US2467801A - Hydraulically set well packer - Google Patents

Description

April 19, 1949. R, C, BAKER 2,467,801

Y HYDRAULICALLY SET WELL PACKER Fi1ed oct. 26, 1946 v 2 sheets-sheet 1 i Pi l N I /Z fev/bef: I Hafer 'lm/ENTOR. V

R. C. BAKER HYDRAULICALLY SET WELL PACKER April 19, 1 949.

2 Sheets-Sheet 2 Filed Oct. 26, 1946 I INVENToR. ien/bm (I infer Patented Apr. 19, 1949 HYDRAULICALLY SET WELL PACKER Reuben C. Baker, Coalinga, Calif., assgnor to Baker Oil Tools, Inc., Vernon, Calif., a corporation of California Application October 26, 1946, Serial No. '706,001

(Cl. 16S-12) 3 Claims. 1

The present invention relates to well packers adapted to be anchored in packed-off condition ln casings, liners, and similar conduits positioned in well bores.

Certain types of well packers embody slips which are held initially in retracted position and which are expanded outwardly into anchoring engagement with the wall of a well casing by hydraulically operated instrumentalities. The slips may be held rmly in retracted position by one or more shear screws that are designed to rupture at fa predetermined pressure of the fluid acting .on the hydaulic setting mechanism of the particular tool employed. Diculties are sometimes encountered, however, in achieving the tripping and setting of the slips at the predetermined pressure. Such difculties are thought to be due to conditions in the well, including the relatively heavy viscosity of the mud and similar fluids within the well casing, and sand or other detritus that may tend to pack and foul the setting mechanism. As a result, it oftentimes occurs that the slips can only be set at an inordinately high pressure or the setting cannot be achieved at all upon elevation of the pressure of the fluid in the tool to a considerable extent above the predetermined value.

Accordingly, it is an object of the present invention to provide a well packer in which assurance is had that the slips will be tripped and released for movement from their` retracted position to anchored position against the casing by hydraulic instrumentalities at approximately the predetermined value at which such release is to occur.

One form which the invention may assume is exemplied in the following description and illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a longitudinal section through a well packer embodying the invention, positioned in a Well casing with certain of its parts in retracted position.

Fig. 2 is a quarter longitudinal sectional view vsimilar to Fig. 1, disclosing the well packer partially set in the casing.

Fig. 3 is a quarter longitudinal sectional view similar to Fig. 1, illustrating the packer fully anchored in packed-off condition within the well casing.

Fig. 4 is a cross-section taken along the line 4-'4 on Fig. l.

As disclosed in the drawings, a well packer A is detachably secured to a setting tool l@ forming the lower end of a tubular string B running to the top of the well bore and by means of which the packer is lowered to the desired setting or anchoring point within the well casing C.

The packer A includes a tubular body I I having an abutment and guide I2 threaded on its lower end and a head i3 at its upper end around which the skirt It of a cylinder is mounted. A cylinder head l5 extends inwardly from the lower end of the skirt and carries suitable side seal rings I6 in ring grooves Il slidably engaging the external surface of the body I I. Suitable side seal rings I8 are also disclosed in body head grooves I9 for slidable engagement with the interior of the skirt Ill.

A set of upper segmented slips 2t are disposed aro-und the body immediately below the cylinder head l5. These slips are held initially in retracted position by shear screws 2 I, attaching them to an upper conical expander 22 initially secured to the body l I by one or more shear screws 23. The converging surfaces of the upper set of slips 2U and upper expander 22 are so disposed with respect to one another as to secure the packer against movement in an upward direction within the casing C, or similar well conduit, following outward expansion of the slips 2S into engagement with the casing.

A set of lower segmental slips 2d is provided adjacent the abutment I2, and these slips are also secured by shear screws 25 to a lower tapered expander 26 attached initially to the body II by one or more shear screws 21. The direction of taper on the exterior of the lower expander 26 and the taper on the cooperable surfaces of the lower slips 2d are such as to hold the well packer against movement in a downward direction following expansion of the slips 24 outwardly to casing engaging position.

A suitable lock is provided between the body I I and lower expander 26 to permit upward movement of the body within this expander, but to preclude its downward movement. Such lock may be constituted by a split tapered wedge ring 28 received within the tapered groove 29in the lower expander 26.

A suitable packing, such as a packing sleeve 30 of rubber or similar pliant material, is disposed around the body between the upper and lower expanders 2l, 26. The ends of the packing sleeve 3l] are received within annular pockets 3I formed between the expander skirts 32 and the exterior of the body II.

The setting tool I!) is threaded, as by a left-hand thread 33, into the head I3 of the packer body. This setting tool has a lower head 34 carrying suitable side seals 35 for sealing engagement with the inner wall of the body. The head 34 is disposed below body ports 36 positioned between the body and cylinder head seals I8, I6 to establish communication between the interior of the body II and the elongated annular clearance space 31 between the body head I3 and cylinder head i5. Elongated ports 33 in the form of slots extend through the setting tool I6 between its threaded portion 33 and head 3i, establishing communication between the interior of the setting tool I6 and elongated annular space 39 between the exterior of the setting tool I and the interior of the body II.

