US2636787A - Casing protector - Google Patents

Description

April 28, 1953 J. F. MEDEARIS 2,636,787

CASING PROTECTOR Filed Sept. 18, 1948 INVENTOR. JAMES F. MEDEAR/S BY 2% M M ATTORNEY which it rotates.

Patented Apr. 28, 1953 UNITED STATES PATENT OFFICE CASING PROTECTOR James F. Medearis, Venture, Calif.

Application September 18, 1948, Serial No. 49.971

6 Claims.

This invention relates to oil well drilling equipment and particularly pertains to a casing protector.

In the drilling of oil wells it is common practice to place non-metallic rings or sleeve sections upon the drill string at intervals therealong so that these members will act to protect the casing through which the drill string extends and within This protection is considered desirable due to the fact that the well bore is not always straight, thus making it possible for the drill string to rub against the casing and to wear the casing as well as the drill string. It may also occur that the drill string will tend to whip in the well and to thus violently strike against the casing through which it extends and through which it rotates. Rubber casing protectors have therefore been provided for this purpose since they can be made with a continuous tubular wall and can be stretched to pass over the relatively large tool joints occurring at opposite ends of a length of drill string and then contract onto the main body of the drill string. In actual practice an attempt is made to position a series of protecting rings at points along a length of drill pipe so that uniform protection will be afiorded for the casing. The protecting rings, however, have a tendency to slide along the lengths of drill. pipe so that they do not give effective protecting action. Attempts have been made to correct this defect by strengthening the rubber rings so that they will exert greater contractive force around the drill pipe, but this gives an added problem due to the fact that greater force is necessary to stretch the rings and to cause them to pass over the enlarged tool joints at the ends of the drill pipe sections. This stretching action not only requires enormous force but it has a tendency to impair the contractive quali ties of the rings so that they will not grip the reduced. diameter of the drill pipe with sufficient strength to retain their positions therealong. It is desirable, therefore, to provide a casing protector which may be applied directly to the body of the drill string and will hold firmly in position. It is the principal object of the present invention to provide a casing protector ring or sleeve which is longitudinally split and is fitted with means whereby it may be drawn tight around the body of a drill pipe and latched in a manner to hold it under tension and without impairing its elastic qualities.

The present invention contemplates the provision of a casing protector ring which is longitudinally split and along the contiguous edges of the split mechanical fastening means are provided to be interlocked and to hold the body of the ring under tension in its embracing position around the pipe.

i The invention is illustrated by way of example in the accompanying drawings in which:

Figure 1= is a view in side elevation showing the casing ring with which the present invention is concerned and indicating it as being mounted upon a fragmentary length of drill pipe.

Fig. 2 is a view in transverse section through the ring as seen on the line 2-2 of Fig. l and shows the ring in its locked position.

Fig. 3 is a view in perspective showingthe latch plates of the ring dissociated from the body of the protector.

Fig. 4.- is a view in transverse section showing another form of the protector ring, the contiguous edges of which are secured together by a pin.

Referring more particularly to the drawings, iii indicates a drill pipe upon which a casing protector II is mounted. This casing protector has a cylindrical tubular wall [2 which is formed of a deformable and flexible material such as rubber and is longitudinally split, as indicated at [3 in Fig. 2. It is preferable that the line of severance shall have an outer portion M disposed radially with relation to the axis of the pipe and an inner portion H) which is disposed obliquely to the plane of the radial portion Hi. This provides an angular toe it which fits under an overlapping shoulder ll' so that the protector will tend to be wrapped around the pipe Ill. Im-

bedded in the wall [2 of the protector and having portions extending toward each other and across the portion l5 of the longitudinal parting line 13 are interlocking plates I8 and i9. These plates are preferably of a length shorter than the overall length of the sleeve so that full resilient end portions of the sleeve will embrace the pipe. These plates, as shown in Fig. 3, are arcuate in shape and at their contiguous edges are formed with hooks 20 and 2!, respectively. The hooks lie within recesses 22 and 23 formed in the wall 52 of the protector to permit them to move into interlocking relation with each other. The walls of said recesses are inclined so that the hooks 20 and 2! will be yieldably urged into their locked position. The body portions of the members [8 and 19 are imbedded within the rubber of the wall l2 and are formed with a plurality of perforations 24 through which the rubber may make a bond. Equally spaced throughout the length of eachof the plates 18 and. G9 are installation perforations 25 .which communicate with holes 26 extending radially and formed through the outer section of the protector wall E2 to terminate within portions 26' formed in the inner sections of the wall it so that a prong-like member may pass inwardly through the holes 26 and the perforations 25 in the plates to draw the protector around the pipe Ill and to bring the hook edges 20 and 25 into interlocking relation with each other, as shown in Fig. 2.

In the fform-of theiinventionishowrrin Fig. '4 the plates l8 and 19 are formed with loops '21 which intermesh with each other along the contiguous edges of the plates l8 and I9 and receive a lock pin 28. Attention is directed to the fazdt thatiin either form of the invention shownthere will he an articulate connection between thecontiguous edges of the plates l8 and .ldsorthatdhebodyaof the sleeve will be free to flex and so that the portion of the sleeve occurring on the outside of the plates 18 and l 9 willifliave sufficient resiliency to function as a non-"metallic :prote'ctor.

