U.S. patent application number 11/769230 was filed with the patent office on 2008-06-26 for temporary containments for swellable and inflatable packer elements.
This patent application is currently assigned to SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Rashmi Bhavsar, Manuel Marya, Nitin Y. Vaidya.
Application Number | 20080149351 11/769230 |
Document ID | / |
Family ID | 39562873 |
Filed Date | 2008-06-26 |
United States Patent
Application |
20080149351 |
Kind Code |
A1 |
Marya; Manuel ; et
al. |
June 26, 2008 |
TEMPORARY CONTAINMENTS FOR SWELLABLE AND INFLATABLE PACKER
ELEMENTS
Abstract
A packer system ready for downhole use includes an elastomer
member, wherein the elastomer member is swellable or inflatable;
and a temporary containment enclosing the elastomer member, wherein
the temporary containment comprises a degradable material A method
for deploying a swellable packer includes running a packer system
into a well to a predetermined location, wherein the packer system
comprises a swellable packer or an inflatable packer that is
enclosed by a temporary containment, wherein the temporary
containment comprises a degradable material; and degrading the
degradable material of the temporary containment to set the
swellable packer.
Inventors: |
Marya; Manuel; (Pearland,
TX) ; Vaidya; Nitin Y.; (Missouri City, TX) ;
Bhavsar; Rashmi; (Houston, TX) |
Correspondence
Address: |
SCHLUMBERGER RESERVOIR COMPLETIONS
14910 AIRLINE ROAD
ROSHARON
TX
77583
US
|
Assignee: |
SCHLUMBERGER TECHNOLOGY
CORPORATION
Sugar Land
TX
|
Family ID: |
39562873 |
Appl. No.: |
11/769230 |
Filed: |
June 27, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60870859 |
Dec 20, 2006 |
|
|
|
Current U.S.
Class: |
166/387 ;
166/195 |
Current CPC
Class: |
E21B 23/00 20130101;
E21B 41/00 20130101; E21B 33/1208 20130101 |
Class at
Publication: |
166/387 ;
166/195 |
International
Class: |
E21B 33/12 20060101
E21B033/12 |
Claims
1. A packer system for downhole use, comprising: an elastomer
member, wherein the elastomer member is swellable or inflatable;
and a temporary containment enclosing the elastomer member, wherein
the temporary containment comprises a degradable material.
2. The packer system of claim 1, wherein the degradable material
comprises a metal or an alloy.
3. The packer system of claim 2, wherein the metal or alloy is one
selected from the group consisting of calcium, aluminum, magnesium,
and an alloy thereof.
4. The packer system of claim 1, wherein the degradable material
comprises a polymer.
5. The packer system of claim 4, wherein the polymer comprises a
functional group that is hydrolysable by a base or a
nucleophile.
6. The packer system of claim 1, wherein the degradable material
comprises an inorganic material.
7. A method for deploying a packer, comprising: running a packer
system into a well to a predetermined location, wherein the packer
system comprises a swellable packer or an inflatable packer that is
enclosed by a temporary containment, wherein the temporary
containment comprises a degradable material; and degrading the
degradable material of the temporary containment to set the
swellable packer or the inflatable packer.
8. The method of claim 7, wherein the degrading of the temporary
containment is by contacting with a fluid.
9. The method of claim 8, wherein the fluid is one selected from
the group consisting of water, hydrocarbon, an acid solution, and
brine.
10. The method of claim 7, wherein the degrading of the temporary
containment is initiated by changing temperature, by changing
pressure, or by changing temperature and pressure.
11. The method of claim 7, wherein temporary containment comprises
a coating on the degradable material such that degradation is
retarded.
12. The method of claim 7, wherein the degradable material is one
selected from the following; a metal, and an alloy.
13. The method of claim 7, wherein the degradable material is a
polymer.
14. The method of claim 7, wherein the degradable material is an
inorganic material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims, under 35 U.S.C. .sctn.119(e), the
benefits of U.S. Provisional Patent Application No. 60/870,859
filed on Dec. 20, 2006. This Provisional Application is
incorporated by reference in its entirety. This application is
related to a co-pending application (Schlumberger Attorney Docket
No. 68.0691), entitled "Smart Actuation Materials Triggered by
Degradation in Oilfield Environments and Method of Use," by Marya
et al., filed herewith.
FIELD OF INVENTION
[0002] The present invention relates generally to oilfield
exploration, production, and testing, and more specifically to
swellable and inflatable packer elements.
