US3316971A - Sand trap for use in well bores - Google Patents

Description

May 2, 1957 J. R. BROWN 3,316,971

SAND TRAP FOR USE IN WELL BORES A TTONSV May 2, 1967 J. R. BROWN SAND TRAP FOR USE IN WELL BORES 2 Sheets-Sheet 2 Filed Feb. l2. 1965 JFRBROWN INVENTOR.

/4 TTO/P/VEY United States Patent Olitice 3,316,971 Patented May 2, 1967 This invention relates to improvements in sand traps, junk catchers or the like, for use in well bores.

In the operation of wells, such as oil and gas wells, which employ pipe strings carrying various types of tools positioned inside a well casing, the accumulation of sand and other detritus settling down on top of the well tools in the well bore frequently creates a severe problem in connection with the removal of well strings and the tools carried thereon.

To meet this problem, various types of sand traps, junk catchers or the like have been designed for installation in the pipe string above the tools, which are more commonly well packers, anchors, down-well pumps, and the like. These prior art traps have generally been rather complicated in construction, frequently requiring varied manipulations of the pipe strings in order to release them for removal and have been generally inefticient in their primary purpose of trapping sand settlings and other detritus while permitting the pipe string and attached tools to be removed from the well when necessary.

Accordingly, it is a primary object of this invention to provide a greatly simplified, economical design of trap which obviate-s the disadvantages of prior designs and which is highly effective both for preventing accumulation of settlings and detritus on the well tools and for ready release when it is necessary to remove the pipe string and the tool supported thereon.

An important object is the provision of a trap construction which is operated entirely by longitudinal movements of the supporting pipe string.

A ymore specific object is the provision of a trap structure employing an upwardly facing, iiexible cup-type catcher element slidably disposed for relative longitudinal movement on a mandrel having by-pass passages and effective, in response to said longitudinal movement, to open and close said by-pass passages, the catcher element being operative in the closed position of the passages to seal the annular space between the pipe string and the well bore wall.

Other and more speciiic objects of this invention will become more readily apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates a useful embodiment in accordance with this invention.

In the drawing:

FIG. 1 is a longitudinal, quarter sectional view of the trap apparatus illustrating the positions occupied by the parts as the device is being run into a well;

FIG. 2 is a view similar to FIG. 1 showing the positions of the parts when the device is being withdrawn from the well; and

FIG. 3 is a view similar to FGS. 1 and 2 showing the parts in the position occupied when the catcher element is in sealing position in the well.

Referring to the drawing, the device comprises a tubular mandrel 10, a positioning sleeve 11 slidably mounted about the mandrel, and an upwardly facing cup-type trap o1' catcher element 12 slidably mounted on the upper portion of mandrel above positioning sleeve 11.

Mandrel 16 is adapted to be installed between upper and lower sections P and P', respectively, of a tubing string which extends into the bore of a well casing C. The upper end of mandrel 101 has a threaded socket 14 for receiving the lower end of upper pipe section P and has an externally threaded lower end portion 15 receivable in the upper portion 16 of a tubular sub or adapter 17, the lower end of which is threaded for connection to lower pipe section P by a conventional collar 18, or the like.

The exterior of mandrel ll()` is reduced in diameter in a series of steps beginning at a point near the upper end thereof where the first reduction delincs the annular, downwardly facing shoulder 19'; the second reduction in diameter is at an intermediate point along the mandrel and defines the downwardly facing annular shoulder 20 (best seen in FIG. 2) and the third reduction in diameter occurs near the lower end of the mandrel defining the exteriorly threaded lower pin portion 15.

Catcher element 12 is slidably disposed on the portion of mandrel 10 below shoulder 19y and above upper end face 21 of positioning sleeve 11. Shoulders 19 and 21 thus provide the limits for relative longitudinal travel between the mandrel and catcher element 12.

`Catcher element 12 is of a generally conventional cupshaped configuration having its 4mouth portion 22 opening upwardly and dened by the flexible lip 23 which is dimensioned to normally be in sldable engagement with the ybore wall of casing C. The lower end portion of catcher element 12 comprises the base section 24 having an axial bore 25l dimensioned to slidably fit closely about the exterior of mandrel 10' extending between shoulders 19 and 20. The upper face of base section 24 defines an upwardly facing annular shoulder 26 adapted to abut shoulder 19 for limiting upward movement of ctacher element 12 relative to the mandrel.

Mandrel Ill has a series of angularly spaced longitudinal grooves 27 in the outer periphery thereof which open to the exterior of the mandrel above shoulder 19 and to a point which will rbe below the lower end of catcher element 12 when the latter is in its uppermost position, shown in FIG. 1. A second series of angularly spaced, longitudinal grooves 28 are provided in the exterior of mandrel ltlfextending from a point spaced below the lower ends of grooves 27 to a point a short distance below shoulder Ztl'. The portion of mandrel 10 extending between the lower ends of grooves 27 and the upper ends of grooves 28` constitutes a cylindrical sealing area 29 adapted to provide a non-slotted surface which is disposed for sealing engagement by base portion 24 of the catcher element, as will appear subsequently.