In operation of the :present invention the protecting rings are 'rnadezassshown in the drawings and are formed with an inner diameter which is normally less than :the outer diameter :of the drill pipe it. This :innerdiam'etenhas been calculated with relation ito theformula :used in making :rubber for the sleeve so :th'atwhen ."theisleeve iszin an embracing position around'the pipe there will be .suificientrtension :inithe :rubberto .hold the protecting ring position .on the pipe and to grip it with sufficient force to prevent :it from slipping longitudinallyeof thezpipe. .After ithe'ring has been thus constructed it is :applied to thepipe :by spreading the longitudinal tsp'lit Lsird'e oi" the ring open so that it will pass around the pipe.

.A suitable tool carrying prongs .is then positioned with the iprongs in "the openings 26 211C125 .of

the ring and through the periorations :25 .in the :of the 'toe iii and thexshoulder ll the wall :of the ring M tends to wrap around the pipe -lll so that I there will not he :a continuous break in the wall throughout a radial plane and-cs that the overlapping portion of throwing :along the-line l will add additional frictional resistance to displacement of the ring on the pipe. dent that due "to the rtact :that the line of :severance forms radial portions 3l'4,'th:ese portions will be drawn against :each other in .a firmly abutting relation so that the plates 18 and 19 will :be'retained'under tension and the hooked edgesiiill '2 l w ill'behe'ld in firm engagement.

It will thus be seen that 'the protecting sleeve here shown is simple in construction and presents a continuous cylindrical resilient surface for contact with the casing, said sleeve being-so designed as to be placed upon "the drill pipe Without passing over the tool j oint and so that it maybe locked and firmly held in "position due to the inherent resiliency of the sleeve wall.

While 'I "have shown the "preferred "form of :my invention as now known to me, it will be understood that various changes may be made in combination, construction and arrangement .of parts by'those skilled in the art, without :depa'rtingrrom the spirit of the invention as claimed.

.It will also be evi- 4 Having thus described my invention, what I claim and desire to secure by Letters Patent is: 1. A casing protector comprising a rubber sleeve having a cylindrical wall which has a single longitudinal split extending the full length thereof said split forming confronting edge faces whereby, when the sleeve is positioned around a drill pipe and stretched into gripping relation therewith, the .edge faces formed by said split 'inay be brought'into abutting relation, independent arcuate metal anchor plates embedded within edgev portions of said wall adjacent said split and bonded to the rubber of said sleeve, and complementary metal hooks formed on outer edges of .said plates and extending out of said edge 'fac'es, there being recesses formed in said edge faces which :are located to respectively receive 'thereto'or'the removal of said sleeve therefrom.

2. A casing protector comprising a rubber sleeve having a cylindrical wall which has a single longitudinal split extending the full "length thereof said split forming confronting edge faces whereby, when the sleeve is positioned around .a

drill pipe and stretched into grip-ping relation therewith, the edge faces formed by said split'may be pressed together in abutting relation, independent arcuate metal anchor plates embedded within edge portions of said wall adjacent said split and bonded to the rubber ofsaid sleeve, and complementary metal hooks formed on outer edges of said plates and extending out of said edge faces, complementary inner portions of said edge faceslying obliquely with relation to a radial plane containing the axis of said sleeve and the center line of said split, there being recesses formed in said edge'faces which are located torespectively receive said hooks when said sleeve is stretched about a drill pipe as aforesaid and said edge faces compressed together so as to deform the same, said hooks thereby being brought into overlapping relation whereupon, when released, said hooks interlock to retain said sleeve stretched tightly about'said drill pipe and holding said edge faces in compressed abutting relation.

3. A combination as in claim 2 in which complementary outer portions oi: said abutting edge faces are angled relative to 5% d inner portions.

4. A combination. in c... i n13 in. which i cylindrical wall and the plates embedded therein areprovided with radial holes openi outu ardiy for reception of sleeve eng g :ements of a tool for constricting said sleeve about a drill pipe 'to-effect the at oz: said sleeve thereto or the removal 0 sleeve therefrom.

Acasing protector comprising a rubber sleeve having a cylindrical wall which has a singl" gitudinal split extending the full length ti split forming confronting edge faces who eby the sleeve may be positioned around a drill pipe and stretched into gripping encircling relation therewith, arcuate anchor plates embedded Withto be interlocked, when said sleeve is stretched about a drill pipe as aforesaid, said connecting means when interlocked, retaining said sleeve stretched tightly about said drill pipe, outwardly opening radial holes being formed in said cylindrical wall and the plates embedded therein, for receptionof sleeve engaging elements of a tool for constricting said sleeve about said drill pipe to eiiect the application of said sleeve thereto or its removal therefrom.

6. A casing protector comprising a rubber sleeve having a cylindrical Wall which has'a single longitudinal split extending the full length thereof, said split forming confronting edge faces whereby, when the sleeve is positioned around a drill pipe and stretched into gripping relation therewith, the edge faces formedby said split may be pressed together in abutting relation, independent arcuate metal anchor plates embedded within edge portions of said wall adjacent saidsplit and bonded to the rubber of said sleeve, and complementary metal hooks formed on outer edges of said plates and extending out of said edge faces, there being recesses formed in said edge faces which are located to respectively receive said hooks when said sleeve is stretched about a drill pipe as aforesaid and said edge faces compressed together so as to deform the same, said hooks thereby being brought into overlapping relation whereupon, when released, said hooks interlock to retain said sleeve stretched tightly about said drill pipe and hold said edge faces in compressed abutting position, said cylindrical Wall and the plates embedded therein being provided with radial holes opening outwardly for the reception of sleeve engaging elements of a tool for constricting said sleeve about a drill pipe to effect the application of said sleeve thereto or the removal of said sleeve therefrom.

JAMES F. MEDEARIS.

References Cited in the file of this patent UNITED STATES PATENTS

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