US3199599A - Scrapers for tubular strings - Google Patents

Description

1965 A. w. KAMMERER, JR 3,199,599

SCRAPERS FOR TUBULARSTRINGS 2 Sheets-Sheet 1 Filed Aug. 20, 1962 INVENTOR. JQQCHEE H Z' KHMMEZQEE, rle.

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1955 A. w. KAMMERER, JR 3,199,599

SCRAPERS FOR TUBULARSTRINGS 2 Sheets-Sheet 2 Filed Aug. 20, 1962 INVENTOR. flea/E2 u: Ham/45252, rle.

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United States Patent Office 3,199,599 Fatented'Aug. 10, 1965 3,199,599 SCRAPERS FGR TUBULAR STRINGS Archer W. Karnmerer, in, Houston, Tex., assrgnor to Bakers Oil Tools, Inc., Los Angeles, Calif., a corporation of California Filed Aug. 29, 1962, 'Ser. No. 218,000 16 Claims. (Cl. 166-173) The present invention relates to subsurface well bore equipment, and more particularly to scrapers for removing substances from the inner Walls of tubular strmgs disposed in well bores, such as coatings of drilling mud, cement, rust, mill scale, paraffin, and embedded bullets, and burrs formed by bullets fired through the tubular strings.

An object of the present invention is to provide a scraper for use in tubular strings, which is of strong and sturdy construction, economical to manufacture, possessed of relatively few parts, and relatively easy to assemble and disassemble.

Another object of the invention is to provide a scraper for use in tubular strings of relatively small diameters, such as in tubing disposed in a well bore, the scraper having considerable strength despite its small size, and well able to withstand safely extreme loads to which it might be subjected.

A further object of the invention is to provide a scraper for use in a tubular strin which has laterally shiftable cutter members that can collectively cover the 360 degree circumference of the inner wall of the tubular string, allowin the scraper to clean the entire circumference of the tubular string as a result of moving the scraper longitudinally therethrough, and which is also effective in cleaning the inner wall of the tubular string upon rotation of the scraper, there being large bearing areas for transmitting torque and longinidinal thrusts from the main body of the scraper tool to the cutter members mounted thereon. Such large bearing areas are present and the body of the tool has great strength despite the making of the tool of small size for operating in relatively small diameter tubular strings, such as tubing strings.

An additional object of the invention is to provide a scraper for cleaning the inner wall of a tubular string disposed in a well bore and through which circulating fluid can be pumped, in which such fluid is prevented from eroding or fluid cutting the main body of the scraper.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a side elevational view of a scraper disposed in a tubular string;

FIG. 2 is an enlarged side elevational view of a portion of the scraper illustrated in FIG. 1;

FIG. 3 is an enlarged cross-section taken along the line 33 on FIG. 1;

FIG. 4 is an enlarged longitudinal section taken along the line 44 on FIG. 1; 7

FIG. 5 is a cross-section taken along theline 55 on FIG. 4, but rotated 90 degrees relative to the position illustrated in FIG. 4;

FIG. 6 is a side elevation of one of the scraper blades;

FIG. 7 is a rear elevation of one of the scraper blades, as seen from the left of FIG. 6;

FIG. 8 is a cross-section taken along the line 88 on FIG. 7.

The scraper A illustrated in the drawings is designed to clean the inner wall of a tubular string B, such as a string of tubing, disposed in a well bore C. The scraper includes a generally cylindrical,elongate body 10 having an upper threadedpin 12 for securing the body of the lower end 13 of a running-in string D, such as a tubular string, which lower end may be constituted as a coupling. The lower end of thebody 10 may be constituted as a threadedpin 14 thereon for attachment to a lower tubing section (not shown), which may, in turn, be secured to a rotary drill bit (not shown).

