US2683490A - Well packer - Google Patents

Description

C. C. BROWN July 13, 1954 WELL PACKER Filed Dec. 19. 1949 ,2 Sheets-Sheet 2 Patented July 13, 195 4 res st fiNHTED STATES FATENT ()FFICE 7 Claims.

This invention relates to new and useful improvements in well packers and relates particularly to packers for use in squeeze and testing operations.

As is well known, a packer employed in squeeze and pipe testing operations requires that the packing element seal the inner space between the well casing and an inner conductor or pipe against pressure acting upwardly from below the packer; it is also desirable that during lowering a by-pass of fluid around the packer be permitted to facilitate such lowering and that said by-pass be closed when the packer is in its set or sealing position.

It is one object of this invention to provide an improved well packer, which is extremely simple in construction and comprises a minimum number of parts and which is particularly adaptable for use in squeeze or testing operations.

An important object of the invention is to provide an improved well packer having a pressure sealing element at its lower portion for sealing on the annular space between the well casing and an inner conductor or pipe, together with means on said conductor for mechanically distorting the element into tight sealing position when the packer is set in its final position within the well bore whereby the mechanical distortion of the element assists the pressure acting against said element to assure efiective sealing by said element.

Another object is to provide a well packer of the character described, wherein the inner conductor or pipe on which the packer is lowered and raised within a well bore is formed with bypass cpenings for allowing a fluid by-pass past the packer during lowering and raising; said bypass openings being movable into the packer assembly to co-act with a closure means after the packer is in its set position, whereby flow of fluid around the packer subsequent to the setting of the packer is prevented.

A further object is to provide a packer, of the character described, wherein the single sealing element, which is acted upon by pressure from below the unit and which seals off between the well casing and the inner conductor, is utilized to transmit a force to the anchoring assembly of the packer with such force being in a direction which urges the anchoring assembly into a tighter locking position.

Still another object is to provide a well packer having a pressure seal cup which is attached to radially displaceable segments, whereby an internal mechanical pressure will displace the seal cup and the segments to which it is attached radially outwardly into a sealing position with the well casing.

The construction designed to carry out the invention will be hereinafter described together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and wherein:

Figure 1 is an elevation of a well packer, constructed in accordance with the invention,

Figure 2 is an enlarged, transverse sectional view, of the packer and illustrating the parts thereof in position while being lowered or raised within the well casing,

Figure 3 is a similar view, with the packer in a set position,

Figure 4 is a horizontal, cross-sectional taken on the line 4-4 of Figure 2,

Figure 5 is a horizontal cross-sectional taken on the line 5-5 of Figure 3, and

Figure 6 is a horizontal, cross-sectional taken on the line 6-6 of Figure 3, and

Figure 7 is a horizontal, cross-sectional view taken on the line 'll of Figure 2.

Figure 8 is an elevational view of a portion of the mandrel of the well packer, illustrating particularly the J-slot in the enlarged diameter section of the mandrel.

In the drawings, the numeral lil designates a well tubing which is adapted to be lowered through the usual well casing ll within a well bore. A tubular support or mandrel Illa is connected in the tubing string by means of a coupling l 2 which is has an external diameter larger than the diameter of the mandrel and said mandrel is formed with fluid by-pass openings or slots l3 which are spaced below the coupling collar. The lower portion of the mandrel is formed with an upset portion or section is which is of larger external diameter than the external diameter or the mandrel and this section is illustrated as integral with said mandrel; however, the upset section could be formed of a sleeve encircling the mandrel and welded or otherwise secured thereto. A J-slot I5 is formed in the upper portion of the upset or enlarged section it and the longitudinal portion lEa of the J-slot eX-' tends downwardly from the upper end of the section M. The lateral or horizontal leg itb of the J-slot extends from the longitudinal or vertical portion of said slot and as is clearly shown in Figure 2 this lateral leg is disposed some disview,

view,

view,

tance above the lower end of the upset section [4 whereby a considerable surface Ma of the upset section is below said J-slot. It is preferable that the upper and lower edges of the upset or enlarged diameter section I l be beveled or inclined as indicated at Mo and M0. The mandrel has an axial bore [b extending entirely therethrough.

The mandrel forms the main supporting ele ment of the well packer which includes an anchoring assembly generally indicated at A and an annular sealing element B. The anchoring assembly includes a tubular slip carrying cage or sleeve 16 having gripping slips I! mounted within radially extending slots 18 formed in the cage. The outer surface of each gripping slip is formed with gripping teeth I!) while the inner surface thereof is inclined as indicated at 26. Outward displacement of the slips from the cage is prevented by the coaction between longitudinal flanges or ribs 2| formed on each slip member with shoulders Zla formed in the walls of each slot l8 (Fi ure '7).

