided at various locations along a string as required. The portion of the tubular  12  depicted in  FIG. 1  includes an uphole end  16  and a downhole end  18 , although it should be understood that the tubular  12  may extend further uphole than shown and further downhole than shown. The tubular  12  includes a tubular wall  20 , which in most cases has a substantially circular cross-section, although not limited thereto. The tubular wall  20  surrounds a passageway  22  for the object  14  to pass, as well as for passing drilling fluid or wellbore fluid. The passageway  22 , under normal operational circumstances, remains substantially obstruction-free. 
         [0018]    The closure assembly  10  further includes a closure system  24  that is triggerable to shut the passageway  22  of the tubular  12  when an object  14  moves downhole at a certain speed that exceeds, or is otherwise outside of a range, of a programmed limit. Thus, the prevention of dropped objects during coiled tubing, EWL, completions and drilling operations within risers and blow out preventers (“BOPs”) is provided by the closure assembly  10 . In ordinary use, the closure system  24  will remain in an open or non-obstructing condition so that tools or other objects  14  can pass freely in and out of the tubular  12 , as well as fluids. 
         [0019]    In order to detect the speed of a passing object  14 , two sensor devices  26 ,  28  are provided on the tubular  12  at a location prior to the object  14  passing the closure system  24 . By “on” the tubular  12 , it should be understood that the sensor devices  26 ,  28  may be located on a manifold on the tubular  12  or otherwise connected to the tubular  12 . Depending on the type of sensors employed in the sensor devices  26 ,  28 , the sensor devices  26 ,  28  may be positioned on an interior surface  30  of the tubular wall  20 , on an exterior surface  32  of the tubular wall  20 , or within the tubular wall  20  itself, such as in a pocket or opening in the tubular wall  20  to protect the sensor devices  26 ,  28  from accidental dislodgement. The sensor devices  26 ,  28  are provided uphole of the closure system  24 , closer to the uphole end  16  of the tubular  12  than the downhole end  18  of the tubular  12 . The sensor devices  26 ,  28 , positioned at points A and B along the tubular  12  respectively, are spaced a longitudinal distance “AB” apart from each other. The first sensor device  26  is located further uphole than the second sensor device  28 , so that the object  14  is first detected by the first sensor device  26  as the object  14  passes the first point A and then after a period of time by the second sensor device  28  as the object  14  passes the second point B, where the period of time depends on the distance AB and the speed of the object  14 . The type of sensor devices  26 ,  28  employed on the tubular  12  cooperates with the objects  14  that are passing within the tubular  12  that are run into and out of the wellbore. 
         [0020]    Objects  14  running into and out of the tubular  12  include, but are not limited to, tubing-conveyed perforating (“TCP”) guns, coiled tubing, EWL, and other tools associated with completions and drilling operations. In an exemplary embodiment, the objects  14  incorporate a sub  34  that contains an emitter  36 . The emitter  36  may include radio frequency identification (“RFID”), or may emit detectable signals such as radioactive (“RA”), magnetic, acoustic, light or optics, etc. The sensor devices  26 ,  28  employed in the closure assembly  10  would thus respectively detect the RFID tag, RA signal, metal or magnetic field, sound waves, light or optical waves, etc. that are emitted from the emitter  36 . RFID tags are easily employed as they can be applied to nearly any object  14 . In an RFID embodiment, the sensor devices  26 ,  28  are positioned on the interior surface  30  of the tubular  12  or within the tubular wall  20  as long as the sensor devices  26 ,  28  are within full range of the radio waves from the RFID, since radio waves emitted by the RFID will not be able to escape through the tubular  12 , assuming it is metal, because a metal tubular is a radio wave inhibiting structure. The emitter  36  may be capable of broadcasting a signal such as an acoustic signal, a magnetic field, a gamma wave signal, a recording (such as a voice), etc. The signal may be continuously broadcast, on a timer, may begin at a selected depth, may begin when contact is made with a certain chemical, when another field is encountered, upon receiving a certain start (or stop) signal, and could be configured to operate utilizing a combination of these or combinations including at least one of the foregoing. The emitter  36  utilizes a wireless signal to communicate with the sensor devices  26 ,  28 . If necessary, the sub  34  includes an on board power source to drive the emitter  36 . The source may be a battery or may be a pressure based energy source or electrochemically based energy source. 
         [0021]    Depending on the emitter  36 , the sensor devices  26 ,  28  may employ one of a magnet/electromagnet sensor to sense a metal moving past, a proximity sensor that detects the proximity of an object without physical contact, an induction sensor that detects metallic objects, a photo electric sensor that uses light sensitive elements to detect objects, and a capacitive sensor that detects metallic and non-metallic objects. The type of sensor devices  26 ,  28  chosen are those types capable of detecting the emitted medium from the emitter  36 . For example, the sensor devices  26 ,  28  are optical if the emitter  36  is light. 
