US3035639A

US3035639A - Hydraulically-actuated well packer

Info

Publication number: US3035639A
Application number: US661816A
Authority: US
Inventors: Cicero C Brown; Chudleigh B Cochran
Original assignee: BROWN
Current assignee: BROWN
Priority date: 1957-05-27
Filing date: 1957-05-27
Publication date: 1962-05-22
Anticipated expiration: 1979-05-22

Description

May 22, 1962 c. c. BROWN ETAL 3,035,639

HYDRAULICALLY-ACTUATED WELL PACKER Filed May 27, 1957 2 Sheets-Sheet 2 C/ce/"Q C. Brow/7 (/n/d/e/yfi 5. Cor/Iran INVENTORS ATTO/PA/EKS United States Patent ()fiice 3,035,639 Patented May 22, 1962 3,035,639 HYDRAULICALLY-ACTUATED WELL PACKER Cicero C. Brown and Chudleigh B. Cochran, both of 2216 Campbell St., Houston, Tex.; said Cochran assignor to said Brown Filed May 27, 1957, Ser. No. 661,816 2 Claims. (Cl. 166-150) This invention relates to well packers and more particularly to well packers which are set by fluid pressure.

It is an object of this invention to provide a well packer which is set by fluid pressure applied directly from the surface to the packing element.

Another object is to provide a well packer set by fluid pressure applied directly from the surface to the packing element in which pressure fluid applied is trapped within the packer until selectively released to release the packer.

Another object is to provide a well packer as in the preceding objects in which the trapped pressure fluid is released by surface manipulation of a valve in the packer.

Another object is to provide a well packer as in the preceding objects in which the trapped pressure fluid is released by surface manipulation of a tubing string in the case of packers utilized with tubing or surface manipulation of a retrieving spear in the case of a packer used as a plug.

Another object is to provide a well packer set by fluid pressure in which the setting pressure need not be more than slightly above well pressure at the level of the packer and which will hold against a well pressure which thereafter rises to a value greater than the original setting pressure.

Another object is to provide a well packer set by fluid pressure in which the pressure holding the packing element against the wall of the well will always equal or exceed the pressure either below or above the packer even though these pressures may exceed the original setting pressure to prevent leakage by the packer.

Another object is to provide a well packer set by fluid pressure in which fluid pressure from either above or below the packer augments the setting fluid pressure when the pressure above or below the packer exceeds the original setting pressure.

Another object is to provide a packer set by fluid pressure applied from the surface which in different forms may be used for single or multiple string completion or which may be used to provide a plug in the well.

Other objects, features and advantages of this invention will be apparent from the drawings, the specification and claims.

In the drawings wherein there are shown illustrative embodiments of this invention and wherein like reference numerals indicate like parts:

FIG. 1 is a view in longitudinal cross section of a packer constructed in accordance with this invention. This packer is designed for use with single string completion or as the lowermost packer in plural string completion;

FIG. 2 is fragmentary longitudinal sectional view on an enlarged scale of a portion of packer illustrated in FIG. 1;

FIG. 3 is a view partially in longitudinal cross section and partially an elevation illustrating a modified form of packer constructed in accordance with this invention and particularly designed to be used as a well plug;

FIG. 4 is a fragmentary view similar to FIG. 3 showing a retrieving spear landed in the packer to release the fluid within the packing element and retrieve the packer; and

FIG. 5 is a fragmentary longitudinal sectional view similar to FIG. 1 illustrating a modified form of the packer illustrated in FIG. 1.

In the drawings (FIGURES 1 and 2) the numeral designates an annular body upon which is mounted an annular elastic packing element 11. The body is formed with a bore 12 extending entirely therethrough and a section 13 of the tubing string is positioned within and extends through the bore with its lower end projecting from the bore in the manner illustrated in FIGURE 1. The upper end of the body 10 abuts an external annular shoulder 14 formed on the exterior of the tubing section and when the parts are in the position of FIGURE 1, the body is releasably attached to the tubing section 13 by a shear pin 15a at the lower end of said body. It is thus apparent that the body 10 and the tubing section 13 constitute a support for the packing element 11. This is the position of the parts during running or lowering of the assembly into the well bore.

