US2609879A

US2609879A - Permanent type packing means for wells

Info

Publication number: US2609879A
Application number: US69305A
Authority: US
Inventors: Jack C Webber
Original assignee: Atlantic Refining Co
Current assignee: Atlantic Richfield Co
Priority date: 1949-01-05
Filing date: 1949-01-05
Publication date: 1952-09-09
Anticipated expiration: 1969-09-09

Description

Sept. 9, 1952 J. c. WEBBER PERMANENT TYPE PACKING MEANS FOR WELLS 2` SHEETS- SHEET 1 Filed Jan.

INVENTOR.

Jack C'. Webber ttozney Sept. 9, 1952 Filed Jan. 5, 1949 HTTE'ST 4.4.4, dgage'- J. c. WEBBER 2,609,879

PERMANENT TYPE PACKING MEANS FOR WELLS 2 SHEETS--SHEET 2 Fure 4 22 a5 26 a1 Z7 as Fajure 3 IN1/Emme. s

Jack C. Webber BY 72M 5w Sli-p cone 9 functions to set and maintain slips 8 in contact with the casing wall. As shown in Figure 1, slip cone 9 is positioned between body section 3 and mandrel yIi, and initially is in a position abutting, as at Ill, the lower end of upper body section 2. Slip cone 9 has a downwardly tapering external surface, the lower portion of which initially engages, as at I I, complementary surfaces formed on the reverse or inner faces of slips 8. While the packer is being run in the `well and prior to setting slips 8, a shear pin I2, associated with each of the slips, secures slips B to slip cone 9 with slips 8 in a retracted position away from casing I and with slip cone 9 abutting the lower end of body section 2, as shown in Figure 1. When a defini-te, preselected pressure is exerted on the upper end of slip cone 9, in a manner below described, pins I2 are caused to shear, permitting slip cone 9 to move downwardly thereby forcing slips -8 outwardly into engagement with the casing. The relative positions of the slip cone and the slips, after setting of the slips, are shown in Figure 3. For maintaining the slip cone in this position within the slips after the latter have been set, the reverse or inner face of each slip has formed thereon a series of teeth, denoted generally by numeral I3, which are adapted to contact the surface o-f slip co-ne 9 in a manner to prevent upward displacement thereof regardless of the pressure exerted thereon from below.

rings I4 carried by mandrel 6 and in sealing engagement with slip cone 9, O rings I5 carried by the slip cone adjacent the upper end thereof and in sealing engagement with body section 3, and O rings I6 carried by mandrel S and in sealing engagement with body section 2 cooperate to isolate the annular space between mandrel 6 and the packer body above and below slip cone 9, and to form an annular chamber I1 communicating with the upper end of the slip cone. Chamber I1 also is in communication with the interior of mandrel 6 through port I 8.

Setting of slips 8 is accomplished by introducing into the tubing string and mandrel 6 oil, water, or other suitable liquid medium under pressure. This liquid passes through port I8 into annular chamber I1 where it impinges on the upper end of slip cone 3. rIhe liquid is prevented initially from passing out of mandrel 6 by a suitable ball check valve removably secured at the lower end thereof. The valve includes valve sleeve I9 which terminates at one end in valve seat 29, and ball 2| which is dropped in the tubing string after the packer has been lowered to the desired position in the well and which falls through the liquid to its proper seating position on valve seat 23. Valve sleeve I9 is temporarily fastened to tubing nipple 22 by means of shear pin 23, tubing nipple 22 being threaded, or otherwise secured, at one end, as at 24, to the end of mandrel E and at its other end, as at 25, to screen 26 for preventing sand, silt, and the like from entering the mandrel. By proper selection of pin 23, after pins I2 have sheared and slips 8 set in casing I as described above, a further increase in the pressure exerted on the liquid in mandrel 6 will cause pin 23 to shear, allowing valve sleeve I9 and ball 2l to drop to the bottom of screen 26, thus opening mandrel 6 to fluid flow downwardly therethrough. Suitable packing means or O rings 21 are provided for preventing flow of fluid between valve sleeve I9 and tubing nipple 22.

