U.S. patent number 3,845,784 [Application Number 05/129,592] was granted by the patent office on 1974-11-05 for float valve for drill strings.
This patent grant is currently assigned to Byron Jackson Inc.. Invention is credited to Wayne N. Sullivan.
United States Patent |
3,845,784 |
Sullivan |
November 5, 1974 |
FLOAT VALVE FOR DRILL STRINGS
Abstract
A float valve for a string of well drilling pipe, the valve
being disposed in a sub above the drill bit and including a
downwardly facing annular seat engageable by an upwardly closing
valve head, the head having non-circular opening in its underside
into which extends a correspondingly non-circular guide stem
projecting upwardly from a spider support, a spring encircling the
stem and acting upwardly on the valve head.
Inventors: |
Sullivan; Wayne N. (Houston,
TX) |
Assignee: |
Byron Jackson Inc. (Long Beach,
CA)
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Family
ID: |
26827725 |
Appl.
No.: |
05/129,592 |
Filed: |
March 30, 1971 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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818261 |
Apr 22, 1969 |
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Current U.S.
Class: |
137/515;
137/543.15; 166/325; 137/536 |
Current CPC
Class: |
E21B
21/10 (20130101); F16K 15/063 (20130101); Y10T
137/7854 (20150401); Y10T 137/7923 (20150401); Y10T
137/7935 (20150401) |
Current International
Class: |
F16K
15/06 (20060101); E21B 21/10 (20060101); E21B
21/00 (20060101); F16K 15/02 (20060101); F16k
015/02 () |
Field of
Search: |
;137/543.15,515,536,522,515.5,515.7,542,540,533.27 ;166/225 |
References Cited
[Referenced By]
U.S. Patent Documents
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2725076 |
November 1955 |
Hansen et al. |
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Primary Examiner: Cline; William R.
Attorney, Agent or Firm: Evans, Jr.; John O.
Parent Case Text
This application is a continuation of application Ser. No. 818,261,
filed Apr. 22, 1969 and now abandoned.
Claims
I claim:
1. In a drill pipe float valve assembly having a valve body
provided with portions adapted to be engaged in the bore of a drill
dollar sub, an upwardly tapered valve seat in said body, a flow
passage circumscribed by said seat, a valve head below said seat
and having an axial cavity in one end and a valve surface on the
other end complementally engageable with said valve seat, said
valve head being reciprocable in said body between a closed
position whereat said surface is engaged with said seat and an open
position displaced downwardly from said seat, a valve stem
extending into said cavity and supporting said head for slidable
reciprocation thereon, a spring disposed about said stem and action
on said head to bias the same into said closed position, and a
spider supported in said body and retained in place therein, said
spider mounting said valve stem, said valve head being movable from
said closed position to said open position in response to downward
flow of drilling fluid through said flow passage, the improvement
wherein said stem and said cavity are of corresponding non-circular
cross-section to prevent spinning of said valve head on said valve
stem when said valve head is moved to said open position in
response to downward flow of drilling fluid through said flow
passage.
2. A drill pipe float valve assembly as defined in claim 1, wherein
said stem and said spider are integral.
3. A drill pipe float valve assembly as defined in claim 1, wherein
said flow passage is cylindrical, and including a hollow sleeve
extending from said head into said flow passage, said sleeve having
a radially opening port therein that is closed by the wall of said
cylindrical flow passage when said valve head is in said closed
position, and that is open for the flow of fluid therethrough when
said head is in said open position.
4. A drill pipe float valve assembly as defined in claim 1, wherein
said cavity and said stem are square in cross-section.
5. A drill pipe float valve assembly as defined in claim 1, wherein
said head has a skirt depending therefrom and encircling said stem
and said spring for the full length thereof to protect the same
when said head is in said open position.
6. A drill pipe float valve assembly as defined in claim 1, wherein
said stem and said spider are integral, and including means
removably supporting said spider in said body.
7. A drill pipe float valve assembly as defined in claim 1 wherein
said stem and said spider are integral, and including means
removably supporting said spider in said body, and said head is
provided with a skirt depending therefrom and encircling said stem
and said spring for the full length thereof to protect the same
when said head is in said open position.
