US2187635A - Well packer - Google Patents

Description

G. F. STAMPS Jan. 16, 1940.

WELL PACKER Filed May 23, 1958 AI? y.

In own for:

4 Gemya E Sia mp8 Patented Jan. 16, 1940 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to a well packer and more particularly pertains to the type of well packers embodying a resilient tube mounted for lowering into a well bore and adapted to be expanded into close contact with the walls of the well bore so as to efiect sealing or packing of the bore at apredetermined point therein.

An object of the invention is to provide a substantial mounting for the packing tube whereby it will be securely held in place and yet be capable of considerable expansion without liability of becoming disengaged or detached from its mounting.

Another object is to provide the packer with means for insuring against excessive expansion of the resilient tube such as might result in rupture of the latter.

Another object is to provide a means for effectively controlling expansion and contraction of the packing tube including a series of valves so mounted and arranged as to be operable to effect delivery of pumped liquid into the interior of the packing tube to expand the latter and retain it in an expanded condition for a desired length of time, and which valve arrangement may also be operated to permit contraction of the tube from an expanded position.

- A further object is to provide a construction in the control valves such that their operation may be readily eiiected in a dependable fashion.

With the foregoing objects in view, together with such other objects and advantages as may subsequently appear, the invention is carried into effect as illustrated by way of example in the accompanying drawing, in which:

Fig. 1 is a view in elevation of the packer with parts broken away and depicting the manner of positioning it in a well bore;

Fig. 2 is a view in longitudinal mid-section with parts appearing in elevation;

Fig. 3 is a detail in horizontal section taken on the line 33 of Fig. 2;

Fig. 4 is a view in horizontal section as seen on the line 4-4 of Fig. 2;

Fig. 5 is an enlarged detail in section of a control valve appearing in Fig. 4, and

Fig. 6 is a view in cross section taken on the line 66 of Fig. 5.

Fig. '7 is a reproduction of a fragment of the left hand portion of Fig. 2, differing from the showing in the latter view only in that the upper end portion of the packer element is shown in the lowered position which it assumes when said element is in an inflated condition.

Referring to the'drawing more specifically A indicates generally the body of the well packer which embodies tubular upper and lower end sections 1 and 8, and anintermediate section 9 comprising a length of pipe which has screw threaded engagement at its ends with the sections 1 and 8 as particularly shown in Fig. 2.

Encircling the pipe 9 in spaced relation thereto is a metallic cylinder H! which seats at its ends in recesses formed in the adjacent end faces of the sections 1 and 8, and which cylinder 10 is formed at intervals therearound and throughoutthe length thereof with openings ll through which liquid may pass as will presently be described.

Encompassing the cylinder 10 is a resilient 1! tube l2 the end portions of which are slidably telescoped with annular flanges I4 and i5 projecting from the contiguous ends of the end sections 1 and 8 respectively; the flanges I4 and I5 surrounding a substantial length of the end porm tions of the tube [2 to permit longitudinal movement of the end portions of the tube relative to the end sections 1-8.

The end portions of the resilient tube I! normally encompassed by the flanges are fitted with .5

reinforcements l6, preferably consisting of woven fabric embedded in the material of the tube, which reinforcements serve to stiffen the end portions of the tube so as to readily permit requisite longitudinal movement thereof relative m Owing to said flanges u and I5 being in a concentric, outwardly spaced relation to the cylinder In annular spaces are provided within which the end portions of the resilient tube It are fitted. Each of the apertures a is in two aligned sections which are located at opposite sides of said annular space; a good working lit and port controlling means is thus provided for the upper end portion of the tube l2.

Mounted intermediate the ends of the pipe 9 is a pair of diametrically opposed outwardly opening valves each of which embodies a tubular housing I! formed with an end wall l8 having a. port l9 and in which housing is arranged a reciprocal valve II which normally closes the port 5 in the latter.

24 to close the passage through the end section 8. The plunger 25 is tubular and is fitted with a ball foot valve 26 and has side openings 21 affording communication between the interior of the plunger and the interior of the pipe 9. The upper end of the plunger 25 is tapered and is connected to a stem 28 which extends upwardly through the pipe 9 and terminates in the upper section 1. Studs 29 project laterally from opposite sides of the upper end of the stem 28 for facilitating connection between the stem and the jaws of a lifting tool (not shown).

The upper end section I is threaded internally at its upper end for screw engagement with a tubular stem 30 by which the packer is lowered into a well bore B, and the lower end section 8 is internally threaded at its lower end for screw engagement with a perforated strainer tube 3|.

In the application and operation of the invention, the packer A fitted with the strainer tube 3| and screwed on the lower end of the tubular stem 30 is lowered into the well bore B to a point where the desired shut-off or packing of the well bore is to be effected, whereupon liquid is directed downwardly through the stem 30 and into the pipe 9 in the packer where the liquid is trapped by the plunger 25 and foot valve 26 However, a portion of the liquid will pass from the pipe 9 through the valve ports l9 into the cylinder l0 and from the latter through the openings ll into the resilient tube l2; the valves 20 opening outwardly in opposition to the springs 2| until pressures equalize on opposite sides of the valves whereupon the valves automatically close under the urge of the springs 2|.

It will be understood that when the packer is lowered into liquid contained in the well bore a portion of such liquid may flow into the pipe 9- through the plunger 25; the foot valve 26 opening upwardly under external pressure of liquid in the well bore until 'pressures interiorly and exteriorally of the packer are equalized whereupon the foot valve 26 closes.

