Abstract:
A packer apparatus that is set with low friction counter-clockwise rotation, and unset with clockwise rotation. A drain valve is opened concurrently as the packer apparatus is unset and closed as the packer apparatus is set. The Packer apparatus requires a minimum of parts and is designed to be used in corrosive environments.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Provisional Patent Application  
         [0002]     Ser. No. 60/664,844 Filed Mar. 23, 2005  
         [0003]     Entitled “ROTATIONAL SET WELL PACKER DEVICE” 
         [0004]     Inventor: Harold Dean Clifton 
        Midland , Tex. 79707       
 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0006]     Not Applicable.  
       REFERENCE TO A MICROFICHE APPENDIX  
       [0007]     Not Applicable  
       BACKGROUND  
       [0008]     This patent application discloses to those skilled in the art a rotational set packer device for use in oil and gas exploration and production.  
         [0009]     The packer device of this invention is of the type that is insertable from the top of a well, which usually will be into a well casing, or other conduit. The packer device broadly comprises means, usually known in the oil field as a packer device or packer apparatus having expansible, resilient packer elements. The packer device is considered a downhole tool forming a part of a tool string for use in isolating various parts of a wellbore or borehole.  
         [0010]     Packer devices are widely used in the oil field for isolating different elevations of the borehole from one another. One example of a packer device is set forth in U.S. Pat. No. 3,800,781, issued Apr. 12, 1974 to inventor Billy Ray Watson. Reference is made to the Watson patent and to the art cited therein for further background of this invention.  
       SUMMARY OF THE INVENTION  
       [0011]     Oil field tools, especially packer devices or packer apparatus, are fabricated with right hand or clockwise rotation for setting the resilient packer elements thereof, whereupon fluid flow thereacross is precluded. One primary function of a packer device as described herein is to arrange the packer elements in series respective the tubing string whereby the annulus formed between the production tubing and the well casing prevents uphole flow of well fluid when the packer elements are expanded and set into engagement with the wall of the casing, thereby filling the annulus between the tubing and casing, whereupon both uphole and downhole flow of well fluid is prevented.  
         [0012]     Packer apparatus often remain downhole for extended lengths of time and when the time arrives to remove the tool string for one reason or another, the deleterious affects of the well fluids may have corroded the various coacting parts of the packer apparatus, making it difficult to unscrew the components of the packer that unseat or relax the packer elements.  
         [0013]     Packer apparatus usually form a component of a tool string wherein there may be a tubing anchor, and other components such as a gas separator and a production pump, for example only, arranged in series relationship. Usually, such a tool string is made up as the recited components thereof are introduced into the casing at the well head or Christmas Tree. Consequently, when downhole problems arise, the packer and the tubing anchor must be unseated, or released from engagement with the casing, otherwise the production tubing along with the tool string cannot be retrieved without resorting to costly fishing expedients.  
         [0014]     In order to overcome these difficulties, several novel improvements are set forth in this disclosure.  
         [0015]     When unseating the resilient packer elements of a prior art packer device having clockwise rotation of the tubing string for setting, the torque is effected upon the entire tubing string and this action is liable to disconnect most any of the threaded joints of the tool string that are located above the hold-down. In such a catastrophe, it would then be necessary to call in the experts to fish for whatever is stuck downhole.  
         [0016]     Consequently, it is desirable to have available a unique packer device which is set by counterclockwise rotation with a torque force less than the force required to unscrew the joints of the tubing string as well as other tools of the tool string. When the packer device of this invention is located above the hold down, as shown in the Figures of the drawings, there can be no separation of the threaded connections of the various tools located therebelow, regardless of the direction of rotation required to unscrew various parts thereof.  
         [0017]     Those skilled in the art, after digesting this entire disclosure, will appreciate that this disclosed packer device can be run above a tubing anchor along with other tools, such as a gas separator hookup, for example. This invention includes equalizing or drain ports that facilitate running and pulling the packer. In the present packer apparatus, approximately three turns left are required to set the packer elements, and right hand rotation to release the packer elements. The tubing can be placed in tension, compression or neutral. Low torque is required for setting the packer elements, and there are no slips or moving parts to wear out from pump movement. When desired, two packers can be run in the same string to isolate a zone for pumping, and furthermore, this packer can be run below a casing leak or perforations, and preferably is fabricated of stainless steel to further avoid the likelihood of corroded threads.  
