FIELD OF THE INVENTION
The present invention relates to an isolation assembly for inflow control
device. The invention relates generally to fluid isolation systems for a well system
through a subterranean formation and, more particularly (although not necessarily
5 exclusively), to isolation assemblies for inflow control devices that can isolate
different sources of production fluid in producing wells.
BACKGROUND OF THE INVENTION
Various production fluids can be produced via a well traversing a
hydrocarbon-bearing subterranean formation. Production fluids from a subterranean
10 formation can include desirable production fluids, such as oil or other
hydrocarbons, and undesirable production fluids, such as water. Mature wells in
which production has been ongoing for a long duration can include larger amounts
of water and other undesirable production fluids than the amounts of desirable
production fluid. Producing hydrocarbons in mature wells can thus produce larger
15 amounts of undesirable fluids such as water than producing hydrocarbons from new
wells. In addition, a hydrocarbon bearing formation can include multiple layers of
stratification having different permeability characteristics. Differences in
permeability at different layers can cause the amount of water in each layer to vary
over different strata of a formation through which a wellbore is drilled. In addition,
20 water or other undesirable fluids may have a higher mobility than desirable
production fluids and may thus predominate with respect to oil in a subterranean
formation.
Current solutions addressing the production of undesirable production
fluids can isolate different zones along the wellbore corresponding to different
25 sections of the subterranean formation. Isolation of the zones can reduce the
production of undesirable fluid. Such solutions can include fluid discrimination
tools, such as inflow control devices deployed in long open hole intervals, such as a
horizontal wellbore where the length of the wellbore is much greater than the length
of the tool. Such isolation tools deployed in long open hole intervals can be
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insufficient for isolating strata in other wells where production zones maybe spaced
more closely, thereby limiting the space available to isolate each tool from one
another.
It is therefore desirable to provide isolation between fluid discrimination
5 devices in a modular and compact manner.
SUMMARY OF THE INVENTION
An isolation assembly is provided that can be disposed in a wellbore
through a fluid-producing formation. The isolation assembly can include one joint
of a tubing section, at least two inflow control devices, and an isolation element.
10 The joint of the tubing section can include at least two ports. Each inflow control
device can be coupled to the tubing section at a respective port. The isolation
element can be positioned between the inflow control devices. The isolation
element can be configured to fluidly isolate the ports from each other.
These illustrative aspects and features are mentioned not to limit or define
15 the invention, but to provide examples to aid understanding of the inventive
concepts disclosed herein. Other aspects, advantages, and features of the present
invention will become apparent after review of the entire disclosure and figures.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic illustration of a well system having isolation
20 assemblies for inflow control devices according to one aspect of the present
invention.
Figure 2 is a longitudinal cross-sectional view of a section of a tubing string
having an isolation assembly for inflow control devices according to one aspect of
the present invention.
25 Figure 3 is a longitudinal cross-sectional view of an isolation element
having an extrusion prevention mechanism according to one aspect of the present
invention.
Figure 4 is a vertical view of a joint having extrusion prevention
mechanisms according to one aspect of the present invention.
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DESCRIPTION OF INVENTION w.r.t. DRAWINGS
Certain aspects and features of the present invention are directed to an
isolation assembly for inflow control devices that can be disposed in a wellbore
through a fluid-producing formation. The isolation assembly can include short
5 sections between inflow control devices and an isolation element providing an
annular barrier between sections. The isolation assembly can include one joint of a
tubing section, at least two inflow control devices, and an isolation element. The
joint of the tubing section can include at least two ports.
As used herein, the term "joint" can refer to a length of pipe, such as (but
10 not limited to) drill pipe, casing or tubing. One or more joints can form a tubing
section of a tubing string. A joint can have any suitable length. Non-limiting
examples of lengths of a joint can include five feet, thirty feet, and forty feet.