The well packer A is run in the well bore with its parts in retracted position, as disclosed in Fig. 1. The cylinder Ill, I is held initially in its upper position by one or more shear screws 46, securing the skirt I4 to the body head I3. During the lowering of the packer in the well casing, the tubular string B is automatically filled with the fluid in the well casing, which flows upwardly'through the central passage 4I in the setting tcol head 34 into the interior of the setting tool and tubular string B.

Upon reaching the point in the well casing at which the packer is to be anchored in packed-off condition, a trip fball 42 is dropped into the tubing string B and is allowed to gravitate or is pumped downwardly into engagement with a seat 63 in the setting tool head, closing the passage Ill through the head and enabling the pressure of the fluid in the tubular string B, setting tool I6, slotted ports 38, elongate annular space 39, body ports 36 and elongate cylinder space 3'! to he .increased to a predetermined degree suihcient to overcome the shear values of the `screws 49, 2l holding the cylinder I4, I5 in its uppermost .position and the upper slips to the upper expander 22. Following rupture of these screws, the cylinder is moved downwardly to slide the upper slips 26 down along the tapered surface of the upper expander 22 and outwardly into engagement with the casing (Fig. 2).

The shear screws 23 securing the upper expander to the body l I have a greater shear value than the cylinder screws 5I and the screws 2I holding the upper slips 26 to the upper expander 22. The screws 21, 25 holding the lower expander 26 to the body II and the lower slips 2li to the lower expander have a. greater shear value than the screws 23 extending through the upper expander 22. It is, accordingly, apparent that only the rst two sets of screws mentioned above are first sheared, moving the upper slips 26 to anchored position against the casing. Following such anchoring, the tubular string B is pulled upwardly to first disrupt the screws 23 holding the upper expander 22 to the body II, and then move the packer body II upwardly within this upper expander, carrying the lower expander 26 with the body toward the upper expander 22 (which is held against upward movement by the slips 26) foreshortening the packing sleeve 30 and expanding it outwardly into rrn sealing engagement with the casing, and also firmly into engagement with the exterior of the packer body I I. As soon as the packing structure has been thus packed oi between the body I I and casing C, a continuation of the upward strain on the tubular string B shears the lower expander screws 21 and lower slip screws 25, causing the abutment I2 to move the lower slips 24 upwardly along the lower expander 26 and outwardly into firm anchoring engagement against the casing (Fig. 3).

Following the complete setting of the upper and lower slips 26, 26, .in the manner described, the tubular string B may be rotated to the right to unscrew the setting tool I6 from the body head I3 at the left-hand thread 33, allowing the tubular string B and setting tool I6 to be removed from the well casing C,

The upper slips 26 prevent upward movement of the well packer and its body II with respect to the well casing. The lower slips 24 prevent downward movement of the well packer and its `body with respect to the well casing, the downward moving tendency of the body being transmitted through the wedge lock 28, 29 to the lower expander 26, and through the slips 24 to the casing C. Thus, the well packer is prevented from moving in either longitudinal direction.

Although the screws 2| securing the upper slips 20 in retracted position have a predetermined shear value and are designed to rupture upon the imposition of a predetermined pressure -to `the fluid within the elongate cylinder space 3l', actual experience has demonstrated that sometimes much higher pressures than the predetermined amounts are required to shear the screws, or the screws cannot be sheared at all regardless of the extent of pressure placed on the uid in the setting tool le and packer Ibody Il. It is believed that Such inability to lset the slips at the desired pressure is due to the plugging of parts of the tool by heavy drilling muds, sand-or other detritus that might be present in the well packer, acting as a solid barrier against the transmission of iluid to the lower cylinder head I5, in order to urge it downwardly with sumcient force againstthe upper set of slips 26. The fluids and combinations of iuids and solid particles in the well tool may also prevent the pressure imposed on the uid in the tubing string B and setting tool I0 frombeing transmitted through the various ports 36, .38 against the full area of the -cylinder head I5.

The present invention overcomes the above noted disadvantage of setting the tool at much higher pressures than intended. It is to benoted that the setting tool itself is provided with relatively long slotted ports 3B, which permits passage of uid and fluid-like materials, but prevents the passage of large :particles as vmight tend to plug the ports 36 of the tool and thecylinder space 3i. It is also to be noted that a relatively long annular space 39 is provided between the ported portion 38 of the setting tool and the inner wall oi the packer body I I and that the body ports 36 are located intermediate the ends of the slotted ports 38 in the setting tool and the annular space 39. Because of this arrangement, any materials that may plug or restrict the slotted ports can do so only along part of its length, and any materials that may settle in the annular space 69 between the setting tool and body can close only part of such space. However, the body ports 36, themselves, will still be in full communication with the annular space 39 around the setting tool for the purpose of receiving fluid under pressure from within the setting tool, which pressure is transmitted freely through a sufliciently open area of the slotted ports 38 and across a suniciently open area in the annular space 39 into and through the cylinder ports 36.

