US2748871A - Well packers - Google Patents

Description

June 5-, 1956 c. c. BROWN 2,748,871

WELL PACKERS .Filed Feb. 20, 1950 I 2 Sheets-Sheet l C "54 5 li 5 I 1 4 C/cero CBrow/I u Z7 INVENTOR.

I, Z9 W m A T TOR/VEKS June 5, 1956 c, c, BROWN 2,748,871

WELL PACKERS Filed Feb. 20, 1950 2 Sheets-Sheet 2 J Z5 Ky 26 C 32 T Y 5 5' A 9 J5 Gwen; C Brow/7 INVENTOR.

United States Patent WELL PACKERS Cicero C. Brown, Houston, Tex.

Application February 20, 1950, Serial No. 145,253

1 Claim. (Cl. 166-129) This invention relates to new and useful improvements in well packers.

It is one object of the invention to provide a well packer which may be employed for substantially any well operation, for example, the packer may be used as a normal well packer to seal the annular space between a well tubing and well casing or if desired may be just as readily employed as a squeeze packer for carrying out squeezing or pipe testing operations.

Another object of the invention is to provide an improved packer which is lowered in the usual manner on the well tubing and having means whereby the differential in pressure above and below the packer is utilized to maintain said packer in its set position; said packer also having means whereby if desired the tubing weight may be employed to assist the differential in well pressures in holding the packer in its set position.

An important object of the invention is to provide an improved well packer which when employed in a normal packing operation has means for circulating completely to bottom, rather than merely circulating at a point just below the packer unit, as is the case with the usual type of well packer.

A still further object is to provide a packer which when employed as a squeeze packer is provided with means for performing the squeezing operation at a point well below the packing unit whereby the squeezing operation may be carried out in the lower end of the well bore while the packer may be set at some distance upwardly within said bore.

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 view partly in elevation and partly in section of the upper portion of the packer with the parts thereof in position prior to setting of the packer,

Figure 3 is a continuation of Figure 2 showing the lower portion of the packer,

Figure 4 is a view similar to Figure 3 illustrating the packer unit in its set position within the well bore,

Figure 5 is a horizontal cross-sectional view taken on the line 55 of Figure 3, and

Figure 6 is a detail of the J-slot connection between the lowering mandrel and the packer unit.

'In the drawings, the numeral 10 designates a well tubing which is adapted to be lowered through the usual well casing 11 within a well bore. A tubular support or mandrel- 12 is connected in the tubing string by means of acoupling 13 and said mandrel is formed with fluid openings or by-pass slots 14 which are spaced at some point 2,748,871 Patented June 5, 1956 below the coupling collar.13. The coupling collar i3 has its lower portion 15 of a larger external diameter than the mandrel whereby an annular shoulder 16 is formed at the intersection of the mandrel and coupling. Above the portion 15 the coupling is further enlarged externally as indicated at 17 whereby a second external shoulder 18 which is preferably beveled is formed on the coupling.

The lower portion of the mandrel 12 is formed with an upset portion or section 19 (Figure 6) which is of a larger external diameter than the external diameter of the mandrel and this section is illustrated as integral with the mandrel; however, the upset section 19 could be formed of a sleeve encircling the mandrel and welded or otherwise secured thereto. A J-slot 20 is formed in the upper portion of the enlarged portion or upset section 19 and the longitudinal portion 20a or J-slot extends downwardly from the upper end of said section. The lateral or horizontal leg 20b of the J-slot extends from the lower end of the longitudinal portion 20a of said slot and said lateral leg is disposed above the lower end of the upset section. It is preferable that the upper and lower edges of the upset or enlarged diameter section 19 be beveled or inclined as indicated at 21 and 22 in Figure 6. The mandrel 12 is formed with an axial bore 12a which extends entirely therethrough and said mandrel has its lower portion inclined inwardly as indicated at 23 in Figure 3. This inwardly directed portion is formed with by-pass slots or openings 24.

