U.S. patent application number 12/208416 was filed with the patent office on 2009-06-18 for sand control system and method for controlling sand production.
Invention is credited to Louis Anthony BERNARDI, JR..
Application Number | 20090151942 12/208416 |
Document ID | / |
Family ID | 40751704 |
Filed Date | 2009-06-18 |
United States Patent
Application |
20090151942 |
Kind Code |
A1 |
BERNARDI, JR.; Louis
Anthony |
June 18, 2009 |
SAND CONTROL SYSTEM AND METHOD FOR CONTROLLING SAND PRODUCTION
Abstract
A method for controlling sand production in a well drilled in a
subterranean formation comprising installing an expandable sand
screen assembly in the well. The expandable sand screen assembly
comprises an expandable sand screen in an unexpanded configuration.
A slurry is pumped down the well and circulated through the annular
space defined by the expandable sand screen and the formation. The
expandable sand screen is expanded thereby dehydrating the slurry
in the annular space.
Inventors: |
BERNARDI, JR.; Louis Anthony;
(Houston, TX) |
Correspondence
Address: |
SHELL OIL COMPANY
P O BOX 2463
HOUSTON
TX
772522463
US
|
Family ID: |
40751704 |
Appl. No.: |
12/208416 |
Filed: |
September 11, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60972013 |
Sep 13, 2007 |
|
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|
Current U.S.
Class: |
166/278 ;
166/227; 166/381 |
Current CPC
Class: |
E21B 43/04 20130101;
E21B 43/103 20130101; E21B 43/08 20130101 |
Class at
Publication: |
166/278 ;
166/381; 166/227 |
International
Class: |
E21B 43/08 20060101
E21B043/08; E21B 43/04 20060101 E21B043/04; E21B 43/10 20060101
E21B043/10 |
Claims
1. A method for controlling sand production in a well drilled in a
subterranean formation comprising: a) installing an expandable sand
screen assembly comprising an expandable sand screen in an
unexpanded configuration into the well; b) pumping a slurry down
the well; c) circulating the slurry through an annular space
defined by the expandable sand screen and the formation; and d)
expanding the expandable sand screen and thereby dehydrating the
slurry in the annular space.
2. The method of claim 1, further comprising forming a gravel pack
behind the expandable sand screen.
3. The method of claim 2 wherein the expandable sand screen is
expanded so that the gravel pack is compressed in step d).
4. The method of claim 3 wherein step d) is performed by displacing
an expansion device through the expandable sand screen wherein the
expansion device is selected from the group consisting of expansion
pigs, mandrels, and cones.
5. The method of claim 4 wherein the expandable sand screen
assembly further comprises blank sections of pipe, additional
sections of expandable sand screens, collapsible centralizers,
expansion tools, or external packers.
6. The method of claim 5 wherein the well is a long horizontal or
deviated well.
7. The method of claim 6 wherein step b) comprises: pumping the
slurry through a tubular inside the expandable sand screen
assembly.
8. The method of claim 6 wherein step b) comprises: pumping the
slurry through a crossover tool into the annular space.
9. A sand control system comprising: a well drilled in a formation;
an expandable sand screen installed in the well in an expanded
configuration; an annular space located between the outer surface
of the expandable sand screen and the formation; and a gravel pack
located in the annular space; wherein the gravel pack was
dehydrated by expanding the expandable sand screen.
10. The sand control system of claim 8 wherein the well is a
horizontal or deviated well.
11. A method for producing oil or gas comprising: a) drilling a
well in a subterranean formation comprising: b) installing an
expandable sand screen assembly comprising an expandable sand
screen in an unexpanded configuration into the well; c) pumping a
slurry down the well; d) circulating the slurry through an annular
space defined by the expandable sand screen and the formation; e)
expanding the expandable sand screen thereby dehydrating the slurry
in the annular space; and f) producing oil or gas from the
well.
12. The method of claim 11 wherein step c) comprises: pumping the
slurry through a tubular inside the expandable sand screen
assembly.
13. The method of claim 11 wherein step c) comprises: pumping the
slurry through a crossover tool into the annular space.
Description
REFERENCE TO PRIOR APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/972,013, filed Sep. 13, 2007, which is
incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates to a sand control system and a
method for controlling sand production in a long horizontal or
deviated well.