         [0022]    In an alternative exemplary embodiment, the object does not include any particular emitting property, and the sensor devices  26 ,  28  sense the passing object by changes in light, acoustics, magnetic induction, etc. as the object passes. This is helpful when the dropped object is not tagged or otherwise outfitted with an emitter, such as a dropped wrench or the like. While two sensor devices  26 ,  28  have been described on the tubular  12 , in another alternative exemplary embodiment, a single sensor device includes a speed detector such as laser gun speed detector that can take many samples by shooting short bursts of infrared laser light that reflect off of the passing object  14  and compare the change in distance between samples to calculate the speed of the object. The speed detector is alternatively a radar gun speed detector, which transmits a microwave pulse, and the frequency of the transmitted pulse is compared to the frequency of the reflection, and the difference between the two frequencies is used to calculate the speed. A separate sensor may be used to trigger initiation of the speed detector within the sensor device. In such an embodiment, sensor device  26  may be an initiating sensor while sensor device  28  includes a speed detector. 
         [0023]    A programmable/preprogrammed microprocessor/controller, hereinafter referred to as a “computer”  38 , is connected to the sensor devices  26 ,  28  and programmed to allow the object  14  to move at a pre-established “allowed rate” through the passageway  22  of the tubular and past the closure system  24 , likely the typical running speed of the tools. Should the object  14  be dropped, the sensor devices  26 ,  28  will detect the emitted signal from emitter  36  or otherwise detect the passage of the object  14 , the computer  38  will calculate the time it takes the object  14  to pass from point A to point B over the distance AB, and compare that time to the allowed running rate. If the allowed rate is exceeded, the computer  38  triggers a control panel  40  connected to the closure system  24 . The computer  38  may also be responsive to the velocity (speed in a given direction) of the passing object  14  and may activate the closure system  24  by a change in velocity outside a preset range, or by a change in the direction of the passing object  14 . For example, if an object  14  is being removed from the tubular  12  in an uphole direction and then it is dropped, the velocity of the object  14 , which will indicate that the object  14  is now moving in the downhole direction, will trigger the closure system  24 . 
         [0024]    In an exemplary embodiment, the computer  38  is coupled to a manifold/control panel  40  for an accumulator “koomey” unit  42 . The accumulator  42  is plumbed to the closure system  24 . Manipulation of the closure system  24  from an open to a closed position may be accomplished by a variation of hydraulic pressure contained within a line  44  extending from the closure system  24  to the control panel  40 . When the control panel  40  sends a signal to activate the closure system  24 , a variation in hydraulic pressure is sent to the closure system  24 , which manipulates the closure system  24  to a closed position. The computer  38  may be programmed to delay a closing of the closure system  24  until after a workstring, such as a gravel pack assembly, is purposefully dropped from a rig floor. Also, the sensor devices  26 ,  28  may be arranged to sense certain objects but not others, such that some objects may be purposefully dropped and pass freely through the tubular  12 , while others trigger a sensor in the sensing devices  26 ,  28  which lead to a closing of the closure system  24 . 
         [0025]    Turning to  FIG. 2 , in another exemplary embodiment, a speed activated closure assembly  100  is similar to the speed activated closure assembly  10  shown in  FIG. 1  except that instead of sensor devices  26 ,  28  positioned uphole of the closure system  24 , sensor devices  102 ,  104  are positioned downhole of the closure system  24  to prevent objects from departing the tubular  12  at a speed in excess of a preset limit, thus preventing projectiles from being launched out of the tubular  12 . The tubular  12  includes an uphole end  16  and a downhole end  18 , and the object  14  moves from the downhole end  18  towards the uphole end  16 , such as by being pulled by a cable  106 . The object  14  may include an emitter  36  on a sub  34  for sensing by the sensor devices  102 ,  104 , or the sensor devices  102 ,  104  may include alternate sensors for otherwise detecting passage of the object  14  as previously described. The first sensor device  102  is positioned closer to the downhole end  18 , and the second sensor device  104  is positioned uphole of the first sensor device  102 , and between the first sensor device  102  and the closure system  24 . When the object  14  passes the first sensor device  102  and then the second sensor device  104 , the computer  38  processes the speed of the object  14  and notifies the control panel  40  to close the closure system  24  if the object  14  is moving through the tubular  12  at an unacceptable speed. 
         [0026]    Turning to  FIG. 3 , in yet another exemplary embodiment, a speed activated closure assembly  200  is similar to both the speed activated closure assembly  10  shown in  FIG. 1  and the speed activated closure assembly  100  shown in  FIG. 2 , except that the speed of the object  14  is detected both uphole and downhole of the closure system  24  using first and second sensor devices  26 ,  28  and third and fourth sensor devices  102 ,  104 , respectively. The closure assembly  200  is thus employable in catching a dropped object  14  as well as preventing an object  14  from being ejected from the tubular  12 . A second computer  202  is shown for computing the speed of the object  14  passing by the third and fourth sensor devices  102 ,  104 , however a single computer  38  may alternatively be used for the first and second sensor devices  26 ,  28  as well as for the third and fourth sensor devices  102 ,  104 . 