The cylindrical body of the tool has a central passage 15 extending completely therethrough, as well as longitudinally spacedlateral slots 16 which are angularly displaced or out of phase with one another circumferentially of thebody of the tool.' Eachslot 16 extends from the periphery of the body at one side thereof through the diametrically opposite side, and also intersects the passage 15 through the tool. Each slot hasparallel side walls 17 and parallel top andbottom walls 18, 19 normal thereto, there being diametrically opposite scraper blades orcutters 20 mounted in each slot and havingexternal scraper teeth 21 for operation upon the inner wall of the tubular string B. Theseteeth 21 are curved to conform substantially to the inner wall of the tubular string when engaged therewith. Theteeth 21 on the exterior of each scraper blade 21' are longitudinally spaced from each other and are inclined or helical, thelower edge 22 of each tooth being suitably hardfaced so as to enhance its wear resistance.

Each blade hasparallel side walls 23 slidable along theside walls 17 of the slot and also top andbottom walls 24, 25 slidable along the top andbottom walls 18, 19 that define each slot. T o prevent eachblade 29 from being mounted in itsslot 16 in an inverted position, the lower end of each blade may be formed with a relatively smalldownward projection 26 slidably fitting Within a centralradial groove 27 opening into thebottom 19 0f the slot.

The width of eachslot 16 is substantially greater than the diameter of the central passage 15 through thebody 10 of the tool. To allow drilling fluid to be pumped down through the device for continued flow to a lower tool, such as a drill bit (not shown), a central tubular member orwash pipe 28 is inserted in the central passage 15, extending substantially from its top to its bottom end-s. Leakage of fluid between the wash pipe and the wall of the body passage 15 is prevented by suitable upper andlower seals rings 29, such as rubber or rubber-like 0 rings, disposed ininternal grooves 30 in thetool body 10 and engaging the periphery of thewash pipe 28. The lower end of the wash pipe or tubular member engages aspacer ring 31 disposed in acounterbore 32 in. thelower pin end 14 of the body, the spacer ring being held in place by a split, snap retainer ring 33 overlying the lower end of the spacer ring and disposed within an intern-a1 groove 34 in the body. Similarly, aspacer ring 35 overlies the upper end of thetubular member 28, being disposed in acounterbore 36 in its upper portion and held in place by a split,snap retainer ring 37 disposed within aninternal groove 38 in theupper portion 12 of thebody and overlying thespacer ring 35. By relmovin-g one or 'both of theretainer rings 33, 37, as a result of retracting them inwardly from theirrespective grooves 34, 33, aspacer ring 31 or 35 can be rernoved and the tubular member or 'Was'hpipe 28 taken from the central passage '15 of thebody 10.

The tubular member-0r circulation tube 28 is easily mounted in the 'body '10 of the tool. Since it is a part separate from thetool body 10, it can be made of a '13 harder material and more resist-ant to fluid cutting or the erosive action of the drilling mud, or other fluid, being pumped down through the tubular string D or drill pipe, or the like, and through thetube 23. Thus, the circulating fluid does not act on the interior of the tool body at all, resulting in the body having :a much longer life. In the event that substantial wear does occur on thecirculation tube 28, it is easily replaced without the necessity for replacing theentire body 10.

For the purpose of increasing the bearing area between thesides 23 of each blade and the companionadjacent sides 17 of eachslot 16, the inner portion of each blade is made concaved or recessed along its entire longitudinal extent, so as to allow'the blade to extend inwardly of theslot 16 and around thewash pipe 23, the latter being received within the longitudinal blade recess 40, :as disclosed in the drawings. Thus, there is a greater side area on each blade 29) engaging thecompanion side 17 of the body slot for the transmission of torque during rotation of the tool in effecting the scraping of the inner wall of the tubular string B.

The diametrically opposedblades 26 each constitute a set, and each set of blades is urged in opposite directions outwardly of the body lil by a spring device. As disclosed, a row of longitudinally spacedhelical springs 41 is provided on each side of thewash pipe 23, engaging inwardly directedflanges 42 of theopposed scraper blades 20, each spring extending between and engaging theflanges 42 of the opposed blades and urging the blades outwardly. To insure the retention of thesprings 41 in appropriate assembled position, their end portions are disposed inspring sockets 43 formed in the side portions orblade flanges 42, the springs bearing against the base or inner ends of the sockets. The force provided by the sets of longitudinally spaced laterally extendingsprings 41 on opposite sides of thewash pipe 28 against theblades 20 can be quite substantial, pressing theblade teeth 21 against the wall of the tubing B.