The coupling collar 13 which connects the upper end of the mandrel with the well tubing is provided with an internal ring 25 which is preferably made integral with the coupling and the inner surface of this ring is formed with screw threads 26. A tubular conductor 27 has its upper end connected to the threads 26 and extends axially through the mandrel 12, the upper end of the bore of said conductor communicating with the tubing 10. The external diameter of the inner conductor 27a is less than the diameter of the bore 12a of the mandrel whereby an annular flow space 28 is provided therebetween. The reduction 23 at the lower end of the mandrel is such that said lower end of the mandrel snugly engages the outer surface of the inner conductor 27 and the lower projecting end of said conductor is coupled through a suitable coupling collar 29 with a tail pipe 30 of any desired length.

The mandrel 12 forms the main supporting element of the well packer which includes an anchoring assembly generally indicated at A, lower sealing cups B and B and an upper sealing cup C. The anchoring assembly comprises a tubular slip carrying cage or sleeve 31 having gripping slips 32 mounted within radially extending slots 33 formed in the cage or sleeve. The outer surface of each gripping slip is formed with gripping teeth 34 while the inner surface thereof is inclined longitudinally as indicated at 35. Outward displacement of each slip from the cage or sleeve is prevented by the coaction of longitudinal side flanges or ribs 36 formed on each slip member (Figure 5) with shoulders 37 provided in the walls of each slot 33.

The slip carrying cage or sleeve 31 is adapted to be detachably coupled or connected with the tubular mandrel 12 by means of a connecting lug or pin 38 which is mounted in the sleeve and has its inner end projecting inwardly from the bore thereof. The projecting inner end of the lug 38 is engageable within the J-slot 2i) and when said lug is disposed in the lateral leg 2% of the J-slot the cage or sleeve is coupled to the mandrel and said mandrel may be utilized to lower and raise said sleeve in the well casing 11.

For coacting with the gripping slips 32 to effect a radial displacement or expansion of said slips an expander or Cone member 39 encircles the mandrel above the upset or enlarged diameter portion 19. The bore of the expander has a sliding fit on the mandrel and its lower end 39a is adapted to engage and be supported upon the upper end 21 of the enlarged section 19. The lower portion of the expander is formed with an expanding cone 40 and the inclination of the outer surface of the cone is complementary to the inclination 35 of the rear surface of the slips 32. An external shoulder 41 is provided on the expander 39 above the expanding cone surface 40 and the upper end of the slip carrying cage or sleeve 31 encircles the cone and extends upwardly above the shoulder 41. A supporting collar 42 is threaded into the bore of the cage or sleeve 31 and the lower end of this collar is arranged to engage the external shoulder 41', whereby the cage or sleeve is suspended from the expander.

When the mandrel 12 is coupled to the slip cage 31 the slips are in a lowered position with respect to the expander and said expander is supported by the engagement of its lower end with the upper end 21 of the enlarged section 19 of the mandrel; in such position the expanding surface of the cone 40 is within the upper portion of the slips and said slips are in a retracted position. The slip carrying cage or sleeve has curved or bowed friction springs 43 secured to its external surface and these springs are in constant frictional engagement with the wall of the well casing 11. Thus, when it is desired to disconnect the mandrel from the cage or sleeve a rotation is imparted to the mandrel while the cage is held stationary by the frictional engagement of the springs 43 with the wall of the casing. Rotation of the mandrel is in a direction to align the longitudinal portion 20a of the J-slot with the connecting lug 38 whereby the mandrel may then be moved downwardly relative to the slip carrying cage or sleeve 31. This moves the cone 40 downwardly within the slips 17 and the coaction between the inclined surfaces 35 with the inclined surface of the cone 40 results in the slips being displaced or expanded radially outwardly to engage their gripping teeth 34 with the wall of the well casing. After such engagement further downward movement of the expander 39 and of the slip carrying cage is prevented. As is clear from Fig. 4, the downward movement of the expander 39 is prevented when the teeth 34 grip the well casing 11 because of the wedging action between the outer surface of the cone 40 and the inclined inner surface 35 of each of the slips.