Description
BACKGROUND OF THE INVENTION
In the drilling of wells, such as oil and/or gas wells, it is the
practice to circulate a drilling fluid, such as mud or gas,
downwardly through the drill pipe string, the fluid passing through
openings in the drill bit into the bore hole, and the fluid then
flowing upwardly through the annular space between the drill string
and the bore hole wall, carrying the cuttings to the surface. The
running of drill pipe back into the bore hole after removal to, for
example, replace the drill bit, on the one hand, and the cessation
of drilling fluid circulation, on the other hand, may cause
problems which have heretofore been to some extent alleviated by
the use of drill pipe float valves. Such valves are called float
valves because they close upwardly and prevent the passage of
drilling fluid into the drill string during running of the string,
so that the drill string remains dry above the float valve and
somewhat bouyant.
Another advantage of a float valve is that it prevents plugging of
the bit openings or orifices when circulation is ceased, as well as
when the drill string is being run into the well. This advantage is
realized even if the drilling fluid is air or other gas and the
valve causes no real floating action.
Heretofore, float valves have been subject to problems of wear and
breakage resulting in the necessity that the drill string be round
tripped excessively, that is unnecessarily, to unplug the bit, or
fluid is allowed to flow into the drill string as it is being
lowered into drilling mud, resulting the surging of fluid onto the
drilling platform where it wets the equipment and personnel.
SUMMARY OF THE INVENTION
The present invention provides a drill pipe valve of the upwardly
closing type, generally referred to as a float valve, which is
rugged in its construction and which resists wear, the valve
therefore being more durable and long lived than float valves
heretofore available.
More particularly, the present float valve provides a massive and
one piece valve head which resists breakage yet is fully functional
as a valve, the assembly further including a one-piece head support
or stem on which the valve is reciprocable, such support being
mounted in the supporting body, the assembly therefore consisting
of few parts and being therefore, not subject to disintegration
into small pieces capable of clogging the bit against the downward
flow of fluid, even if the components should ultimately break due
to long, hard service and the erosive action of drilling fluid.
Furthermore, the invention provides a structure in which the valve
head is held against spinning relative to its support, thereby
reducing the tendency to wear. In accomplishing this, the valve
head has a non-circular opening in its underside for receiving the
valve stem on which the head reciprocates, the stem having a
similar non-circular configuration.
According to one embodiment, the valve combines the structure of a
poppet valve with an upwardly extended sleeve which functions like
a sleeve valve, such a structure being more particularly suited for
drilling with air or other gas. The upward extension also
functions, in addition to its sleeve valve function, as a centering
means whereby vibration of the head due to high velocity fluid flow
is eliminated, resulting in longer life of the stem.
Other objects and advantages of the invention will be hereinafter
described or will become apparent to those skilled in the art, and
the novel features of the invention will be defined in the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section showing a valve made in accordance
with the invention and installed in a drill string, in the normally
closed condition;
FIG. 2 is a view corresponding to FIG. 1, but showing the valve
open;
FIG. 3 is a view in transverse section, as taken on the line 3--3
of FIG. 1;
FIG. 4 is a view corresponding to FIG. 1, but showing a modified
valve construction, particularly adapted for air or gas drilling,
the valve being in its normally closed condition;
FIG. 5 is a view corresponding to FIG. 4, but showing the valve
open; and
FIG. 6 is a view in transverse section, as taken on the line 6--6
of FIG. 4 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, a valve mechanism V is incorporated in a
string of drill pipe or drill collar D which is adapted to extend
to the top of the well bore, and through which drilling fluid is
pumped in a downward direction as the drill string is rotated to
rotate a drill bit on its lower end, the drill bit sub being
designated B. The valve V may be incorporated at any convenient
location along the drill string D, but, as here shown, it is
mounted in a short drill collar sub 10 ordinarilly placed just
above the bit sub B. The drill collar sub 10 has an enlarged bore
11 providing a cylindrical wall and a lower radial shoulder 12.
Illustratively, the sub 10 has a lower threaded pin 13 engaged in
the upper threaded box 14 of the bit sub B. The upper end of the
sub 10 is constituted as a threaded box 15 secured to the lower pin
end 16 of the adjoining drill collar or pipe section 17. The lower
shoulder 12 and the lower end 18 of the collar or pipe section 17
provide axially spaced abutments between which the valve assembly V
now to be described is disposed.
