061k. 21, 1969
`
`R, H, ALLEN
`FLOAT VALVE UNIT FOR WELL PIPE
`
`Filed Aug. 28, 1967
`
`3,473,609
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`MEGCO Ex. 1017
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`

`

`ice
`States Patent 0 "
`
`3,473,6?9
`Patented Get. 21, 1969
`
`1
`
`3,473,609
`FLOAT ‘VALVE ‘UNIT FOR WELL PIPE
`Richard H. Alien, Charleston, W. Va, assignor to Well
`Service inc, Charleston, W. "21., a corporation of
`West Virginia
`Filed Aug. 28, 1967, Ser. No. 663,597
`lint. til. Flak 13/04, 21/04; E211) 41/00
`US. Cl. 166-224
`4 Claims
`
`10
`
`ABSTRACT OF THE DlSCL-SSURE
`A ?oat valve unit for use in ?oating and cementing
`well pipes and which features a releasable ?oat valve
`assembly installed within a support collar connectible
`in series with the well pipe. In the event that the ?oat
`valve becomes clogged, the entire valve assembly can be
`removed from the collar to clear the well pipe simply by
`pressurizing the ?uid in the well pipe length above the
`collar to exert a predetermined downward pressure differ
`ential across the valve, higher than that which normally
`exists, to sever a shearable member that normally se
`cures the Valve assembly in place within the collar.
`
`40
`
`BACKGROUND AND SUMMARY
`OF THE INVENTION
`The present invention relates to ?oating equipment for
`use in lowering and cementing well pipe and more par
`ticularly to a ?oat valve unit having a ?oat valve assem
`bly which in the event of clogging can be released from
`the surface to clear the well pipe by pressurizing the ?uid
`in the well pipe length above the valve.
`It is common within the well servicing industry to
`employ a check valve, commonly designated as a ?oat
`valve, to maintain a seal at or near the bottom of a long
`string of pipe so that when the pipe string is lowered into
`a well bore, the empty string will have an increased
`buoyancy and will be partially supported by ‘the hydro
`static pressure of the mud, water, oil or other ?uid ordi
`narily present in the well bore after drilling. By provid
`ing a ?oat valve arranged to permit downward ?ow of
`?uid through the pipe and to prevent upward ?uid ?ow
`therethrough, the entire pipe string can be ?oated down
`the well to the intended depth and upon arrival at such
`depth, a cement slurry can be pumped down through the
`pipe and out through the valve to ?ll up the spacing be
`tween the outside of the pipe and the well bore, with
`the ?oat valve serving to prevent any reverse flow of
`cement back up the pipe under the in?uence of the hydro
`static pressure of uncured cement existing at the lower
`end of the pipe string.
`Conventional prior art ?oat valve units have valve as
`semblies which are permanently connected by screw
`threads or welding within housing collars that are coupled
`to the well pipe, and can perform the same pipe string
`?oatation and cementing functions as the ?oat valve
`unit of the invention except that When such prior art
`valve units become clogged they cannot be cleared with
`out considerable di?iculty and expense.
`When any ?oat valve unit is installed on the lower
`end of the well pipe, or between pipe sections near the
`lower end of a pipe string, and the pipe is lowered and
`suitably positioned in the Well bore, frequently during
`?uid circulation pumping or cementing operations the'
`?oat valve will become prematurely plugged or blocked
`by foreign debris clinging to the inside of the well pipe,
`lost circulation material solids added to the drilling mud
`in the well bore, and various commonly used solids in
`troduced into the cement slurry used for cementing the
`outside of the pipe to the well bore. Upon occurrence
`of such valve plugging, generally all of the well pipe
`
`2
`must be removed from the well bore to permit removal
`of the valve obstruction at the surface, and the pipe
`string and ?oat valve unit made up again and lowered
`into the Well bore. If premature valve plugging should
`occur during the cementing operation, it is necessary to
`drill out the ?oat valve and such cement as is inside the
`pipe, and then re-cement the well pipe, an extremely
`hazardous and expensive remedial operation.
`The invention provides a novel ?oat valve unit which
`avoids the need for such hazardous and expensive ?x
`operations in the event of valve plugging, and which
`permits easy removal from the surface of the entire
`?oat valve assembly downwardly and out of its housing
`collar and any well pipe sections below the collar to
`clear the entire Well pipe length thereby allowing nor
`mal continuation and successful completion of ?uid or
`cement pumping operations previously in progress.