The sealing elements B and B are connected'to the lower end of the anchoring assembly A and as is clearly shown in Figure 3, the cup B is annular and encircles the lower portion of a tubular coupling 44. The cup may be molded to the coupling member and said coupling has its upper end threaded onto the lower end of the slip carrying cage or sleeve 31. A retaining collar 45 which also encircles the mandrel is threaded onto the lower end of the coupling member 44 and-confines the sealing cup B in position on the coupling. The sealing cup is provided with an annular downwardly directed sealing lip which is flared outwardly so that its external surface is in constant engagement with the well casing as the unit is lowered therethrough. The lower sealing cup has its upper end molded or otherwise secured to a metallic ring 4'7 which is threaded onto the retainer collar 45 and it is thus apparent that both sealing cups B and B are both carried by the slip'carrying cage or sleeve 31. The lowermost sealing cup is formed with a pair of downwardly directed sealing lips 48 and 49 and suitable reinforcing wire 50 may be molded Within the cup to reinforce or strengthen the same.

The listed sealing lips 48 and 49 of the lowermost sealing cup B are adapted to engage the inner wall of the inner casing 11 and external surface of the mandrel 12 whereby the annular space between the casing and mandrel is sealed by said cup. it is noted that the diameters of the sealing lips of the cup 13 are such that said cup is in constant engagement with the casing and the mandrel. Any pressure from below the unit acts upon the sealing lips 48 and 49 to urge the same into a tighter sealing engagement with the casing and mandrel. The second sealing cup B is provided as an additional seal member in the event that a leakage past the sealing lip 48 of the lower cup might occur.

The upper sealing cup C is molded or otherwise secured to an annular metallic ring or collar 51 which is threaded onto the upper end of the expander 39 and said sealing cup is formed with upwardly directed flared sealing lips 52 and 53. The outer sealing lip 52 engages the wall of the well casing 11 while the inner sealing lip engages the inner surface of the mandrel 12 and thereby seals the annular space between the mandrel and the casing. Any pressure acting downwardly on the sealing cup will of course be transferred directly to the upper end of the expander and will tend to urge said expander in a downward direction.

The bore 54 of the upper sealing cup 53 is normally of the same diameter as the bore 39a of the expander and said bore is adapted to be enlarged by radial displacement of the sealing cup C by the enlarged diameter lower end 15 of the connecting coupling 13, which coupling connects the mandrel to the tubing. When the portion 15 of the coupling moves within the bore 54 of the upper sealing cup C said cup is displaced radially outwardly so that in effect its bore is enlarged, thereby allowing the lower portion 15 of the coupling to move downwardly therethrough until the lower end 16 of said coupling engages a beveled shoulder 3% formed within the upper end of the bore 39a of the expander. It is evident that as the enlarged portion 15 of the coupling moves through the upper sealing cup, as shown in Figure 4, the sealing lips 52 and 53 of said cup are displaced into tighter sealing engagement with the well casing and with the coupling whereby a seal of the annular space between the casing and tubing is assured.

In the operation of the device the slip carrying cage 31 is coupled to the mandrel 12 by engaging the connecting lug 38 within the lateral leg 20b of the J-slot 20 and in such position the slips are in a retracted position. Also, the bypass openings 14 in the mandrel are spaced above the upper sealing cup with the by-pass openings 24 in the lower portion of the mandrel being disposed below the lower sealing cup. The inner conductor 27a extends axially through the mandrel 12 and has its lower projecting end connected with a tail pipe 30 of suitable length. As the device is lowered within the Well casing 11 the sealing cups ride downwardly on the wall of the well casing and aby-pass of fluid through the assembly is permitted not only through the conductor 27a but also through the mandrel 12. By-pass through the mandrel is permitted through the by-pass openings 24 in the lower end of said mandrel and upwardly through the annular space 28 between the mandrel and the inner conductor 27a and then outwardly above the upper sealing cup C through the bypass openings 14. For preventing a pressure lock between the upper cup C and the lower cup B, a vent opening 60 is provided in the mandrel below the upset section 19 and communicates with the space between the cups when the mandrel is connected to the anchoring assembly.

