US3739847A

US3739847A - Combination well bailer and swab

Info

Publication number: US3739847A
Application number: US00187007A
Authority: US
Inventors: J Reynolds
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-09-25
Filing date: 1971-10-06
Publication date: 1973-06-19
Anticipated expiration: 1990-06-19

Abstract

A combination well bailer and swab having a plunger slidably disposed in the body of the bailer and a swab cup supporting mandrel secured to the lower end of the bailer with an overload relief valve disposed below the swab cup. Ports are provided through the swab mandrel above the swab cup, communicating with the annulus exteriorly of the swab mandrel, with an upwardly opening flapper check valve between the ports and the plunger so that upon upward movement of the plunger the flapper valve is opened, drawing fluid interiorly of the body from above the swab cup, thereby drawing suspended sand and other foreign material into the body where it may be collected or expelled, and an undue accumulation of sand within the body will open the safety relief valve and dump same into the well below the swab cup.

Description

United States Patent 1 Reynolds 1 June 19, 1973 COMBINATION WELL BAILER AND SWAB 2,785,756 3/1957 Reynolds 166/107 [76] Inventor: John M. Reynolds, 403 Monrovia L 0 Primary Exammer Dav1d H. Brown Street Shreveport a 71] 6 Attorney-Howard E. Moore and Gerald G. Grut- [22] Filed: Oct. 6, 1971 singer App]. No.: 187,007

Related US. Application Data [57] ABSTRACT A combination well bailer and swab having a plunger slidably disposed in the body of the bailer and a swab cup supporting mandrel secured to the lower end of the bailer with an overload relief valve disposed below the swab cup. Ports are provided through the swab mandrel above the swab cup, communicating with the annulus exteriorly of the swab mandrel, with an upwardly opening flapper check valve between the ports and the plunger so that upon upward movement of the plunger the flapper valve is opened, drawing fluid interiorly of the body from above the swab cup, thereby drawing suspended sand and other foreign material into the body where it may be collected or expelled, and an undue accumulation of sand within the body will open the safety relief valve and dump same into the well below the swab cup.

9 Claims, 6 Drawing Figures PATENTEB 3.739.847

oo may:

9 INVENTOR V JOHN M. REYNOLDS A TTOR Y5 COMBINATION WELL BAILER AND SWAB 1969, now US. Pat. No. 3,621,925 which issued Nov.

BACKGROUND OF THE INVENTION Hydraulic bailers either with or without percussion tools attached thereto are often employed to remove sand, cement,metal objects, bridge plugs, packers and drill bits from the well bore. Bailers of the type disclosed in US. Pat. Nos. 3,177,956, and 3,168,152, and in my Patent application Ser. No. 861,078 now US. Pat. No. 3,621,925, are employed for a variety of purposes in the drilling, completion, extension and reworking of wells. However, such tools have definite limitations in that in some instances they become impacted with sand to an extent that they cannot be retrieved from the well. Thus, their capacity for removal of sand on each trip is limited.

Swab equipment heretofore employed for removal of fluid from wells has definite limitations, particularly in wells having an excessive amount of sand suspended in the fluid therein.

There have been two general types of swab cups employed, to-wit; (1) the reinforced types having reinforcing wires or other supports embedded in the wall thereof to strengthen same and prevent same from turning over and dumping fluid, and (2) so-called sand cups which have unreinforced flexible flanges thereon which when they get under an excessive load of sand will turn over or rupture to dump the sand and allow retrieval of the swab from the well. The reinforced type is objectionable for use in sand-laden wells because sand becomes impacted above it so that it sticks in the well. The unreinforced type is objectionable because it will not lift as great a load of fluid from the well on each run as the reinforced type, but same is necessarily used in wells having an excess amount of suspended sand in the oil to prevent sticking.

SUMMARY OF INVENTION This invention is addressed to a combination well bailer and swab cup which utilizes the function of the well bailer plunger to draw suspended sand and fluid from above a swab cup suspended therebelow into the barrel of the bailer and to deposit sand inside the mandrel where an excess amount thereof will open a relief check valve to allow same to be deposited in the well below the swab cup, to thereby prevent an excess amount of sand from accumulating above the swab cup to an extent that would cause same to stick and become lodged in the well.

Such a device allows the use of reinforced swab cups in wells having excess amount of suspended sand therein with safety, and thereby permits the removal of a greater amount of fluid from the well on each run into the well.

It is desirable to employ a well bailer with a plunger of the type disclosed in my co-pending application Ser. No. 861,078 which has spaced rings thereon with annular grooves in the outer surfaces thereof to receive sand, said rings being enabled to wobble on the support therefor to permit solid particles which would tend to cause excessive wear on the outer surface thereof to work past the ring; and having rigid fins or plates secured to the mandrel of the plunger to provide hydraulic damping to minimize rotation of the plunger relative to the body of the bailer.