BACKGROUND
[0003] In a variety of wellbore environments, completion tools such
as packers need to be safely and controllably deployed to precise
locations to provide basic functions, such as zonal isolation,
tubing anchoring, casing protection, and flow control. Packers
typically include production packers, zonal isolation packers and
gravel pack packers. Most packers are surface controlled and set by
mechanical and/or hydraulic mechanisms.
[0004] A type of packers known as inflatable packers uses an
inflatable bladder to expand the packer element against the casing
or wellbore to provide zone isolation. In preparation for setting
the packer, a drop ball or series of tubing movements are generally
required, with the hydraulic pressure required to inflate the
packer provided by carefully applying surface pump pressure.
Inflatable packers are capable of relatively large expansion
ratios, an important factor in through-tubing work where the tubing
size or completion components can impose a significant size
restriction on devices designed to set in the casing or liner below
the tubing.
[0005] Another type of packers, known as swellable packers, does
not require any mechanical or hydraulic setting mechanisms. These
packers include a swellable material, which volume expand upon
contacting a selected fluid. The selected fluids may be water-based
(including diluted acids and brines) or hydrocarbons. Depending
upon the types of fluids and elastomers used, the chemical swelling
process may increase the volume of a packer by as much as several
hundred percents. In such a swelling process, the swellable packer
element typically expands quickly during the initial phase. Then,
the swelling continues at a slower rate.
[0006] Due to their simplicity of actuation, swell packers are
attractive for zonal isolation applications. Such packers may be
used for cased hole and open hole applications. In open hole
applications, the use of swellable packers is more challenging and
the packer elements are more likely to be damaged.
[0007] If the packer swells too quickly, the packer may not reach
its intended downhole destination. Swelling that starts prematurely
would make impossible the safe delivery of the packer to the
desired location and could result in permanent damages to the
sleeve, and evidently improper sealing.
[0008] If, on the contrary, the packer expands too slowly, the
swell packer is likely to loose its advantages. A packer that is
slow to set would inevitably create rig time waste. Rig times are
extremely costly, and deployment and setting of the packers should
be conducted within a limited time. The ability to control the
settings of such packers is therefore very important for their
use.
[0009] Some swellable packer designs simply use an exposed element
that begins to swell upon insertion into a wellbore, with the idea
that the swelling will progress slowly enough to allow enough time
for the delivery of the packer to a desired location downhole. Some
examples of such packers are disclosed in: U.S. Pat. Nos.
6,848,505; 4,137,970; 4,919,989 4,936,386; and 6,854,522.
[0010] In another design of swellable packers, the swellable
material is covered by a protective envelope, which is made of
high-tear resistant elastomers. Examples of such a design are
disclosed in: U.S. Pat. Nos. 6,073,692; 6,834,725; 5,048,605; and
5,195,583.
[0011] In yet another design, a swellable packer may be covered
with a protective cover that may be removed downhole to allow a
predetermined time to deliver the packer to the desired location
before the onset of swelling. Examples of swelling packers with a
delay feature to facilitate delivery are disclosed: U.S. Pat. Nos.
4,862,967; 6,854,522; 3,918,523; and 4,612,985.
[0012] Another design makes use of a swaging (a retaining device),
wherein a swelling member is held by a mechanical retainer during
the delivery of the packer to the desired location in the well.
Upon reaching the desired location, the expansion of the swellable
materials breaks the retainer or otherwise defeats it so that
swelling can take place. A packer involving a swaging device is
disclosed in U.S. Pat. No. 6,854,522.
[0013] Another design uses multilayer packer elements to insure a
proper deployment. A typical multilayered packer element includes
an elastomeric element covered with another elastomeric material
that provides a slow rate of reaction in the packer setting
fluid.
[0014] While these prior art packer elements are useful in many
downhole operations, there remains a need for improved swellable
packer elements.
SUMMARY
[0015] One aspect of the invention relates to swellable packers. A
swellable packer in accordance with one embodiment of the invention
includes a packer having a swellable material; and a temporary
containment enclosing the packer, wherein the temporary containment
comprises a degradable material that protects the swellable
elastomer of the packer, and prevent premature and undesirable
swelling.
[0016] Another aspect of the invention relates to inflatable
packers. An inflatable packer in accordance with one embodiment of
the invention includes a packer having a inflatable elastomer part;
and a temporary containment enclosing the packer, wherein the
temporary containment comprises a degradable material that prevents
the inflatable packers to accidentally inflate.
[0017] Another aspect of the invention relates to methods for
deploying a swellable packer or an inflatable packer in a wellbore.