The slip carrying cage or sleeve i6 is adapted to be detachably coupled or connected with the tubular mandrel l9 by means of a connecting lug 22 which is mounted in the cage and which has its inner end projecting inwardly from the bore thereof. The projecting inner end of the lug 22 is engageable within the J-slot l and when said lug is disposed in the lateral leg I5b of the J-slot, it is evident that the cage or sleeve is coupled to the mandrel and the mandrel may be utilized to lower and raise said cage within the well casing l I.

For coacting with the slips I! to effect a radial displacement or expansion of said slips an expander or cone member 23 encircles the mandrel above the upset or enlarged diameter portion 1 3. The bore of the expander is provided with an internal annular shoulder 24 which is adapted to engage and be supported upon the upper end I40 of the enlarged section It. The 1 wer portion of the expander is provided with an expanding cone 25 having an inclined expanding surface 26 which is complementary to the inclination 20 of the slips ll. An external shoulder 2? is formed on the expander and the upper end of the slip carrying cage encircles the lower portion of the expander with its upper end being disposed above the shoulder El. A supporting collar 28 is threaded into the upper end of the cage or sleeve l6 and the lower end of this collar is adapted to engage the external shoulder 2'! whereby the cage is suspended from the expander.

When the mandrel I0 is coupled to the slip cage 56 the slips are in a lowered position with respect to the expander 23 and said expander is supported by the engagement of the shoulder 24 of said expander with the upper end 140 of the enlarged section M of the mandrel; in such position the expanding surface 25 of the cone is within the upper portion of the slips I1 and said slips are in a retracted position. The cage I6 is provided with curved or bowed friction springs 29 which are secured to its external surface and which are in constant engagement with the wall of the well casing ll. Thus, when it is desired to disconnect the mandrel from the cage a rotation is imparted to the mandrel while the cage is held stationary by the frictional engagement of the springs 29 with the wall of the casing. Rotation of the mandrel is in a direction to align the longitudinal portion I5 1 of the J-slot with the connecting lug whereby the mandrel may then be moved downwardly relative to the slip carry-'- ing cage Hi. This moves the expanding cone 25 downwardly within the slips I1 and the coaction between the inclined surfaces 25 of the slips with the inclined surfaces 25 of the cone results in the slips being displaced or expanded radially outwardly to engage their gripping teeth 29 with the wall of the casing. After such engagement further downward movement of the expander 23 and of the slip carrying cage is prevented.

The sealing element B comprises an annular sealing cup 39 having downwardly directed sealing lips 3! which engage the casing H and the mandrel H) to seal off the annular space therebetween. The upper end of the sealing cup has a plurality of arcuate segments 32 molded thereto and the arcuate segments coact with each other to form a substantially annular metallic retaining element 33. Each segment is connected through a headed bolt 34 with a coupling collar 35 and as is clearly shown in Figure 4, each bolt extends within a radial slot 36 formed in the coupling and has its head engaging horizontal shoulders 31 provided at each side of the slot. With this arrangement downward displacement of the segments 32 and their attached sealing cup 3!} from the coupling is prevented while a radial or lateral movement of each segment with r spect to the coupling is permitted because each bolt is movable radially within its respective slot. It will be evident that the lower end of the sealing cup is subjected to the pressure from below the unit and said pressure acts against the sealing lips 3| to assure a tight sealing engagement of the cup with the bore of the well casing and the external surface of the mandrel. The coupling 35 to which the segments 32 are attached through the bolts 34 is threaded onto the lower end of the slip carrying cage or sleeve iii whereby the sealing cup is carried by said cage or sleeve.

When the mandrel is connected to the anchoring assembly as illustrated in Figure 2, the lower end Mb of the enlarged section I l of the mandrel is spaced above the segments 32 of the sealing cup and isdisposed within the upper portion of the coupling 35. Upon a rotation and subsequent lowering of the mandrel with respect to the slip carrying cage, the enlarged section M of the mandrel moves into the bore 32a formed by the arcuate segments 32 and functions to mecha'nically spread said sections from the position shown in Figure 5 to the position shown in Figure 6. Continued lowering of the mandrel moves the enlarged section M of the mandrel within and through the bore 30a. of the sealing cup 30 and functions to similarly displace the sealing cup radially outwardly. Obviously, as the enlarged portion I4 contacts the inner sealing lip 38 to displace this lip outwardly, a tighter engagement of the sealing lips with the outer surface of the mandrel and the inner wall of the bore of the casing is effected.