The lower end of positioning sleeve 11 is slidably disposed over the upper reduced diameter portion 30 of adapter 17 which defines the upwardly facing shoulder 31 adapted to form a stop for the lower end of sleeve 11 in its longitudinal movements relative to the mandrel. Reduced portion 30 is provided with a series of angularly spaced, longitudinally extending grooves 32 adapted to receive guide pins 33` projecting inwardly from the lower end of sleeve 11. The upper and lower ends of grooves 32 are deiined by walls forming shoulders 34 and 35, respectively, and are adapted to be engaged by guide pins 33 to limit the relative longitudinal travel of sleeve 11. The upper end of sleeve 11 is provided with a plurality of angularly spaced, vertically extending slots 36 vhich open through the upper end of the sleeve and tre angularly positioned to be substantially in regis- ;er with grooves 28 in the mandrel. Sleeve 11 is provided at a point just below the lower ends of slots 36 with an inwardly extending annular enlargement defining an upwardly facing shoulder 3'7 and a downwardly facing shoulder 38. Upwardly facing shoulder 37 is adapted to be engaged by shoulder 2li on the exterior of the mandrel for limiting upward movement of sleeve 11 relative to the mandrel. The radial dimensions of mandrel and sleeve 11 are made such as to define an annular space 39 between the sleeve and the mandrel between shoulder 38 and the upper end of adapter portion 16. A coil spring 40 is disposed in compression in annular space 39, having its opposite ends bearing, respectively, against shoulder 38 and the upper end of adapter portion 16, whereby to normally bias sleeve 11 upwardly relative to mandrel 10. Sleeve 11 is provided with a plurality of vent or relief ports 41 through the wall thereof below shoulder 38 to prevent trapping of uid in the annular space during relative movement of the sleeve.

In operation, the device will be installed between pipe sections P and P', as shown in FIG. l, and will be run into a well bore. It will be understood that other tools, such as packers, anchors, down-well pumps, and and the like will be mounted below the trap device on pipe section P. When the pipe string is run into the well carrying the trap structure, the friction between lip 23 of the catcher element and the well wall, as represented by' casing C, will restrain the catcher element suiciently to allow shoulder 19 on the mandrel to engage shoulder 26 of the catcher element, pushing the latter downwardly with the pipe string. The force of spring 40 will hold sleeve 11 in its upward position, also as shown in FIG. l. With the parts in the position shown in FIG. 1, it will be seen that grooves 27 will extend from below catcher element 12 to points above base 24 of the latter so as to provide a plurality of by-pass passageways through the catcher element for fluid encountered in lowering the tools into the well bore.

When the tool string has attained its desired position in the well, catcher element 12 will settle down along the mandrel under its own weight and the weight of any liuid thereabove until the lower end of base section 24 comes into contact with end face 21 of the sealing sleeve. At this point, it will be seen that base 24 will be opposite and surrounding the non-slotted section 29 of the mandrel and will form a seal therewith, as best seen in FIG. 3. Thus, any sand or other detritus settling down from above will be trapped in catcher element 12, since the latter will have sealed off between portion 29` and the wall of casing C. Thus, no such settlings or detritus can pass below the catcher element and will thereby be kept o'f of the equipment or tools in the well -below the catcher element.

When it is desired to pull the pipe string and its supported equipment from the well, an upward force applied to the pipe string will pull mandrel 10 upwardly relative to catcher element 12 which will be -frictionally held against the wall of casing C by the load of settlings trapped therein. This relative upward movement of the mandrel will move the latter upwardly until upper end face 21 of positioning sleeve 11 abuts the lower end of the catcher element, as seen in FIG. 2. Continued upward movement of the pipe string will move the mandrel upwardly relative to sleeve 11 compressing spring 40 because of the resistance oliered by catcher 12 seated on the upper end of the sleeve, until guide pins 33 engage bottom shoulders 35- of grooves 32. This terminates upward movement of the mandrel relative to catcher element 12 and positioning sleeve 11. At this point, it will be seen that grooves 28 now form by-pass passages around base portion 24 of the catcher element so that as the tool String is drawn upwardly through casing C fluid above catcher element 12 will by-pass the latter through grooves 28 to the annular space below the catcher element, the lower ends of grooves 28 being in communication with slots 36 in the upper end of sleeve 11. While some very iine sand may pass downwardly through the by-pass passages when grooves 28 are thus opened, this will generally not be suicient to interfere with the removal of the tool string as the slots will ordinarily be dimensioned to prevent the passage of larger fragments which might otherwise prevent release of the tool string.