'11o-further preclude the effects of plugging of the hydraulic portion of the mechanism, which `may prevent transmission of the entire fluid pressure over the full area of the cylinder head'IS, the cylinder head is spaced a substantial distance below the body ports 36, the latter .exiting into .the elongate annular cylinder space 31 formed transversely between the inner wall of the cylinder skirt I4 and an intermediate portion d5 of the body Il, which is greater in diameter than the internal diameter of the cyl, inder head I but substantially less in diameter than the interna-1 diameter of the cylinder skirt. The intermediate body head portion 45, in effect, forms a shoulder against which the cylinder head l5 may abut to provide the relatively long annular cylinder space 39 .between the cylinder head I5 and body head I3 when the cylinder I4, I5 is in its uppermost position. The body ports 36, themselves, communicate with the elongated cylinder space 3l at its upper end.

rlhe fluid under pressure is transmitted through `the body ports 36 and into the cylinder space 3l. In view of the relatively large length or" this space 31, when the upper slips 2B are in retracted position, any materials of a solid or non-fluid transmitting nature that might be present in the space 3'1 can have very little, if any, effect upon the transmission of the pressure against the full annular area of the cylinder head I5, since the ports 3E are suiiicient in number and the solid particles that might be present in the cylinder space 3l will be insunlcient to ll this space along its entire length. Part of the elongate space 31 might be plugged, and the fluid press-ure can still be transmitted around the plugged portion for action against the head I5. An eiective annular area around the cylinder space will still be present to enable the Ipressure to be transmitted either through or around the solid particles, and possibly to press the particles themselves iirmly against the cylinder head I5. It is believed that the provision of substantially no initial clearance space between the cylinder head and the body head las in prior devices, permits the relatively short annular cylinder space to be plugged very readily by non-fluid materials, and presents transmission of the fluid pressure around the full area of the ,cylinder head.

Actual operation of the well packer setting tool and cylinder arrangement described in this specification has disclosed that the slips 20 are tripped and set hydraulically at or near the predetermined pressures -and values of the shear screws 2| While I have shown the preferred form `of my invention, it is to be understood that various changes may be made in its construction by those skilled in the art without departing from the spirit of the invention as defined in .the appended claims.

Having thus ydescribed my invention, what I claim and desire to secure by Letters Patent is:

1. A Well tool, including a tubular body adapted to be positioned in a well casing, said body having a main portion and a head of a larger external diameter than said main portion, said body also having an intermediate shoulder between said head and main body portion having an external diameter which is smaller than said head diameter but grea-ter than the diameter of said main body portion, said shoulder having one or more ports extending therethrough adjacent said head, normally retracted slips on said main body portion, an expander on said main body portion for -eiecting movement of said slips into engagement with said casing, an annular cylinder having a skirt slidable along said head an-d 1disposed over said shoulder ports, said cylinder having an annular cylinder -head slidable along said main body portion and positioned adjacent said slips and shoulder -when said slips are in retracted position.

2. A well tool, including a tubular body adapted to be positioned in a well casing, said body having `a main `portion and a head `of a larger external diameter than said main portion, said body also having an intermediate shoulder between said head and main body portion having an external diameter which is smaller than said head diameter but greater than the diameter of said main body portion, said shoulder having one or more ports extending therethrough adjacent said head, normally retracted means of said main body portion, means on said body for shifting said normally retracted means into engagement with said casing -comprising an annular cylinder having a skirt slidable along said head and disposed over .said shoulder ports, said cylinder als-o having an annular cylinder head slidable along said main body portion and positioned adjacent said normally retracted means when said normally retracted means is in retracted position.

3. A well tool, including a tubular body adapt-` ed to be positioned in a well casing, said body having a main portion and a hea-d of -a larger external diameter than said main portion, said body also having an intermediate shoulder between said hea-d and main body portion which is of a smaller external dia-meter :than said head diameter but greater than the diameter of said main body portion, said shoulder -having one or more ports extending therethrough adjacent said head, normally retracted means on said main body portion, means on said body for shifting said normally retracted means into engagement with said casing comprising an annular cylinder having a skirt slidable along said head and dispose over said shoulder ports, said cylinder also having an annular cylinder head slidable along said -main body portion and positioned adjacent said normally retracted means when said normally retracted means is in retracted posi-tion, a t-ubular setting tool secured :to said body and havving a head sealed against the inner wall of said body and disposed a substantial distance below said one -or more ports, said tubular setting tool having circumferentially spaced slots through its w-all extending upwardly from said setting tool head along and a substantial distance on both sides of said ports.

REUBEN C. BAKER.

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

UNITED STATES PATENTS Number Name Date 2,189,703 Burt et al. Feb. 6, 1940 2,228,241 Baker et al. Jan. 14, 1941

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