US2274756A - Cementer - Google Patents

Description

3mm/wolf1 March 3, 1942. w. J. 'r'RAvE-Rs. JR

- CEMENTEE Filed Sept. 23, 1940 A Patented Mar. 3, l11942 UNITED -ST'EES .PATENT FFICE 'CEMENTEE William J. Travers, Er., Bakersfield, Calif. Application september 23, 1940, serial No. 357,91i

(cl. lss-12) 1 Claim.

This invention relates generally to oil well tools and more particularly to tools used for performing cementing operations in wells.

In the drilling and completing of oil wells it is practically always necessary to perform oementing operations at various points in the well. In certainof these operations cement slurry is forced through holes in the well casing, .the holes being provided by perforating the casing when it -is in place in the well or being originally provided in the casing as in the case of what are known as combination production strings of casing. With ordinary conventional apparatus the cementing process takes considerable time and leaves obstructionsor plugs in the well which must subsequently be removed by drilling out. l It is a primary object of this invention to provide a simple, relatively inexpensive tool` for quickly performingone or a multiplicity of cementing operations in a well without leaving any obstructions of anykind in the well. In this connection it is an object to provide a tool which is entirely removable from the well andwhich can be ushed clean of cement while in the well and which may be further used in flushing the well itself clean of cement. v It is a particular object of this invention to provide a tool embodying casing engaging packing members and means forming a by-pass passage to opposite sides of the casing engaging packing members to allow the tool to be easily lowered or raised in a well and to further provide means associated with the by-pass passage whereby the same may be closed-against upward ow of fluid therethrough -when desired.

It" is also an-object of this invention to provide means for holding a by-pass closure element in inoperative position and a release means associated therewith to render ineffectivev thev holding means.

These and other objects will be apparent from the drawing and the following description. Referring tothe drawing which is for illustrative purposes only; Y

Fig. 1 is a' sectional elevation of a well casing and a .tool thereinv embodying a form of the invention;

Fig. 2 is a sectional plan view on line 2-2 of Fig. 1;

Fig. 3 is a vfragmentary sectional elevation of the lower end portion of the tool of Fig .l showing the parts in position to prevent flow of uid upwardly through the by-pass passage.

MoreV particularly describing' the invention,

reference numeral Il generally indicates a well casing which is shown as provided with perforations l2 through which it is desired to force cement. Numeral Il generally indicates-a cementing tool embodying the invention which may be suspended in a well by means of a string of pipe I5 fragmentarily indicated on the drawing and attached to the upper end of the`tool I5 by means of an ordinary lcoupling I6. The t'ool Id comprises an elongate tubular member I 8 which is threaded at its upper end to accom- Y modate the coupling l6.as shown and which is perforated in any suitable manner asby the holes I9 in a region intermediate its ends. A pair of packers, or Vcasing engaging packing members are xedly mounted on opposite sides of the openings I9. These packers, each indicated by numeral 20, may be of ordinary form andconstruction and are arranged facing each theror opposed in order that they may serve to prevent escape of fluid under pressure inthe annular space'ZI between them when the tool` is inside a well casing.

In order to provide a means of by-passing fluid to opposite sides of the pair of packers, so that the tool may be readily lowered or raised in a well casing having fluid therein, the tool is provided with a by-pass tube 22 mounted in the tubular member I8 and having its upper terminus disposed in an aperture 23 above the uppermost packer 20. At its lower end the tube 22 terminates in a closure or plug 24 mounted in the lower end of the member I8.

Mounted on the lower en d of tubular member I8 by means of threads 26 is what will be termed a float guide shoe member 2l. This guide member contains a barrier or annular restriction member -28 provided with a passage 29 which terminates at itsv lower end in a valve seat 30. Below the element 28.the shoe is provided vwith openings 3|. With this construction it is apparent that a by-pass passage, generally indicated by numeral 32, is provided through the major portion of the tool to opposite sides of the pair of packers b'y the aforementioned tube or conduit 22 and the shoe 21 with its passage 29 and openings 3|.

In order to perform certain types of cementing operations in the well it is desirable to be able to plug oi or pack oi that portion of the well below thetool to prevent any possibility of circulationof iiuid upwardly past or through the is provided a relatively light weight or oatable tool in order that there will be no .possibility of migration of cement forced'behind the casing Il down to a vpoint below the tool and back into the well. In order to accomplish this, there shearable means such as the wire 31. `The rod 36 is slidably received in' a bushing 36 and is provided at its inner end with a head 38 to facilitate the wiring `of the ball valve to it. In this connection the openings 3l are made much larger than would be necessary to accommodate theuid flow in order that the valve and release rod may easily be wired together.