As used herein, the term "inflow control device" can refer to any device or
equipment for controlling the rate of fluid flow from a well for extracting fluids
15 from a subterranean formation. An inflow control device can be used to balance
inflow throughout the length of a tubing string of a well system by balancing or
equalizing pressure from a wellbore of horizontal well. For example, several inflow
control devices disposed at different points along a tubing string of a well can be
used to regulate the pressure at different locations in the tubing string. A flow
20 control device otherwise used for inflow control can also be used to stimulate
production of fluid from a well. For example, a flow control device can be used to
inject fluid into the wellbore to stimulate the flow of production fluids, such as
petroleum oil hydrocarbons, from a subterranean formation. Such a device can
function as an outflow control device and can be referred to as an inflow control
25 device.
Each inflow control device can be coupled to the tubing section at a
respective port. The inflow control devices can be coupled to the tubing section via
bushings with tapered threads. The inflow control device and bushing can be
threaded directly into the tubing string by threading the inflow control device and
30 bushing onto a threaded end of a tubing section.
The isolation element can be positioned between the inflow control devices.
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The isolation element can be configured to fluidly isolate the ports from each other.
Isolating the two ports from each other can include preventing production fluid
flowing into the wellbore from a first portion of a subterranean formation adjacent
to a first inflow confrol device from flowing to a second portion of the wellbore
5 adjacent to a second inflow control device.
A non-limiting example of an isolation element is a swellable rubber
element that can swell in response to hydrocarbon exposure in the wellbore.
Another non-limiting example of an isolation element is a mechanical isolation
element, such as a packer. Another non-limiting example of an isolation element is
10 a chemical isolation element, such as an epoxy or other chemical compound
adapted to expand in response to pressure from or contact with hydrocarbons or
other production fluids in a wellbore.
Each section of the wellbore can include one or more inflow control devices
isolated from one or more adjacent inflow control devices. As water or other
15 undesirable fluids are produced from a section of the subterranean formation, each
isolated inflow control device or group of inflow control devices can restrict the
flow of water or other undesirable production fluid. In some aspects, such
restriction can be performed autonomously by an autonomous inflow control
device, thereby allowing sections of the subterranean formation in which water is
20 not being produced to continue to produce freely.
The isolation assembly can reduce the production of water or other
undesirable fluid from a subterranean formation by a well system, thereby
increasing the amount of oil or other desired hydrocarbons produced from a
subterranean formation as compared to the amount of undesirable fluids produced.
25 For example, for a well system in which the amount of undesirable fluid produced
is lowered by 10-20%, production of desirable fluid can be increased and resources
devoted to separating desirable production fluid from undesirable production fluid
can be reduced.
In additional or alternative aspects, the inflow control devices can be
30 autonomous inflow control devices. An autonomous inflow control device can
discriminate desirable production fluid from undesirable production fluid without
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intervention fi^om an operator. Autonomously discriminating desirable production
fluid from undesirable production fluid can allow the inflow control device to adjust
to changing proportions of desirable production fluid and undesirable production
fluid in a subterranean formation over time. Autonomously discriminating
5 desirable production fluid from undesirable production fluid can also allow the
inflow control device to apply a different degree of restriction to undesirable fluids
than is applied to desirable fluids.
In additional or alternative aspects, the isolation assembly can include one
or more filtering elements. Each filtering element can be coupled to the tubing
10 section at or near a respective inflow control device. A filtering element can reduce
or prevent particulate material from flowing into the inner diameter of a tubing
section via an inflow control device. A non-limiting example of a filtering element
is a sand screen coupled to sections of a tubing string of a well system. A sand
screen can filter particulate material from production fluid by allowing the
15 production fluid to flow through the sand screen and by preventing particulate
material in the production fluid from passing through the sand screen. One example
of a sand screen is a wire wrapped helically around a perforated piece of pipe. The
helically wrapped wire is spaced and/or gauged based on the size of the particles to
be filtered. Another example of a sand screen is a mesh filter. A mesh filter can
20 include a group of fibers or other materials that are woven perpendicularly to
another group of fibers or other materials, thereby forming pores allowing the flow
of fluid through the mesh filter. Another non-limiting example of a filtering
element is a porous medium. The porous medium can be a material having one or
more pores adapted to allow a fluid to flow through the porous medium and to
25 prevent one or more particles from flowing through the porous medium.