Normally when the bailer assembly strikes an obstruction or the bottom of the well bore the sudden release of tension on the cable supporting same causes twisting of the cable and spinning of the piston rings in the body of the bailer and a torque motion applied to the body of the bailer, thereby tending to cause the loosening of threads attaching the body to the swab mandrel.

Provision is made in the combination well bailer and swab herein described and claimed to compensate for such tendency to unthread the swab mandrel from the bailer body by the provision of radially arranged slots or recesses in the head of the barrel which receive hydraulic force caused by pressurized fluid in the barrel when the plunger is moved upwardly therein to thereby tend to rotate the barrel with reference to the swab mandrel to tighten the threaded connection therebetween and prevent disengagement thereof.

It is therefore a primary object of the invention to provide a combination well bailer and swab which will permit the removal of a greater amount of sand laden fluid from the well with heavy duty swab cups without the danger of lodging or sticking the assembly in the well.

Another object of the invention is to provide a com bination well bailer and swab incorporating a plunger in the body which draws fluid from the annulus in the well above the swab cup and deposits same in the body where it may be dumped by an overload relief valve below the swab cup to prevent the sticking of the swab by an excess amount of sand collected thereabove.

Still another object of the invention is the provision of means in response to fluid pressure inside the plunger barrel to cause tightening, of threads between the plunger barrel and the swab mandrel to prevent disengagement thereof while in use.

Other and further objects of the invention will become apparent by referring to the detailed description and drawing annexed hereto.

DESCRIPTION OF DRAWING A drawing of a preferred embodiment of the invention is annexed hereto so that the invention may be better and more fully understood, in which:

FIG. I is a partially sectionalized view of the bailer and swab combination;

FIG. 11 is a cross sectional view taken along line II--Il of FIG. 1;

FIG. III is a cross sectional view taken along line III- -III of FIG. I;

FIG. IV is a cross sectional view taken along line lV-IV of FIG. I;

FIG. V is a cross sectional view taken along line VV of FIG. I; and

FIG. VI is a lower end view taken along the line VI-VI of FIG. I.

Numeral references are employed to indicate like parts throughout the various figures of the drawing.

DESCRIPTION OF A PREFERRED EMBODIMENT In the drawing the numeral 1 generally designates a well bailer having a body comprising a hollow tubular barrel 2, the upper end of which is rigidly connected to a head 4 as by welding 3, and having a cylindrical bore 6 extending longitudinally therethrough.

The upper tubular stem section 10 of a plunger assembly 8 is slidably disposed through the bore of head 4. The head 4 has shoulders 12 and a reduced section 14 at the upper end thereof with threads or teeth 16 disposed thereabout to facilitate connecting a fishing tool (not shown) thereto to remove the bailer from a well bore, should it be necessary to do so.

Suitable lowering means, such as wire rope 18, is secured to the upper end of stem section of the plunger assembly 8 and extends upwardly through the well bore to suitable dispensing means such as the drum of a wench (not shown).

A traveling valve cage 20 is secured to the lower end of stem section 10, said valve cage having a curved shoulder portion 22 on the upper end thereof arranged to enter and engage the beveled lower end 24 of bore 6 which extends through the head 4.

Valve cage 20 has apertures 26 extending through the walls thereof and the lower end of the valve cage is threadedly connected at 28 to the upper end of a hollow tubular mandrel 30. Mandrel 30 has a passage 32 extending longitudinally therethrough. A valve seat 34 is formed in the upper end of passage 32 and receives valve element 36 to p'event the flow of fluid downwardly through passage 32.

The mandrel 30 has rings 65 mounted thereon below the lower end of the traveling valve cage 20. Rings 65 are rigid cylindrical elements having a bore 66 extending therethrough. Referring to FIGS. 1 and III, it should be noted that bore 66 through ring 65 is of larger diameter than the outside diameter of mandrel 30, thus providing clearance between mandrel 30 and ring 65.

Each ring 65 is restrained from axial movement along mandrel 30 by

shoulders

68 and 69 which extend outwardly from mandrel 30 above and below each ring 65. Clearance is also provided between the lower edge of upper shoulder 68 and the upper edge of ring 65 so as not to prevent rocking motion of ring 65 relative to mandrel 30.

The outer circumference of each ring 65 has one or more annular grooves 70 formed therein with lands or ridges 72 extending around the upper and lower edges of each groove 70.

