US2253415A

US2253415A - Means for centering tubular well strings

Info

Publication number: US2253415A
Application number: US294010A
Authority: US
Inventors: Gerson H Brodie
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-09-08
Filing date: 1939-09-08
Publication date: 1941-08-19
Anticipated expiration: 1958-08-19

Description

Aug. 19, 1941.

G. H. BRODIE 2,253,415

MEANS FOR CENTERING TUBULAR WELL STRINGS Filed Sept. 8, 1939 clam/M414.

` Patented Aug. 19, 194i y 2,253,41Q35H y MEANS Fon CENTERING. TUBUI-.An WELL s'rmNGs y Gerson H. Brodie, Houston, Tex. Application september 8,1939, serial Ne. 94,010 1s claims. (cl. 16e-1) This invention relates to means. for centering tubular well strings.. such as a casing string, in a wellbore.

The primaryobject of the invention is to insure that the cement used in the completion of the well encircles the casing completely, leaving no portion of either the wall of the bore or the casing uncovered by cement.

-A further object is to furnish means that will positively move the casing away from any portion of the bore-hole wall, against which it may be leaning due tothe crookness of the hole or for any other, cause.

A still further object is to supply means to perform the operation of moving the casing away from the bore-hole wall in a minimum of time, without resorting .to running drill pipe into the hole to accomplish the task.

Another object is to provide means suiiiciently strong to be lowered into a deep hole without being damaged, and which will effect sigaling the successful completion of the operation of cementing by means of the pressure gauge normally used on the mud system in drilling oil wells.

With the foregoing objects outlined and with Fig. 7 is an elevation of one of looking from the inner` side thereof.

Fig. 8 is a bottom plan view of one of the wedges.

Fig. 9 is a side elevation of one of the wedges.

the wedges Referring to the drawing, Ill designates the 4 wall of a well hole in which a tubular well string.

such as a casing string Il. is inserted. In the string, I interpose, at suitable points, centering other objects in view which will appear as the description proceeds, the invention consists in the nov/e1 features hereinafter described vin de.- tail, illustrated in the accompanying drawing, and more particularly pointed out in the appended claims. v

In the drawing: Fig. 1 is a vertical sectional view of a. portion of a well hole and showing my improved means arranged therein, such means being shown partially in elevation and partially in vertical sectionand with a pair ofcentering collars with their wedges extended. Fig. 2 is a vertical sectional view partly in elev' tion of one of the centering collars shown inte ed in the casing string and with the wedges in etracted position.

F7155. 3 is a horizontal sectional view taken on line 3 2 of Fig.. 2. l

Fig. 4 is a vertical sectional view illustrating the manner in which the plug causes projectionA of the wedges of a centeringcollar. A l Fig. 5 is a horizontal sectional view taken on the rune 5 5 of Fig. 4.

Fig. 6 is a perspective view of one ofthe i merle@ latches employed in holdin: af-wedge in vprojected 90811210- collars I2; two such collars being shown in Fig. l.

As best shown in Fig. 2, each collar may consist of a section ofpipe I3 havingan internal diameter substantially equal to the internal diameter of the casing sections I4, and provided at its ends with. internal threads to engage' external threads on the 'casing sections as indicated at I5.

As best illustrated in Figs. 3 and 5, the collar I2 is provided with vertically disposed slots I6 to accommodate or guide wedges or wedge-shaped centering elements I1.

The upper or small end of each wedge is hingedly connected by any suitable means located at I8 to the collar I2, and the lower or large end of each wedge is of arcuate shape as indicated at I9 so as to snugly ilt the lower end portion of the slot in which the wedge operates.

As it is necessary when the wedges are projected to seal the joints between the wedges and the slots, the inner portion of each wedge is provided with oppositely disposed beveled surfaces 20 to impinge against beveled surfaces 2| at the inner portions of the slots I8. In practice the beveled section 20 of each wedge will be treated with vulcanized rubber prior to introduction of the string into the well to insure sealing when the wedges are extended. `Such vulcanized rubber would be of gradually increasing thickness toward the lowermost part of the wedseilare. l

At the lower end of each wedge, a knurled latch 22 (Fig. 6)4 extends into the slot in which the web operates, and 'such latch'tlmctions to hold the wedge in projectedn position after it has been extended, in a manner hereinafter explained. Each latch has a resilient .shank 2l that is secured to the exterior of the collar I2 by means of a screw 24 or the` like.