When the device is to be set a rotation is imparted to the mandrel while the slip carrying cage 31 is maintained stationary by the engagement of the friction springs 43 with the wall of the well casing assistedby the frictional engagement of the sealing cups B and B. Rotation of the mandrel aligns the longitudinal or vertical portion 200 of the J-slot 20 with the connecting lug 38, and the mandrel may be subsequently lowered with respect to the slip carrying cage. As the mandrel is lowered the expander 39 ismoved within the slips so that the cone 40 coacts with'su'ch slips to displace the same radially outwardly into gripping position with the well casing, as shown in Figure 4; and when this occurs the cage and expander are locked against movement within the casing.

The mandrel is lowered until the upper by-pass openings 14 are disposed below the lowermost sealing cup B and at such time, further by-pass through the mandrel 12 is prevented. By the time the by-pass openings 14 move downwardly below the lowermost sealing cup B the enlarged portion 15 of the coupling 13 has moved within the upper sealing cup C and has further displaced the same radially outwardly. Downward movement of the mandrel may continue until the shoulder 16 of the coupling 13 engages the shoulder 3911 on the upper end of the expander 39.

It will be evident that any pressure below the assembly will act against the lowermost cup B and will urge the slip cage and slips in an upward direction while any pressure from above the device acting upon the upper cup C will move the expander downwardly. It is therefore evident that the differential in pressures above and below the assembly will tend to move the slips into a tighter locking engagement with the well casing. This maintenance of the slips in their set position by means of the diiferential in pressures may be assisted by tubing weight and this is accomplished by merely slacking oif on the tubing so as to impose the desired amount of weight upon the upper end of the expander 39, thereby urging the expander in a downward direction.

Any desired squeeze or testing operation may then be carried out through the tubing and downwardly through the conductor 27 and through the tail pipe 29. Obviously the material employed in the squeezing operation will be ejected from the lower end of the tail pipe which is spaced well below the lower sealing cup B. Of course, the pressure below the device which is built up by the squeeze or testing operation will act against the lower seal cup to assure maintenance in its set position.

If the packer is employed in the usual packer operation the provision of the inner conductor 27 permits circulation to be carried out to the bottom of the well bore. This circulation is through the inner conductor and through the tail pipe and is not directed through the mandrel, because as pointed out, the by-pass openings through the said mandrel have been shut ofi upon setting of the device within the well casing.

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 and re-engaging the J-slot 20 with the connecting pin or lug 38. As the mandrel is first moved upwardly the upper end 21 of the enlarged or upset section 19 may engage first the lower end of the expander so that an upward jarring on the expander may occur which will assist in moving the expander from between the slips. After re-engagement of the lug 38 with the J-slot the unit may be removed from the well casing.

The device is simple in construction and provides a minimum number of parts and is arranged so that it may be employed either as a normal packer for sealing off the annular space between the casting and the well tubing or as a squeeze type packer. In both instances the provision of the inner conductor makes its possible either to circulate to bottom or to perform a squeeze operation in a plane well below the packing elements. The particular sealing cup arrangement utilizes the pressures above and below the packer to maintain the same in its set position and said pressures may be assisted by tubing weight, if such tubing weight is necessary. It is apparent that after the anchoring assembly is once set within the well casing it will be firmly held in its set position and yet when desired the assembly may be readily removed from the well bore.

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 claim.

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 drawings is to be interpreted as illustrative and not in a limiting sense.

Having described the invention, I claim:

A well packer adapted to be lowered within a well casing and including, a tubular support, an anchoring assembly mounted on the support and detachably connected therewith, sealing means attached to the anchoring assembly for sealing the annular space between the support and the well casing into which the packer is lowered, and an inner circulating conductor disposed axially within the tubular support and having its upper end secured to the support with its lower end projecting a substantial distance below the lower end of the support, whereby fluid may be circulated downwardly below the well packer when the same is in position within a well casing, the sealing means encircling the support in constant sealing engagement therewith and being located above and below the anchoring assembly and an enlarged diameter portion on said tubular support adapted to enter the bore of said sealing means located above said anchoring assembly to expand same and to impose the weight of the support on the assembly for maintaining said assembly in an anchoring position with the casing.

References Cited in the file of this patent UNITED STATES PATENTS

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