The outside diameter of each land 72 is of smaller diameter than that of bore 60 which extends through the barrel 2 of the body of the bailer. Provision of clearance between the outside edge of lands 72 and the inner wall 74 of bore 60 allows each ring 65 to tilt or wobble relative to the inner wall 74 of the barrel 2 as the plunger assembly 8 moves vertically relative to the body portion of the bailer.

From the foregoing it should be readily apparent that the rigid rings 65 are restrained from axial movement by

shoulders

68 and 69 on mandrel 30 of the plunger assembly 8 and that each ring 65 is free to rock and tilt as the plunger assembly 8 moves through the bore 60 of the body portion of the bailer to prevent wedging of solid materials between the outer edges of the piston 65 v and the wall 74.

Annular grooves 70 in the edges of each rigid ring 65 cause agitation of fluid which flows through the clearance between the outer edges of lands 72 and the inner wall 74 of barrel 2 to increase the vacuum forming camandrel 30 between

shoulders

68 and 69 and extend outwardly from said mandrel between rigid rings 65. Fins 86 are fixedly secured to the lower end of mandrel 30 below the lowermost ring 65.

Since check valve 52 in the swab barrel prevents the flow of fluid downwardly through bore 60, fluid is normally present in said bore. The weight of bailer 1 suspended from a long length of wire rope 18 causes the wire rope to stretch, resulting in the exertion of a considerable torque on plunger assembly 8 when the weight of the bailer is suddenly removed from wire rope 18 as the swab assembly therebelow strikes an obstruction in the well bore.

Fins

80, 82, 84 and 86 on the traveling valve cage 20 and the mandrel 30, respectively, provide hydraulic braking action to reduce the tendency of plunger assembly 8 to spin relative to the barrel 2 of the bailer body.

A tubular swab support mandrel 40 is threadedly attached by threads 41 to barrel 2. Longitudinally spaced perforations 43 are provided through the wall of support 40 which cause communication between the bore 42 of support 40 and the annulus between same and the surrounding casing or other pipe in the well.

An overload valve assembly is formed on the lower end of swab support mandrel 40 which includes a partition having a valve passage 44 therethrough with a seat 46 about the lower end thereof closed by a valve ball 47.

Valve ball 47 is urged against seat 46 by a spring 48 which is supported by a ring 49 having passages 49a therethrough. The ring 49 is mounted on the inner end of threaded stud 50 having a head 50a thereon. The stud 50 threadedly extends through the lower end 102 of swab body so that by rotating the stud 50 the tension of spring 48 may be adjusted. The lower end 102 is a web providing passages 51 through which sand may be dumped when valve 47 opens.

A flapper valve 52 is pivotally mounted on hinge 52a and is arranged to seat upon partition 54 and close the passage 53 therethrough.

A flexible swab cup 55 which may take any form, either the reinforced or unreinforced type, is secured to the .mandrel 40 below perforations 43 in a suitable manner such as by being seated on a support shoulder 56 and held in place by a bushing 57 attached about the mandrel 40. The swab cup 55 is arranged to expand under load imposed thereabove into sealing engagement with a surrounding pipe to trap fluid thereabove to remove same from the well.

As shown in FIG. V radially extending closed end passages 58 are provided in the head 4; each said passage communicating at its inner end with the annular passage 6 and being closed at its inner end 59.

The operation and function of the device hereinbefore described is as follows:

The plunger 8 is moved up and down through barrel 2 until a maximum load is drawn into loading chamber 60 through the perforations 43 and through check valve 52 inside barrel 2.

As plunger 8 is moved vertically upward, fluid is drawn from the well above swab cup 55 through openings 43 to the inside of mandrel 40 and moves upwardly through flapper valve 52.

Downward movement of plunger 8 causes fluid to move upwardly through passage 32 in plunger 8 and out through openings 26 above rings 65. The next upward stroke of plunger 8 draws more fluid through openings 43 while moving fluid above rings 65 up wardly to discharge same around cable 18 through passage 6 in the head 4 at the upper end of the barrel 2 into the annulus above swab cup 55. As the stem on the upper end of plunger 8 moves upwardly in passage 6 the area through which fluid can flow is greatly reduced, resulting in a dampening action, increasing pressure above rings 65.

As best illustrated in FIG. V, pressurized fluid is directed from passage 6 into passages 58 to impact the closed end 59 of each passage 58 to exert a twisting action to barrel 2, tending to tighten the threads 41 between barrel 2 and mandrel 40.