The packing element 11 comprises an annular sleeve of elastic material having its end portions 11a reduced in diameter. The upper reduced end portion is confined within an annular retaining collar 11b which abuts an external shoulder 10a on the body 10 and which is secured to the body by a coupling sleeve 10]). The lower reduced end portion of the packing element is confined within a similar retaining collar which is secured to the lower end of the body 10 by suitable screws 11d. Packing rings lle within the bores of the retaining collars 11b and lie seal with the exterior of the body. Anchoring means in the form of gripping

members

17 and 18 are molded or otherwise secured in the outer surface of the packing element 11 within the upper and lower portions thereof and said gripping members are adapted to engage the wall of the well casing or pipe 16 when the annular packing element 11 is moved outwardly into sealing position with said casing.

The end portions of the packing element are thus firmly attached to the body and the space between the bore 11 of the packing element and the outer surface of the body forms an annular chamber 15 which, as will be explained, is arranged to receive a pressure fluid. When pressure fluid is introduced into the chamber 15, the packing element 11 is urged outwardly in a radial direction so that the exterior surface of its central portion sealingly engages the casing with the

gripping members

17 and 18 also engaging the casing wall to prevent displacement of the assembly. Upon the relief of pressure from chamber 15, the inherent resiliency of the packing element 11 will return said element to its initial undistorted position (FIGURE 1) which may be referred to as the retracted position of the element.

For controlling the entry of a pressure fluid into the chamber 15, a plurality of radial ports 19, which are arranged in an annular path, are provided in the body 10. When the tubing section 13 is connected to the body by the shear pin 15a, the ports 19 lie in the same horizontal plane as an annular external recess 24a which is formed in the exterior surface of the tubing section. Radial openings 24 extend through the wall of the tubing section and establish communication between the bore of the tubing section 13 and the inlet ports 19 in the body. As illus trated, two of the ports 19 are shown but it is obvious that the number may vary. To assure that pressure fluid flowing through the openings 24 will pass to the ports 19,

annular sealing rings

25 and 26 are provided above and below the annular recess 24a and these rings seal the joint between the exterior surface of the tubing section 13 and the bore of the body.

It is evident that pressure fluid from the bore of the tubing section may enter the chamber 15 through the ports 19 and in order to provide a second entry for pressure into the chamber 15, additional inlet ports 32 are formed in the body. These ports are spaced upwardly from the ports 19 and extend from the bore of the body into the chamber. The upper end of the body is formed with an inclined port 33:: which establishes communication between the area above the packer assembly and the bore of the body 16. Since there are no sealing rings between the inclined passage 33a and the inlet ports 32, pressure from above the assembly may pass downwardly through passage 33a, then through the space between the exterior of tubing section 13 and the bore of the body to the inlet ports 32 from where it may flow into the chamber 15. A sealing ring 38, preferably mounted on the tubing section, seals the Space between the section and the bore at a point below the inlet ports 32 when the parts are in the position shown in FIGURE 1.

For permitting the admission of pressure fluid through each port 19 while preventing a back flow through said port, a check valve 21 is provided and is adapted to engage a conical seat 23 (FIGURE 2) formed at the extremity of each inlet port. The check valve includes a semispherical member engageable with the seat and this member is attached to one end of a leaf spring 22 which is disposed within a recessed portion 22a in the exterior of the body 10. The leaf spring has its central portion connected to the body by a suitable stud 35 which is threaded into the body. The inherent resiliency of the spring maintains the valve 21 in seated position; however, the application of pressure fluid from the bore of the tubing section through each inlet port 19 acts against the valve 21 associated with such port, unseats that valve and permits a flow into the chamber 15. If the pressure within chamber 15 exceeds the pressure within the tubing section, the valve 21 will automatically seat to prevent how in an opposite direction.

For providing one-way flow through each of the upper inlet ports 32, a check valve 33 is adapted to engage a seat 34 formed at the inner end of each port 32. This valve is mounted on the opposite end of the leaf spring 22 and said spring functions to constantly urge the valve toward a seated position. It is evident that the pressure fluid which may pass downwardly from the area above the assembly through passage 33:: and to the ports 32, may unseat the valve 33 at any time that this pressure is greater than the pressure within the chamber 15; however, reverse fiow of pressure from the chamber 15 through each port 32 is prevented by its respective valve.