A method in accordance with one embodiment of the invention
includes running a packer system into a well to a predetermined
location, wherein the packer system comprises a swellable packer or
an inflatable packer that is enclosed by a temporary containment,
wherein the temporary containment comprises a degradable material;
and degrading the degradable material of the temporary containment
to set the packer.
[0018] Other aspects and advantages of the invention will be
apparent from the following description and the appended
claims.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 shows a schematic illustrating a swellable packer
having a temporary containment that is made of a degradable
material in accordance with one embodiment of the invention.
[0020] FIGS. 2A and 2B illustrate a swellable packer element before
and after deployment in accordance with one embodiment of the
invention.
[0021] FIGS. 3A and 3B show a schematic illustrating inflatable
packer elements having temporary containments used in zonal
isolation with sand screen in accordance with one embodiment of the
invention.
[0022] FIGS. 4A and 4B show two charts each illustrating the effect
of increases in temperature and pH, respectively on the rate of
degradation of a degradable material in accordance with one
embodiment of the invention.
DETAILED DESCRIPTION
[0023] In the following description, numerous details are set forth
to provide an understanding of the present invention. However, it
would be understood by those skilled in the art that the present
invention may be practiced without these details and that numerous
variations or modifications from the described embodiments may be
possible without departing from the scope of the invention.
[0024] Embodiments of the invention relate to temporary
containments for swellable and inflatable packers that may be fully
degraded downhole once the packers are delivered to its intended
location. The materials used to provide a temporary containment for
the swellable packers may be metals, alloys, polymers, plastics,
ceramics, and composites or combinations of these different
materials provided that they may be induced to degrade by a
selected reagent or condition. The degradable materials in
accordance with embodiments of the invention are selected, and/or
specifically designed for their ability to degrade under
predetermined conditions; e.g., the existing wellbore environment,
or by injection/pumping of an active fluid (i.e. a fluid that would
degrade the materials of the temporary containment).
[0025] The "degradation" as used herein refers to any process that
converts a degradable material from a first state (or phase) to a
second state (or phase). The "degradation" may be in the form of
dissolution, disintegration (defragmentation), swelling, or
shrinkage. The degradation of the degradable materials may be by
contacting selected fluids, or by changing temperatures and/or
pressures. In addition, the pH of the fluids may also be changed to
influence degradation of the degradable materials, in particular
rate of degradation. With changing temperature and/or pressure as
the degradation mechanism, the materials may be so selected that
the changes in temperatures and/or pressure (i.e., in typical
downhole applications) either reduce or increase degradation rates.
FIGS. 4A and 4B show two charts illustrating how degradation rates
(i.e., the degradation of the degradable materials) may be
controlled by temperature (FIG. 4A) and pH (FIG. 4B).
[0026] In accordance with some embodiments of the invention, the
degradation may be activated by contacts with selected fluids. The
so-called fluids that can be used to degrade the degradable
materials of the temporary containment may be solvent to the
particular materials such that these materials will dissolve in the
fluids. For oil and gas applications, the active fluid may be
aqueous or non-aqueous. Examples of degradable materials may
include hydrophobic materials that can be dissolved by hydrophobic
solvents, or hydrophilic materials that can be dissolved by
water.
[0027] Thus, in accordance with embodiments of the invention, a
simple example of degradable materials for temporary containment
for swellable and inflatable packers may be a hydrophobic material
that is not soluble in an aqueous solvent, but is readily soluble
in a hydrophobic solvent. Such a hydrophobic material may be used
to construct a portion (or all) of a packer element. The presence
of the hydrophobic material (temporary containment) keeps the
device in an initial state. When actuation of the device is
desired, a solvent may be brought into contact with the device. The
hydrophobic solvent dissolves the hydrophobic material and removes
the temporary containment. As a result, the device adopts a second
state. Similarly, a hydrophilic material may be used in a device to
be deployed in a non-aqueous environment. When actuation is needed,
water or an aqueous solution may be used to dissolve the degradable
material.
[0028] In accordance with embodiments of the invention, the
degradable materials may be metallic (or alloy), organic (e.g.,
polymers or composite), inorganic (e.g., water glass), or ceramic.
