US1782518A - Screen pipe and method of making same - Google Patents

Description

Nov. 25, 1930. R. A. STEPS ,7

SCREEN PIPE AND METHOD OF MAKING SAME Filed July 8, 1929 Fig. 2

@NVENTOR- Patented Nov. 25,1930

" ROBERT nnnxe'nnnnsrnrs, or LOS menus, cnnmoamn 'fscnEEN fIrn Am) ms'rnon or name SAME Application filed July 8,1929. Serial No. 376,732.

The kind of screen pipe to which this in. vention relates is used in oil or water wells. It is placed in the oil or water bearing strata for the purpose of letting the fluid into the Well while at. the same time holding the sand and gravel out. Tobe most eflicient I have discovered thatsuc'h screen should have the following qualities-z first, the slots should be tapered, i. e. narrower at the outside than 19 at the inside to prevent clogging by gravel particles-etc. that occasional pass through with the oil: second, the metal should if possible be toughened at the outer entrance or mouth of the slot to reduce the abrasive'action' of the sand which enters with the .oil: and third, the outer entrance or mouth of I the slot should be depressed below the outer 1 curved contour of the pipe so as to protect the slot while setting the screen, and prevent so the formation from scraping into the slot and partially packing and sealing it. Sometimes, especially in the heavier welghts of pipe or casing it'is also desirable to eliminate any shoulders at the ends of the slot. This invention results in e the above quahties, and the novel method of producingit, as hereinafter set forth permits t to bequickly and economically produced. Figure 1 shows the saw or circular cutter 3 which I use in cutting the original slot. Fig. 2 is aside view of the saw. Fig. 3 shows a roller which I use in forming the slot after it is cut.- Fig. 4 is aside view of this roller.

- Fig. 4: shows another type ofroller which can be used. Fig. 5 shows an entirely difi'er ent kind of tool that can be used. as a substitute for the roller. Fig. 5" is a modified .form

of the tool shown in Fig. 5. Fig. 6 is a side view of the tool shown 1n Figure 5. Fig. 6

is an enlarged dia rammatic view in which the'curvatureof t e pipe is somewhat exaggerated in order tomore clearly bring out the efiiect of the toolsshown in and 5. Fig. 7 shows a piece of my finished 46 screen pipe. Fig.8 is atransverse section of the screen taken along the line X a of remove the Fig. 7 Fig. 9 illustrates how I shoulders from the ends of the slots.

w My novel'method of fabricating myscreen consists in slqttiiig the pipe 1 many suitable operation the side slot.

Figs. 3, 4,

with a circular cutter 2" as ig. 1, at the end ofwhich walls of the slot are parallel as shown in this figure. After this a tool having a properly formed pressure face is. 5 applied under pressure to theoutside of the slot toform or forge the latter. Some of the types of tools that can be usedfor this purpose are shown in Figs. 3, 4?, and5, the characteristic of these tools being that they so are so formed that when the are placed in position over" the slot they iirst-make contact with the pipe along the edges of the slot. This is est brought out in Fig':-6"-- where the dotted line- 3 representin the as tools shown in Figs. 3 and 5, and the otted inc 4; representihg the flat tool shown in Fi 4, are seen to make their first contact vwit pipe 1 immediately at the edges 5 of the en pressure is then applied to the tools in this position it sinks somewhatinto way, pre ferabl indicated in the pipe'and the shape of thejslot changes from the straight slot 6 shown in Fig; 1 to thetapered slot 7 shown in Figs. 3, 4, 5 and producing a screen having all 6 In View of this pressing or forging operation the metal immediately under thepressing tool is naturally. com ressed and is somewhat densified and toughened by the operatiom'this being nfos't pronounced along the edges 5 of the. slot because with tools that so contact there first as above indicated, the

-densifying action naturally is greatest there.

In other words the act of forcing the tool a into the pipe in this manner to give the new slot contour shown by dotted line 7 Fig. 6,

produces three, distinct advantages or features .in the slot. First, it causes the slot to be tapered, i.- e. narrower at the outside than at the inside of the pipe; second, it densifies and toughens the metal at the mouth 0f,the slot articularly along the edges of the slot ".WhlC have been depressed to 5 ,'thereby in.- creasing the resistance of the slot against sandalbrasion; and third, the mouth of the slot between edges 5 is depressed below the outer curved contour 8 of the pipe to'prote'ct the slot against scraping itself full'of dirt and. clay as it rubs against the formation while being lowered .-.into the well. These three desirable in a. well Fi 4 is sufi'icient to produce the results,

7 an comes within the spirit of this invention.

v of theslot then Instead of using such flat faced tools however, I prefer in practice to use tools having a convexed pressure face one form of which is shown in Figs. in Fig. 3 is a hardened steel roller andpressure may be applied thereto by means of pin 10, and by means of this same pin the roller is drawn back and forth along the slot so as to form the latter asstated throughout its entire length. The tool 11 shown in Figs. 5 and 6 is not a roller, but serves as a substitute therefor. It is seen that its pressure face 12 is generally of a convex form the same as pressure face 12' of roller 9, Fig. 3.