For the purpose of releasing the pressure from chamber 15 when the packer is to be removed, as will be explained, the stud 35 which attaches the leaf spring 22 to the body is formed with an axial opening 36 which is in registration with a vent passage 37, the latter extending through the wall of the body and establishing a communication between the chamber and the space between the exterior of the tubing section 13 and body 10. With the parts in the position shown in FIGURE 1, the sealing rings and 33 are disposed above and below the vent openings 37 and will, of course, prevent an escape of pressure from chamber 15.

When the pin 15a is sheared and the tubing section is.

moved upwardly with respect to the body 10, the annular recess 24a can move upwardly opposite the vent openings 37 and when this occurs, any pressure within the chamber 15 may be vented through the openings 37 and through the ports 24 into the bore of the tubing section 13. At the time that the tubing section is moved upwardly relative to the body, an equalizing port 39, provided in the upper end of the section 13 just below the shoulder 14, moves upwardly above the body 10 and allows equalization of pressures across the device. It might be noted that when the tubing section 13 is in the position shown in FIGURE 1, flow through the equalizing ports 39 is prevented by packing rings 39a which are disposed above and below said ports and which seal between the exterior of the section and the bore of the body.

The lower end of the tubing section 13 has a support collar 27 threaded thereon and within the bore of this collar is an annular seat element 29 which is connected to the collar by means of a pin 31. As will be explained, a retrievable plug 25 may be lowered through the tubing string to engage the upper end of the annular seat member 29 to close the bore of the tubing section, whereby pressure may be built up therein. Normally the plug 23 will be retrieved by a wire line but if for some reason this can not be done, the application of sufiicient pres sure to the plug to shear pins 31 would permit the plug and its seat member to be displaced downwardly out of the tubing section.

In operation the parts are connected as shown in FIGURE 1 and are lowered to proper position within the well casing 16. The plug 28 is then dropped through the tubing to engage the seat 29 and close the bore of the tubing section. Thereafter, pressure is built up within the bore of the tubing section and the pressure fluid may flow through ports 24 and inlet ports 19, opening check valves 21 and into the chamber to apply an internal pressure to the elastic packing element 11. The element is thus distorted or deformed outwardly in the manner shown in FIGURE 2 so that its exterior portion sealingly engagesthe wall of the casing 16 while the

gripping elements

17 and 18 engage said casing to prevent lon gitudinal displacement of the assembly within the pipe. After sufiicient pressure has been built up to effect the proper seal, the pressure may be relieved from the tubing string and the check valves 21 will maintain the pressure in chamber 15 to assure that the packer remains in set position. Thereafter, the plug 28 is retrieved by means of a wire line or by pumping the same outwardly from the lower end and then the tubing string is utilized as a production string in the usual manner. In the event that pressure below the packing element increases to a point in excess of the pressure within the chamber 15, this pressure might tend to get between the exterior surface of the packing element 11 and the casing, and if sufficient, could result in a retraction of the packmg element. However, this pressure is also present in the tubing string 13 and if it exceeds the pressure in chamber 15, it will flow through inlet ports 19, unseating the check valve and thus will assure that the packing element will remain in set position.

Similarly, any pressure from above the packer, that is in the annulus between tubing and casing behind the pressure present within the chamber, may pass downwardly through passage 33a, inlet ports 13 to unseat the check valves 33 and thereby enter the chamber. Therefore, when the packer is in set position, any excessive increase in pressure either above or below the packer is automatically conducted into the chamber 15 to assure that the packer will be maintained in its set position.

In order to release the packer, it is only necessary to shear the pin 15a which connects the tubing section 13 to the body 10 and to thereafter move the tubing upwardly to register the ports 24 in the tubing section with the vent openings 37 in the body. When this occurs, the pressure within the chamber 15 may pass into the bore of the tubing section and be relieved whereby the inherent resiliency of the packing element will return the element to its normal retracted position. The collar 27 at the lower end of the tubing then engages the lower end of the body 10 so that the assembly may be retrieved.

It is pointed out that the construction is relatively simple with both check valves being mounted on the single leaf spring. The vent opening 37 which relieves pressure is arranged to extend through the fastening stud 35 which fastens each leaf spring in position. When in set position, the assembly can not be displaced by a excessive pressure which may be present either above or below the device. The device may be employed as an ordinary production packer but finds particular application in multiple formation production, such application being more clearly illus trated and described in our co-pending application, Serial No. 659,197, filed April 26, 1957, now Patent No. 2,991,833.