The blades can shift inwardly of its slot 15 against the force exerted by thesprings 41. The extent of shifting of each blade outwardly of'the body is limited by a suitable stop device. As shown, there is an enlarged transverse opening extending through each blade through which a stop element, such as theshank 51 of astop screw 52, extends, this shank having a much smaller diameter than the diameter of the opening 59. Thehead 53 of the stop screw is disposed in a suitable external body recess 54 so as to lie within the periphery of thebody 10, this head bearing against asuitable lock washer 55 engaging the base of therecess 54. Theopposite end 55 of the screw is threaded and is threadedly received within a companion threadedbore 57 in thebody 10 of the tool. By suitable tightening of thescrew 52, it will remain attached to the tool body 110, extending through the enlargedopening 50. When the tool A is out of the tubular string B, thespring 41 can only expand thecutter blades 20 outwardly of the periphery of the body to the extent determined by engagement of the inner portions of each blade, which, as shown, are theflange portions 42, with thestop screw 52.

As illustrated in the drawings by way of example, the tool A has three sets ofscraper blades 20 disposed in threeslots 16 extending completely through thebody 10 of the tool and intersecting its central passage 15. Thebody slots 16 receiving the sets of cutter blades are disposed progressively out of phase with one another, so that thecuttter blades 20 disposed in the slots and theirteeth 21 collectively cover the entire circumference of the inner wall of the tubular'string B in which the tool is disposed. Wit-h the three sets of blades specifically shown in the drawingsfthe progressive displacement of each set of blades, from the upper to the lower set, about 60 'degress from one another, with thecutter teeth 21 on each blade covering about 60 degree of arc, will result in all of thecuttters 20 collectively covering the entire circumference of the inner wall of the tubular string B in which the scraper is being operated.

The scraper can be attached to a string of drill pipe D, or the like, and lowered in the well tubing B. The mere movement of the scraper longitudinally through the tubing, without rotation, will cause its inclinedhelical teeth 21 to scrape the entire circumference of the tubular string B. If desired, the drill pipe D and tool A can be rotated, and because of the inclination of theteeth 21, the wall of the tubular string will also be scraped to remove foreign substances therefrom, effecting it thorough cleaning. During the longitudinal movement, or rotation, or both, of the tubular body it) of the tool and of thescraper blades 20, thesprings 41 are urging the teeth 2-1 against the foreign substances and the wall of the tubular string with substantial force, which force depends upon the strength of the helical compression springs. A large hearing area exists between the upper ends 18 of theslots 16 and the upper ends 24 of the cutter blades in forcing the scraper tool A downwardly through the well casing, and a large bearing area is also present between the trailingsides 17 of each slot and the trailingsides 23 of each blade for the transmission of substantial torque in scraping the inner wall of the tubular string, as a result of rotating the apparatus. Such large areas and their substantial inward extent insure the proper guiding of thescraper blades 20 in thebody slots 16 and prevents their cocking or binding therewithin. They also insure a long and useful life of the body Ill of the tool and of thescraper blades 20 themselves. Despite the use of comparativelywide slots 16 through the tool body, its minimum cross-sectional area is still very large, resulting in the body possessing great strength, capable of safely withstanding extremely heavy torques and longitudinal forces to which it might be subjected. Such large cross-sectional area is maintained despite the making of the scraper body of a comparatively small diameter to enable effective use of the apparatus A in tubing strings B of comparatively small diameter. The scraper apparatus is easily assembled land dismantled and has relatively few parts. Its manufacture is comparatively simple and economical, since theslots 16 through the body are readily formed and thescraper blades 20 themselves are easily made through simple castin procedures, requiring essentially no finishing, other than the application of hardfacing to thescraper teeth 21.

