US3409085A - Well packers - Google Patents

Description

0. N. OLIVER Nov. 5, 1968 WELL PACKERS 3 Sheets-Sheet 1 Filed Oct. 15, 1965 FIG. lc PM INVENTOR OWEN NORMAN OLIVER @yZwM) FIG. Eb Y/j fl ATTORNEYS,

FIG. l0

NOV. 5, 1968 O OLIVER 1 3,409,085

WELL PACKERS Filed Oct. 15, 1965 5 Sheets-Sheet 2 FIG. 2

FIG. 4

- -OWEN MRMAN OLNER ATTORNEYS INVENTOR Nov. 5, 1968 o. N. OLIVER 3,409,085

WELL PACKERS Filed Oct. 15, 1965 5 Sheets-Sheet 5 HG 5 INVENTOR OWEN NORMAN OLIVER ATTORNEYS United States Patent 3,409,085 WELL PACKERS Owen N. Oliver, Duncan, Okla., assignor to Halliburton Company, Duncan, Okla., a corporation of Delaware Filed Oct. 15, 1965, Ser. No. 496,275

8 Claims. (Cl. 166-134) ABSTRACT OF THE DISCLOSURE A well packer having a packer element that expands radially upon being compressed axially. The packer includes a mandrel on which the packer element is mounted and upper and lower sets of slips mounted on opposite sides of the packer element. Each set of slips has teeth which project outwardly from the mandrel and the teeth on the upper set of slips slope away from the .teeth on the lower set of slips. The sloping teeth grip the well casing pipe and resist displacement of the slips away from the packer element. The slips, however, may be displaced axially toward the packer element in order to compress the packer element axially. The packer includes apparatus for selectively moving one of the sets of slips toward the other upon movement of the mandrel in either an upward or downward direction relative to the packer element. This arrangement permits the packer to be set in the well casing by applying either tension or compression to the mandrel through the tubing string to which the mandrel is attached.

This invention relates to well packers, and more particularly to mechanically set packer apparatus. In deep wells, the weight of the pipe can be set down on the packer to impose suflicient exanding force on the packer element to expand the packer element tightly against the wall of the casing and to maintain the packer element in an expanded condition. When a mechanically set packer is used at a shallow depth, however, there may be insufiicient pipe weight available for maintaining the packer element expanded against the wall of the casing and to resist the fluid pressure differential on the packer. Also, if the hole is deviated, or there are other adverse conditions, it may be difficult to transmit the weight of the pipe to the bottom of the hole where the packer is located. As a result, insufficient force may be applied to the packer, so that the packer either does not expand tightly against the wall of the casing or the pressure differential may cause the packer to collapse after it has been set.

These difficulties may be overcome by utilizing a tool that can be set in tension at shallow depths, or where insuflicient pipe weight is available, if it is known in advance that these conditions are present. On the other hand, in straight holes where there is suflicient pipe weight for setting the packer, a conventional packer that is set in compression may be used. Often, however, it cannot be determined before the packer is run in the well whether or not suflicient pipe weight will be available at the depth at which the packer is to be set. If it should become necessary to remove aconventional compression packer from the well in order to replace it with a tension packer, operating time is lost which increases the cost of the well operation.

Another problem is that there are a variety of operations in which very cold or very hot fluids may be pumped down through the packer and into the formation. For example, liquid carbon dioxide or steam may be injected into the formation. The fluids are conducted through the central mandrel of the packer and then into the formation. A very high temperature or low temperature fluid passing through the mandrel of a conventional packer may cause a corresponding increase or decrease in the length of the mandrel due to contraction or expansion of the metal. This change in length'of the mandrel may be suflicient to relax the compressive force on the packer element, thereby causing leakage between the casing and the packer element.

In view of the defects of prior well packers, it is an object of this invention to provide a well packer which may be set either in compression or tension.

It is a further object of this invention to provide a well packer which may be set in compression or tension selectively after the packer has been run in a well casing.