Examples of polymer degradable materials may include any polymer
having a functional group that can be converted into a different
type of functional group. After conversion, the physical and/or
chemical properties of such polymers are changed. The functional
groups that are useful in this regard, for example, may include
hydrolyzable functional groups such as anhydrides, lactones,
esters, imides, lactams, and the like. Note that the anhydrides,
lactones and esters include thioanhydrides, thiolactones and
thioesters. A common property of these functional groups is that
they can be readily hydrolyzed by a base (e.g., OH.sup.-) or a
nucleophile (e.g., ammonia, a hydroxylamine, or an amine
R--NH.sub.2). A base may be any base commonly known in the art,
such as sodium hydroxide, potassium hydroxide, lithium hydroxide,
or the like. When a base is added to or generated in a solution,
the pH of the solution is raised. Thus, adding or generating a base
may be referred to as raising the pH of a solution.
[0029] Examples of such polymers may include ISOBAM 600.RTM.
manufactured by Kuraray Co., Ltd. (Tokyo, Japan). ISOBAM 600.RTM.
is a co-polymer of isobutylene with maleic anhydride. This polymer
is insoluble in water under acidic or neutral conditions. However,
the polymer becomes water soluble in the presence of a base or a
nucleophile because the anhydride groups can be readily opened up
by the base or the nucleophile. Upon hydrolysis this polymer
becomes water soluble.
[0030] Other examples may include modified polyvinyl alcohol
(PVOH). PVOH is typically prepared by polymerizing vinyl acetate,
followed by hydrolysis of the acetate groups. The hydrolysis step
can be controlled to occur to a desired extent such that the PVOH
has a desired property--not soluble in water. Examples of such
modified PVOH polymers are described in U.S. Pat. No. 5,137,969,
issued to Marten et a. (Col. 5, lines 1-11). Some of these modified
PVOH are sold by Celanese Chemicals (Dallas, Tex., U.S.A.) under
the trade name of Vytek.TM.. Such PVOH can be hydrolyzed by based
to become water soluble. Similarly, low-viscosity latex, such as
those supplied by Hexion Specialty Chemicals (Columbus, Ohio), may
also be prepared to retain some functional groups such that it is
not soluble in aqueous medium until such functional groups are
hydrolyzed by base. These materials are described in a co-pending
application Ser. No. 11/610600, entitled "Fluid Loss Control Agent
With Triggerable Removal Mechanism," by Hoefer et al.
[0031] In addition to adding a base (increased pH) or nucleophile,
these degradable polymer materials may also be degraded by
increased temperatures. These materials are susceptible to slow
hydrolysis in aqueous medium even without added base or
nucleophile. The slow background rates may be increased by
increasing temperatures. For example, the background hydrolysis
rates of these polymers at room temperature may not be noticeable.
However, the same reaction may become sufficiently fast to degrade
these polymers in downhole conditions.
[0032] The degradable materials in accordance with embodiments of
the invention are selected for their ability to degrade under
predetermined conditions and may comprise, for example, calcium,
magnesium, or aluminum, as one constituent of the material. In
accordance with some embodiments of the invention, such degradable
materials may be metals, alloys, or composites of metals and alloys
that may include non-metallic materials such as polymer, plastics,
other organic materials (e.g. pasty fluids), or ceramics.
[0033] Typical examples of degradable metals and alloys in
accordance with embodiments of the invention may include alkaline
and alkaline-earth metals such as calcium (Ca safely dissolves in
water regardless of pH), magnesium (Mg dissolves at low pH),
aluminum (Al dissolves at low pH), and alloys and composites of
those metals that degrade in water at rates that depend upon
temperature, pressure, and fluid composition. For example, acids
may accelerate degradation of these metals or alloys.
[0034] The following Table lists some examples of metal and alloy
degradable materials in accordance with embodiments of the
invention. The Table lists metal and alloy compositions,
degradation rates at normal pressure (1 atm) in water of specific
pH and temperature, as well as their approximate
ambient-temperature strength. As shown in this Table, an alloy of
calcium containing 20 percent by weight magnesium degrades much
slower than pure calcium metal (i.e., 99.99% Ca) and is also about
10 times stronger (i.e., its strength is comparable that of
quenched and tempered steels). In addition, note that aluminum can
be made degradable in neutral water with suitable alloying
elements.