Although the scraper has been described in connection with running it in the tubular string B on drill pipe D, or the like, it may, if desired, be used on a wire line or cable. As an example, the cable may be attached to suitable sinker bars and jars (not shown) which are conneoted to theupper end 12 of thebody 10 of the tool, the sinker bars and jars providing suflicient weight for forcing the scarping tool A downwardly through the casing. Such longitudinal movement in a downward direction will scrape the entire circumference of the wall of the tubular string B, in viewof the fact that thescraper teeth 21 collectively cover a full 360 degree extent of the tubular string wall.

I claim:

1. In a tubular string scraper: a main body having means for attachment to a running-in string and having a central longitudinal passage therethrough; said body having opposed lateral slots extending inwardly from its periphery and opening directly into said passage throughout substantially the entire length of said slots; a tubular member in said passage extending across said slots for conducting drilling fluid through said body; opposed cutters slidable laterally in said slots, each cutter having inner portions extending partially around and astride said tubular member, said inner portions being slidable along the sides of said slots; and means normally urging said cutters laterally outwardly.

2. In a tubular string scraper: a main body having means for attachment to a running-in string and having a central longitudinal passage'therethrough; said body having opposed lateral slots extending inwardly from its periphery and opening directly into said passage throughout substantially the entire length of said slots; a tubular member in said passage extending across said slots for conducting drilling fluid through said body; opposed cutters slidable laterally in said slots and having inner portions extending partially around said tubular member and slidable along the sides of said slots; and yieldable means extending transversely of said tubular member and on opposite sides thereof and disposed between and engaging said cutters for urging said cutters laterally outwardly.

3. In a tubular string scraper: body means adapted for attachment to a running-in string and having a longitudinal passage therethrough; said body means having opposed lateral slots extending inwardly from its periphery and directly opening into said passage; oppose cutters slidable laterally in said slots and having inner portions confronting each other, said cutters having scraping teeth disposed at least partially longitudinally of said body means to scrape the tubular string upon rotation of said body means; and yieldable means common to said cutters and located between and engaging said confronting inner portions of said cutters for urging said cutters laterally outwardly.

4. In a tubular string scraper: body means adapted for attachment to a running-in string and having a longitudinal passage therethrough; said body means having opposed lateral slots extending inwardly from its periphery and opening into said passage; opposed cutters slidable laterally in said slots, each cutter having external scraping teeth extending at least partially longitudinally of said cutter to engage the wall of the tubular string along an extended length to scrape the same upon rotation of said body means; and a plurality of springs between said cutters, each spring engaging said opposed cutters to urge said cutters in opposite directions laterally outwardly.

5. In a tubular string scraper: a main body adapted for attachment to a running-in string and having a longitudinal passage therethrough; said body having opposed lateral slots extending inwardly from its periphery and opening into said passage; a tubular member in said passage extending across said slots for conducting drilling fluid through said body; opposed cutters slidable laterally in said slots and having inner portions extending partially around said tubular member; and a plurality of springs between said cutters, each spring engaging said opposed cutters to urge said cutters in opposite directions laterally outwardly.

6. In a tubular string scraper: a main body having means for attachment to a running-in string and having a central longitudinal passage therethrough; said body having opposed lateral slots extending inwardly from its periphery and opening into said passage; a tubular member in said passage extending across said slots for conducting dn'lling fluid through said body; cutters slidable laterally in said slots and having concave inner portions extending partially around said tubular member and providing opposed inner side flanges on each of said cutters on opposite sides of an astride said tubular member, said flanges being slidable along the sides of said slots; and yieldable means common to said cutters and located between and engaging said side flanges to urge said cutters laterally outwardly.

7. In a tubular string scraper: a main body adapted for attachment to a running-in string and having a longitudinal passage therethrough; said body having opposed lateral slots extending inwardly from its periphery and opening into said passage; a tubular member in said passage extending across said slots for conducting drilling fluid through said body; cutters slidable laterally in said slots and having concave inner portions extending partially around said tubular member and providing opposed inner side flanges on said cutters on opposite sides of said tubular member; and a plurality of springs between 6 said opposed side flanges on opposite sides of said tubular member, each spring engaging said opposed side flanges to urge said cutters in opposite directions laterally outwardly.