BACKGROUND
[0003] The art of completing wells to exclude solids particles
produced by well fluids is commonly known in the literature as
gravel packing. In many well completions, unwanted formation solids
(e.g. sands, fine materials, and other debris) are produced into
the well along with the production fluids. These solids are often
undesirable and many methods of stopping these solids from flowing
into the well whilst producing the fluids are well defined.
[0004] A common technique for controlling the production of
particulates from a well is known as "gravel packing." In a typical
gravel pack completion, a well screen is lowered into the wellbore
and positioned across the interval of the well that is to be
completed. Particulate material, collectively referred to as
gravel, is then pumped as a slurry down the tubing on which the
screen is suspended. The slurry exits the tubing above the screen
through a "crossover" tool or the like and flows downward in the
annulus formed between the screen and the well casing or open hole,
as the case may be.
[0005] The liquid in the slurry flows into the formation and/or the
openings in the screen that are sized to prevent the gravel from
flowing through them. As the fluid is drawn out of the slurry it
dehydrates. This results in the gravel being "screened out" on the
screen and in the annulus around the screen where it collects to
form the gravel pack. The gravel is sized so that it forms a
permeable mass which blocks the flow of any particulates produced
with the formation fluids.
[0006] Gravel packing fills the annular space between the formation
and a screen with a clean well-sorted sand or gravel. The gravel
pack forms a volumetric filter that prevents fines from plugging
the screen and sand from entering the well. It structurally
supports the formation, and it prevents flow in the annulus between
screen and the open hole. All of these features increase the
completion's durability in weak and heterogeneous formations;
however, conventional methods for gravel packing vertical wells are
not suited for long horizontal wells.
[0007] One of the main problems with gravel packing, especially
when long horizontal or inclined intervals are completed, is
obtaining uniform distribution of the gravel along the entire
completion interval and completely packing the annulus between the
screen and the casing (in cased hole completions) or between the
screen and the wellbore (in open hole completions). Incomplete
packing of the interval resulting in voids/unpacked areas in the
gravel pack is often caused by the improper dehydration of the
gravel slurry into portions of the formation interval. This can
occur because the pressure required to pump the fluid slurry into
the production interval may exceed the fracture pressure of the
formation, which results in the liquid carrier of the fluid slurry
leaking off into the formation. Improper dehydration causes the
formation of gravel "bridges" in the annulus before all of the
gravel has been placed. These bridges block the transport of slurry
past the bridge. This results in the insufficient placement of the
gravel because gravel fails to fill the annulus downstream of the
bridge. Subsequently, the portion of the screen that is not covered
or packed with gravel is thereby left exposed to erosion by the
solids in the produced fluids or gas and/or that portion of the
screen is then easily blocked or "plugged" by formation
particulates, that would have been filtered out of the inflow by a
properly placed gravel pack.
[0008] Consequently, a number of methods for installing sand
control in long horizontal (greater than 200 m) or deviated wells
(greater than 80.degree. from vertical) have been developed. One
technique used to reduce the required pressure for gravel packing a
long production interval that is inclined, deviated or horizontal
is the alpha-beta gravel packing method described in U.S. Pat. No.
6,311,772 which is hereby incorporated by reference. In this
method, the gravel packing operation starts with the alpha wave
depositing a bed of gravel on the low side of the wellbore
progressing from the near end (heel) to the far end (toe) of the
production interval. Once the alpha wave has reached the far end
(toe), the beta wave phase begins wherein gravel fills the high
side of the wellbore, on top of the alpha wave deposition,
progressing from the far end (toe) to the near end (heel) of the
production interval. Shunt tubes may optionally be installed to
allow an alpha wave to by-pass a bridge or obstruction so that it
can continue past the blockage and propagate down the open hole to
the toe.
[0009] A drawback of the alpha-beta method is that it is sometimes
made impractical by logistical considerations including the
uniformity of the completion zone, the availability of fluid
storage, and the type of carrier fluid used. Gravel packs are more
tolerant to non-uniform and heterogeneous completion zones but have
installation risks that make them unsuitable for some long
horizontal wells in low strength, unconsolidated formations.
Additionally, fluid storage and handling volumes are limited for
some rigs especially in remote locations. Conventional horizontal
alpha-beta methods use low sand concentrations and require large
volumes of clean fluid to deploy. The required volumes for
alpha-beta packs increase in low fracture gradient environments,
where low sand concentrations must be used. Conventional alpha-beta
packing uses water-based carrier fluids. In cases where the
reservoir section must be drilled with oil-based or synthetic-based
drilling fluid, usually the open hole must be displaced to a water
based fluid prior installing the screens and gravel pack. This
increases the probability of a hole collapse or other hole problems
that could result in an incomplete or failed gravel pack job.
