US3054453A - Well packer - Google Patents

Description

Sept. 18, 1962 J. w. BONNER 3,054,453

WELL PACKER Original Filed March 14, 1955 Jam ea W 150/70 er 73 INVENTOR. 7/

B Y 74 2/ w M /0/ Patented Sept. 18, 1962 free 3,054,453 WELL PACKER James W. Bonner, 8305 Baker, Houston, Tex. Continuation of application Ser. No. 494,169, Mar. 14, 1955. This application Sept. 15, 1958, Ser. No. 761,249 8 Claims. (1. 166138) This invention pertains to well packers, especially permanent type production packers, and to apparatus for setting same.

Advantages of the invention include ability to set packer, circulate, and set flow tube all in a single trip into the well, assurance that the packer will not set prematurely, simplicity, ease of operation, reliability, and low cost.

This application is a continuation of my prior copending application Serial No. 494,169 for Well Packer, filed March 14, 1955, now abandoned.

For a description of a preferred embodiment of the invention reference is made to the accompanying drawings in which FIGURES 1A and 1B, which are partly in section and partly in elevation, show respectively, the upper and lower portions of an apparatus according to the invention.

Referring to the drawings, there is shown alocator sub 10 whose upper end is exteriorly threaded at 11 for connector to the well tubing on which the apparatus is lowered into the well. The locator sub has aninternal thread 12 for connectiontoseal nipple 13.

Seal nipple 13 is provided at its lower end with collar 14 welded thereto at 15, and which may preferably be integral therewith. Collar 14 has an internal thread 16 into which is screwed the upper end of aflow tube 17 which, as shown in FIGURE 13, extends clear to the lower end of the apparatus. The lower end of the flow tube is externally chamfered at 18 to provide a guide surface. Thesub 10,seal nipple 13, collar 14, andflow tube 17 thus form one continuous pipe.

The lower end oflocator sub 10 is threaded externally at 20 with six left hand threads, this being the opposite hand to the usual threaded connections of the tubing string on which the apparatus is run and opposite to the other threaded connections of the apparatus which are right handed except as noted. The lower end of the locator sub is screwed into the upper end ofmandrel 21.Shoulders 22 and 23 on the locator sub and mandrel limit the engagement thereof.

Mandrel 21 extends nearly to the bottom of the apparatus. At itslower end mandrel 21 is provided with anexternal screw thread 24 on which is screwed aslip retainer ring 25. The lower end ofring 25 is externally threaded at 26 whereon ajunk pusher tube 27 is screwed. Tube 27 is provided withslots 28 to allow fluid to pass up insidetube 27 and thence outslots 28 when the apparatus is being lowered in a well, any junk in the hole which might interfere with the slips being trapped intube 27 or pushed ahead out of the way.

The inner edge of the lower end ofring 25 is bevelled to form a taperedvalve seat 30 having anannular groove 31 in which an 0 ringtype seal ring 31a is disposed. Acheck valve 32 is pivotally mounted at 33 on the lower end ofring 25. Valve 32 is tapered correlative tovalve seat 30. Valve 32 is made of cast iron or other drillable material. The check valve prevents fluid from rising in the well above the packer if theflow tube 17 is removed.

A plurality ofslips 40, having downwardly directedteeth 41 adapted to resist downward motion when engaged with a well casing, are disposed aroundmandrel 21. The slips have inturnedflanges 43 engaged inannular groove 44 inring 25 whereby the slips are held against axial motion on the mandrel unless they are first moved radially outward.

Helical garter spring 45 around the slips ingrooves 46 tends to prevent such radial outward motion.

Above slip 40 ashear ring 50 is disposed in anannular groove 51 around the mandrel.Shear ring 50 is preferably an O-ring of neoprene or other material of like strength which will shear when a load of about 10,000 pounds is placed on it. This shear ring supports downwardly taperedslip expander cone 52 slidably mounted thereabove onmandrel 21.

The upper end ofcone 52 is provided with an upwardly directedflange 53 at its outer edge, forming anannular pocket 54 between the flange and mandrel. Apacker sleeve 55 of 85 durometer hardness synthetic rubber compound (such as Hycar) is disposed aroundmandrel 21 and its lower end is tapered at 56 to fit intopocket 54.Packer sleeve 55 can slide on the mandrel when forced to do so, not being bonded thereto but not either being a loose fit.