The valve assembly V includes a body 20 adapted to fit in the bore
11 of collar 10, and the length of the body 20 may be slightly less
than the distance between the shoulders 12 and 18. Illustratively,
the body 20 includes an upper cylindrical portion 21 provided with
sealing ring means, such as an O-ring 22 for sealing engagement
within the bore 11 to prevent bypass of fluid about the outside of
the body 20 and resultant erosive wear.
At its lower end, the body 20 has a lower cylindrical portion 23
adapted to fit within the bore 11. Otherwise, the body 20 may be of
lesser diameter than the bore 11.
Internally, the body is provided with a valve chamber 24 having an
upwardly tapered conical surface 25 constituting a valve seat which
circumscribes a flow passage 26 which extends between the upper end
of the body 20 and the valve chamber 24. Reciprocable in the valve
chamber 24 is a valve head 27, this head being supported and
centered in a valve stem 28 and spring biased to a seated position
(FIG. 1) by a coiled compression spring 29 which abuts at its upper
end on an internal shoulder 30 in the head 27 and which seats at
its lower end on a spider-like supporting disc 31.
This disc 31 seats in a bore 32 at the lower end of the valve body
20, there being a downwardly facing shoulder 33 engaged by the disc
31, and a snap ring 34 or other retainer means being employed to
retain the disc 31 in place. The valve stem 28 is formed integral
with the disc 31 and projects upwardly therefrom into a reduced
cavity 35 formed in the underside of the valve head 27. Depending,
in encircling relation to the spring 29, from the shoulder 30 is a
skirt 36 which, when the valve is open (FIG. 2) shields the spring
29 and the stem 28 from the erosive action of drilling fluid
flowing downwardly past the valve head and through a number of
ports 37 formed in the disc 31. The upper end of the valve head 27
is formed as a cone 38 corresponding to the seat cone 25 for
effectively sealing the valve assembly against the upward flow of
fluid when the valve is closed.
The construction described above is a durable one, in that the head
27 is separate from the stem 28 and is a one piece construction.
The stem 28 is durable in that it is an integrated unit with the
disc 31 and is shielded by the skirt 36 during exposure to maximum
wear.
Reference to FIG. 3 shows to best advantage that the cavity 35 in
the valve head 27 is non-circular or square in cross section, and
likewise, the upper end portion 28a of the stem 28 is
correspondingly non-circular or square in cross-section, whereby
the valve head is incapable of spinning on the stem 28 as would be
the case were the pin circular. Thus, the connection between the
valve head 27 and the stem is not subject to rapid wear due to
relative movement in an abrasive environment during drilling
operations.
In use, the valve V will be normally closed during running of the
pipe string into the well bore, so that the entry of fluid into the
drill string with cuttings entrained in the fluid is prevented, the
tendency of the bit orifices to be plugged thereby being
substantially reduced. However, when drilling fluid circulation
resumes, the valve will be opened but held against spinning of the
head by the non-circular engagement between the stem and head, the
stem and the valve spring being protected from the erosive action
of the drilling fluid.
Referring to FIGS. 4 - 6 a similar valve structure is shown and the
same reference characters are applied. However, this embodiment is
particularly adapted for use when drilling with air or other
gaseous drilling fluid.
In this embodiment of the invention, the valve is a combined poppet
and sleeve valve in that above the conical portion 38 of the valve
head 27 it has an upwardly extended sleeve section 100. This sleeve
section 100 extends upwardly into the flow passage 26 of the valve
body 20 a distance greater than the permitted downward movement of
the valve head 27 and serves as a pilot for the upper end of the
valve head 27, whereby vibration of the head due to high velocity
drilling fluid flow is precluded.
In order to permit the downward flow of drilling fluid or air where
the valve is open (FIGS. 5 and 6) the sleeve 100 has a central bore
101 therein and a plurality of radially open and circumferentially
extended ports 102. Preferably, the combined flow area of the ports
102 is equal to or greater than the flow area through the valve in
the absence of such sleeve and ports so that no restriction to flow
is caused thereby.
Other variations in the details of construction may be resorted to
without departing from the spirit of the invention.
* * * * *