In FIGURES 3 and 4 a modification of the invention is illustrated. This form comprises an annular body or support 110 having a bore 110a extending entirely therethrough. The upper portion of the bore is counter-bored as shown at 47. The annular packing element 11 is mounted on the body and includes the

gripping elements

17 and 18. The upper end of the packer is retained by a retaining collar 111b while the lower end is retained by a retaining collar 111c. A coupling collar 112 is connected to the upper retaining collar 111b and has' connection through a shear pin 49 with the coupling 45 of the tubing string. The coupling collar 112 is provided with a passage 113 which establishes communication between the area above the packer and the counter-bore 47 of the body 110.

The body is formed with one or more lower inlet ports 119 which extend through the body and establish communication between the bore of the body and the chamber 15 which is formed between the exterior of the body and the packing element 11. Each inlet 119 has a check valve 48 associated therewith with the valve being mounted on one end of a leaf spring 49. The other end of said spring is attached to the exterior of the body and the inherent resiliency of the spring maintains the valve in closed position.

One or more upper ports 132 communicate with the chamber 15 and extend through the body ata point within the counter-bore 47. For defining an annular passage 47a, an elongate sleeve 45a extends downwardly from the coupling 45 and into the bore of the body 110 to a point below the counter-bore 47. A seal ring 46 seals the space between the exterior of the sleeve 45a and the body. A check valve 51 mounted on a leaf spring 52 controls admission of pressure fluid into the chamber through the passage 132. It will be evident that pressure from above the assembly may pass downwardly through the passage 113 through the annular area 47a and then through the port 132 into the chamber 15.

It might be noted that in the form shown in FIGURE 3 the upper and

lower check valves

48 and 51 are mounted as individual elements, each being secured to its separate leaf spring; in FIGURE 1 a simpler type of construction is shown in that a single leaf spring carries one of the check valves at one end and the other check valve at its opposite end. However, the operation is the same in both instances.

The lower end of the body 110 projects downwardly and has a seating collar 11017 secured thereto and a closure plug 43 is adapted to be dropped downwardly to close the bore through the tubing string and body in a manner similar to that of plug 28 shown in FIGURE 1 and discussed above.

The operation of this form is believed to be evident from the previous description. The plug 43 is dropped through the tubing to close the bore through the tubing string and body, and thereafter pressure is built up within the tubing and within the bore 110a of the body 110. The pressure fluid enters each port 119 unseating the check valve 48 and flows into chamber 15 to move the packing element to set position. After the packer is set, plug 43 is removed.

With the packer in set position, any increase of pressure below the packer which might tend to move the same to an unset position may pass upwardly through bore 110a, then through each port 119 and into chamber 15 to assure that the packing element will remain set. Similarly, any pressure from above which might be in excess of pressure in the chamber 15 may flow downwardly through passage 113, annular space 47 and past the check valve 51 into the chamber.

If it is desired to employ the packer as a bridge plug which would completely close the bore of the well, this may be done with the form shown in FIGURE 3. The

6. bore a of the body 110 is provided with a locking recess 55 and this recess is adapted to receive the usual locking dogs 55a of a wire line retrievable plug which is generally indicated at 44. The retrievable plug is well known in the art, one type being manufactured by the the Otis Pressure Control, Inc., of Dallas, Texas. See the 1958-1959 Composite Catalog of Oil Field Equipment, vol. 3, page 3969, wherein a Type F Otis Removable Collar Stop is illustrated. Although the details of the plug form no part of the present invention since any retrievable type plug may be employed, it is pointed out that such plug employs an outer sleeve 54 which carries the radially movable dogs 55a and which has the packing 57 thereon. An inner mandrel 56 having an expander projection 57a is slidable relative to the outer sleeve or carrier. Normally the device is lowered by means of a wire line which is engaged with the fishing neck of the mandrel and also with the sleeve 54 whereby the carrier and dogs are in lowered position relative thereto. This places the radially movable dogs opposite the reduced lower end of the mandrel 56 so that said dogs are in retracted position. The plug is moved downwardly through the tubing string sleeve 45a until a shoulder at the lower end of the outer sleeve 54 of the plug engages a shoulder 54a within the bore; this halts downward movement of the carrier and the radially movable dogs are positioned opposite opposite the recess. Thereafter downward jarring on the inner mandrel moves the same relative to the sleeve and causes the expander projection 57a to co-act with the dogs 55a to'thereby move said dogs radially outwardly into the locking recess 55. When the plug is used, the bore through the device is closed and the unit functions as a bridge plug. If desired, the tubing may be pulled upwardly to shear pin 49 to remove the tubing and permit the device to remain in the well bore.

