US2081190A - Well screen - Google Patents

Description

May 25, 1937. H, D WILSON 2,081,190

WELL SCREEN Filed June 15, 1956 V 3 2. a a

#121 a mam". INVENTOR.

Patented May 25, 1937 UNITED STATES 3 Claims.

This invention relates in general to screen pipe such as is customarily used at the bottoms of oil wells and the like, and has particular reference to the means of finishing the end portions 5 of a wire wrapped screen at the points where the wire wrapping terminates and is fastened to the perforated tubular body of the screen.

In forming screen pipe for the purpose set forth, it is quite customary to wrap upon a perforated support, usually consisting of a perforated section of pipe having raised portions or ribs along its outer surface, a specially designed wire which forms the screen proper. This wire is customarily provided at intervals with lugs which serve to space the various convolutions one from the other by exactly the required distance, usually .010 inch or less. The wire wrapping is continued beyond the ends of said ribs a short distance, and solder or the like is then applied to the end of the winding, usually extending along the winding past the ends of the ribs, to secure the end portion of the winding in place and to prevent the entry of well fluid between the ends of the ribs. .It has been found, however, that in wells where very high pressures are encountered, as in many modern oil wells, such high pressures are sufiicient to force'this relatively soft and plastic solder coating or collar in through the break in the winding which is present where the ends of the ribs occur, and form an opening of considerable size atthis point. The wash which then takes place through such opening and between the ribs to the nearest perforation in the support will in a very short time out an opening l in the support of such size as to render the screen useless and cause the well to sand up. This necessitates the great expense of shutting the well down, removing and junking the expensive screen, cleaning the well, and replacing the screen, as well as involving a tremendous loss due to the fact that the well must stand idle during the time required for this work. Moreover, when such a screen is lowered into a well, various projections within the well may catch on the screen wire and rip it loose from its support, and various other difliculties may arise due to the fact that the screen wire projects beyond the contour of the support and is not protected in any way.

It is an object of this invention to provide a means for finishing the ends of the wire wrappings of screens of this type which will avoid the dimculties above set forth.

It is a further object to provide for the ends of such wire wrappings a smooth continuous support beyond the ends of the ribs on the main support, thus avoiding any break in the contour of the wrapping through which a washout might occur.

It is a further object to provide a relatively strong and solid means for closing the ends of the spaces between the ribs of such a screen. and providing strong continuous supports of the same diameter as said ribs for the ends of the wire Wrappings. j

It is an object of this invention to provide a means for protecting the wire winding of a screen such as above referred to.

It is a further object of this invention to provide a means for finishing off the ends of. a wire winding on a screen such as above set forth in such a manner that the wire will be amply protected by a solid member mounted upon the support itself. v

Other objects and advantages will become apn parent from the following description taken in connection with the accompanying drawing, it being understood that the same are by way of illustration and example only, and not by way of limitation, and that the scope of this invention is to be considered as defined by the prior art and by the terms of the appended claims.

Reierring now more particularly to the drawing in' which like numerals indicate corresponding parts throughout:

Fig; 1- illustrates an elevation of a screen constructed in accordance with this invention, parts being broken away for the purpose of illustration.

Fig. 2 is a view showing one of the elements of the screen illustrated in Fig. 1.

Fig. 3 is a vertical sectional view of the central portion of the screen illustrated in Fig. 1.

As shown in Fig. 1, the screen comprises a substantially cylindrical support designated by the numeral l, and provided on its outer surface with a plurality of longitudinally arranged substantially parallel raised ribs 2. Intermediate these ribs this support is perforated as shown at 3 to Permit the passageof the fluid into the interior of the support. Wound upon the support i over the ribs]. is a wire 4 which may be of any type customarily employed for this purpose, and which is preferably provided at intervals with lugs or projections for the purpose of properly spacing the various turns or convolutions of the wire 0 when it is wound upon the support. Such lugs are indicated by the numeral 5.