         [0018]     When the packer elements of this disclosure are set with counterclockwise rotation of the tubing string, the clockwise torque that must be effected on the tubing string cannot disconnect any of the threaded connections in the string when the packer device is located immediately above the hold-down, or tubing anchor.  
         [0019]     Accordingly, a primary object of the present invention is the provision of a packer apparatus that can be run downhole to a selected elevation and set by rotating the supporting upper part of the packer counterclockwise respective a lower part thereof.  
         [0020]     Another object of this invention is the foregoing packer apparatus that has upper and lower mandrels rotatable clockwise in order to unseat the packer device.  
         [0021]     Still another object of this invention is a packer apparatus or packer device that forms a part of a tool string, has an axial passageway longitudinally extending therethrough, and further includes a valve device that is closed upon setting the packer elements thereof with a counterclockwise rotation between coacting parts thereof.  
         [0022]     A further object of this invention is the provision of a packer apparatus that can be run downhole to a selected elevation and set by rotating the supporting upper part of the packer counterclockwise respective a lower part thereof and furthermore contains upper and lower mandrels rotatable clockwise in order to unseat the packer device; and further includes a valve device that is closed upon setting the packer elements thereof with a counterclockwise rotation between coacting parts thereof.  
         [0023]     A still further object of this invention is the provision of a new combination of apparatus that include a packer device that is set by rotating part of the packer device in a counterclockwise direction and is unseated by rotating the last said part clockwise, in combination with a tubing anchor having selected prior art tools such as for example, a gas separator associated therewith.  
         [0024]     These and other objects of the invention are attained in accordance with the present invention by the provision of a combination of elements which are fabricated in a manner substantially as claimed and described herein.  
         [0025]     These and other objects and advantages of the present invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accompanying drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]     While the invention is claimed in the concluding porions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying drawings where like parts in each of the several diagrams are labeled with like numbers:  
         [0027]      FIG. 1  of the drawings is a part diagrammatical, part schematical representation of an oil well having disclosed therein the assembled packer tool of various embodiments of this invention;  
         [0028]      FIG. 2  of the drawings is an enlarged part cross-sectional, part elevational, schematical representation of the assembled packer tool of one embodiment of this invention;  
         [0029]      FIG. 3  is an enlarged representation of a side elevational view of the assembled packer tool of the preferred embodiment of this invention; and,  
         [0030]      FIG. 4  illustrates a side elevation of the combination of the packer device and hold-down of this disclosure.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]      FIG. 1  of the drawings diagrammatically discloses a producing well bore  10  formed through the surface of the earth and extends downhole through a fluid producing formation F. There is a surface pipe or upper casing  11  for protecting the upper aquifer. Within surface casing  11  there is axially received a main well casing  12  extending downhole into proximity of the bottom  13  of the borehole. Production tubing  14  is also axially received respective casings  11  and  12 . Accordingly, an annulus  16  is formed between casing  12  and tubing  14 . Tubing  14  is a production pipe string, sometime referred to as a tool string for it is series connected respective to various oil field apparatus such as, for example only, the instant packer device  18 , made in accordance with this invention, the details of which are more fully described later on herein.  
         [0032]     The surface casing  11 , well casing  12 , and production tubing  14  are attached to a wellhead  17 , also called a Christmas tree.  
         [0033]     The tubing string  14 , also referred to as a tool string  14 , therefore discloses the packer apparatus  18  of this invention, a tubing hold-down  20  having slips  21 , and other downhole apparatus such as a pump  22 , as well as various other tools as may be desired or required.  
         [0034]     As seen in  FIG. 2 , together with other figures of the drawings, the packer device  18  of this invention has annular packer elements  24 ,  24 ′ spaced from one another. The packer elements  24 ,  24 ′ are expansible, resilient, annular bodies made of an elastomeric product such as vulcanized rubber.  
         [0035]     Looking now to  FIG. 3  of the drawings, the uppermost end of upper mandrel  26  terminates in a box end  28  which is adapted to threadedly engage a complementary threaded end of production string  14 , and a lower end  30  having a threaded marginal pin end received respective an upper threaded box end, seen at  32 , of a lower mandrel  34 . The lower mandrel  34  has an upper circumferentially extending enlarged terminal end portion  36 ; with the lower end of the lower mandrel terminating at pin end  38 , thereby forming the lowermost end of packer device or apparatus  18 .  
         [0036]     An element compressor  40  of annular configuration is threadedly affixed to the upper mandrel  26  by the illustrated coacting threaded surface illustrated at  41  and therefore is considered a removable part of the upper mandrel  26 . The element compressor  40  terminates in an upper circumferentially extending end  42  which abuttingly engages the illustrated external complementary shoulder formed on the upper mandrel.  