         [0027]    The closure system  24  may include a dedicated valve assembly that is similar in construction to that of a blowout preventer (“BOP”). While BOPs are normally used to seal or otherwise control oil or gas wells to prevent tubing, tools, and fluid from being blown out of a wellbore during a blowout, a BOP employed in the speed activated closure assembly  10 ,  100 , or  200  is triggered when an object  14  is detected by the pair of sensors  26 ,  28  or  102 ,  104  going a speed that is greater than an allowed rate, thus preventing the object  14  from falling into the tubular  12  or being too quickly ejected from the tubular  12 . 
         [0028]      FIGS. 4-9  show various embodiments of the closure system  24  usable in the closure assemblies  10 ,  100 ,  200 . As shown in  FIG. 4 , in one exemplary embodiment, the closure system  24  is a full close “blind ram”  50 , such as a sliding gate of a gate valve that has no hole, space, or cutouts therein. The blind ram  50  shown in  FIG. 4  includes first and second plates  52 ,  54  that are pushed together in opposite directions to close the passageway  22  of the tubular  12 . Alternatively, as shown in  FIG. 5 , a blind ram  56  includes a single plate  58  that closes the tubular passageway  22  from one side to the other. In either embodiment shown in  FIGS. 4 and 5 , the blind ram  50 ,  56  may be modified to be a shear ram by including a sharpened edge to slice through a cable, wireline, or other tool passing through the tubular  12 . 
         [0029]    In another exemplary embodiment shown in  FIG. 6 , the closure system  24  includes a “slip/grip” design to grab the outer diameter of the object and slow it to a stop. While various gripper designs are usable within the closure system  24  herein, the gripper design shown in  FIG. 6  is a slip ram  60  that uses first and second ram blocks  62 ,  64  that each include a semicircular cutout  66 ,  68 , respectively, that defines a bore when the ram blocks  62 ,  64  are closed together. One or both of the cutouts  66 ,  68  may include slips  70  that engage with the falling object to prevent it from dropping further down the tubular  12 . Other gripping surfaces can be provided on the ram blocks  62 ,  64 , and the cutouts  66 ,  68  may be variously sized to cooperate with the object that is being passed therethrough. 
         [0030]      FIG. 7  shows another exemplary embodiment of a closure system  24 , this one employing an annular shaped elastomeric packing member  72  positioned between the tubular  12  and a hydraulic piston  74  that, when activated, forces the packing member  72  into the tubular  12  to fill the tubular  12  and prevent further movement of a speeding object, or surrounds the speeding object to stop its further motion. 
         [0031]      FIG. 8  shows still another exemplary embodiment, where the closure system  24  is that of an inflating “reverse annular” bag  78 , such as an inflatable donut-shaped annular preventer  76  that is triggered to inflate and either surround the falling object to stop its further motion, or fill the passageway  22  to catch the dropped object. 
         [0032]    In yet another exemplary embodiment shown in  FIG. 9 , the closure system has a flapper type construction. The flapper  80 , such as a flapper valve, is held against an interior wall  30  of the tubular  12  until the closure system  24  is activated, at which time the flapper  80  is pivoted either downwardly or upwardly, depending on the pivot point  82  location, to close the tubular  12 . The flapper  80  may further include a slot  84  for wireline cable to pass in a tool-catcher style when the flapper  80  is in a closed position blocking the passageway  22 . 
         [0033]    In any of the above-described embodiments, instead of completely closing the tubular passageway  22 , the closure system  24  may instead be designed or instructed by the computer  38  and control panel  40  to only partially close a portion of the passageway  22 , such that a shoulder is formed within the passageway  22 , but a fluid passageway is still enabled. That is, the rams  50 ,  56 ,  60  shown in  FIGS. 4 to 6  and the packing member  72  shown in  FIG. 7  may be pushed only partially into the passageway  22  such that a shoulder is formed. Likewise, the inflatable annular donut  78  of  FIG. 8  and the flapper  80  of  FIG. 9  may be constructed with reduced dimensions to provide a partial obstruction within the tubular passageway  22  rather than blocking an entire cross-sectional area of the passageway  22  when the closure system  24  is activated to a closed condition. In an exemplary embodiment, a shoulder movable between an open condition and a closed condition may be positioned further downhole from a riser to catch a dropped fish at a predetermined location. 
         [0034]    After the object  14  has been halted by the closure system  24 , the computer  38 ,  202  may send a signal to the control panel  40  to re-open the closure system  24 , such as after the object  14  has been recovered after being dropped, or after it is determined that the object  14  will not eject from the tubular  12  if the closure system  24  is re-opened. 
         [0035]    While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.