The upper end ofsleeve 55 is also tapered at 57 to fit intoannular recess 58 formed betweenmandrel 21 and downwardly directedflange 59 on upwardly taperedslip expander cone 60 which is slidably mounted onmandrel 21. Cone 60 is held against upward axial motion byshoulder 61 onmandrel 21.

Abovecone 60 there are a plurality of slips disposed around themandrel 21. The upper ends of these slips are provided with inturnedflanges 71 which engage withannular recess 72 inslip support ring 73, thereby preventing axial movement of the slips up or down independent ofring 73 unless there is first a radial outward motion of the slips. Ahelical garter spring 74 disposed around the slips ingrooves 75 tends to prevent such radial outward motion of the slips.

Slip support ring 73 has aninternal thread 76 engaging a four threadleft hand thread 77 onmandrel 21. Stoppins 78, 79 on the ring and mandrel prevent these threads from being made up tight. Drag means comprising a plurality of bowedleaf wiper springs 80 are secured to ring 73 at their lower ends byscrews 81. The upper ends of the springs are secured to astabilizer ring 82 byscrews 83.

Betweenseal nipple 13 and the enlarged interior base of the upper portion ofmandrel 21 there are a plurality of sets of packing rings 9|), 91, 92, 93, preferably each set comprising a plurality of chevron packing rings, alternate sets being oppositely directed. Between the sets of packing rings arejunk rings 94, 95, 96, 97, 98. There is thus provided a long travel telescopic sliding joint and seal. Themandrel 21, as indicated by the break in the drawing, FIGURE 1A, may be of "any desired length dependent on the desired length of travel of the telescopic joint, but the sealing means including the packing rings -93 need not be as long as the travel of the joint, andjunk ring 93 is made long enough to fill the remaining space.

The upper end ofjunk ring 98 engages an O-ringtype seal ring 99 disposed in an annular rabbet on the inner edge of the lower end oflocator sub 10, so that all the sets of packing rings and junk rings are firmly held onseal nipple 13 between the locator sub and collar 14, whereby the seal means including the packing rings is removable from the mandrel with the seal nipple as a unit. On reinserting the seal means in the mandrel collar 14 acts as a guide to insure centering of the seal means relative to the mandrel before the seal means enters the mandrel. Since theflow tube 17 fits closely inside the lower portion of the mandrel and the seal means onseal nipple 13 fits inside an enlargement in the upper end of the mandrel, the flow pipe is of large diameter so that full size tubing can be used without restriction at the lower end.

The apparatus is lowered into a well on a string of tubing to a level below the production zone and fluid is circulated. The apparatus is then raised to a level above the production zone. The packer is then set by rotating the tubing to the right four turns tofree ring 73 which is held. against rotation by springs 8% which form a drag means frictionally engaging and bearing on the inside of the casing.

It will be noted that while the connection between mandrel and locator sub, comprisinglocator sub threads 20, the mandrel threads engaged therewith,shoulders 22, 23, and the parts of the sub and mandrel engaged with the shoulders, can be made up tight, thestop pins 78, 79 prevent such tight makeup of the connection between mandrel and slip support ring, comprisingthreads 76, 77, so that the mandrel-sub connection stays connected upon initial right hand rotation of the tubing. Only later when the packer sleeve has gripped the casing, as will be described, is there enough holding force .on the mandrel to enable the mandrel-sub connection to be unscrewed.

Following disconnection of thering 73 from the mandrel, an upward pull on the tubing then liftscone 60 intoslips 70 which are held against upward motion bysprings 80 andring 73. Cone 60 causes expansion of the slips until they are firmly anchored to the casing.