         [0037]     The lower end  44  of element compressor  40  encloses the reduced diameter part of rubber packer elements  24 ,  24 ′ and acts as a seal as it bears against the illustrated packer elements.  
         [0038]     An outwardly directed circumferentially extending groove  46  receives a carrier brass screw  46 ′ in low friction relationship therewithin and admits axial movement of element compressor  40  respective lower mandrel  34  to thereby compress the pair of confroning packer elements  24 ,  24 ′ responsive to rotation of the upper mandrel respective the lower mandrel.  
         [0039]     An annular equalizing chamber  48  is formed between the upper mandrel  26  and the element compressor  40  as shown in  FIG. 2 . Within equalizing chamber  48  there is slidably received in a reciprocating manner the before mentioned enlarged upper marginal terminal end  36  of the lower mandrel  34 . Inner and outer equalizing ports  50 ,  52 , respectively, are formed in members  26 ,  40 , respectively, and thereby complete the fluid flow path from within the tool string, through inner port  50 , into chamber  48 , and out of outlet port  52  when the packer is in the illustrated running in or unseated configuration of  FIG. 2 , thus enabling flow from the tubing string into the annulus  16  in order to drain or equalize the tool string upon unseating of the packer apparatus  18 .  
         [0040]     The opposed ends of an annular element spacer  54  engages similar complementary confronting ends of the packer element and separates the two packer elements  24 ,  24 ′. The element spacer  54  is slidably received in close tolerance relationship about the lower mandrel to transmit the resultant compressive forces that occur as the upper and lower mandrels are screwed together at low friction left-hand threaded surface  32 .  
         [0041]     A lower gauge  56 , in the form of an inverted annular cap, threadedly engages the lower mandrel  34  by means of a threaded surface  58 . Disposed within the gauge or cap  56  is an annular ring  60  that bears against reduced diameter lower sealing end  62 ′ of the lower packer element  24 ′ as follower  61  is urged against the lower mandrel and gauge responsive relative rotation between the upper and lower mandrels; which effectively lengthens and shortens the distance between the lower edge  44  of the element compressor  40  and gauge  56 , and thereby compresses or relaxes the packer elements, which also sets and unseats the packer.  
         [0042]     As pointed out above and claimed herein, the packer device can be used in combination with a downhole pump and tubing anchor, and often a gas separator hookup is advantageously included by connecting the recited apparatus in series relationship with respect to one another. An important feature of this invention is the provision of equalizing ports arranged to be closed and opened, respectively, in response to the rotation of the tubing string to move the packer elements into the set and unseated configuration, respectively, and thereby facilitate running and pulling the packer with a dry string. The packer is set by rotating the tubing from above the ground approximately 3 turns to the left; and opposite rotation of the tubing to the right for release.  
       CATALOG OF PARTS  
       [0000]    
       
           10  producing wellbore  
           11  surface casing  
           11 ′ surface of earth  
           12  main casing  
           13  lower end of casing  12   
          F formation  
          P perforations  
           14  tubing string  
           14 ′ outlet for  14   
           15  lower end of  14   
           16  annulus  
           16 ′ outlet for upper annulus  
           18  packer of this invention  
           20  tubing hold down  
           21  slips of  20   
           22  Downhole pump and other tools  
           24  elements are expansible resilient packer rubber  
           24 ′ as  24   
           FIG. 2 :  
           26  upper mandrel  
           28  upper box end, threaded  
           30  lower end of  26   
           32  threaded to engage  34   
           34  lower mandrel  
           36  upper circumferentially extending end of  34   
           38  pin end forming the lower end of packer  18   
           40  element compressor  
           42  upper end abuts external shoulder on  26   
           44  lower end encloses reduced diameter part of elements  24 ,  24 ′ 
           46  locking groove  
           46 ′ carrier brass screw received within  46  admits moving  40  axially concurrently respective to movement of  26 .  
           47 ′ set screw received within  40  preventing relative axial movement of  40 / 26   
           48  equalizing chamber  
           50  inner port connected to  48   
           52  outer port connected to  52   
           54  element spacer  
           56  lower gauge in form of a cap  
           58  threads attaching  56  to  34   
           60  ring  
           61  seal ring or follower  
           62 ,  62 ′ lip seal received within complementary cavities  
           66  pumping string  
           68  side string  
           70  gas separator or other tool 
 
 end catalog parts