8. In a tubular string scraper: a main body having means for attachment to a running-in string and having a longitudinal passage therethrough; said body having opposed lateral slots extending inwardly from its periphery and opening directly into said passage, each slot being defined by top, bottom and side body walls, said passage opening into said opposed slots at said top and bottom walls of each slot; a tubular member in said passage extending across said slots for conducting drilling fluid through said body; cutters slidable laterally in said slots, each cutter being engageable with all walls of its slot to prevent longitudinal and transverse movement of said cutter with respect to said body and being guided in its lateral movement by all Walls of its slot, said cutters having scraping teeth disposed at least partially longitudinally of said body to scrape the tubular string upon rotation of said body; and means normally urging said cutters laterally outwardly.

9. In a tubular string scraper: a main body adapted for attachment to a running-in string and having a longitudinal passage therethrough; said body having opposed lateral slots extending inwardly from its periphery and opening directly into said passage, each slot being defined by top, bottom and-side body walls; a tubular member in said passage extending across said slots for conducting drilling fluid through said body; opposed cutters slidable laterally in said slots, each cutter being engageable with all walls of its slot to prevent longitudinal and transverse movement of said cutter with respect to said body and being guided in its lateral movement by all walls of its slot; and a plurality of springs between said cutters, each spring engaging said opposed cutters to urge said opposed cutters in opposite directions laterally outwardly.

It In a tubular string scraper: body means adapted for attachment to a running-in string and having a longitudinal passage therethrough; said body means having opposed lateral slots extending inwardly from its periphery and opening directly into said passage, each slot being defined by top, bottom and side body walls, said passage opening into said opposed slots at said top and bottom walls of each slot; opposed cutters slidable laterally in said slots and having inner portions confronting each other, each cutter being engageable with all walls of its slot to prevent longitudinal transverse movement of said cutter with respect to said body means and being guided in its lateral movement by all walls of its slot, said cutters having scraping teeth disposed at least partially longitudinally of said body to scrape the tubular string upon rotation of said body; and yieldable means common to said cutters and located between and engaging said confronting inner portions of said cutters for urging said cutters laterally outwardly.

11. In a tubular string scraper: a main body having means for attachment to a running-in string and having a longitudinal passage therethrough; said body having opposed lateral slots extending inwardly from its periphery and opening directly into said passage, each slot being defined by top, bottom and side body walls; a tubular member in said passage extending across said slot for conducting drilling fluid through said body; opposed cutters slidable laterally in said slots, each cutter being engageable with all walls of its slot to prevent longitudinal and transverse movement of said cutter with respect to said body and being guided in its lateral movement by all walls of its slot, said cutters having concave inner portions extending partially around said tubular member and providing opposed inner side flanges on each of said cutters on opposite sides of and astride said tubular member, said flanges being slidable along the sides of said slots; and yieldable means common to said cutters and H I located between and engaging said side flanges to urge said cutters laterally outwardly.

12. In a tubular string scraper: a main body adapted for attachment to a running-in string and having a longitudinal passage therethrough; said body having opposed lateral slots extending inwardly from its periphery and opening into said passage, each slot being defined by top, bottom and side body walls; a tubular member in said passage extending across said slot for conducting drilling fluid through said body; cutters slidable laterally in said slots, each cutter being engageable with all walls of its slot to prevent longitudinal and transverse movement of said cutter with respect to said body and being guided in its lateral movement by all walls of its slot, said cutters having concave inner portions extending partially around said tubular member and providing opposed inner side flanges on said cutters on opposite sides of said tubular member; and a plurality of springs between said opposed side flanges on opposite sides of said tubular member, each spring engaging said opposed side flanges to urge said cutters in opposite directions laterally outwardly.