Each wedge is provided with a semi-cylindrical shield 2l, secured to thevwedge by any suitable means. auch as screwsv 2l,l andsuch shields carry shear pins 21 which/extend intoihe eeuu u] allowed to float down A bottom,

' `From the foregoing.' it is invention may be readily (Fig. 3) and normally hold the wedges inretracted position.

The wedges are expanded by any suitable means, 'such as the plug l28, shown in Figs. l, 4

and 5. Such plug is of substantially cylindrical form and has an ellipsoidal nose 23 at its lower` end. Such nose'is constructed-of-steel or any other type of hard4 metal and the outside diameter of the plug approachesthe inside diameter of the collar.

The plug is of tubular formation and provided thr ugh which-the drillingmud and cement may at the proper time.

A sealing cup 36 is arranged at the top of the plug to insure maintenance of pressure while.

the plug is forced downwardly through the casing string under the pressure of the pump. An abutment 31 attached to the stem 32 bewith the flow shoe 33 so as`to cause shearing of the pin 33 and opening of the valve 3| when the plug 28 reaches the bottom of the casing string.

In operation, when it is desired to center a I string of casing in the we ii hole, one or more of I2 are inserted in the the centering collars string at desired positions before the latter is 'inserted in the hole. When the string is made up, the plug 23 is -dropped intq the easing and until stopped bythe retracted wedges I1 of the uppermost centering collar. A drilling mud connection is made at the top of the string and a pump pressure lower than that required to break the shearlpns 21V is low the shear pin 33 is adapted to cooperate applied. When the pump stops, it is certain .A

that wedges I1 are still closed, Pressure is then increased by the pump until the breaking point .of the shear pins 21 is reached, at which 'time the pumps move freely, inlicating passage of the plug -through the centering collar. This procedure is repeated'as the-plug encounters the .several collars.

When the plug forces` appended shields .25 open, the knurled latches 22 coact with the lower ends of the wedges and prevent the` return of the wedges to closed position.

When the plug 23 has been pumped to the the abutment 31 comes into forcible contact with the noat shoe 38 with the result that the stem. 32 is halted on its downward movement while the plug 23 shears the pin 331 and continues downwardly .until it contacts such abutment. This causes opening of the valves 3| and 33 and permits the drilling mud and the cement to circulate freely through the plug, out of the casing and into the drill hole. When circulation is thus freely obtained, the casing is centered at the desired depths in the bore hole. believed that the construction, operation and advantages'o'f the uriderstood and I am aware that changes lmay be made in the' details disclosed without departing from the spirit of the invention. as expressedy in the claims.

What I claim and desire to secure by Letters the wedges and their i l adapted to open the assegni ing interposed therein normally retracted but projectable elements adapted to be extended outwardlyfrom various sides of the string and to engage the "wall of a bore hole for centering the string therein, a plug adapted to travel down the string and provided with means for projecting said centering. elements, and latching means cooperating with said elementsy for holding the same in projected position.

2. In combination, atubuiar well string having interposed therein normally retracted but projectable wedges, adapted to be extended outwardly from various sides of the string and to engage the wall of a bore hole for centering the string therein. each wedge having its smaller end at the top thereof, a plug adapted to travel down the string and provided with means for engaging said wedges and projecting the same outwardly as theplug travels downwardly, and latching means arranged at the lower end of Jeach wedge for holding the same in projected position.

3. In combination, a tubular well string provided with slots at various sides thereof, normally retracted but projectable elements arranged t`o operate in said slots and to engage the wail of a` bore hole for centering the string therein, and a plug adapted to travel down `the string and provided with means for projecting said centering elements, the well string and elethe string and provided with means for project- 4ing s'aid centering elements, a shield united with each element, and fragible means for securing the shields to the well string.

5. In combination, a tubular 'well string having interposed therein normally retracted but proj ectabie elements adapted to extended outwardly from various sides of e string ,and to engage the wall of a bore hole for centering the string therein, a normally closed valve at the bottom of 4the string, and a valved plug adapted to travel down the stringand provided with means for projecting said centering elements and for opening said valve.