Further upward motion of the tubing shears ring so that themandrel 21 can move axially upwards relative toslips 70,cone 60,packer sleeve 55, andcone 52, untilslips 40 are engaged oncone 52.Slips 40 are moved radially bycone 52 until they are firmly engaged with the casing. Further upward movement of the tubing causes slips 40 andcone 52 to move upwardly relative tocone 60 and slips 70 whose upwardly pointingteeth 101 resist such motion, andsleeve 55 is axially compressed therebetween until it expands radially into sealing engagement with the well casing as well asmandrel 21. The downwardly directedteeth 41 onslips 40 prevent slips 40 and cone 5 from moving down when the upward pull on the tubing is discontinued.

The radial motion of theslips 60 and 40 during setting of the packer may be enough to free them fromrings 73 and 25 if desired.

After the packer has been set, the tubing can be rotated six turns to the right to disengage the locator sub from the mandrel which is held against rotation by the packer sleeve engaging the casing. The tubing can then be elevated, taking the seal nipple and its packing and the flow tube with it and the well can be circulated above the packer. The tubing can then belowered to replace the flow tube and seal nipple in the packer and the well produced. It is not necessary to screw the locator sub back into the mandrel since the seal nipple seals to the mandrel as soon as its sealing means enters the mandrel; however, it can be screwed back if desired. To theextent flow tube 18 extends below the packer sleeve the fluids initially in the well are trapped between thecasing 27 and flowtube 18, after the packer is set, so that the packer is in contact with these initial well fluids, e.g. mud, rather than the oil subsequently produced, thus protecting the packer against deterioration.

The flow pipe and the mandrel and the means sealing and connecting them together may be said to form a pipe means, and the packer sleeve when set seals between the well casing and the pipe means to direct the well fluid from the casing into the pipe means.

It will be seen that theslips 40 and 70 and thecones 52 and 60 provide casing gripping wedge means above and below thepacker sleeve 55, both the cones and the slips being wedges. Thesprings 80 constitute casing engaging friction means and are connected to the upper casing gripping Wedge means throughring 73. Disconncctable connecting means to connect the friction means to the mandrel to prevent relative axial motion thereof includes thethreads 76, 77. The function of the friction means is to engage the casing, which has two results. .First of all it holds thering 73 stationary while the mandrel is rotated to disconnect thethreads 76, 77. Second- 4 ly, the friction means holdsring 73 stationary while the mandrel is moved axially to set the wedge means.

The casing engaging friction means 8?, together with thethread 76, 77, andring 73,flanges 71, 72,garter spring 74,shoulder 61,groove 51, shear ring 5!garter spring 45, andflanges 43, 44, constitute elements of mechanically releasable means (as distinguished from hydraulically releasable means) to hold the casing gripping wedge means out of easing gripping position. The release of this mechanically releasable means is initiated by turning the mandrel to the right untilthreads 76, 77 are disconnected, the friction means holdingring 73 against turning. Thereafter upward movement of the mandrel relative to the friction means, which tends to be stationary in the well, causes the casing gripping wedge means to be moved into casing gripping position as the other elements of the mechanically releasable means, such as the shear ring, are overcome. Disconnectable means .to connect the flow pipe to the mandrel comprises thethreads 20, and this latter disconnectable means is disconnectable only after the first mentioned disconnectable means (threads '76, 77) has been disconnected, for the packer vmust be set in order to hold the mandrel against rotation while the flow pipe is rotated to unscrewthreads 20. While a preferred embodiment of the apparatus of the invention has been shown and described, many modifications thereof can be made by one skilled in the art without departing from the spirit of the invention and it is desired to protect by Letters Patent all forms of the invention falling within the scope of the following claims.

I claim:

1. In combination, a mandrel having an axial passage therethrough; a packer sleeve on said mandrel; upper and lower casing gripping slip and expander type wedge means on said mandrel respectively above and below said packer sleeve in abutment therewith actuatable to casing engaging position with said sleeve compressed therebetween by relative axial motion of said means towards each other from an initial position of greater separation; mechanically releasable means for holding both of said casing gripping slip and expander type wedge means in said initial position to keep them out of casing gripping position, said mechanically releasable means including casing engaging friction means on said mandrel connected to one of said casing gripping wedge means, said mechanically releasable means also including connecting means disconneotable upon relative rotation between said mandrel and friction means but when connected holding said friction means to said mandrel to prevent relative axial motion thereof, said connecting means being disconnected by rotation of said mandrel while said friction means is held against rotation by casing engagement, said casing gripping wedge means being actuatable to casing gripping position by axial motion of the mandrel relative to said friction means after said connecting means is disconnected, said packer sleeve expanding radially into binding casing and mandrel engagement upon axial compression between said upper and lower casing gripping means; a flow pipe; second connecting means disconnectable by relative rotation between said flow pipe and mandrel only upon application of torque thereto greater than that required to disconnect the first said connecting means but when connected holding said pipe to said mnadrel to prevent relative axial motion therebetween, the second said connecting means being disconnectable' by rotation of said pipe while said sleeve is in binding engagement with said casing and mandrel; said pipe having a portion extending into said axial passage in the mandrel when said pipe is connected to said mandrel; and means to seal between the outside of said pipe and the inside of said mandrel when said pipe portion is in said axial passage.

'2. In combination, a mandrel having an axial passage therethrough; a packer sleeve on said mandrel; upper .and lower casing gripping slip and expander type wedge means on said mandrel respectively above and below said packer sleeve in abutment therewith actuatable to casing engaging position with said sleeve compressed therebetween by relative axial motion of said means towards each other from an initial position of greater separation; mechanically releasable means for holding both of said casing gripping slip and expander type Wedge means in said initial position to keep them out of casing gripping position, said mechanically releasable means including casing engaging friction means on said mandrel connected to one of said casing gripping wedge means, said mechanically releasable means also including connecting means disconnectable upon relative rotation between said mandrel and friction means but when connected holding said friction means to said mandrel to prevent relative axial motion thereof, said connecting means being disconnected by rotation of said mandrel while said friction means is held against rotation by casing engagement, said casing gripping wedge means being actuatable to casing gripping position by axial motion of the mandrel relative to said friction means after said connecting means is disconnected, said packer sleeve expanding radially into binding casing and mandrel engagement upon axial compression between said upper and lower casing gripping means; a flow pipe; second connecting means disconnectable by relative rotation between said flow pipe and mandrel only upon application of torque thereto greater than that required to disconnect the first said connecting means but when connected holding said pipe to said mandrel to prevent relative axial motion therebetween, the second said connecting means being disconnectable by rotation of said pipe while said sleeve is in binding engagement with said casing and mandrel; said pipe having a portion extending into said axial passage in the mandrel when said pipe is connected to said mandrel; and means to seal between the outside of said pipe and the inside of said mandrel when said pipe portion is in said axial passage, the upper portion of said axial passage in the mandrel being of larger diameter than the lower portion thereof, said pipe having a guide portion adapted to fit slidingly inside said enlarged portion, and said sealing means being disposed on said pipe above said guide portion and being adapted to seal with said enlarged portion of said axial passage, said pipe below said guide portion thereof fitting slidingly inside the lower portion of said axial passage.

3. The combination of claim 1 in which both of said disconnectable connecting means comprise left hand threads, the casing engaging friction means serving to resist rotation in the casing whereby said disconnectable means connecting said friction means to the mandrel can be released by clockwise rotation of the pipe, and said packer sleeve when set holding the mandrel against rotation whereby said second disconnectable means connecting said mandrel to the pipe can be released by clockwise rotation of said pipe, the last mentioned disconnectable connecting means including more turns of thread than the other disconnectable connecting means to insure disconnection of the former only after the latter.

4. In a well apparatus comprising:

pipe means including a flow pipe and a mandrel having an axial passage therethrough and telescopically engaged with said flow pipe first connecting means for holding said flow pipe to said mandrel to prevent relative axial motion therebetween but disconnectable by relative rotation therebetween, and

packing means to seal between a portion of said flow pipe and a portion of said mandrel;

a packer sleeve on said mandrel;