Body section 2 is of a reduced internal and external diameter and has formed at one end 4 shoulder 28 for supporting packing element 29, the external diameter of shoulder 28 preferably being equal that of body section 3. The packing element, preferably, comprises a plurality of resilient packing rings snugly tted about body section 2, the end rings having beveled surfaces adapted to be contacted, as at 30 and 3l, by complementary surfaces of gaskets 32 which are formed of lead and function to prevent cold flow of the resilient packing element 29 between the packer and casing I under high pressures. Downward movement of packing element 29 relative to body section 2 is limited by shoulder 23. It is obvious that a single tubular packing element may be substituted for the plurality of packing rings of the preferred form of packing element. Provided about body section 2 for slidable movement therealong and in contact with the gasket 32 at the free end of packing element 29 is a compression ring 33 which is adapted to compress the packing element 29 into sealing engagement with casing I when suiiicient force is exerted thereon by virtue of the threading of collar 34 on the end of body section 2. A sufficient length of body section 2 is provided with threads to permit collar 34 to be threaded on, as at 35, the body section until packing element 29 is sealed tightly against the wall of casing I.

It is a purpose of this invention to provide means whereby packing element 29 may be brought into sealing engagement with the casing under a compressional force of a definite, preselected amount by manipulation of the tubing string from the Well surface. To this end, collar 34 is threaded, as at 36, by means of a left-hand thread to coupling 31 which, in turn, is threaded internally, as at 38, to mandrel 6 and which is adapted to be connected at its other end to the tubing string. Shear pin 39 initiallyv secures coupling 31 to collar 34 and when the tubing string is rotated to the right, collar 34 will be threaded on body section 2 in a manner so as to f cause compression ring 33 to act against the free end of packing element 29. However, by proper selection of pin 39, when packing element 29 has been compressed under the desired force, pin 39 will shear, and as the right-hand rotation is continued coupling 31 will become disconnected from collar 34 and the pressure exerted on packing element 29 will no longer increase, but will remain constant` It is seen that with coupling 31 detached from collar 34, mandrel 6 may be pulled from the packer body if desired.

For reasons pointed out hereinafter, there is provided in collar 34 port 40 which provides communication between the exterior of the packer above packing element 29, and annular space 4I between collar 34 and mandrel 6.

Figures 3 and 4 are similar, respectively, to Figures 1 and 2 with the exception that in the latter the various elements are shown in their relative positions prior to setting of slips 8 and compression of packing element 29 while in the former the elements are shown in their relative positions after such operations.

In operation, after the packer has been assembled as shown in Figure 1, it is lowered into the well to a. desired position on the end of a tubing string threaded in coupling 31. Ball 2l is dropped into the tubing and comes to rest on valve seat 20. The tubing string and mandrel are then rlilled with oil or water, or other suitable liquid medium, which liquid will be prevented from flowing out of the mandrel by ball 2I, but a portion thereof will enter into chamber I1 through port I8 and exert pressure on the upper end of slip cone 9. The liquid then is subjected t0 an increasing pressure at the well surface until pins l2 are sheared, permitting slip cone 9 to move downwardly to force slips 8 into engagement with the wall or casing l. shearing of pins l2 will be indicated at the well surface by a slight 'dropin the fluid pressure. Since it is a purpose of the invention that all pressures exerted on the packer in either direction be carried solely by the slips, itis desirable to initially setthe slips rml'yyand securely in the casing. This is accomplished by increasing the pressure on the liquid in the tubing, which pressure is transmitted through the slip cone to the slips, to a point sufiicient to embed the slips in the casing to an extent necessary to withstand the maximum pressures which are exerted on the packer; By proper selection of the pin 23 when the pressure on the liquid is increased above this point, the pin will shear, causing ball 2l and sleeve lil to fall to the bottom of screen 26 resulting in a substantial pressure drop which indicates to the operator at the well surface that the slips have been properly set.

After setting slips 8 the resilient packing element 29 is compressed into sealing engagement with casing l. This is accomplished simply by rotating the tubing string to the right, which motion is imparted to collar 34 through couplng 3l, as pointed out hereinbefore. Rotationv of collar 34 results in the threading of the` collar on body section 2, which forces compression ring 33 against Ythe free end of packing element 23. It is readily seen that as rotation of the tubing string is continued, compression ring 33 acting on the free end of packing element 29 will cause the latter to be compressed longitudinally until the desired seal is obtained, at which time additional rotation of the tubing string will cause pin 39 to shear. Continued rotation or the tubing string will unthread coupling 3l from collar 34 and release mandrel t from the body member. It is obvious that the maximum compression force applied to the packing element is dependent upon and controlled by the selection ofshear `pin 39. Propersetting of the packing element isindicated through the ease with which the tubing string may thereafter be rotated. Y

