US2451762A

US2451762A - Packing ring

Info

Publication number: US2451762A
Application number: US603127A
Authority: US
Inventors: Charles V Millikan
Original assignee: Geophysical Research Corp
Current assignee: Geophysical Research Corp
Priority date: 1945-07-04
Filing date: 1945-07-04
Publication date: 1948-10-19
Anticipated expiration: 1965-10-19

Description

C. V. MILLIKAN .PACKING RING Oct. 19, 1948.

Filed July 4, 1945 V I 3. m

IN VEN TOR.

Patented Oct. 19, 1948 PACKING RING Charles V. Millikan, Tulsa, Okla., assignor to Geophysical Research Corporation, New York, N. Y., a corporation of New Jersey Application July 4, 1945, Serial No. 603,127

1 This invention relates to packing rings.

In th patent to Charles V. Millikan, No. 2,374,- 557, granted April 24, 1945, there is disclosed a procedure of separately testing the type of fluid being produced in each of several zones in a well and the rate at which the fluid is being produced. In the practice of this procedure, it is necessary to divide up a portion of the well into zones by a series of packing rings mounted tightly upon the exterior of the tubing through which the well is produced and with the outer circumference of each packing .ring contacting the interior of the casing lining the well. The tubing must be lowered into the well with the packing rings attached and, thereforathe rim of the packing ring cannot be made to fit too tightly in the well casing because the abrasion necessarily occurring while the tubing is being lowered would severely dam- :age the packing ring before it reaches its proper position in the Well.

An object of this invention is a packing ring .of such structure that it will pass through a long well casing while mounted on the tubing without sufiering material damage and when it arrives at its proper position in the well casing will effectively co-operate therewith to form a fluidtight seal.

Other objects, novel features and advantages of this invention will-become apparent from the following specification and accompanying drawings, wherein:

Fig. 1 ice. fragmentary section through a well containing a tubing and having mounted thereon packing rings embodying the invention;

Fig. 2 is a plan view of the acking ring shown in section in Fig. 1;

'Fig. 3 is an enlarged section similar to Fig. 1, and

Fig. 4 is a fragmentary view of the inner surface of the packing ring substantially on the line i4 of Fig. 3.

In Fig. 1, H1 is a standard steel casing set into a bore hole in the ground with cement H in. the usual. manner. "Within the casing in is a discharge tubing |2 which is provided at intervals with a number of packing rings .13, only two of which are herein illustrated, the packing rings contacting the inner surface of the casing ID to form annular zones [4. While the spacing of the packing rings l 3 may be varied, it has'been found that aspacing of approximately three feet is satisfactory.

The casing I is provided with the usual apertures l5 communicating through passages IS with the strata, surrounding the well, these apertures I 6 Claims. (Cl. 166-10) gral sealing flange '23.

2 and the passageways being formed in the usual manner after the casing has been set in place by bullets shot from a special gun lowered into the casing. The discharge tubing [2 is provided with one or more apertures I 1 between @each pair of packing rings i3to provide communication between each chamber and the interior of the discharge tubing '12. Within the discharge tubing 12 is arranged the testing instrument l8 disclosed in detail in said Millikan Patent No. 2,374,557.

On the inner wall of the discharge tubing l2 are provided packing rings I!) which are spaced apart approximately the same distance as the packing rings l3 and are located closely adjacent the same. Each pair ofpacking rings 19 forms :an annularchamber 20 with the exterior of the instrument I8 when the instrument is so arranged that its exterior-contacts both rings of the pair. The rings 1'!) are so designed that the instrument l8 fits them snugly but the instrument is capable of movement relative thereto so that it may be placed in and removed from the discharge tubing. When in proper position, the inlet 2| of the instrument l8 communicates with a single chamber 20 which in turn communicates with a singlezone l4 so that only fluid from such zone is permitted to pass into the instrument I8.

The packing ring I3 is composed of suitable flexible and resilient material such, for example, as oil-resistant rubber compound, rubber, etc. This ring comprises a sleeve 22 having an inte- The flange 23 extends from the outer surface of the sleeve 22'midway the ends thereof outwardly and has a surface 24 contacting th inner surface of the casing Ill. The flange 23 is sufficiently flexible that when a packing ring is being passed through the wall casing, it bends easily to disengage the surface 24 from the inner surface of the casing l0 so that damage to the sealing surface 24 is avoided.

The central portion of the inner surface of the sleeve 22 is hollowed out to form an annular recess 25. The ends of the surface of the sleeve constitute sealing surfaces 25 contacting the outer surface of the tubing 12. When the packing ring is mounted on the tubing. the recess 25 forms a chamber having a portion of the tubing forming its inner wall. A short distance above and below the recess 25, the inner surface of the packing ring 22 is cut circumferentially by slits 21 to form flexible lips or flaps -28. At each end of the sleeve 22, one or more passageways 29 lead from the exterior of the sleeve to the recess 25. The passageways 29 are normally closed at their inner endsby the flaps 28 which form one-way valves.