upper and lower casing engaging wedge means of the slip and slip expander type disposed respectively above and below said packer sleeve in abutment therewith and actuatable to casing engaging position with said sleeve compressible therebetween by relative axial motion of said wedge means towards each other from an initial position of greater separation; mechanically releasable holding means for keeping both of said wedge means in said initial position, said holding means including drag means for frictionally engaging well casing, said drag means being disposed on said pipe means and being connected to one of said wedge means, second connecting means for holding said drag means to said pipe meansto prevent relative axial motion therebetween and thereby prevent axial motion between said one of said Wedge means and said mandrel, said second connecting means being disconnectable by relative motion between said pipe means and drag means upon application of torque less than that required to disconnect said first connecting means, which torque is created by turning said pipe means while said drag means resists rotation due to contact with said well casing, such disconnection freeing said one of said wedge means for axial motion relative to said mandrel to move said wedge means to casing engaging position in which said packer sleeve expands radially into binding casing and mandrel engagement, said first connecting means being disconnectable by turning said flow pipe while said mandrel is held against rotation by said binding engagement of said packer sleeve; the improvement according to which said second connecting means connects said drag means to the mandrel portion of said pipe means whereby when said first connecting means is disconnected said flow pipe can be removed from said mandrel Without carrying with it said drag means, thereby facilitating reinsertion of said flow pipe into said mandrel.

5. The combination of claim 4 further characterized in that said packing means is on said flow pipe and is of greater axial length than said first connecting means whereby said packing means can be partially engaged Without connecting said first connecting means, as when said flow pipe is brought back to said mandrel after removal therefrom.

6. The combination of claim 5 in which the upper portion of said axial passage in the mandrel is of larger diameter than the lower portion thereof, said flow pipe has a guide portion adapted to fit slidingly inside said enlarged portion and said packing means disposed on said flow pipe is above said guide portion and is adapted to seal with said enlarged portion of said axial passage, said flow pipe below said guide portion thereof fitting slidingly inside the lower portion of said axial passage.

h 7. The combination of claim 4 further characterized in t at:

said mandrel is provided with a downwardly opening check valve;

said flow pipe has a portion extending inside said mandrel past said check valve holding said check valve open,

said first connecting means comprises left hand threads on said flow pipe and mandrel, said second connecting means comprises left hand threads on said drag means and mandrel, and

said second connecting means has fewer turns of threads than said first connecting means, to facilitate disconnection of the second connecting means prior to the first connecting means.

8. Well apparatus comprising a mandrel having an axial passage therethrough;

a packer sleeve on said mandrel;

upper and lower casing gripping wedge means of the slip and slip expander type disposed on said mandrel respectively above and below said packer sleeve in abutment therewith and actuatable to casing engaging position with said sleeve compressed therebetween by relative axial motion of said wedge means towards each other from an initial position of greater separation;

mechanical means for holding both of said wedge means in said initial position and releasable by a predetermined motion of said mandrel when said apparatus is'inside a well casing, said mechanical means in- V eluding:

a flow pipe separate from said drag means and insertable telescopically within said axial passage of said mandrel from one end thereof;

disconnectable means for connecting said flow pipe to said mandrel to enable said predetermined motion of the mandrel required for release of said mechanical means to be imparted to said mandrel from said flow said flow pipe having a first portion extending inside said axial passage in the mandrel when said pipe is connected to said mandrel;

seal means independent of said disconnectable means and sealing between the outside of said pipe portion and the inside ofsaid mandrel when said portion is in said axial passage; and

a check valve carried by said mandrel biased to position closing said axial passage through said mandrel and opening in the direction of flow through said passage from said one end thereof;

said pipe having a second portion extending through said mandrel past said valve when said first portion is in position to be sealed with said mandrel, said second portion then holding said check valve open;

said flow pipe being of full unrestricted opening throughout its length including said first and second portions thereof; 7

whereby said packer sleeve can be set, the well above the packer sleeve can be cleaned with the flow pipe separated from the mandrel and disposed thereabove, and the flow pipe re-engaged with the mandrel and the well produced, all in one trip into the well.

References Cited in the file of this patent UNITED STATES PATENTS 2,189,697 Baker Feb. 6, 1940 pipe and dlsconnectable by a certain motion of said 2 189 703 Burt et al v Feb 6 1940 flow pipe relative to said mandrel after said mandrel Baker 1941 is held by Said binding engagement ofSaid Packer 30 2 551 240 Bonner May 1 1951 sleeve between said mandrel and well casing;

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