Following the setting of the packer, iiuid circulation thereabove may be accomplished merely by pulling the tubing string until port I8 in mandrel 6 coincides with annular space 4l and comp munication thereby established between the inn terior of mandrel 6 and the exterior of thepacker. In some instances it may be desirable toconnect a relatively long tail pipe between tubing nipple 22 and screen 26. In such cases, circulation of fluid below the packer may be carried out merely by pulling the tubing string until 0 rings lll and I6 are abovev the packerbody, and then pumping iluid downwardly through the tubing string, which fluid will pass out ofthe perforations of screen 26 and upwardly in theannular space between the tail pipe and Ypacker body into the `annular space between the tubing string and casing labove packing element 29.`

In order that each of the slips 8 may at all times bear on slip cone 9 at two points, `regardless of the relative positions thereof, there is formed It is readily seen that all pressures from above and below are carried directly by slips 8; thus pressure from above packing element 23 is trans-1 mitted through body section 2 to body section 3 and thence to slips 8. In a similar manner, pressures from below on packing element 29 are 'transmitted to slips 8 through compression ring 33, collar 34, and

body sections

2 and 3.

As pointed out hereinbefore, this packer is of a permanent type` and may be removed from the wellonly by drilling. Due to the fact that the slipsare located adjacentthe lower end of the packer body and since the packer `will not move while the slips are in engagement with the casing,` the parts of the packer will not rotate untilv the drilling out is completed to a point near the bottom of the slips, and, forthis reason, the packer is adapted to ready and simple removal by drillmg.

It should be pointed out that a blowout disk i3 may be secured in a suitable opening t4 in body section 3, which opening connects the exterior of the packer below lpacking element 29 and an nular chamber l1 so that if at any time the pressure in mandrel 6 or the pressure exteriorly oi the packer below the packingelement increases above preselected values as a result of plugging of screen26, or for any other reason, blowout disk 43 will be ruptured `to establish communication directly between the interior of mandrel ,e and the exterior of the packer below

packing element

2,9. The purpose of the blowout disk is to prevent excessively high pressures inside mandrel 6 from bursting body section 3, .andfroin driving slip cone 5 into slips ll so hard that the compressional force on the cone causes it to collapse or that the force of slips 8 causes casing l to burst. Further, the blowout diskrelieves excessively high` pressures acting externally on the packer below paching element 29 by providing `direct communication between the exterior .and interior of the packer when thev disk isvruptured by such high pressure.

Although' the packer `has `been described used for sealing the annular space between the well casing and a string of tubing, the invention should not be construed as so limited but mayV be employed whenever conventional well packers are used..

I claim:

l. In aipermanent type packer for a well a body member adapted to be positioned in a well casing and having an upper body section and a lower body section, said lower body section having an internal diameter greater than said upper body section, normally retracted slips for securing said body member to the casing against pressures from above and below, each of said slips being disposed in an aperture in said lower body section so that relative longitudinal movement therebetween is prevented, a mandrel ex tending through said body member, a slip cone disposedbetween said mandrel and said lower body section for effecting movement of said slips into engagement with said casing, sealing means between said mandrel and said upper body section, said mandrel and said slip cone, and said slip cone `and said lower body section forming an annular' chamber communicating with the upper 7 Y 2. In a permanent typepacker for a well a body member adapted to be positioned in a well casing and having an upper :body section and a lower body section, said lower body section having an internal diameter greater thansaid upper body section, normally retracted slipsffor securr ing said body member to the casing against pressures from above and below, each of said slips being disposed in an aperture in said lower body .section so that relative longitudinal movement therebetween is prevented, a mandrel extending through said body memben-a slip cone disposed between said mandrel and said lower body section for effecting movement of said slips into engagement with said casing, sealing means between said mandrel and said upper body section, said mandrel and said slip cone, and said slip cone and said lower body section forming an annular chamber communicating with the upper end of said slip cone, and an aperture in said mandrel providing communication between the interior of the mandrel and said chamber, said mandrel being provided with an internal valve seat below said aperture, and a shearable pin securing said valve seat to said mandrel. v

3. In a permanent type packer rfor a w l a body member adapted to be positioned in a well casing and having an, upper bodysection and a lower body section, said lower body lsection having an internal diameter greater than said upper body section, normally retracted slips for securing said body member to the casing against pressures from above and below, each-of said slips being disposed in an aperture in said lower body section so that relative longitudinal movement therebetween is prevented, ya mandrel extending through said body member, a slip cone disposed between said mandrel and said lower body section for effecting movement of said slips into engagement with said casing, sealing means between said mandrel and said upper body section, said mandrel and slip cone, and said slip cone and said lower body section forming anv annular chamber communicating with the upper end of said slip cone, and an aperture in said mandrel f,

providing communication between the interior oi the mandrel and said chamber for admitting duid pressure to the upper. end of said slip cone to eiect downward movement thereof with respect to said slips, and means for thereafter preventing upward movement of said slip cone with respect to said slips, said last named means comprising teeth on the reverse face of said slips for engaging the external surface of said slip cone.