The expander 23 which as has been explained moves downwardly within the slips l? to expand the same into the gripping position has a tubular body 38 threaded onto its upper end. The body encircles the mandrel l H and has an annular recess 39 formed in the wall of its bore 38a and disposed within this recess is an annular sealing sleeve 40. The central portion of the bore of the sleeve or sealing element is recessed and above and below the recessed portion is provided with upper and lower annular sealing lips 4| and 42 which engage and ride upon the external surface of the mandrel [0a. The sealing element 40 is provided for the purpose of sealing or closing the by-pass openings or slots I 3 which are formed in the upper portion of the mandrel and such sealing effected when the mandrel is moved downwardly with respect to the anchoring as sembly. Proper positioning of the slots or openings is opposite the sealing sleeve 40 is efifected by reason of the lower end of the coupling !2 engaging the upper end of the tubular body. Not only does the coupling i8 provide a stop means which properly locates the openings with respect to the sealing element but said coupling also functions to permit the weight of the tubing string to be imposed upon the expander 23, Thus, when the device is in its finally set position the weight of the tubing it will apply a downward force to the expander 23 while the pressure from below the unit acting against the sealing cup 30 will apply an upward force against the slip cage i6 and gripping slips ll whereby said slips are constantly urged into a tighter gripping engagement with the wall of the casing.

In the operation of the device the slip carrying cage 55 is coupled to the mandrel ID by engaging the connecting lug 22 with the lateral leg [5b of the .l-slot and in such position the slips ll are in a retracted position. A suitable tail pipe 43 of any desired length may be connected to the lower end of the mandrel It and fluid from below the device may flow upwardly through the tail pipe and then through the mandrel It and outwardly above the assembly through the by-pass openings or slots l3. It is evident that as the device is lowered through the well casing H the seal cup at is engaging the well casing and the mandrel to seal the annular space therebetween, thereby protecting the anchoring assembly A which is above the seal cup from direct contact with the fluid. During the lowering operation the by-pass slots are open and the enlarged section i l on the mandrel is disposed above the arcuate segments 32 which are secured to the upper end of the seal cup 30.

i /"hen the device is to be set a rotation is imparted to the mandrel and the slip carrying cage it is maintained stationary by the engagement of its friction springs 29' with the wall of the well casing. Rotation of the mandrel aligns the longitudinal or vertical portion a of the J-slot [5 with the connecting lug 22 and the mandrel may be subsequently lowered with respect to the slip carrying cage. As the mandrel is lowered the expander 23 is moved within the slips to displace the same radially into gripping engagement with the Well casing and as soon as this occurs the cage and expander are locked against movement within the casing.

As the mandrel continues to be lowered the enlarged section it on said mandrel moves between the arcuate segments 32 and then through the bore tea of the seal cu whereby said segments and said cup are displaced radially outwardly so that a tighter engagement of the seal cup with the casing and with the mandrel is effected. Downward movement of the mandrel continues until the lower end of the coupling 12 which connects the mandrel to the tubing engages the upper end of the tubular body 38 and at this time the by-pass slots or openings I3 are disposed opposite the sealing element 40 with the sealing lips ll and d2 of the sealing element being located above and below said slot as shown in Figure 3. A slacking ofi on the weight of the tubing will then impose the desired weight upon the body 38 and the expander 23 to which 6 said body connected. Pressure from below acting against the seal cu 30 will urge the slips upwardly and thus unintentional disengagement of the anchoring assembly is prevented.

Any desired squeeze or testing operation may then be carried out through the tubing and through the tail pipe 43. Obviously the by-pass around the packer has been closed and any pressure within the tubing will act upon the sealing lips 4! and 42 of the sealing element to assure a tight seal between the mandrel and the tubular body 38. Of course, the pressure below the device which is built up by the squeeze or testing operation will act against the seal cup to assure the maintenance of a seal between the well casing and the mandrel IIJ.

Removal of the device from the well casing is carried out by merely lifting the mandrel with respect to the anchoring assembly and its associate parts. As the mandrel is moved upwardly the upper end Me of the enlarged section M will first engage the shoulder 24 of the expander 23 and through the engagement of these parts an upward jarring may be imparted to the expander to retract said expander from within the slips. The mandrel is then rotated to realign the longitudinal or vertical portion [5a of its J-slot with the connecting lug I517, after which upward movement of the mandrel continues until the lateral leg I522 is opposite said lug. The mandrel is then rotated to re-engage the lug 22 within the lateral leg and thereafter the entire assembly may be removed by means of the mandrel and tubing. It is noted that as the mandrel is reconnected with the anchoring assembly, the by-pass slots or openings l3 move above the tubular body so that a by-pass of fluid may occur during the removal of the assembly from the well casing.