It is a still further object of this invention to provide a well packer which compensates for changes in length of the tubing due to expansion or contraction.

These objects are accomplished in accordance with the preferred embodiment of the invention by a packer having a central mandrel extending through the entire length of the tool. A packer element is mounted between the opposite ends of the tool with shoes on opposite ends of the packer element. Slips at the opposite ends of the packer element have teeth that project away from the packer element. When the teeth are in engagement with the casing, the teeth resist displacement of the packer shoes axially away from the packer element, but do not resist movement toward the packer element. J-slots control the setting of the upper and lower slips.

An axial compression force for expanding the packer may be applied downwardly against one end of an intermediate mandrel, or an axial force in the opposite direction may be applied by lifting up on the central mandrel to move one of the packer shoes into engagement with the opposite end of the intermediate mandrel. Since the slips are in engagement with the wall of the casing, either upward or downward displacement of the intermediate mandrel causes the packer element to expand and one of the slips to move in the direction of the force by sliding along the wall of the casing.

After the packer has been set either in tension or compression, steam or other high temperature fluid may be pumped down through the central mandrel and as it expands, the tubing string may be picked up sufficiently to compensate for the expansion of the central mandrel relative to the other components of the packer. In this manner a constant tension force is applied to the mandrel. Similarly, contraction of the mandrel due to low temperature fluids may be compensated. The packer element may be formed of a composition to resist the heat of the steam and high temperature seals are provided at opposite ends of the packer element. Other high temperature seals resist the leakage of fluid through the tool, between the mandrels.

This preferred embodiment of the invention is illustrated in the accompanying drawings in which:

FIG. la is an elevational view, partially in cross section of the upper portion of the packer of this invention, showing the packer element collapsed;

FIG. 1b is an elevational view, partially in cross section of the middle portion of the packer;

FIG. 10 is an elevational view, partially in cross section of the lower portion of the packer;

FIG. 2 is a detail view of the J-slot in the J-slot body;

FIG. 3 is a detail view of the J-slot in the intermediate mandrel;

FIG. 4 is a detail view of the J-slot in the drag spring sleeve;

FIG. 5a is an elevational view, partially in cross section, of the upper portion of the packer after it has been set in a well casing;

FIG. 5b is an elevational view partially in cross section, of the middle portion of the packer in a well casing; and

FIG. 5c is an elevational view partially in cross section, of the lower portion of the packer in a well casing.

As shown in FIG. la, the packer includes an adapter 2 having internal threads for coupling the packer to the end of a tubing string. An overshot 4 is threadedly secured to the outside of the adapter 2 and a central mandrel 6 secured to the adapter 2 by internal threads which cooperate with external threads on the mandrel. The mandrel extends throughout the length of the tool and has a shoe 8 secured to its lower end, as shown in FIG. 16. A tubular J-slot body 10 is mounted on the mandrel 6 and a portion of the body 10 extends between the overshot 4 and the mandrel 6. A J-slot 12 is formed in the external surface of the body 10. A lug 14 on the overshot 4 extends into the J-slot for controlling relative movement between the mandrel and the body 10. A detail view of the ]-slot .12 is shown in FIG. 2. The body 10 also has a radial shoulder 16 which is engaged by the lower end of the overshot 4 for applying a downward force to the body 10 when the lug 14 is in the position shown in FIGS. la and 2.

An upper slip control body 18 is threadedly secured to the lower end of the J-slot body 10. A split ring collar 20 is secured over the lower end of the control body 18 by cooperating flanges at their adjacent ends. 'At the opposite end of the collar 20 there are a plurality of T-slots 22 for receiving slips 24. A mechanical slip body 26 is mounted on the mandrel 6 and extends into the space between the lower end of the collar 20 and the mandrel 6. The body 26 has a plurality of radial slots 28 for receiving each of the slips 24 and sloping T-slots 30 for wedging the slips 24 against the wall of the casing. The \upper end of the slip body 26 is secured to an upper slip J-slot body 32 which has a J-slot 34 formed in its external surface. The J-slot 34 is shown in FIG. 3. A lug 36 on the upper slip control body 18 projects into the 1- slot 34.