`Essentially, the invention provides a ?oat valve unit
`having a hollow collar adapted for connection to the well
`pipe, a check valve assembly disposed within the collar
`and operable to restrict the ?ow of ?uid therethrough
`to a single direction, preferably downward, and means
`disposed Within the collar to releasably connect the valve
`assembly thereto. This releasable connection means can
`be varied in accordance with the several embodiments of
`the invention, but in general can be said to include at
`least one shearable member having material properties
`and a cross sectional area which will shear or otherwise
`sever upon occurrence of a predetermined ?uid pressure
`differential across the valve assembly to release same for
`removal out of the collar and well pipe to clear same.
`This shearable member can be a ring, a pin, or any
`other fastening or locking member that will hold the
`valve assembly in a generally ?xed position within the
`collar for performing its normal functions, and which
`will sever at the design valve overpressure corresponding
`to a plugged valve condition. ‘Nhile as described herein
`such member or plurality thereof are designated as
`shearable members, it is to be understood that the in
`vention is not restricted to any speci?c failure mode
`such as shear, but contemplates the use of such members
`as may sever to release the valve assembly through tensile
`rupture or bending fracture. The only basic criterion upon
`such expendable releasable connection elements is that
`they fail in such a way at the speci?ed overpressure as
`to allow the valve assembly to move freely away from
`its originally installed position and out of the collar un
`der the in?uence of gravity with an initial assistance from
`such overpressure forces.
`The valve assembly need not be directly connected to
`the collar itself by a shearable member, but in accordance
`with a preferred embodiment of the invention, the over
`all releasable connection means can include parts that
`remain within the collar after the valve assembly has
`been sheared out. For example, the releasable connection
`means can include a seat body connected to the collar
`by a substantially permanent fastening means, and dis
`posed to receive a cementing top plug passed down
`through the well pipe from the surface, and the valve
`assembly is connected to the seat body by one or more
`shearable members. Thus, upon plugging of the valve, 21
`?uid pressure differential will build up until at the speci
`?ed overpressure the shearable member, or all shearable
`members sever to release the entire valve assembly for
`ejection from the collar and pipe, and the seat body will
`remain inside the collar to receive the cementing plug at
`completion of the cementing operation.
`It is therefore, an object of the invention to provide a
`?oat valve unit for a well pipe which will seal the pipe
`for increased buoyancy during the lowering thereof into
`a well bore, and which will permit the flow of cement
`
`MEGCO Ex. 1017
`
`

`

`10
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`35
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`3,47 3,609
`3
`4
`slurry and other ?uids downwardly through the pipe and
`take the upward thrust of assembly 20, the ring 21 can
`prevent reverse ?uid ?ow up the pipe.
`be dimensioned to shear at a downward force which 1s
`Another object of the invention is to provide a ?oat
`less than the maximum anticipated upward force on
`assembly 20.
`valve unit as aforesaid having a releasably connected
`Ring 21 is expediently designed to shear and release
`valve assembly which, upon the occurrence of a pre
`determined pressure di?erential acting upon it, will auto
`the valve assembly 20 at a net downward pressure dif
`matically separate from the remainder of the unit and be
`ferential thereacross approximately 50 percent higher
`removed to clear the well pipe.
`than that which occurs during normal operation when
`A further object of the invention is to provide a ?oat
`the ?uid F is pumped down through the unit 10.
`valve unit as aforesaid having means installed within
`To seal against any ?uid leakage past valve assembly
`the unit to remain therewith, even if the valve assembly
`20, a pair of O-rings 31 and 32 seated in grooves 17 and
`should be removed, to receive a plug passed down the
`18 respectively are provided.
`well pipe.
`The valve assembly 20 is essentially a check valve
`Still another and further object of the invention is to
`device which has a captive ball 33 which can rest against
`provide a ?oat valve unit as aforesaid which is relatively
`a plurality of angularly spaced-apart ribs 34 to permit
`simple and economical to construct, and highly reliable.
`downward circulation of the ?uid P, which can be cement
`Other and further objects and advantages of the inven
`slurry, water, etc., through the ori?ce 35. The ball 33
`tion will become apparent from the following description
`itself is preferably fully buoyant so that in the absence
`of preferred embodiments of the invention and the ac
`of any downward ?uid F circulation, it will rise against
`companying drawing.
`seat 36 to seal ori?ce 35 and thereby prevent any reverse
`?uid ?ow upward therethrough. Actually, ball 33 can be
`BRIEF DESCRIPTION OF THE DRAWING
`somewhat less than completely buoyant, if some transient
`In the drawing:
`reverse ?ow can be tolerated, provided that its buoyancy
`FIG. 1 is an elevation view, partly in section, of a ?oat
`is not so low that the tolerable reverse ?ow will not sweep
`valve unit according to a preferred embodiment of the
`it up against seat 36. In such case, once ball 33 is against
`invention as installed in a typical well pipe.