In order to effect expansion of the resilient tube l2 in closing off a well bore while submerged in liquid in the latter, either a suflicient head of liquid is delivered into the tubular stem 30 to dilate the tube l2, or liquid is forced into the stem under pump pressure. On pressure being developed internally of the tube l2 in excess of well pressure the intermediate portion of the resilient tube expands outwardly and in so doing causes the reinforced end portions thereof to slide toward each other in the encompassing flanges II and I5. The length of movement of the end portions of the tube l2 relative to the flanges l4 and I5 is proportional to the extent of expansion of the intermediate portion of the tube, and is determined by the upper end portion of the tube I 2 moving to a position where the open apertures a in the flange I4 will be uncovered since the fluid under pressure will then flow in part from the interior of the packer to the exterior thereof through the apertures a. In this fashion the extent of expansion of the resilient tube I2 is limited thereby obviating possible rupture of the tube under excess internal pressure.

By providing a series of the pressure venting apertures a lengthwise of the flange H, the extent of regulated expansion of the tube l2 may be varied as occasion may require by closing certain of the apertures and opening others by means of the plugs b; opening of the apertures 11 closest the end of the tube 12 terminating expansion of the tube at one point, and opening of the apertures progressively from the end of the tube terminating expansion of the tube I2 at progressively greater intervals.

In order to minimize possibility of the lower end of the tube l2 being withdrawn out of engagement with the flange l5 before the upper end thereof uncovers aperatures a, the flange I5 is formed of a length exceeding that of the flange It so as to overlie a greater length of the tube.

Manifestly the tube I2 is designed to expand to such extent as to come into contact with the walls of the well bore as indicated by the broken lines 0 in Fig. 1, but there are occasions where the well bore is excessively enlarged, as by caveins, and accordingly it is highly advantageous to provide means whereby expansion of the pack ing tube may be limited as above set forth in event the packer should be disposed at such excessively enlarged portions of the well bore.

When the well bore is packed by the dilated packing tube l2, liquid content of the well below the packer may be removed by actuating suitable pumping mechanism applied to the stem 30; the pumped liquid flowing upwardly through the foot valve .26 without disturbing the body, of liquid sustaining the packing tube 12 in its extendedsposition.

When it is desired to release the packer from engagement with the walls of the'well bore, a suitable tool is lowered on a cable or rod through the stem 30 and engaged with the lugs 29 on the upper end of the stem 28, whereupon the stem 28 is lifted to elevate the plunger 25 and bring it into engagement with the knobs 23 on the valves 20; the plunger acting through the knobs to unseat the valves 20 and thereby permit venting of the liquid confined in the cylinder l0 and tube l2 under pressure on reduction of pressure in the pipe 9 to an extent lower than that of the liquid in the tube l2.

The intermediate portion of the tube I2 being resilient and being expanded by the liquid under pressure therein. will automatically contract on relief of its expansive pressure so as to expel liquid contained therein through the then open ports I!) back into the pipe 9; the tube 12 in contracting then being disengaged from the walls of the well bore so that the packer may be withdrawn from the well or shifted to another position therein as occasion may require.

While I have shown and described a specific embodiment of the invention, it is not limited to the exact construction shown, and accordingly the invention embraces such features and instrumentalities as come within the purview of the appended claims.

I claim:

1. In a well packer, a resilient tube, spaced apart supports for theends of said tube relative aromas away therefrom, and means for directing liquid under pressure to the interior of said tube to thereby inflate said tube and withdraw its end portion from covering said apertures.

2. In a well packer, a resilient tube, a support for the ends of said tube including spaced apart annular flanges loosely encircling the end portions of said tube, means to rigidly support said flanges in their said spaced apart relation, an aperture in at least one of said flanges normally covered by an end portion of said tube, and means for directing liquid under pressure into said tube to eiIect dilation thereof and by a consequent contraction of its length eiiect inward longitudinal movement of said end portion thereof relative to said aperture to uncover same.

3. In a well packer, a pair of spaced tubular end sections having annular flanges on their adjacent ends, means to support said sections in their spaced apart relation, a resilient tube having-its ends telescopically engaged in said flanges, and meansfor directing liquid under pressure into said tube to expand same and by a consequent contraction of its length eflect inward movement of at least one end thereof relative to its encompassing flange; the flange encompassing the movable end of said tube being formed with a series 01' apertures spaced apart in'the direction or movement of the tube end, said apertures being positioned to be successively uncovered by said tube end when the length of the tube is contracted as aforesaid.

4. In a well packer, a pair of spaced tubular end sections, a pipe connecting said end sections, a cylinder encircling said pipe in spaced relation thereto having openings formed therein, ports in said pipe leading to the space interiorly of said cylinder, a resilient tube encompassing said cylinder and having stiffened end portions thereby reducing their expansibility under internal pressure, and annular flanges on the adjacent ends of said end portions extending over the stifiened end portions of said tube, at least one of said stifiened end portions sliding within the flange which encompasses it when the midlength portion of the tube is dilated thereby reducing its length.

5. The subject matter of claim 4 and, the aforesaid means to support said sections in their spaced apart relation including a cylindrical part in a concentric, inwardly spaced relation to the flange which surrounds the movable end of said tube, thereby providing an annular space in which such end of the tube has a working flt.

GEORGE F. STAIWPS.

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