An intermediate mandrel 38 is mounted over the central mandrel 6 and is secured at its upper end to the mechanical slip body 26. A top shoe 40 is also secured to the intermediate mandrel 38 adjacent the body 26. The top shoe is preferably formed of a soft metal which will yield under the pressure imposed on the shoe 40 when the packer element is expanded. A similar lower shoe 42 is mounted for movement relative to the intermediate mandrel 38. Between the top and bottom shoes, a packer element 44 is mounted. The packer element is preferably formed of elastic composition having asbestos fibers embedded therein. Wires in the form of a screen also may be embedded in the packer element to add strength. The composition of the packer element 44 is selected to resist high temperatures encountered in steam injection processes.

The bottom shoe 42 is secured to a lower mechanical slip body 46 by screws 48. The body 46 has sloping T-slots 50 for receiving one end of each of the slips 52. In order to displace the body 46 upwardly, a shoulder 54 is provided on the intermediate mandrel 38 in position to engage the lower end of the body 46.

The upper and lower slips 24 and 52 have teeth which slope away from the packer element 44. This causes the teeth to bite into the casing upon displacement of the slips away from the packer element 44, but they do not resist movement toward the packer element. Therefore, the packer element can be set by moving both the upper and lower slips into engagement with the surface of the casing and then sliding either of the slips toward the packer element 44. The other stationary set of slips will bite into the casing and resist the axial force imposed on the packer element. When displacement of the slips stops, the slips that were moving axially are displaced in the opposite direction a suflicient distance by the inherent resilience of the packer element to cause the teeth on the slips to bite into the casing and securely hold the packer element in its expanded condition.

The lower end of each of the lower slips 52 is received in a T-slot 56 formed in a lower split ring collar 58. The collar 58 in turn is secured to a drag spring sleeve 60 by cooperating flanges at the adjacent ends of the collar and the sleeve. A plurality of drag springs 62 are. mounted on the sleeve 60 and project outwardly to engage the inner wall of a casing. The drag spring sleeve 60 has a J-slot 64 which cooperates with a lug 66 on the intermediate mandrel 38 for controlling relative movement between the drag spring sleeve and the mandrel 38. The drag spring sleeve and its J-slot 64. are shown in FIG. 4.

The lower end of the intermediate mandrel 38 has an internal cylindrical recess 68 for receiving packing rings 70 and packing 72. Although chevron type packing is illustrated in FIG. 1c, square packing or other conventional packing may be used. Where the tool is to be used in steam injection processes, the packing should be resistant to high temperatures. The packing is secured in the recess 68 by a packing gland nut 74.

A tension setting sleeve 76 is mounted in sliding relation over the lower end of the intermediate mandrel 38. The sleeve 76 is retained on the mandrel 38 by a retainer ring 78 which is secured to the sleeve 76 by threads. The lower end of the retainer ring 78 abuts against a shoulder 80 on the mandrel 38. The upper end of the retainer ring 78 is in position for engaging the lower end of the drag spring sleeve 60 upon axial displacement of the sleeve 76 and the ring 78 toward the sleeve 60. The lower end of the sleeve 76 has a ring 82 which projects inwardly toward the central mandrel 6 and forms an abutment for engagement by the shoe 8 on the mandrel.

In operation, the packer is secured to the end of a tubing string and is run in a casing with the various components of the packer in the positions shown in FIGS. 1 to 4. When the desired depth is reached, the tubing string is given a righthand rotation. The drag springs 62 engage the surface of the casing 84 and resist rotation of the drag spring sleeve 60. The rotation of the tubing string is transmitted through the overshot 4 and the lug 14 to the intermediate mandrel 38 to cause the lug 66 to move into the long axial leg of the J-slot 64. When the lug is in this position, the intermediate mandrel 38 is free to move downwardly relative to the drag spring sleeve until the lower slips 52 are wedged outwardly against the casing 84 by the sloping T-slots 50 of the lower mechanical slip body 46.