When it is desired to release the packing element 11 of the form shown in FIGURE 3, the plug 44 is first retrieved by a wire line, such release being efiected by a straight upward pull on the inner mandrel 56 which moves the expander projection 57a from behind the locking dogs 55 to permit their retraction. Thereafter, a conventional retrieving spear S is lowered by means of a lowering pipe until the spear enters the counter-bore 47 of the bore 110a of the body. See the 1958-1959 Composite Catalog of Oil Field Equipment, vol. 2, page 2388, which illustrates one type of spear which could be employed, such spear being manufactured and offered by the Houston Oil Field Material Company. The external diameter of the outer surface 59 of the spear is such that said spear will engage an extending lug 53 which is formed on the check valve 51, the extremity of such lug extending into the counter-bore 47 and having its innermost end rounded whereby the lug is forced radially outwardly by an element, such as the spear S, passing through the counter-bore 47. This results in the check valve 51 being opened to allow escape of pressure from the chamber 15 so as to equalize pressures across the assembly so that the packing element may return to its original undeformed position. The spear includes gripping slips 59a which engage the Wall of the counter-bore 47 and upon upward movement of retrieving pipe and spear, the assembly may be removed from the bore.

Referring back to the form of the invention shown in FIGURE 1, it is noted that the inlet openings 24 which communicate with the inlet ports 19 are normally open during running in of the assembly. There may be instances where excessive pressures built up during the running of the assembly may cause premature setting of the packer element. To positively prevent the entrance of any pressure into chamber 15, the bore of the tubing section 13 may have a valve sleeve 61 mounted therein to span the ports or openings 24. As shown in FIGURE 5, the sleeve 61 is connected by a shear pin 64 to the body and is provided with packing rings 62 and 63 which are 7 located one on each side of the openings 24 when the sleeve is in position. The sleeve actually forms a closure of the openings 24 and thus during running in of the device, premature setting is prevented.

When it is desired to set the packer, a ball 65, or if desired, a go-devil (not shown) may be dropped downwardly to seat on the upper end of the valve sleeve 61, and upon application of pressure, the pins 64 are sheared to remove the sleeve and open the port 24. The packer will then be set in the manner heretofore described.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and the various changes in size, shape and materials as well as in the details of the illustrated construction may bemade within the scope of the appended claims without departing from the spirit of the invention. See for instance the various forms of this invention illustrated in our copending application'identified hereinabove.

What is claimed is:

l. A well packer comprising, a support having a bore extending therethrough, an annular elastic packing element mounted on the support and secured thereto at spaced points to provide a fluid chamber between the packing element and support, means establishing fluid communication between the bore of the support and the chamber, check valve means in said communication establishing means permitting fluid flow from the bore into the chamber while preventing flow from the chamber, additional means in the support establishing communication between the area above the packing element and the chamber, check valve means in said additional communication-establishing means permitting fluid flow from above the packer into the chamber while preventing flow from the chamber, and means for selectively releasing the'fiuid from the chmber comprising a pressure release passageway between the chamber and bore of the support and a tubular valve member forming part of the support and having said bore therein, said relief passageway being opened by shifting of the tubular valve element.

2. A well packer comprising, a tubularsupport, an annular packing element surrounding the support and having its end portions attached thereto, the space between the exterior of the support and the bore of the packing element forming an annular pressure chamber, said support having an inlet extending from the bore of the support into the chamber, a back check valve means for admitting pressure fiuid through the inlet into the chamber while preventing reverse flow through said inlet, the support having a second inlet for'conducting pressure to said chamber, back check valve means co-acting with said second inlet, passage means within the support for establishing communication between the area above the packing element and said second inlet, the first inlet and the second inlet being spaced longitudinally from each other, both said check valve means being carried by a spring supporting means attached to the outer surface of the support, said spring supporting means constantly urging said check valves toward closed position.

References Cited in the file of this patent UNITED STATES PATENTS 2,177,601 Smith Oct. 24, 1939 2,231,282 Norris Feb. 11, 1941 2,451,762 Millikan Oct. 19, 1948 2,798,560 Allen July 9, 1957