6. In combination, a tubular well string having a normally closed vaive at the lower end thereof and provided with interposed normally retracted but projectable elements adapted to be extended outwardly from various sides of the string and to engage the wall of a bore hole for centering the string therein, a tubular plug adapted to travel down the string and provided with means for projecting said centering elements said plug therethrough, a Isecond valve adapted to close said passageway and provided with a depending stem which extends through the plug and is first-mentioned valve.

'7.In combination, a tubular well string having a normally` closed valve at the lower end thereof and provided with interposed normally retracted but projectabie elements adapted to be extended outwardly from various sides of the string and to engage e wall of a bore hole for 1. Imcombination. a tubular well' string hav- 75 centering the string thesei\n, a 'plug having a passageway extending Vadapted tocpen the first-mentioned valve, and

frangible means for normally holding the stem in such position as to close said second valve.

8. In combination, a tubular well string having interposed therein normally retracted but projectable elements adapted to be extended outwardly from various sides of the string and to engage the wall of va bore hole'for centering the string therein, a normally closed valve associated with .the well string and arranged below said elements, and valved means adapted to travel down the string, to project said centering elements and open said valve. 9. A method of centering and cementing oil well casing comprising forcing a plug down the casing and utilizing such plug to project centering'elements' from the casing and to open a discharge valve of the casing, and then forcing cement through said plug and valve into the bore hole in which the casing is centered.-

10. A centralizing device'for well casing and the like, comprising a hollow body secured to said casing, longitudinally restrained radially extensible members positioned in said body intermediate its ends, means for holding said members in a -retracted position in said body to be substantially ilush with its outer surface, rigid means adapted to be introduced into said body to ll the bore thereof to release said holding means and positively extend said members radially from said body, and means associated with said extensible members to retain them in an extended position independently of said rigid means.

11. A centralizing device for well casing and the like, comprising a hollow body adapted to be secured to said casing, longitudinally restrained radially extensible members movably positioned in said body, means for holding said members in a retracted position in said body, said extensible members and said holding means adapted to be actuated by means operable from the top of said casing to release said holding means and positively ext-end said members from said body, and means associated with said extensible members for holding them in their expanded position independently of the surface operable means.

12. A centralizing device for well casing and the like, comprising a hollow body adapted to be secured to said casing, a pluralitybf longitudinal slots circumferentially spaced in said body, a 1ongitudinally tapered foot in each of said slots, means at one end of said slots for retaining, said feet against inward or outward motion therein, the wider ends of said feet adapted to be displaced outwardly from said body by a rigid object introduced therein, and means associated with' said feet for holding them in their expanded position independently of said rigid object.

13. A centralizing device for well casing and the like, comprising a tubular body member adapted to be connected to a well string, longitudinal slots in said body member, a longitudinally restrained radially extensible element positioned in each of said slots, and holding means for nor'- mally holding said elements in retracted position, said holding means being releasable by a'rigid object introduced into the body member to move said element outwardly from said body member.

14. A centralizing device for well casing and the like, comprising a tubular body'member'ada'pted to be connected to a well string, longitudinal slots 15. In combination, a tubular well string hav.4

ing interposed therein normally retracted` but projectable elements adapted to extend outward- 1y from various sides of the string, and a. valved plug adapted to travel down the string, said plug being adapted to cooperate with said projectable elements to extend the same outwardly into contact with the wall of a bore hole for centering the string therein.

16. In combination, a tubular well string havin g interposed therein normally retracted but projectable elements adapted to extend outwardly from various sides of the string, and a ported plug provided with an obturating member, said plug being adapted to cooperate with said projectable elements to extend the same outwardly into contact with the wall of a bore hole for centering the string therein.

GERsoN H. BRoDrE.

CERTIFICATE oF CORRECTION.V

Patent No. 2,255,ll.l5. August 19, 19111.

` GERsoN H. B RoDIE.

-It is hereby certified thaterror appears in me printed specification o" the above: numbered patent requiringcorrection ne follows: -Page 5, second-column, line 12, beginning with "15. A centralizing" strike out all to and lincluding 'the wordend period "memben" in line 2l, comprisingcl-aixn 15, and for the elaime now appearing as 11i, 15, and 16, read 15, lh, and

15 respeetively; and that the said Letters.Patent shou1dbe read with this correction therein that the same may conform to the record ofthe ,case in the Patent office.

Signed andeealed this 50th day of September, A. D. 19111.

. Henry Van Arsdale, (Seal). A'cting Commissioner of Patents.