An end ring can be coupled to each end of the outer diameter of the filtering
element. Coupling the end ring can include, for example, crimping the end ring
onto the tubing section or shrinking the end ring onto the tubing section via heating
and cooling.
30 In additional or altemative aspects, the isolation element can include an
extrusion prevention mechanism. The extrusion prevention mechanism can apply a
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force to an isolation element, thereby preventing the isolation element from
expanding axially. Axial expansion of the isolation element can obstruct, damage,
or otherwise interfere with the operation of the inflow control devices and or the
filtering elements. Non-limiting examples of an extrusion prevention mechanism
5 can include a bonded steel ring or a metal protrusion of the end rings.
In additional or alternative aspects, multiple isolation assemblies can be
coupled to a tubing string, thereby creating a cost-effective joint that can be
installed into a wellbore of a subterranean formation.
These illustrative examples are given to introduce the reader to the general
10 subject matter discussed here and are not intended to limit the scope of the disclosed
concepts. The following sections describe various additional aspects and examples
with reference to the drawings in which like numerals indicate like elements, and
directional descriptions are used to describe the illustrative aspects. The following
sections use directional descriptions such as "above," "below," "upper," "lower,"
15 "upward," "downward," "left," "right," "uphole," "downhole," etc. in relation to the
illustrative aspects as they are depicted in the figures, the upward direction being
toward the top of the corresponding figure and the downward direction being
toward the bottom of the corresponding figure, the uphole direction being toward
the surface of the well and the downhole direction being toward the toe of the well.
20 Like the illustrative aspects, the numerals and directional descriptions included in
the following sections should not be used to limit the present invention.
Figure 1 schematically depicts part of a well system 100 having a tubing
string 108 with isolation assemblies, such as the isolation assembly 112, according
to certain aspects. The well system 100 includes a bore that is a wellbore 102
25 extending through various earth strata. The wellbore 102 may include a tubing
string 108 cemented at an upper portion of the substantially vertical section 104.
The substantially vertical section 104 extends through a hydrocarbon
bearing subterranean formation 110. The tubing string 108 within wellbore 102
extends from the surface to the subterranean formation 110.
30 The subterranean formation 110 includes strata 120a-d and strata 122a-d.
The strata 120a-d can store desirable production fluid, such as oil or other
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hydrocarbons, as depicted by the cross-hatching within the strata 120a-d. The strata
122a-d can store undesirable production fluid, such as water.
The tubing string 108 can provide a conduit for formation fluids, such as
production fluids produced from the subterranean formation 110, to travel from the
5 substantially vertical section 104 to the surface. Pressure from a bore in a
subterranean formation can cause formation fluids, including production fluids such
as gas or petroleum, to flow to the surface.
The well system 100 can also include one or more isolation assemblies, such
as isolation assembly 112. Any number of isolation assemblies can be used within
10 a tubing string 108. Each isolation assembly 112 can be coupled to a tubing section
the tubing string 108. Each isolation assembly 112 can include an isolation element
114 and an inflow control device assembly 116. The isolation element can provide
isolation between strata 120a-d and strata 122a-d. The inflow control device
assembly 116 can include two or more inflow control devices configured to
15 discriminate oil and other desirable production fluids from water and other
undesirable production fluids.
Although Figure 1 depicts the isolation assemblies 112 positioned in a
substantially vertical section 104, any of one or more isolation assemblies can be
located, additionally or alternatively, in a substantially horizontal section of a
20 wellbore. Isolation assemblies can be disposed in cased wells, such as is depicted in
Figure 1, or in open hole environments. Isolation assemblies can be disposed in
well systems having other configurations including horizontal wells, deviated wells,
slanted wells, multilateral wells, etc.
Figure 2 depicts a longitudinal cross-sectional view of a joint 201 of a
25 tubing string 108 having an isolation assembly 112. The isolation assembly 112
can include the isolation element 114 and the inflow control device assembly 116.
The inflow control device assembly 116 can include the inflow confrol devices
202a, 202b and the filtering elements 204a, 204b.
