COMBINED FRACTURING OUTLET AND PRODUCTION PORT FOR A TUBULAR STRING

SORTIE DE FRACTURATION ET ORIFICE DE PRODUCTION COMBINES POUR UN TRAIN DE TIGES TUBULAIRE

English Abstract

One or more openings in a zone have an adjacent screen assembly that is axially movable to a position away from the port when pressure in the tubing exceeds the annulus pressure by a predetermined value. Upon the differential being reduced below a predetermined value or when annulus pressure exceeds the tubing pressure, the screen moves over the port to block at least some of the solids in the formation or the well fluids from entering the tubing string. The screen movement can be aided by a bias force and the movement can be locked in to prevent the screen that has moved to a position over the port from moving back away from the port.

French Abstract

L'invention concerne une ou plusieurs ouvertures dans une zone qui présentent un ensemble tamis adjacent axialement mobile vers une position à distance de l'orifice lorsque la pression à l'intérieur de la colonne dépasse la pression annulaire d'une valeur prédéterminée. Lorsque la différence est réduite et passe au-dessous d'une valeur prédéterminée ou lorsque la pression annulaire dépasse la pression de la colonne, le tamis se déplace sur l'orifice de manière à empêcher au moins une partie des solides dans la formation ou les fluides de puits de pénétrer dans la colonne de production. Le mouvement du tamis peut être assisté par une force de sollicitation et le mouvement peut être bloqué afin d'empêcher que l'écran qui a été déplacé dans une position sur l'orifice s'éloigne à nouveau de l'orifice.

Claims

We claim:
1. A completion apparatus for subterranean use, comprising:
a housing having an internal passage and at least one wall flow port
from said passage that is automatically reconfigured as to flow restriction
therethrough.
2. The apparatus of claim 1, wherein:
said port has an unrestricted configuration and a screened
configuration.
3. The apparatus of claim 2, wherein:
said reconfiguration is responsive to pressure differential between said
internal passage and subterranean pressure around said housing.
4. The apparatus of claim 3, further comprising:
a movably mounted screen assembly in said passage.
5. The apparatus of claim 4, wherein:
a pressure port extending through said wall of said housing and leading
to a variable sealed volume between said wall and said movably mounted
screen assembly.
6. The apparatus of claim 5, wherein:
screen assembly comprises a first and second opposed annular
surfaces, said second annular surface defines at least a part of said variable
volume.
7. The apparatus of claim 6, wherein:
said first annular surface on said screen assembly moves said screen
assembly, in response to pressure in said passage, to reduce the volume of
said
variable volume.
8. The apparatus of claim 7, wherein:
said screen assembly is biased toward a position where said port is in
said screened configuration.
9. The apparatus of claim 8, wherein:
said biasing comprises at least one of a coiled spring, Belleville washer
or a compartment holding a compressible fluid.
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10. The apparatus of claim 9, wherein:
said screen assembly comprises a sleeve assembly in said passage
having an outer surface;
said variable volume and said biasing disposed in said housing
between said sleeve and said wall.
11. The apparatus of claim 10, wherein:
said sleeve comprises a plurality of wall openings covered by at least
one annularly shaped screen.
12. The apparatus of claim 11, wherein:
said at least one screen selectively aligns with at least one
circumferential row of wall flow ports.
13. The apparatus of claim 10, wherein:
said sleeve assembly moves only in a direction toward putting said port
in a screened configuration.
14. The apparatus of claim 10, wherein:
said sleeve assembly moves in opposed directions.
15. The apparatus of claim 10, wherein:
said sleeve is restrained with a breakable member.
16. The apparatus of claim 14, wherein:
said sleeve puts said port in said screened configuration in response to
at least one pressure application and removal cycle in said passage.
17. The apparatus of claim 10, wherein:
said port further comprises a telescoping passage.
18. The apparatus of claim 8, wherein:
said bias and pressure in said variable volume against said second
annular surface push said screen assembly toward a position where said port is
in said screened configuration.
19. The apparatus of claim 18, wherein:
passage pressure acting on said first annular surface opposes the force
of said bias and variable volume pressure on said second annular surface.
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20. The apparatus of claim 1, wherein:
said at least one flow port comprises multiple flow ports in an isolated
subterranean zone.
8