The upper slips 24 also become operative upon righthand rotation of the tubing string. When the lug 66 moves into the long leg of the J-slot 64, the mandrel 38 is restricted against rotation relative to the casing by the drag springs 62. Therefore, the central mandrel 6 and the upper slip control body 18 continue to rotate in a right-hand direction. As the body 18 rotates relative to the intermediate mandrel 38, the lug 36 moves into the axial leg of the J-slot 34 to permit axial movement of the slip control body 18 relative to the mandrel 38 and relative to the upper mechanical slip body 26. This downward movement causes the upper slips 24 to be wedged outwardly against the casing by the sloping T-slots 30 in the mechanical slip body 26.

At this point, the operator can decide whether to expand the packer element 44 under tension or compression. If the operator elects to expand the packer element under compression, a downward force is imposed through the tubing string on the overshot 4 which transmits a force through the shoulder 16 in the body 10 to the collar 20. Since the lower slips 52 are in engagement with the casing 84, the teeth on the slips will resist downward movement of the lower mechanical slip body 46. As the body 18 moves downwardly, the lower end of the J-slot body 10 engages the upper slip J-slot body 32 and transmits an axial force through the mechanical slip body 26 to the top shoe 40. The packer element 44 is then compressed axially between the top shoe and the bottom shoe 42. As the packer element expands against the casing 84, the teeth of the upper slips 24 slide along the surface of the casing unit and packer element 44 is fully expanded against the casing. The downward force on the overshot 4 then may be partially released to cause the packer element 44 to displace the slips 24 upwardly, thereby we'dging the teeth into the casing and securing the packer element 44 in its expanded condition.

The packer element may be collapsed after it has been set in compression by picking up on the tubing string, thereby raising the lug 14 to the upper end of the closed leg 86. An upward axial force is then transmitted to the J-slot body to draw the split ring collar upwardly relative to the mechanical slip body 26 and thereby retract the upper slips 24. As soon as the upper slips 24 are released, the packer element 44 springs back to the position shown in FIG. 1 through its own internal resilience. The intermediate mandrel 38 is then drawn upwardly by means of the lug 36 at the top of the J-slot 34. The shoulder 54 on the mandrel engages the lower end of the body 46 and displaces it upwardly and movement of the sloping T-slot 50 causes the lower slips 52 to be retracted away from the wall of the casing. The tubing string is then given a left-hand rotation to move the lug 36 into the closed end of the horizontal portion of the J-slot 34 and to move the lug 66 to the position shown in FIG. 4 in the J-slot 64. The tool may then be moved relative to the casing.

In order to set the packer by applying tension to the tubingstring, the slips 24 and 52 are first displaced outwardly into engagement with the casing by right-hand rotation of the tubing string and applying a downward axial force, as described above. The tubing string is then given a right-hand rotation and picked up. Since both the lugs 36 and 64 are in the axial portions of their respective J-slots, the master J slot body 10 is restrained against rotation by the slips and the drag springs 62. Therefore, rotation of the string moves the lug 14 into the open leg 88 of the J-slot 12 in the body 10 (FIG. 2). When the lug 14 passes out of the top end of the J-slot 12, upward movement of the mandrel 6 is unrestricted until the shoe 8 on the lowerend of the mandrel engages the ring 82 on the tension setting sleeve 76. Applying an upward axial force on the tubing string causes the sleeve 76 and the retainer sleeve- 78 to move upwardly relative to the lower mandrel 38. The sleeve 78 engages the drag spring sleeve 60 and transmits the force through the lower split ring collar 58 to the lower slips 52. The upper slips 24 have teeth sloping away from the packer element 44 and they bite into the casing and resist displacement of the slips 24 in an upward direction. Therefore, the intermediate mandrel 38 is restricted against upward axial movement. Upward movement of the slips 52 and body 46 relative to the mandrel 38 causes the packer element 44 to expand outwardly against the casing. The components of the packer are then in the positions shown in FIGS. 5a, 5b and 50.