`seat 35, it will be held there by the upward ?uid pressure
`FIG. 2 is an elevation view, partly in section, of a ?oat
`differential that would otherwise effect such reverse ?ow.
`valve unit according to another embodiment of the inven
`It should be noted that the invention is not necessarily
`tion as installed in a typical well pipe.
`limited to the use of ball-type check valves and as de
`FIG. 3 is an elevation view, partly in section, of a ?oat
`sired other types of valve designs can be incorporated
`valve unit according to a further embodiment of the
`into the valve assembly 20 in lieu of those speci?cally
`invention.
`shown and described herein.
`Insofar as the choice of a particular shearable member
`DESCRIPTION OF THE PREFERRED EMBODI
`is concerned, the invention is not restricted to the use of
`MENTS OF THE INVENTION
`a shear ring 21, and as desired one or more shear pins
`The ?oat valve unit 10 shown by FIG. 1 has a gen
`37 such as are shown in FIG. 2, or shearable threads 38
`erally cylindrical hollow collar 11 open at both its upper
`as shown in FIG. 3 can be substituted.
`end 12 and its lower end 13 which are respectively inter
`While as previously mentioned, the ball 33 can be fully
`nally threaded and externally threaded, the upper end
`buoyant, the overall valve assembly 20 is not, and is
`for direct connection to externally threaded well pipe
`preferably weighted, as with concrete, so that upon being
`section 14A, and the lower end for connection to a simi
`released will be easily pushed down out of collar 11 and
`larly threaded well pipe section 148 via a threaded cou
`lower pipe section 14B and will fall to the bottom of the
`pling 15.
`well bore 25.
`Hollow collar 11 is provided with an internal shoulder
`FIG. 2 shows a ?oat valve unit 10’ wherein the releasa
`16, preferably having an inside diameter approximately
`ble connecting means employed has a seat body 41 that
`equal to that of well pipe sections 14A and 1413 or slightly
`is connected to collar 11' in a substantially permanent
`less and three internal ring grooves 17, 18 and 19.
`manner, as by nonshearable threads 42, and serves to re
`A generally cylindrical valve assembly 20 is installed
`ceive a cementing plug 43 passed down from the surface
`within collar 11, the upper end of valve assembly 20
`through pipe section 14A at the termination of cementing
`being positioned to abut against shoulder 16, and the
`operations. Seat body 41 is preferably fabricated from an
`lower end portion of assembly 20 being secured to collar
`easily drillable material such as aluminum, so that it can
`11 by means of a shearable ring 21, which is preferably
`be removed if desired.
`slit so that it can be compressed for insertion into collar
`Valve assembly 20’ functions in a similar manner to
`groove 19 and then released to assure a normal con?gura
`_ valve assembly 20, and has a ball 33’ held captive by a
`tion in which it is retained by groove 19 and abuts against
`plurality of cage bars 44, and urged against a seat 36’ by
`a circumferential shoulder 22 provided on the lower end
`a spring 45, to permit downward ?uid ?ow through ori?ce
`of assembly 20.
`35’ and to check reverse flow therethrough.
`Thus, shear ring 21 serves to normally prevent valve
`Instead'of being connected directly to collar 11' by a
`assembly 20 from being forced downward and out of
`shearable member, valve assembly 20' is connected to
`collar 11 by pressure differential forces that normally
`seat body 41 by a plurality of shearable pins 37. Seat
`exist when valve assembly 20 functions to permit down
`body 41 is provided with an internal shoulder 16' that
`ward ?uid ?ow from upper well pipe section 14A to lower
`serves to take up such upward forces as are exerted upon
`well pipe section 14B and out through the open bottom
`valve assembly 20’ by ?uid underneath it, and functions
`thereof, as for example, during cementing operations.
`just as in the case of the internal shoulder 16 to relieve
`Collar shoulder 16 is expediently designed to take up
`the shearable pins 37 of upward forces, and allow them
`substantially all of the upward thrust load exerted upon
`to be designed purely on the basis of the selected down
`assembly 24} and for such purpose a limited axial clear
`ward pressure differential for valve assembly 20' ejection.
`ance is provided between shoulder 22 and ring 21, so that
`Pins 37 are so dimensioned and designed to shear (all
`the shear ring 21 need only be designed to sustain a down
`of them) and release valve assembly 20' whenever the
`ward thrust on assembly 20 up to that corresponding to
`net downward pressure differential thereacross reaches a
`a predetermined release pressure. For example, the up
`prescribed value, expediently 50 percent higher than the
`ward thrust acting upon assembly 20 due to the hydro
`normal down pumping value.