[0010] Expandable sand screens (ESS) were developed for use in long
horizontal wells as an alternative to gravel packs in combination
with conventional screens. An example of a method utilizing ESS
technology is in U.S. Pat. No. 5,901,789, which is hereby
incorporated by reference. When expansion is large enough to
eliminate most or all of the annular space between the formation
and the expanded screen, annular flow can be limited or prevented.
When the expandable screen is in continuous contact with the
formation (referred to by those skilled in the art as "full
compliant expansion"), it supports the formation and prevents
disaggregation of the rock that could release fines and sand
particles that might erode or plug the screen.
[0011] Because the amount of expansion that is possible with ESS
systems, expandable sand screens do not always achieve full
compliant expansion leaving an annular space between the screen and
the formation. Any significant gap between the screen and open hole
defeats some of the perceived benefits of ESS. Additionally,
expandable sand screens have features that limit their application
to formations with uniform grain sizes where they are most likely
to be successful. Other ESS design parameters such as screen
aperture sizes, mesh type, unexpanded screen diameters, and
expansion ratios are also not robust to uncertainties in rock
quality encountered while drilling long lateral sections.
[0012] Thus there is a need for a reliable method of installing
sand control in long horizontal or deviated wells.
SUMMARY OF THE INVENTION
[0013] The invention includes a method for controlling sand
production in a well drilled in a subterranean formation comprising
installing an expandable sand screen assembly in the well. The
expandable sand screen assembly comprises an expandable sand screen
in an unexpanded configuration. A slurry of gravel and carrier
fluid is circulated into the annular space between the unexpanded
expandable sand screen and the formation or between the unexpanded
expandable sand screen and the casing. In one embodiment, a slurry
of gravel and carrier fluid is pumped down a tubular inside the
expandable sand screen assembly and circulated up through the
annular space between the expandable sand screen and the formation.
Alternatively, a slurry is pumped through a crossover tool above
the sand screen into the annulus between the formation and the
unexpanded expandable sand screen, where fluid displaced by the
slurry is circulated up a tubular inside the expandable sand screen
assembly. The expandable sand screen is expanded, thereby
dehydrating the slurry in the annular space. The method further
comprises forming a gravel pack behind the expandable sand
screen.
[0014] The inventions also include a sand control system comprising
a well drilled in a formation, an expandable sand screen installed
in an expanded configuration, an annular space located between the
outer surface of the expandable sand screen and the formation, and
a gravel pack located in the annular space. According to one
embodiment of the invention, the gravel pack was dehydrated by
expanding the expandable sand screen.
[0015] The inventions also include a method for producing oil or
gas comprising drilling a well in a subterranean formation
comprising, installing an expandable sand screen assembly
comprising an expandable sand screen in an unexpanded configuration
into the well, pumping a slurry down the well, circulating the
slurry through an annular space defined by the expandable sand
screen and the formation, expanding the expandable sand screen
thereby dehydrating the slurry in the annular space and producing
oil or gas from the well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention is better understood by reading the
following description of non-limitative embodiments with reference
to the attached drawings, wherein like parts of each of the figures
are identified by the same reference characters, and which are
briefly described as follows:
[0017] FIG. 1 illustrates a well with an expandable sand screen in
an unexpanded configuration during circulation of a slurry.
[0018] FIG. 2 illustrates the expandable sand screen as it is
expanded and being used to dehydrate the slurry.
DETAILED DESCRIPTION
[0019] Referring to FIG. 1, a wellbore 101 is shown drilled in a
subterranean formation 102. In the embodiment shown, wellbore 101
is an open hole wellbore; however the invention could theoretically
be practiced in a cased wellbore environment.
[0020] An expandable sand screen (ESS) assembly 103 is run in an
unexpanded configuration into wellbore 101 using a workstring (not
shown). The ESS assembly may include any combination of expandable
sand screens 104, blank sections of pipe, collapsible centralizers
or external packers (not shown). Prior to installing ESS assembly
103, additional tools may have been installed in the well including
landing tools (not shown) for a wash pipe 105 and an expansion tool
(not shown in this Figure). Wash pipe 105 could alternatively be
run simultaneously as part of the ESS assembly 103.