The inner annular surfaces 30 of the flaps 28 are slightly relieved so that they do not make close contact With the tubing !2. When the pressure in a, zone It! is greater than the pressure in the chamber 25, fluid flow is directed from the exterior of the packing ring 22 to the chamber 25 by deflection of a flexible flap 28 as illustrated in Fig. 3 (bottom flap) or Fig. 4. The remaining flap 28 remains in its normally closed position as shown in Fig. 3 (top flap). For ease of illustration, the passageways 29 have been shown in the same vertical radial plane whereas actually no two of the passageways are necessarily in the same vertical radial plane.

Assume that the packing ring I3 is in the position shown in the well casing with the surface 24 of the flange 23 engaging the inner surface of the casing I and that equal pressure exists above and below said flange. The same pressure exists in the chamber 25 and both sets of passageways 29 are obstructed at their inner ends by the flaps 28 being closed. Under these circumstances, there will be no tendency for the fluid to flow between the surface 24 and the inner surface of the casing III.

In the event that the pressure on one side of the packing ring flange 23 exceeds the pressure on the other side thereof, fluid will tend to flow between the surface 24 and the inner surface of the well casing from the side of higher pressure to the side of lower pressure. However, the increased pressure on one side of the flange 23 is also applied to the flaps 28 at the inner ends of the passageways 29 communicating with the higher pressure side to deflect said flaps and as shown in Fig. 4, thus permit the higher pressure to be applied through the open slits 2'1 over the entire inner wall of the chamber 25. The remaining flaps 28 prevent fluid flow through the chamber 25 and remaining passageways 29 to the lower pressure side. The force thus exerted on the chamber wall urges it outwardly and engages the surface 24 of the sealing flange 23 tightly against the surface of the casing 10. The increased pressure in the chamber 25 also tends to produce leakage from the chamber 25 between the surface of the tubing l2 and the sealing surface 26 on the lower pressure side. Such leakage is very small because the packing ring 13 is made to flt very snugly on the tubing [2 and is insufficient to interfere with the above-described operation. The small amount of leakage which does occur is desirable since it permits the pressure in the chamber 25 to bleed off as the packing ring I3 is being removed from the casing and thereby avoids damage to the flange 23 during removal. A very small pressure increase applied to the interior of the chamber 25 produces a very large outward force against the sealing flange 23 by reason of the large area over which the pressure is applied.

It is of course understood that various changes may be made in the structure above described without in any way departing from the spirit of the invention as defined in the appended claims, for example, the one-way valves at the ends of the passageways 29 may be differently made than as specifically disclosed, the flap arrangement merely being an example of a convenient form of valve.

I claim:

1. A packing ring comprising a flexible resilient sleeve having an integral flexible resilient peripheral flange, an annular recess in the inner surface of said sleeve, passageways leadin to said recess from the exterior surface of said sleeve at either side of said flange, and means for preventing fluid flow from said recess through said passageways while permitting flow in the reverse direction.

2. A packing ring for use between a Well tubing and a well casing, said ring comprising a flexible resilient sleeve adapted snugly to surround the tubin and having an integral flexible resilient peripheral flange adapted to contact the casing, an annular recess in the inner surface of said sleeve constituting a chamber having a section of the well tubing surface forming a portion of its wall, passageways leading to said recess through the sleeve from the exterior thereof at either side of said flange, and means for preventin flow from said chamber through either passageway while permittin flow in the reverse direction.

3. A packing ring comprising a flexible resilient sleeve having an integral flexible resilient flange, a recess in the inner surface of said sleeve, a passageway leading toward said recess from the exterior surface of said sleeve at either side of said flange, and a slit in said sleeve leading from the inner end of each passageway to said recess, said slit permitting flow through said passageway into said recess but preventing flow from said recess into said passageway.

4. A packing ring for use between a well tubing and a well casing, said ring comprising a flexible resilient sleeve adapted snugly to surround the tubing and having an integral flexible resilient peripheral flange adapted to contact the casing, a recess in the inner surface of said sleeve constituting a chamber having a section of the well tubing surface forming a portion of its wall, a passageway leading toward said chamber from the exterior of said sleeve at either side of said flange, and a slit in said sleeve leading from the inner end of each passageway to said recess, said slit permitting flow from said passageway into said chamber but preventing flow from said chamber into said passageway.

5. A packing ring comprising a flexible resilient sleeve having an integral, flexible, resilient peripheral flange, and an annular recess in the inner surface of said sleeve, said sleeve having provision for admitting fluid from the exterior of said sleeve at either side of said flange into said recess while preventing flow in the reverse direction.

6. A packing ring for use in the annular space between two concentric different-diameter tubes, said ring comprising a flexible resilient sleeve adapted snugly to surround the inner tube and having an integral, flexible, resilient peripheral flange adapted to contact the outer tube, and an annular recess in the inner surface of said sleeve constituting a chamber having a section of the inner tube surface forming a portion of its wall, said sleeve having provision for admitting fluid into said chamber from either side of said flange while preventing flow out of said chamber.

CHARLES V. MILLIKAN.

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

UNITED STATES PATENTS Number Name Date 1,513,228 Crotto Oct. 28, 1924 2,334,788 OLeary Nov. 23, 1943 2,374,557 Millikan Apr. 24, 1945 2,395,137 Millikan Feb. 19, 1946