The device comprises a minimum number of parts and utilizes the single sealing cup as a sealing element for packing 01f the annular space between the well casing and the well tubing. This cup is of the pressure seal type and is expanded into more effective sealing engagement by the pressure developed through the squeeze or testing operation. The by-pass openings provide a free by-pass around the packer during lowering and raising and yet are effectively sealed or closed when the device is in its set position. The provision of the enlarged diameter section It on the mandrel assures that the sealing cup at is moved into a sealing engagement since said cup is mechanically displaced radially by said section. After the anchoring assembly is set within the well casing the pressure from below and the weight of the tubing imposed from above function to urge the gripping slips into tighter engagement with the wall of the well casing to obviate any possibility of unintentional displacement of the assembly from its set position.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying 7 drawings is to be interpreted as illustrative and not in a limiting sense.

Having described the invention, I claim:

1. A well packer for use in a surrounding well pipe, including, a tubular support having an anchoring assembly slidably mounted on said support, said assembly including pipe gripping slips and a slip expander for expanding said slips radially into gripping engagement with the surrounding well pipe, detachable means connecting said slips with said support to detachably hold said slips against longitudinal movement relative to said support prior to detachment of said detachable means, holding means on the support for holding and preventing said slip expander from expanding said slips radially prior to the detachment of said detachable means, an annular radially expansible seal on the lower end of the anchoring assembly for sealing oil" between the surrounding well pipe and the sup port, and an enlarged diameter section on the tubular support being positioned to enter the bore of said annular seal when the support is moved downwardly relative to the anchoring assembly and seal for mechanically expanding the seal radially outwardly, detachment of said detachable means and downward movement of the support and the holding means relative to said snchoring assembly permitting said slip expander to move said slips into gripping contact with the surrounding well pipe and also permitting said enlarged diameter section to enter the bore of the seal to mechanically expand the seal raoutward.

2. A well packer including, a tubular support having an enlarged diameter section and having by-pass openings spaced above said section, an anchoring assembly including an expanding cone and slip means including pipe-gripping slips slidably mounted on the support, means for detachably connecting said slip means to the support to detachably hold said slips against axial movement relative to said support prior to detachment of said detachable means, means on the support for preventing said expanding cone from expending said slips radially into pipe-gripping contact prior to the detachment of said detachable means, an annular, radially-expansible seal cup secured to the lower end of the assembly for ealing the annular space between the support and a well casing within which the packer is lowered, said enlarged diameter section onthe support being disposed above the seal cup and the by-pass openings being located above the anchoring assembly when the support is connected with the slip means and the expanding cone, detachment of the support from the slip means and setting of the slips within a well casing permitting downward movement of the support relative to the assembly to move the enlarged diameter section of the support into the bore of the seal cup to mechanically displace the same radially and to also move the by-pass openings in the support within the assembly to close said openings.

3. A well packer as set forth in claim 2, together with fluid pressure-actuated seal means within the assembly for engaging the outer surface of the support above and below the by-pass openings to seal said openings upon detachment of the slip means from the support.

4. A well packer as set forth in claim 2, wherein the seal cup has downwardly-flared sealing lips exposed to the fluid pressure therebelow whereby said pressure maintains the cup in tight sealing engagement with the support and well casing.

5. A well packer as set forth in claim 2, wherein the seal cup has downwardly-flared sealing lips exposed to the fluid pressure therebelow whereby said pressure maintains the cup in tight sealing engagement with the support and well casing, and also wherein the seal cup is attached to the slip means of the anchoring assembly, whereby the fluid pressure acting on the seal cup is transmitted to the slips in a direction urging said gripping slips into tighter locking engagement with the well casing.

6. A well packer as set forth in claim 2, together with an annular fluid pressure-actuated seal sleeve mounted in the bore of the expanding cone of the anchoring assembly, and stop means on the support above the by-pass openings and engageable with the upper end of the anchoring assembly for halting downward movement of the support relative to the anchoring means when the by-pass openings in the support are aligned with said sleeve.

7. A well packer as set forth in claim 2, together with means connecting said slip means to said seal cup to form a unit of said assembly movable relative to said expanding cone within limits for utilizing the fluid pressure below the anchoring assembly for urging the seal cup and gripping slips upwardly, and coacting shoulder means on said support and said expanding cone for imposing the weight of the support upon the expanding cone to urge the same downwardly relative to the slip means whereby slips and core are urged toward each other so that the anchoring assembly is more firmly locked within the well casing by the pressure and weight acting in opposite directions on the slips and cone.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,187,482 Baker et al Jan. 16, 1940 2,343,076 Otis et a1. Feb. 29, 1944 2,506,680 Otis May 9, 1950 2,568,295 Page Sept. 18, 1951 2,585,706 Ware Feb. 15, 1952

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