`static pressure of a column of uncured cement 24 in well
`Upon such occurrence, valve assembly 28' is ejected to
`bore 25 may be much higher than the desired release
`the bottom of the well bore 25, and seat body 41 re
`pressure force, and by designing collar shoulder 16 to
`mains within collar 11' to receive cementing plug 43,
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`75
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`60
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`MEGCO Ex. 1017
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`

`

`8,473,609
`6
`valve assembly disposed within said collar including a
`As exempli?ed by FIG. 3, a shearable threaded part 38
`valve member disposed to permit ?uid ?ow through said
`can be provided on valve body 20" for meshing engage
`collar in the downward direction and to prevent ?uid
`ment with a similarly threaded part 47 On collar 11" to
`?ow through said collar in the upward direction, and
`normally hold valve assembly 20” in a given ?xed posi
`means disposed within said collar to releasably connect
`tion with respect to collar 11’. Threads 38 are dimen
`said valve assembly thereto, said releasable connecting
`sioned to shear at the prescribed downward overpressure
`means including a threaded part on said valve assembly
`to release valve assembly 20" for ejection to the bottom
`and a similarly threaded part on said collar disposed for
`of the well bore,
`'
`meshing engagement with the threaded part on the valve
`From the foregoing, it can be appreciated by the artisan
`assembly to normally secure same in a given position
`that the invention provides a valve assembly 20, 20', 20"
`with respect to the collar, one of said threaded parts
`which is held within a collar 11, 11', 11" to function as
`being dimensioned to shear at a predetermined net down
`a reverse ?ow check valve under normal downward ?uid
`ward ?uid pressure differential across said valve assembly
`circulating conditions, and which will, upon clogging or
`to release same for downward movement out of said
`occurrence of any other condition which increases the
`collar.
`downward ?ow resistance above a predetermined value,
`2. The ?oat valve unit according to claim 1, including
`be ejectable simply by increasing the pressurization on
`retainer means disposed within said collar and supported
`the ?uid within the upper well pipe section 14A..Auto
`thereby for engagement with said valve assembly to resist
`matic valve assembly ejection can be realized simply by
`upward forces acting thereupon and thereby relieve said
`using pressurization equipment (not shown) at the surface
`shearable member of such upward force.
`which is capable of producing the design shearing pres
`3. The ?oat valve unit according to claim 1 including a
`sure at the level of the valve assembly, so that no auxil
`seat body connected to said collar and disposed to receive
`iary pressurizing equipment is needed.
`a plug passed through the Well pipe into said collar.
`Consequently, with the invention, the entire well pipe
`4. The ?oat valve unit according to claim 3 including
`length can be cleared at any time that the valve assem
`means de?ning an internal shoulder within said seat body
`bly should become blocked.
`disposed for abutting engagement with said valve assembly
`Preferably the valve assembly 20, 20', 20" is of a
`to resist upward forces acting thereupon and thereby
`diameter which will allow it to pass freely through the
`relieve said shearable member of such upward forces.
`size of well pipe used, so that if a lower well pipe sec
`tion 14B is used, there will be no di?iculty encountered
`in clearing both the collar 11, 11’, 11" and such pipe
`section 14B. However, the valve assembly 20, 20', 20"
`can be larger in diameter than the well pipe in cases
`where no lower well pipe section 14B is used, provided
`that the minimum diameter opening in the collar 11, 11',
`11" is su?icient to allow passage of the valve assembly
`20, 20', 20” out through the lower end thereof.
`From the foregoing, it can be appreciated by the artisan
`that the invention is susceptible of numerous obvious
`modi?cations and variations to suit the needs of a par
`ticular application. However, the invention is intended to
`be limited only by the following claims in which I have
`endeavored to claim all inherent novelty.
`What is claimed is:
`11. A ?oat valve unit for a well pipe, which comprises
`a hollow collar adapted for connection to the well pipe, a
`
`References Cited
`UNITED STATES PATENTS
`6/1927 Baker __________ __ 137-5153
`1,631,509
`7/1941 Westall ___________ ___ 166-28
`2,249,511
`2,300,854 11/1942 Allen et al _______ __ 166- 224 X
`2,662,602 12/1953 Schnitter ________ __ 166-225 X
`2,751,023
`6/ 1956 Conrad __________ __ 166-225
`2,890,861
`6/ 1959 Cook ____________ __ 175-318
`
`CHARLES E. O’CONNELL, Primary Examiner
`IAN A. CALVERT, Assistant Examiner
`
`U.S. Cl. X.R.
`137-71, 515.3, 515.5
`
`45
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`l O
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`20
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`25
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`30
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`35
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`MEGCO Ex. 1017
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