13. In a tubular string scraper: a main body having means for attachment to a running-in string and having a longitudinal passage therethrough; said body having a lateral slot extending inwardly from its periphery and opening directly into said passage throughout substantially the entire length of said slot; a tubular member in said passage extending across said slot for conducting drilling fluid through said body; a cutter slidable laterally in said slot and having inner portions extending partially around and astride the tubular member, said inner portions being slidable along the sides of said slot; and means urging said cutter laterally outwardly.

14. In a tubular string scraper: a main body having means for attachment to a running-in string and having a slot opening through the periphery of the body at diametrically opposite sides thereof; said body having a central longitudinal passage therethrough opening into the upper and lower ends of said slot; a tubular member in said passage extending across said slot for conducting drilling fluid through said body; opposed cutters on diametrically opposite sides of said tubular member and slidable laterally in said slot and adapted to project in opposite directions beyond the periphery of said body, said cutters having scraping teeth disposed at least partially longitudinally of said body to scrape the tubular string upon rotation of said body; and means urging said cutters laterally outwardly of said body.

15. In a tubular string scraper: a main body having means for attachment to a running-in string and having slot opening through the periphery of the body at diameto rically opposite sides thereof, said slot having parallel side walls; said body having a central longitudinal passage therethrough opening into the upper and lower ends of said slot; a tubular member in said passage extending across said slot for conducting drilling fluid through said body; opposed cutters on diametrically opposite sides of said tubular member and slidable laterally in said slot along its side walls and adapted to project in opposite directions beyond the periphery of said body, each cutter having inner portions extending partially around and astride said tubular member, said inner portions being slidable along the sides of said slot; and means common to said cutters and located between and engaging said inner portions for urging said cutters laterally outwardly.

16. In a tubular string scraper: a main body having means for attachment to a running-in string and having a slot opening through the periphery of the body at diametrically opposite sides thereof; said body having a central longitudinal passage therethrough opening into the upper and lower ends of said slot; a tubular member in said passage extending across said slot for conducting drilling fluid through said body; opposed cutters on diametrically opposite sides of said tubular member and slidable laterally in said slot and adapted to project in opposite directions beyond the periphery of said body,

said cutters having scraping teeth disposed at least partially longitudinally of said body to scrape the tubular string upon rotation of said body; and yieldable means extending across the periphery of said tubular member from a cutter on one side thereof to a cutter on the opposite side thereof and engaging said cutters to urge said cutters in opposite directions laterally outwardly of said body.

References Cited by the Examiner UNITED STATES PATENTS 1,011,384 12/11 Sly 175291 1,372,894 3/21 Minton 175291 X 2,603,163 7/52 Nixon 166212 2,693,239 11/54 Emanuel 166--173 2,713,913 7/55 Ragan 166-173 2,743,781 5/56 Lane 166-17O X 2,836,251 5/58 Claypool et al 166-173 2,857,141 10/58 Carpenter 166--l74 X 3,088,532 5/63 Kellner 166212 X 3,123,162 3/64 Rowley 166-212 FOREIGN PATENTS 106,451 1/ 99 Germany.

CHARLES E. OCONNELL, Primary Examiner.

BENJAMIN HERSH, Examiner,

Claims (1)

1. IN A TUBULAR STRING SCRAPER: A MAIN BODY HAVING MEANS FOR ATTACHMENT TO A RUNNING-IN STRING AND HAVING A CENTRAL LONGITUDINAL PASSAGE THERETHROUGH; SAID BODY HAVING OPPOSED LATERAL SLOTS EXTENDING INWARDLY FROM ITS PERIPHERY AND OPENING DIRECTLY INTO SAID PASSAGE THROUGHOUT SUBSTANTIALLY THE ENTIRE LENGTH OF SAID SLOTS; A TUBULAR MEMBER IN SAID PASSAGE EXTENDING ACROSS SAID SLOTS FOR CONDUCTING DRILLING FLUID THROUGH SAID BODY; OPPOSED CUTTERS SLIDABLE LATERALLY IN SAID SLOTS, EACH CUTTER HAVING INNER PORTIONS EXTENDING PARTIALLY AROUND AND ASTRIDE SAID TUBULAR MEMBER, SAID INNER PORTIONS BEING SLIDABLE ALONG

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