At the ends of the ribs 2 the support I is provided with a solid collar 6 which is of the same internal diameter as the outer diameter of the PATENT OFFICE f 6 is beveled at its end remote from the winding support I, and which is of the same outer diameter as the outer diameter of the winding of the wire 4. One end of this collar is in contact with and interengages with the ends of the ribs 2, this portion 1 being of the same radial extent as the ribs 2, and being slotted, at 8 to receive the ends of these ribs. It will thus be seen that this portion 1 is of the same outer diameter as the inner diameter of the winding 4, and that the winding 4 may be continued so that its end will overlie the portion 7 of the collar 6, and will abut the shoulder 9 thereon. The collar 6 is secured to the support I in any manner desired, such as for instance by welding, and. the end of the wire 4 may be secured to the portion 1 of this collar by soldering or the like. It is to be noted that the portion 7 of the collar 6 in efiect forms a continuation of the ribs 2, and that the winding 4 may be continued thereover without interrupting its regular outer contour. It is further to be noted that the outer diameter of this collar 6 is substantially the same as the outer diameter of the winding 4, and that when the winding is complete with its end abutting against the shoulder 9, the large portion of the collar 6 will form a continuation of the contour of the winding. The collar as shown at l0, so that as the screen is run into a well, any obstructions which might be encountered will be deflected outwardly by the beveled portion ID of the collar and the enlarged portion of the collar 6, to protect the end of the winding against contact with such obstructions.

It is noted that the support I is extended below the collar 6 as shown at I l, and is threaded at its lower end l2. It will be appreciated, however, that this portion of the construction does not form a part of the present invention, and that it may be varied as desired.

The band or collar 6 is preferably made of a hard metal capable of resisting wear and hard usage. The band is preferably secured in place by welding or the like, and if desired each of the ribs 3 may be secured in the corresponding slot 8 by welding, pinning, soldering, or any other suitable method. It will be appreciated, however, that various changes and modifications may be made in the particular embodiment of this invention within the spirit and scope of the appended claims.

It is apparent that that portion of the collar which projects between the winding and the main support pipe serves to close the ends of the spaces between the ribs with a relatively strong solid member, and that it forms a continuous support for the winding beyond the ends of the ribs without interrupting or causing a break in the contour of the winding at the ends of the ribs through which a washout might occur. In short, the ends of the wire wrapping have been finished in a ,manner to remove from the solder or the like used for fastening the wrapping in place the burden of withstanding the tendency of the formation pressure to force itself into the interior of the screen at the ends thereof.

At the same time there has been set forth a well screen of the wound wire type in which a means is provided for finishing the end of the wire winding in a manner which will protect such winding and prevent it from being damaged or torn out of place by various obstructions during the time it is being lowered into a well. It is further noted that the embodiment illustrated and described is fully capable of accomplishing this and all of the other objects sought by this invention.

It is to be understood that the term "ribs as employed in this specification and the following claims is not intended to be limited to the particular type of ribs shown in the drawing, but is intended to refer to any raised portions or members extending along the surface of a support pipe for supporting the screen proper out of full contact therewith.

Having described my invention, I claim:

1. A screen pipe comprising a support having raised ribs on its surface, a wire wound about said support on said ribs, and a'solid collar secured on said support abutting said wire at the end of the winding thereof, said collar having a part of the same radial thickness as said ribs, and slotted to receive the ends of said ribs, said part projecting beneath the end portion of said winding into inter-engagement with the end portions of said ribs.

2. A screen pipe comprising a support having ribs extending along its outer surface, means substantially closing the space between the ends of said ribs and providing a. continuous supporting surface, said means being of substantially the same radial extent as said ribs at the ends thereof, and a wire wound about said support on said ribs and onto said continuous supporting surface beyond the ends of said ribs.

3. A screen pipe comprising a support having raised ribs on its surface, a wire wound about said support on said ribs and a solid collar secured on said support and abutting said wire at the end of the winding thereof, said collar having a part of the same radial thickness as said ribs projecting beneath the end portion of said winding to a position at least even with the ends of said ribs, the portion of said collar which abuts the end of said winding being of substantially the same diameter as the outer diameter of said winding.

HILL D. WILSON.

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