The rod 36 -is provided intermediate its ends with an abutment flange 39 to limit upward movement of the member. Wickers or springs 40 are mounted on the lower end of the rod by means of a nut 4|. With this construction the tool may be lowered to a desired point in the well and subsequently raised until the wickers by engagement with a joint in the well casing or some other irregularity such as a perforation, or until by reason of frictional engagement with the casing walls only, serve to pull the rod 36 downwardly with relation to the remainder of the tool and thereby sever or break the wire 31, releasing the valve 34.

The parts have been shown in the released position in Fig. 3, the floatable valve member having moved upwardly to seat against the valve seat 30 and serve to prevent flow of fluid upwardly through by-pass passage 32.

Although only one means has been shown of closing the by-pass passage against upward flow of fluid therethrough, it is within the scope of the invention to provide other means of accomplishing this, as by the provision of ordinary types of valves, and of providing other means for releasably holding the passage closure means in an inoperative position until such time as it is desired that the closure means should become effective. It is also contemplated that the closure means could be located at other points in the passage.

I In the operation of the tool for performing a cementing operation at, some point intermediate the top and bottom of the well, as for example the forcing of cement through the perforations I2 shown in the casing I I, the tool is rst lowered into the well on the end of a string of pipe such as I5. The perforations I2 may be located in a vgeneral way by reason of the fact that their v a region of perforated casing for the reason that circulation can be established down through the tool and out through openings I9 and any perforations in the casing which are located between the packers. If the tool is in blank pipe culation cannot be established.

After theplace to be cemented has been located By using the pump presitself.

this cirthe tool is lowered to a point below and then l raised to permit the wickers to engage an irregularity n the casing such as a joint or coupling or-to operate by friction with the casing walls. Further raising of the .tool .will cause breakage of the wire31 as the release rod 36 is pulled downwardly relative to the rest of the tool.

This releases the valve. 36v and permits it to float up to engage the valve seat 30 and close off the The cementing operation may then be pei*- formed by forcing cement slurry under pressure down the pipe I5 and then through the tool I4 where it will emerge through the openings I 9 between the packers and escape through the perforations in the casing to the desired region behind the casing. The packers 20 serve to provide a blocked off annular area 2I and prevent migration of the cement slurry in the casingl beyond eitherV packer. The fioatable valve 34 by closing oif the by-pass passage 32 against upward owof uid closes or blocks olf the portion of the well below the tool and thereby serves to prevent the migration of fluid and possibly cement downwardly on the outside of the casing and into the well at a point below the tool and then upward through the by-pass.

After sufcient cement has been placed behind the well casing the tool may be raised into a region of blank or unperforated casing and flushed clean by reversing the circulation, that is, by forcing fluid downwardly between pipe I5 and the casing. This fluid will pass the packer 20 by reason of the fact that this packer is turned downwardly, and enter the tool through the openings I9 cleaning out any cement slurry in the region between the packers and in the tool The toolA of course may be used to perform another cementing operation higher in the well without necessitating the Withdrawal of the tool from the well. When the toolV is raised, .fluid is free to by-pass the packers lthrough passage 32, the -valve 34 being ineffective to prevent such passage.

Although the invention has been particularly shown and described, it is contemplated that various changes may be made without departing from` the scope of the invention and it is intended to cover such changes as .come within the scope .of the claim. L

Ivclaim as my invention:

In a cementing tool, a tubular member adapted to be lowered into a well on the end of a string of pipe; closure means for the lower end of said tubular member; a pair of o spaced packers mounted on said tubular member and adaptedto engage a well casing; said tubular member having an opening in its wall between said packers; means providing a by-pass fluid passage through said tubular member to opposite sides of the pair of packers said passage being isolated Nfromcommunication with such interior portion of the tubular member as is in communication with said opening in the wall of said tubular member between said packers; means providing a valve seat in said by-pass passage; a iloatable valve member below said seat and adapted for engagement therewith to prevent flow of fluid upwardly through said passage; a valve cage limiting movement of said valve member; a release rod movably mounted in said tubular member and having a portion extending to the exterior thereof; severable means securing said valve member to. said rod; and a flexible casing engaging member on said rod adapted to engage the well casing to move said rod relative to said tubularA member upon upward movement of said tubular member to break said `severable means and release said valve member. v

WILLIAM J. TRAVRS, Jn.

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