4. In a permanent type packer for a well a body member adapted to be positioned in a well casing and having an upper body section and a lower body section, said lower body section having an internal diameter greater than said upper body section, normally retracted slips for securing said body member to the casing against pressures from above and below, eachV of said slips being disposed in an aperture in said lower body section so that relative longitudinal movement therebetween is prevented, a mandrel extending through said body member, a slip cone disposed between vsaid mandrel and said lower body section for eiecting movement of said slips into engagement with said casing, shearable pins for normally securing said slips to said slip cone, sealing means between saidV mandrel and said upper body section, said mandrel and saidslip cone, and said slip cone and said lower body section forming an annular chamber communicating with the upper end of said slip cone, and an aperture in said mandrel providing communication between the interior of the mandrel and said chamber.

5. In a permanenttype packer for a well a body member adapted to be positioned in a well casing and having an upper body section and a lower body section, said lower body section having an internal diameter greater than said upper body section, and said upper body section having an external diameter less than the said lower body section and being providedwith a threaded portion at its upper end and an external shoulder adjacent its lower end, normally retracted slips for securing said body member to the casing against pressuresfrom above and below, each of said slips being disposed in an aperture in said lower body section so that relative longitudinal movement therebetween is prevented, a mandrel extending through said body member, a slip cone disposed between said mandrel and said lower body section for eiecting movement of said slips into engagement with said casing, sealing means between said mandrel and said upper body section, said mandrel and said slip cone, and said slip cone and said lower body section forming an annular chamber communicating with the upper end of said slip cone, an aperture in said mandrel providing communication between theinterior of the mandrel and said chamber, a resilient sleevelike packer disposed about said upper body section with one of its ends in contact with said shoulder, and a compression collar threaded on the upper end of said upper body section and adapted to be threaded down thereon for subjecting said packer to endwise compressive force to expand said packer into sealing engagement with said casing.

6. In a permanent type packer for a well a body member adapted to be positioned in a well Y casingV and having an upper body section and a lower body section, said lower body section having an internal diameter greater than said upper body section, and said upper body section having an external diameter less than the said lower body section and being provided with a threaded portion at its upper end and an external shoulder adjacent its lower end, normally retracted slips for securing said body member-to the casing against pressures from above and below, each of said slips being disposed in an aperture in said lower body section so that relative longitudinal movement therebetween is prevented, a mandrel extending through said body member, a slip cone disposed between said mandrel and said lower body section for effecting movement of said slips into engagement with said casing, sealing means between said mandrel and said upper body section, said mandrel and said slip cone, and said slip cone and said lower body section forming an annular chamber communicating with the upper end of said slip cone, an aperture in saidmandrel providing communication between the interior of the mandrel and said chamber, a resilient sleeve-like packer disposed about said upper body section with one of its ends in contact with said shoulder, a compression ring disposed about said upper body section and in contact with the other end of said packer, and a collar threaded on the upper end of said upper body section and adapted to be threaded down thereon for subjecting said ring and said packer to endwise compressive force to expand said packer into sealing engagement with said casing. v

7. In a permanent typeA packer for a well a 9 body member adapted to be positioned in a well casing and having an upper body section and a lower body section, said lower body section having an internal diameter greater than said upper body section, and said upper body section having an external diameter less than the said lower body section and being provided with an external shoulder adjacent its lower end, normally retracted slips for securing said body member to the easing against pressures from above and below, each of said slips being disposed in an aperture in said lower body section so that relative longitudinal movement therebetween is prevented, a mandrel extending through said body member, a slip cone disposed between said mandrel and said lower body section for eiecting movement of said slips into engagement with said casing, sealing means between said mandrel and said upper body section, said mandrel and said slip cone, and said slip cone and said lower body section forming an annular chamber communieating with the upper end of said slip cone, an aperture in saidv mandrel providing communication between the interior of the mandrel and said chamber, a resilient sleeve-like packer disposed about said upper body section with one of its ends in contact with said shoulder, a compression ring disposed 4about said upper body section and in contact with the other end of said packer, and

l0 a collar threaded on the upper end of said upper body section for subjecting said ring and said packer to endwise compressive force to expand said packer into sealing engagement with said casing, said collar being threadably connected to a coupling provided on the upper end of said mandrel whereby said collar may be threaded down on said body member to compress said packer, and a shearable pin normally maintaining said coupling and said collar in threaded engagement.

JACK C. WEBBER.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Baker Apr. 19, 1949