From the foregoing, it will be seen that this device provides a comparatively simple, easily operated, and efficient sand trap or junk catcher having the various advantages noted previously.

it will be understood that various changes and modifications may be made in the details of the illustrative embodiment within the scope of the appended claims but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. A device for trapping detritus settling in a well bore, comprising, a tubul-ar mandrel connectible into a well pipe string to form a part thereof, longitudinally spaced-apart upper and lower elongate groove means in the exterior of said mandrel, a non-grooved cylindrical sealing section separating said upper and lower groove means, an upwardly facing cup-shaped catcher element slidably disposed on the mandrel for relative longitudinal movement thereon between an upper by-pass position opposite said upper groove means, an intermediate position -about said sealing sec-tion, and a lower by-pass position opposite said lower groove means, a positioning sleeve means longitudinally slidably `disposed about said mandrel below said catcher element for movement between an upper position adapted to stop said catcher element at said intermediate position and a lower position permitting the catcher element to attain said lower by-pass position, means resiliently biasing said sleeve means toward said upper position, and means limiting relative upward movement of said catcher element to said upper by-pass position.

2. A device according to claim 1 wherein said catcher element includes a iiexible lip portion about its upper end slidably engageable with a surrounding well wall, and a base portion having an axial bore adapted for close iitting engagement aboutsaid sealing section.

3. A device according to claim 1 wherein s-aid lastmentioned means comprises cooperating shoulders on said mandrel and said catcher element abuttable upon attainment by the catcher element of said upper by-pass position.

4. A device for trapping detritus settling in a well bore, comprising, a tubular mandrel connectible into a well pipe Istring to form a part thereof, longitudinally spacedapar-t upper and lower elongate groove means in the exterior of said mandrel, a non-grooved cylindrical sealing section separating s-aid upper and lower groove means, an upwardly facing cup-shaped catcher element slidably disposed on the mandrel for relative longitudinal movement thereon between an upper by-pass position opposite said upper groove means, an intermediate position about said sealing section, and a lower by-pass position opposite sai-d lower groove means, a positioning sleeve means longitudinally slidably disposed about said mandrel below said catcher element for movement between an upper position adapted to stop said catcher element at said intermediate position and a lower position permitting the catcher element to `attain said lower by-pass position, means resiliently biasing said sleeve means toward said upper position, means limiting relative upward movement of said catcher element to said upper by-pass position, and means limiting the movement of said sleeve means to said upper and lower positions.

5. A device according to claim 4 wherein said catcher element includes an outwardly aring exible lip portion ing section, said base portion having a length less than.

that of said upper grooves, and wherein said means limiting relative upward movement of said catcher element comprises cooperating shoulders on said mandrel and s-aid catcher element abuttable upon attainment by the catcher ele-ment of said upper by-pass position.

6'. A device according to claim 4 wherein the upper end portion of said sleeve means is provided with openings registering With said lower groove means at both said upper and lower positions.

References Cited by the Examiner 5 UNITED STATES PATENTS 2,786,534 3/1957 Page 166-183 X 2,935,132 5/1960 Arterbury et al. 166--202 X 3,066,614 12/ 1962 Grandstaf 103--225 10 CHARLES E. OCOINNELL, Primary Examiner.

D. H. BROWN, Assistant Examiner.

Claims (1)

1. A DEVICE FOR TRAPPING DETRITUS SETTLING IN A WELL BORE, COMPRISING, A TUBULAR MANDREL CONNECTIBLE INTO A WELL PIPE STRING TO FORM A PART THEREOF, LONGITUDINALLY SPACED-APART UPPER AND LOWER ELONGATE GROOVE MEANS IN THE EXTERIOR OF SAID MANDREL, A NON-GROOVED CYLINDRICAL SEALING SECTION SEPARATING SAID UPPER AND LOWER GROOVE MEANS, AND UPWARDLY FACING CUP-SHAPED CATCHER ELEMENT SLIDABLY DISPOSED ON THE MANDREL FOR RELATIVE LONGITUDINAL MOVEMENT THEREON BETWEEN AN UPPER BY-PASS POSITION OPPOSITE SAID UPPER GROOVE MEANS, AN INTERMEDIATE POSITION ABOUT SAID SEALING SECTION, AND A LOWER BY-PASS POSITION OPPOSITE SAID LOWER GROOVE MEANS, A POSITIONING SLEEVE MEANS LONGITUDINALLY SLIDABLY DISPOSED ABOUT SAID MANDREL BELOW SAID CATCHER ELEMENT FOR MOVEMENT BETWEEN AN UPPER POSITION ADAPTED TO STOP SAID CATCHER ELEMENT AT SAID INTERMEDIATE POSITION AND A LOWER POSITION PERMITTING THE CATCHER ELEMENT TO ATTAIN SAID LOWER BY-PASS POSITION, MEANS RESILIENTLY BIASING SAID SLEEVE MEANS TOWARD SAID UPPER POSITION, AND MEANS LIMITING RELATIVE UPWARD MOVEMENT OF SAID CATCHER ELEMENT TO SAID UPPER BY-PASS POSITION.

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