TABLE-US-00001 Strength Temperature pH Degradation Material (MPa)
(.degree. C.) range rate (mm/h) Calcium metal ~70 25 3-11 ~5
(99.99% Ca) 65 3-11 10-11 90 3-11 17-20 Calcium alloy ~700 25 3-11
~0.05 (Ca--20 wt. % Mg) 65 3-11 0.2-0.3 90 3-11 1.2-1.7 Aluminum
metal ~100 90 7 <0.0001 (99.99Ca) Aluminum alloy ~ 90 7 ~0.17
(Al--21Ga) Aluminum alloy ~ 90 7 ~0.03 (Al--10Ga--10Mg) Aluminum
alloy ~ 25 7 0.5-0.6 (Al--5Ga--5Mg--5In) 90 7 0.8-0.9
[0035] Typical examples of degradable ceramics are those made of
alkaline and alkaline-earth metals, such as calcium carbonates,
calcium phosphate, and calcium sulfate, to name a few. The
dissolution behavior of such ceramics will depend on their
composition, processing, final form, as well as local pH and
pO.sub.2.
[0036] Embodiments of the invention may be used with any swellable
packers known in the art. FIG. 1 shows a swell packer 11, which
includes a swellable elastomer 12 on a basepipe or mandrel 13. The
swellable elastomer 12 has anti-extrusion rings 14 made of metal on
both sides. The swellable elastomer 12 may be bonded to the base
pipe 13 on its inner side. The outer surface of the swellable
elastomer 12 is protected by a temporary sleeve or temporary
containment 15. The temporary containment 15 can be made of a
degradable material in accordance with embodiments of the
invention, such as degradable polymers and degradable
metals/alloys. In accordance with some embodiments of the
invention, the temporary containment 15 may be made of inorganic
materials, such as water glass (or soluble glass). Water glass is a
colorless, transparent, grasslike substance available commercially
as a powder or as a transparent, viscous solution in water.
Chemically it is sodium silicate, potassium silicate, or a mixture
of these. It is prepared by fusing sodium or potassium carbonate
with sand or by heating sodium or potassium hydroxide with sand
under pressure. Water glass is very soluble in water, but the
glassy solid dissolves slowly, even in boiling water.
[0037] In accordance with some embodiments of the invention, the
temporary containment 15 may be made of polymers or composites that
include particles of soluble polymer or metals. That is, the
temporary containment 15 need not be entirely made of a degradable
material. For instance, it may be a layer that contains both
degradable and non-degradable materials. When such temporary
containments come in contact with appropriate fluids, the
degradable materials will dissolve to leave behind a layer
(non-degradable part) with very high porosity and permeability.
[0038] In accordance with embodiments of the invention, an
inflatable packer is first delivered to the desired location (as
shown in FIG. 2A) and then the temporary containment is degraded to
allow the packer to inflate and seal the wellbore (as shown in FIG.
2B). FIG. 2A shows an inflatable packer 21 on a basepipe 23 has
been delivered to the desired location in a wellbore. In order to
prevent damage to the outer elastomer layer of the packer, a
temporary containment 25 is provided on the outside of the
inflatable packer 21. When the temporary containment 25 comes in
contact with an appropriate fluid, it disintegrates and/or
dissolves. As a result, the temporary containment 25 loses its
mechanical integrity, which in turn allows the inflatable packer 21
to be deployed in an unhindered manner, as shown in FIG. 2B. The
advantage of the temporary containment 25 is to protect the
delicate elastomer layer from damages (such as abrasion, wear and
gauging), while the inflatable packer 21 is being run in hole. The
temporary containment 25 also prevents the elastomer layers from
swabbing off. Therefore, the operators can run the packer to the
setting depth at a faster rate.
[0039] A swellable packer in accordance with embodiments of the
invention may be used in any downhole operations that require a
packer. FIGS. 3A and 3B show an example of packers used in sand
screening. FIG. 3A shows swell packers 31 with temporary
containments 35 to control the swelling of the packers 31 that can
be used as annular constrictors for use with sand screens 36. The
temporary containment 35 can be made of any degradable material in
accordance with embodiments of the invention, such as metals,
alloys, or polymer that readily reacts with appropriate fluids
(e.g., a fluid with high or low pH). In accordance with some
embodiments of the invention, the containment 35 can also be made
of water soluble materials (for use in a hydrocarbon environment)
or hydrocarbon soluble materials (for use in an aqueous
environment). In accordance with some embodiments of the invention,
the temporary containment 35 may be made to dissolve or
disintegrate by spotting acids. Once the temporary containment 35
is degraded, the swellable packers 31 can be inflated by contacting
a fluid to seal the wellbore into different zones, as shown in FIG.
3B.
[0040] While the invention has been described with respect to a
limited number of embodiments, those skilled in the art, having
benefit of this disclosure, will appreciate that other embodiments
can be devised which do not depart from the scope of the invention
as disclosed herein. Accordingly, the scope of the invention should
be limited only by the attached claims.
* * * * *