Description

CA 02823257 2013-06-27
WO 2012/100012
PCT/US2012/021804
COMBINED FRACTURING OUTLET AND PRODUCTION PORT
FOR A TUBULAR STRING
Inventors: Richard Y. Xu and Tianping Huang
FIELD OF THE INVENTION
[0001] The field of the invention is fracturing systems that allow
subsequent production through the fracture openings and more particularly an
automatic way to control solids from entering during the transition time
between fracturing and production.
BACKGROUND OF THE INVENTION
[0002] A variety of systems that allow fracturing ports to be opened to
fracture a zone have been developed. Some of these systems also use
telescoping members that extend out of the sting and across an annular gap to
contact the borehole wall. In some designs the impact with the borehole wall
from an extension of these telescoping passages is intended to start the
fracture
process which is then continued with the delivery of fluid through the ports
at
high velocities that result from high applied pressures. The fluid usually
contains high concentration of proppants.
[0003] The openings for fracturing are preferably not obstructed with
screens for handling subsequent production. As a result the designs have
provided one set of ports for fracturing and another for subsequent production
where a sliding sleeve or some other valve operator is used to shift between
the wide open tubular ports and the production ports that have screens.
However, in this arrangement there is a transition time to shift a variety of
sliding sleeves from fracturing mode to production mode. In that transition
time the tubing pressure can drop below the formation pressure and some
solids or proppant migration can take place into the tubular string and create
operational difficulties with the uphole equipment. Putting screens in the
fracturing outlets provides protection against solids or proppant return flow
after fracturing operation is completed. Some examples of related previous
designs are USP 7,401,648; 7,591,312; US Publication 2010/0263871 and
2010/0282469.
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[0004] What is needed is a system that allows a given port to be wide
open
for fracturing and then have a screen material move into place over the port
when the fracturing is done. In a preferred embodiment the movement of the
screen would be automatic and it could further be triggered by pressure
reduction in the tubing string. Optionally the movement of the screen can be
tied to a differential pressure between the tubing and the surrounding annulus
that moves the screen. The screen can be biased to assist in the movement and
the movement can be locked against a return to the former screen position.
These and other advantages of the present invention will become more
apparent to those skilled in the art from a review of the description of the
preferred embodiment and the associated drawings while recognizing that the
full scope of the invention is to be determined by the appended claims.
SUMMARY OF THE INVENTION
[0005] One or more openings in a zone have an adjacent screen assembly
that is axially movable to a position away from the port when pressure in the
tubing exceeds the annulus pressure by a predetermined value. Upon the
differential being reduced below a predetermined value or when annulus
pressure exceeds the tubing pressure, the screen moves over the port to block
at least some of the solids in the formation or/and proppants in fracture from
entering the tubing string. The screen movement can be aided by a bias force
and the movement can be locked in to prevent the screen that has moved to a
position over the port from moving back away from the port.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a section view showing the screen out of the way of the
port during fracturing; and
[0007] FIG. 2 is the view of FIG. 1 with the tubing pressure reduced to
the
point that formation pressure and an optional bias force push the screen
assembly into alignment with the fracturing port that can now be used for
production.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0008] FIG. 1 illustrates a portion of a tubular string 10 that extends
through a zone that is defined at opposed ends such as by packers 12 and 14
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that are schematically illustrated. Although a single port 16 is illustrated
in the
zone 18, those skilled in the art will appreciate that multiple ports 16 and
their
associated equipment described below can be used. The string 10 can extend
beyond zone 18 on either or both ends but such extension or extensions are
omitted for greater clarity in the FIG. The port 16 can optionally have a
telescoping assembly 20 that extends the outlet 22 to the borehole wall where
the impact initially can cause formation fractures on extension. Pumped fluid
from the surface through passage 24 as represented by arrow 26 also pushes
on piston area 30 as indicated by arrows 28. The piston area 30 is preferably
is
just below a series of rows of ports 34. Those skilled in the art will
appreciate
that different styles of screens can be used such a wire wrap or Dutch Twill
or
simply a porous cylindrically shaped block near the piston area 30 and inside