When the combined bailer and swab is being removed from the well by engagement of

shoulders

22 and 24, sand above cup 55 may tend to stick the tool in the well. If so, the plunger 8 may be reciprocated up and down in barrel 2, drawing sand laden fluid through openings 43, and when a predetermined pressure (regulated by screw 50) is reached, valve 47 will open to dump the sand through passage 51 into the well below cup 55,allowing the cup and tool to be released and moved upwardly through the well without rupturing or damage to the swab cup.

Having described my invention I claim:

1. In a well tool, a tubular body having a plunger assembly slidably disposed in the bore; one or more perforations provided through the wall of the body; a swab cup about the body below the perforations; an upwardly opening check valve in the body between the perforations and the plunger; and a check valve below the swab cup arranged to open downwardly when a predetermined pressure is imposed thereon.

2. In a combination plunger and well swab, a hollow barrel; a plunger in the barrel; a head on the barrel having a central passage therethrough; a stem attached to the plunger movably extending through the passage, the stem being smaller in diameter than the central passage to provide an annular restricted flow passage thereabout; a central passage through the plunger communicating with area above and below the plunger; an

upwardly opening check valve in the passage through the plunger; a swab assembly suspended to the barrel, said swab assembly including a tubular body having perforations through the wall thereof; a swab cup disposed about the body below the perforations; a downwardly opening check valve in the body below the swab cup; and passage means through the lower end of the body below the check valve.

3. The combination called for in claim 2 with the addition of an upwardly opening check valve in the body above the perforations.

4. The combinationcalled for in claim 2 with the addition of an enlarged head on the plunger engageable with the lower end of the passage through the head to allow retrieval of the tool.

5. The combination called for in claim 2 wherein the barrel is threadedly engaged with the swab body; and a plurality of radially arranged closed end passages in the head communicating with the central passage through the head arranged to receive pressure from the said passage when the plunger is raised to apply torque to the barrel to tighten the threaded connection between the barrel and the body.

6. In a well tool, a tubular body having a plunger assembly slidably disposed in the bore; a head on the upper end of the body, said head having a passage therethrough; a stern on the plunger assembly movable vertically in said passage, the stem being smaller in diameter than the passage to provide an annular restricted flow passage thereabout; one or more perforations provided through the wall of the body; a swab cup about the body below the perforations; and a check valve below the swab cup arranged to open downwardly when a predetermined pressure is imposed thereupon.

7. The combination called for in claim 6 with the addition of a pair of radially disposed closed end passages in the inner wall of the head communicating with the passage through the head arranged to receive fluid pressure from said restricted passage when the plunger is moved upwardly to impart a rotative motion to the body.

8. The combination called for in claim 6 with the addition of an enlarged head on the plunger below the stem arranged to engage the passage to allow retrieval of the assembly from the well by a cable attached to the stem.

9. In a well tool, a tubular body having a plunger assembly slidably disposed in the bore, said plunger having a passage therethrough to allow communication between areas in the body above and below the plunger; an upwardly opening check valve in the passage to control flow therethrough; one or more perforations provided through the wall of the body; a swab cup about the body below the perforations; and a check valve below the swab cup arranged to open downwardly when a predetermined pressure is. imposed thereupon. :0: a:

Claims

2. In a combination plunger and well swab, a hollow barrel; a plunger in the barrel; a head on the barrel having a central passage therethrough; a stem attached to the plunger movably extending through the passage, the stem being smaller in diameter than the central passage to provide an annular restricted flow passage thereabout; a central passage through the plunger communicating with area above and below the plunger; an upwardly opening check valve in the passage through the plunger; a swab assembly suspended to the barrel, said swab assembly including a tubular body having perforations through the wall thereof; a swab cup disposed about the body below the perforations; a downwardly opening check valve in the body below the swab cup; and passage means through the lower end of the body below the check valve.

4. The combination called for in claim 2 with the addition of an enlarged head on the plunger engageable with the lower end of the passage through the head to allow retrieval of the tool.

6. In a well tool, a tubular body having a plunger assembly slidably disposed in the bore; a head on the upper end of the body, said head having a passage therethrough; a stem on the plunger assembly movable vertically in said passage, the stem being smaller in diameter than the passage to provide an annular restricted flow passage thereabout; one or more perforations provided through the wall of the body; a swab cup about the body below the perforations; and a check valve below the swab cup arranged to open downwardly when a predetermined pressure is imposed thereupon.

9. In a well tool, a tubular body having a plunger assembly slidably disposed in the bore, said plunger having a passage therethrough to allow communication between areas in the body above and below the plunger; an upwardly opening check valve in the passage to control flow therethrough; one or more perforations provided through the wall of the body; a swab cup about the body below the perforations; and a check valve below the swab cup arranged to open downwardly when a predetermined pressure is imposed thereupon.