[0021] If not already deployed as part of the ESS assembly, wash
pipe 105 is run inside expandable sand screen 104. A slurry
consisting of gravel pack sand or ceramic proppant suspended in a
carrier fluid is pumped down wash pipe 104 and circulated into the
annular space 107 between expandable sand screen 104 and the wall
of formation 102. The direction of circulation of the slurry is
shown by arrows 106. Optionally leading spacers or chemical
treatments may be pumped ahead of the slurry to improve open hole
displacement and wellbore clean up. The slurry may include internal
breakers or other chemicals needed to facilitate the clean up the
gravel pack once deployed for oil, synthetic, or water based fluid
systems.
[0022] After the slurry is circulated, wash pipe 105 is pulled out
of the wellbore and may be used to pick up the parts of ESS
assembly 103 which are no longer needed. Alternatively, these parts
of the ESS assembly may be retrieved on a subsequent trip into the
well. In another embodiment, the expansion tool assembly could be
parked in an expansion tool-launching sub at the top of the ESS
assembly, so that when the lower end of the wash pipe engages the
expansion tool. Once engaged, the combined assembly is ready to
expand the screen. The gravel pack sand or proppant remains
disposed between expandable sand screen 104 and the borehole,
forming a gravel pack, albeit one in which significant liquid may
be present.
[0023] As shown in FIG. 2, expandable sand screen 104 is then
expanded using expansion tool 201. Expansion tool 201 may be any
conventional expansion tool known in the art known including but
not limited to expansion pigs, cones, and mandrels. Expansion of
expandable sand screen 104 may be accomplished using a top down or
bottom up expansion method. In one embodiment, expandable sand
screen 104 is expanded against or into formation 102; however,
expandable sand screen 104 may also be partially expanded or
expanded to a threshold just before being expanded into or against
the formation.
[0024] FIG. 2 shows expandable sand screen 104 in an expanded
configuration. Expansion of expandable sand screen 104 pushes the
outside of the screen toward the wall of the formation. A force is
applied in the direction of arrows 210 thereby compressing annular
space 107. This properly and uniformly dehydrates the slurry 202 in
annular space 107 between expandable sand screen 104 and the wall
of formation 102. The expansion force prevents the formation of
voids in the gravel pack during the dehydration process. As the
slurry is dehydrated, gravel pack 203 is compressed behind
expandable sand screen 104, filling voids due to hole
irregularities or wash outs.
[0025] When the expansion is complete, the work string used to
deploy the expansion tool is pulled out of the hole. If needed, the
work string may be used to place breakers or other chemicals along
the completion as it is pulled back inside the newly expanded
screen.
[0026] Installation of a gravel pack according to this method
limits the necessary fluid volumes needed to deploy the completion.
Consequently, this method can be deployed in regions where
logistics and fluid storage makes alpha-beta packing impossible or
impractical.
[0027] This method of installation may also increase the
probability of success of an open hole completion in sections that
are drilled with non-water-based (non-aqueous) drilling fluids.
Unlike gravel packing via the alpha-beta method, this method is
compatible with a wellbore in which oil-based or synthetic drilling
fluid was used.
[0028] Installation of a gravel pack in this method may provide
backup insurance of gravel covering screen if the expansion is not
sufficient to protect against fines liberation on hole collapse and
fines plugging the entire screen. The slurry volume and
concentration may be varied to make up for an out of gauge hole if
drilling conditions become unstable or difficult.
[0029] One of the advantages cited for expandable sand screens that
are expanded against the formation is that fines in the
unconsolidated formation are "locked" in place because deforming
and disaggregating of sand is limited as the well is drawn down.
Because open holes are rarely exactly in gauge or circular, the
fluid sand slurry can move to fill the space and provide full
contact between the expanding screen and formation. Expansion
according to this method increases the probability that this "fines
locking" stress is applied uniformly along the open hole.
[0030] Those of skill in the art will appreciate that many
modifications and variations are possible in terms of the disclosed
embodiments, configurations, materials, and methods without
departing from their spirit and scope. Accordingly, the scope of
the claims appended hereafter and their functional equivalents
should not be limited by particular embodiments described and
illustrated herein, as these are merely exemplary in nature and
elements described separately may be optionally combined.
* * * * *