the passage 24 or an annularly shaped screen member over the ports 34 in the
sleeve 32.
[0009] Sleeve 32 has an external ring 36 with an o-ring 38 against the
inner wall 40 of the tubular 10. The tubular 10 has an inner ring 42 with an o-
ring 44 against an outer wall 46 of the sleeve 32. As a result, there is an
annular variable volume 48 with access to the formation through passage 50.
Arrow 52 represents formation or surrounding annulus pressure acting in
volume 48.
[0010] Biasing sleeve 52 has a biasing member such as a spring 54
supported off an internal shoulder 56 from the inside wall 40 of the tubular
10.
Other biasing techniques can be used such as a stack of Belleville washers or
a
pressurized chamber of compressible fluid. Although sleeves 32 and 52 are
shown as separate sleeves they can be one integrated sleeve as to one or a row
of ports 16 or to axially spaced circumferential rows of ports 16.
[0011] The telescoping members 20 can be initially extended by fluid
velocity through ports 22 or by rupture discs (not shown) that can break under
pressure after the telescoping assemblies 20 fully extend and pressure
continues to be built up.
[0012] Depending on the strength of the spring 54 and the pressures
represented by arrows 26 and 52 the sleeves 32 and 52 will be in the FIG. 1 or
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FIG. 2 positions. In FIG. 2 arrow 58 represents inflow of production and fluid
in the wellbore through the port 16 and the screen 33 that has automatically
shifted into alignment with port 16 due to the bias of spring 54 and pressure
in
volume 48 from ports 50 represented by arrow 60 exceed the pressure in
passage in passage 24 and the opposing force it puts on piston area 30. In
FIG.
2 the piston area 62 pushing the screen 33 to the port 16 using the pressure
indicated by arrow 60 and the added force from spring 54 overcomes the
opposing force in passage 24 acting on the area of opposing surface 30, which
is preferably the same piston area as 62. If the sleeves 32 and 52 are
unrestrained during run in, the FIG. 2 position happens when pressure in the
passage 24 is equal to or less than the annulus pressure outside the housing
10.
As the tubing pressure rises relative to the annular pressure to overcome the
force of the spring 54,such as at the start of fracturing, the sleeves 32 and
52
move the screen 33 away from port 16. If fracturing pressure is lost the
screen
33 can move back to the port 16. Such opposed direction movement can be
repeated unless otherwise restrained.
[0013] Spring 54 can be nested and or stacked coil springs as an option.
As another option the spring 54 can be eliminated so that movement to the
FIG. 2 position is just a function of pressure differential between the tubing
pressure in passage 24 and the surrounding formation and well pressure in the
zone 18. Alternatively, the FIG. 1 position can be held by a breakable
member, not shown that is broken when the differential between formation
and tubing pressure exceeds a predetermined value. As another option the
sleeve 32 or 52 can have a one way ratchet (not shown) so that it will stay in
the FIG. 2 position once reaching it or alternatively it will only move in the
direction toward the port 16 and not in the reverse direction.
[0014] Those skilled in the art will appreciate that the movement of the
screen into position by a port that had been used earlier to fracture lends
many
advantages. For one, the same port can be used at different times and in
different conditions for fracturing and then production. Another advantage is
that the system is pressure sensitive to reconfigure the fracturing ports to
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filtration mode on a loss or reduction of tubing pressure to a predetermined
amount.
[0015] As another alternative to avoid an automatic conversion from
fully
open ports as in FIG. 1 to fully screened ports as in FIG. 2 when any pressure
change happens, a j-slot (not shown) between the sleeves 32, 52 and the inner
wall 40 of the tubular 10 can be provided. If that is done any momentary
pressure loss during fracturing will not necessarily move the screen 33 into
alignment with the port 16. Instead, there will need to be a defined number of
pressure applications and removals using the j-slot before sufficient movement
of the screen 33 occurs to place it in alignment with the port 16. Even with
the
j-slot the final movement of the screen 33 into alignment with the port 16 can
still be a one way movement by engaging a ratchet (not shown) at the end of
such movement that puts the screen 33 in alignment with the port 16.
[0016] As another configuration if the fracturing pressure is lost
momentarily resulting in shifting of the screen 33 into alignment with the
port
16, the pressure in the tubing passage 24 can simply be raised to reverse such
movement if the fracturing process has still not been completed.
[0017] The above description is illustrative of the preferred embodiment
and many modifications may be made by those skilled in the art without
departing from the invention whose scope is to be determined from the literal
and equivalent scope of the claims below:

Representative Drawing