After the packer element is set against the wall of the casing, a high or low temperature fluid may be pumped down the tubing string and through the central mandrel 6. The length of the mandrel and the tubing string will increase or decrease according to the temperature of the fluid. This change in length may be suflicient to cause the expanding force imposed on the packer element by the shoes 40 and 42 to decrease, but by adjusting the axial force on the mandrel 6, the effects of expansion or contraction may be overcome. For example, the slack caused by expansion may be compensated for by continuing to apply an upward force on the mandrel 6, and although the mandrel expands longitudinally, the shoe 8 remains in engagement with the ring 82 and an upward axial force is applied continuously to the lower end of the packer element 44 to maintain it in its expanded condition.

The packer element 44 and the slips 24 and 52 may be retracted by displacing the mandrel 6 downwardly and rotating the tubing string until the lug 14 on the overshot 4 is aligned with the upper end of the open leg 88 of the J-slot 12. Downward movement of the overshot 4 relative to the master .l-slot 'body .10 causes the lug 14 to move to the position shown in FIG. 2. The tubing string is then picked up to move the lug upwardly to the upper end of the closed leg 86 of the J-slot 12. The upward force on the overshot 4 causes the lug 36 to move to the top of the J-slot 34, thereby drawing the upper slips 24 away from the wall of the casing. At the same time, the shoulder 54 on the intermediate mandrel 38 displaces the lower mechanical slip body 46 upwardly to draw the lower slips 52 away from the wall of the casing. During this interval, the packer element 44 expands axially and returns to the position shown in FIG. 1b. By turning the tubing string to the left, the lug 36 moves to the closed end of the horizontal portion of the J-slot 34 and subsequently the lug 66 moves to the upper end of the J-slot 64 in the position shown in FIG. 4. The packer may then be moved through the casing.

The packer of this invention may be expanded selectively, either by a compressive force due to the weight of the tubing string on the packer, or by an upward tension force applied to the tubing string. Accordingly, the packer has many versatile applications, particularly where the operator cannot tell until after the packer is positioned at the desired depth whether he will have sufficient weight on the packer to expand the packer element and maintain a tight seal against the casing.

Another important advantage of the packer of this invention is that it may be used where high or low temperature fluids are encountered, such as injecting steam into the formation. The particular arrangement of the components of the packer of this invention requires only a minimum of seals to prevent fluid communication between the central mandrel 6 and the packer element 44, when the packer is expanded. The only packing that is necessary is the packing ring 72 at the lower end of the intermediate mandrel 38. Rubber O-rings that are usually provided between relatively sliding components of a conventional packer, have been eliminated because they would be ineffective at very high or very low temperatures. The packer element itself is formed of a high temperature resistant material, and yet has suflicient resiliency to form a tight seal against the wall of the casing. The top and bottom shoes 40 and 42 are preferably formed of a soft metal so that when an axial force is applied to expand the packer element, the soft shoes can conform to any changes in shape at the opposite ends of the packer element 44 and maintain a fluid seal between the packer element and the intermediate mandrel 38.

The particular arrangement of components of this packer compensates for changes in length of its components, and particularly compensates for changes in length of the central mandrel 6 which passes through the entire length of the packer. The same packer may be used either for very cold fluids or very hot fluids, by adding pipe sections to the lower end of the mandrel 6 to change the free distance between the shoe 8 and the ring 82.

While this invention has been illustrated and described in one embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims.