The tool 11 does not roll in the ordinary sense, and if its width is less than the length this tool is drawn back and forth along the slot as the forming .process continues. .Pressure may be applied to tool 11 in any suitable manner preferably an air hammer, or hand hammer, Either in roller 9 or tool 11, instead of the pressure face 12 being convexed in the manner shown in Figs. 3 and 5 it may beconvexed alonga true curve as shown in Fig. 5, but as above the convexed form shown in Figs. 3 and 5. .When this type of tool is used the slight depression formed around the slot and below the outer surface of the pipe has a neat and finished appearance as shown in Fig. 7 where these depressions are indicated by the reference numeral 13, the same being also truly indicated in.

gince the original slot was formed in the pipe by a circular saw or cutter as indicated in F' 1 and 2, it is obvious that curved shou ders 14, see Fig. 9, will be fbrmed at the ends of the slot. Sometimes particularly when the pipe is very thick, it is desirable to remove these shoulders so asv to give freer entry for the fluid. Ordinarily the removal of these shoulders is difficult because of the narrowness of the slots, but my, method makes this removal very easy. As indicated in Fig. 9I use a double acting saw 15, in which the teeth 16 along one edge are adapted to cut the adjacent shoulder during the while the'teeth 16' along the otherv alternately feeding is against" one shoulder or the other, the shoulders are rapidly removed until the end of the slot is either vertical, or tapered backward as indicated by the dotted lines 17 Fig- 9. In Fig. 7 the 3 and 5. The tool 9 shown.

' face of the pipe.

the slots as extending lengthwise of the pipe,

' which is the arrangement that I prefer, but

the slots can obviously cut and formed crosswise of the pipe or in anyother direction, without departing from the spirit of this invention.

y In conclusion I wish to call attention to some features of my screen which will be apparent from the previous description and drawings. 7 For 1 instance, the depth of the depression 13 is onlysuch that the narrowest portion of the slot, which comprises the mouth, lies nearer to the outside surface of the pipe, rather than the inside surface, although this mouth in fact lies between these two surfaces. Also it is obvious that the depression 13 completely surrounds its slot, the

perimeter of the depression being spaced apart from the slot all around,'so that the entire mouth of the slot, includingthe ends as well as the sides lies in the base of the depression, and therefore below theoutside sur- This is important and insures that neither the ends of the slot scrape formation into the slot either while raising or lowering the screen through the bored well, nor will the sides of the slot scrape formation therein in case the screen should happen to be rotated while lowerin it through the bored well. Also the use 0 a roller having two 0 posed :frusto-conical portions with their arge ends abutting, as illustrated in Fig. 3, has an especial advantage in that when the center of such roller presses at the extremitiesof the slots, its curved circumferential shape; causes it to press into the unslotted part of the pipe at places beyond the ends of the slots and inline with the slots including .that portion that lies between,the projected parallel side walls of the slots, assuming that these side walls are so 'theoreticall project'- ed beyond the-endsof the slots. his is all clear-from previous descri 'tions herein set forth, taken in connection'with the drawings, and illustrates how the entire slot, including the extreme ends as well as the side walls thereof, is depressed below the outer surface of the pi e, to give the good results previously descri edxn I claim: I

1. The method of making screen pipe consisting of slottin the pipe with a circular cutter operatin om the outside surface of the pipe inwar also removing the shoulders at the ends ofthe slot b a double acting 'reciprocating on the forward stroke and the other shoulder on the return stroke, and also drawing a roller back and forth under pressure over the tool adapte to cut one shoulder also having outside of the slot and lengthwise thereof, said roller comprising two opposed frustoconical vportions with their large ends abutting so that when the' center of said roller works at the extremities of said slot it presses into the unslotted art of said pipe at places beyond the ends 0 said slot and between the projected side walls thereof.

2. The method of making screen pipe consisting of slotting the. pipe with a circular cutter operating from the outside surface of the pipe inward, and then removingthe shoulders at the ends of the slot by a double acting reciprocating tool adapted to cut the one shoulder on the forward stroke and the other shoulder onthe return stroke.

3. The method of making screen pipe, consisting of slotting the pipe with a slot having parallel side walls, and subsequently drawing a roller back and forth under pressure over the outside of the slot and lengthwise thereof, said roller comprising two opposed frustoconical portions with their large ends abutting so that when the center of said roller works at the extremity of said slot it presses into the unslotted part of said pipe at places beyond the, ends of said slot and between the projected side walls of the slot.

it. Screen pipe consisting of pipe having elongated slots the narrowest portion of each slot comprising a toughened mouth lying between the inner and outer surfaces of said pipe but nearer said outer surface, said pipe pressure-formed depressions in its outside surface one completely surrounding each of said toughened slot mouths respectively, the perimeter of each of said depressions lying in the outside surface of said pipe and being completely spaced apart from its-slot and completely surrounding its slot, the said depression becoming deeper all around its slot from the perimeter of said depression toward the slot so that the entire mouth of the slot including its ends as well as its sides lies below the outside surface of said 1pc. r p ROBERT ALEXANDER STEPS.

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