I claim:

1. Packer apparatus comprising:

a packer element, a central mandrel, an intermediate mandrel on said central mandrel, means mounting said packer element on said intermediate mandrel;

a top set and a bottom set of slips at opposite ends of said packer element, means mounting said slips for longitudinal and radial movement relative to said intermediate mandrel, said slips having teeth and said teeth on said top set of slips sloping away from said teeth on said bottom set of slips;

top wedge means rigidly secured on said intermediate mandrel for displacing said top slips outwardly relative to said intermediate mandrel upon longitudinal movement of said slips toward said packer element, bottom wedge means mounted for longitudinal sliding movement on said intermediate mandrel between said bottom slips and said packer element, said bot- "tom wedge means displacing said bottom slips outwardly relative to said central mandrel upon longitudinal movement of said bottom wedge means to ward said bottom slips;

a drag spring sleeve, means securing said bottom slips against longitudinal movement relative to said sleeve, means for selectively moving said sleeve longitudinally relative to said intermediate mandrel;

' a compression abutment on said intermediate mandrel, a tension abutment on said intermediate mandrel, a compression shoulder on said central mandrel in opposing relation to said compression abutment, a tension shoulder on said central mandrel in opposing relation to said tension abutment, and means for selectively moving said central mandrel longitudinally relative to said intermediate mandrel for engagement of said tension shoulder with said tension abutment and said compression shoulder with said compression abutment, whereby said packer may be set in a well casing by applying tension or compression.

2. Packer apparatus according to claim 1 wherein said intermediate mandrel includes a tension setting sleeve mounted for sliding movement longitudinally of the remainder of said intermediate mandrel, said tension abutment being on said tension setting sleeve, said drag spring sleeve being positioned on said intermediate mandrel between said tension setting sleeve and said bottom wedge means, whereby upward movement of said central mandrel transmits an axial force through said tension setting sleeve and said drag spring sleeve to displace said bottom slips outwardly relative to said bottom wedge means.

3. Packer apparatus according to claim 1 wherein said packer mounting means includes a top shoe and a bottom shoe, said top shoe being interposed between said top wedge means and said packer element, said bottom shoe being interposed between said bottom wedge means and said packer element, at least one of said shoes being metallic and deformable under the compressive force on the packer element while the packer element is expanding radially. V

4. Packer apparatus according to claim 3 wherein said packer element is formed of material;

5. Packer apparatus according to claim 1, wherein said sleeve moving means includes first J-slot means between said sleeve and said intermediate mandrel, and saidcentral mandrel moving means includes second J-slot means between said central mandrel and said intermediate mandrel, whereby said first and second J-slot means provide positive control during setting of the lower and upper slips. Y

6. Packer apparatus according to claim 5 including an upper slip control body .mounted on said intermediate mandrel, means on said slip control body for displacing said slips outwardly upon longitudinal movement of said body relative to said top wedge means, said second .T-slot being between said slip control body and said intermediate mandrel, and means for transmitting rotation from said central mandrel to said slip control body for turning said body relative to said intermediate mandrel for operation of said second J-slot.

7. Packer apparatus according to claim 6 including third J-slot means between said slip control body and said central mandrel for selectively releasing said central mandrel for longitudinal movement relative to said slip control body.

8. Packer apparatus according to claim 7 wherein each of said I-slots operates for. releasing cooperating components for longitudinal movement upon rotation of said central mandrel in the same direction, thereby assuring sequential operation of the J-slots.

a high temperature resistant References Cited I UNITED STATES PATENTS 2,739,651 3/1956 Brown l661 19 2,929,453 3/ 1960 Conrad 166-217 X 2,970,649 2/ 1961 Brown l66134 X 3,119,450 1/1964 Evans l661l9 3,283,821 11/1966 Brown 166'134 3,295,606 1/1967 Bumpus 116-119 X 3,308,886 3/1967 Evans 166-l34 3,265,131 8/ 1966 Ehlert l66120 3,356,142 12/1967 Crow et al. 166-134 DAVID H. BROWN, Primary Examiner.

CIMRLES E. OCONNELL, Assistant Examiner.

Images