Each of the inflow control devices 202a, 202b can discriminate undesirable
30 production fluid from desirable production fluid flowing from the subterranean
formation 110 through the ports 205a, 205b into the inner diameter of the joint 201.
8
The inflow control devices can be positioned at multiple points of a joint
201. The inflow control devices 202a, 202b can be coupled to the joint 201 via any
suitable mechanism. The inflow devices 202a, 202b, can be positioned intemal or
external to the outer surface of the joint 201. The non-limiting example of Figure 2
5 depicts the inflow control devices 202a, 202b coupled to the joint 201 via the
bushings 206a-d. The inflow control device 202a can be threaded into the bushings
206a, 206b. The inflow control device 202b can be threaded into the bushings 206c,
206d. The bushings 206a-d can be respectively coupled to a threaded portion of
each of ports 205a, 205b. Other aspects can include threading or otherwise
10 coupling the inflow control devices 202a, 202b to a metal plate. The metal plate
can be coupled to the joint 201 by, for example, welding the plate to one or more
openings in the side wall of the joint 201.
In some aspects, the inflow control devices 202a, 202b can be more
restrictive to an undesirable production fluid than to a desirable production fluid.
15 The difference in restriction of undesirable production fluid and desirable
production fluid can discriminate the undesirable production fluid from the
desirable production fluid. Discriminating the undesirable production fluid from
the desirable production fluid can allow desirable production fluid to be produced
from the formation 110 and reduce or prevent the production of undesirable
20 production fluid from the formation 110. In additional or alternative aspects, each
of the inflow control devices 202a, 202b can be an autonomous inflow control
device. An inflow control device can be formed from any suitable material, such as
(but not limited to) tungsten carbide.
The filtering elements 204a, 204b can respectively provide filtration for the
25 ports 205a, 205b of the joint 201. Each of the filtering elements 204a, 204b can be
coupled to the joint 201 at or near the inflow control devices 202a, 202b. In some
aspects, the filtering elements 204a, 204b, can circymferentially surround the joint
201. The filtering elements 204a, 204b can prevent particulate matter from entering
the inflow control devices 202a, 202b. In other aspects, the filtering elements 204a,
30 204b can be disposed within the inner diameter of the joint 201. Non-limiting
examples of the filtering elements 204a, 204b can include a wire wrap screen, a
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mesh screen, a porous media with a predetermined porosity configured to prevent
particulate matter of a size greater than a predetermined size from passing through
the porous medium, etc.
The filtering elements 204a, 204b can be coupled to the tubing section or
5 otherwise secured in a stable position via any suitable mechanism. Figure 2 depicts
the filtering element 204a coupled to the joint 201 via the end rings 208a, 208b and
the filtering element 204b coupled to the joint 201 via the end rings 208c, 208d.
Each end ring can be secured to the joint 201 via any suitable mechanism or
process. A non-limiting example of securing each end ring to the joint 201 is
10 crimping the end rings. The end ring can be compressed by a force from a
compression tool, such as a vice, or an impact tool, such as a hammer.
The isolation element 114 can include any device, mechanism, compound,
etc. suitable for providing an annular barrier between the inflow control devices
202a, 202b. An annular barrier between the inflow control devices 202a, 202b can
15 prevent or reduce the flow of production fluid from a first portion of the
subterranean formation 110 adjacent to the inflow control device 202a to a second
portion of the subterranean formation 110 adjacent to the inflow control device
202a, and vice versa.
An isolation element can include any material or device suitable for forming
20 an annular barrier between isolation assemblies such that production fluid is
isolated between ports or other inflow points. Examples of material for forming an
isolation element 114 can include (but are not limited to) a swellable element such
as rubber, a chemical compound, a mechanical isolation element, an inflatable
isolation element, etc. A non-limiting example of a chemical isolation element can
25 be an epoxy injected in a gap between the end rings 208b, 208c along the outer
diameter of the joint 201. A non-limiting example of a mechanical isolation
element is a packer. A packer can include an element that can be inserted between
the end rings 208b, 208c, such as an expandable elastomeric element or a flexible
elastomeric element such as a packer cup, to create a hydraulic seal. Any number
30 of packers, including one, can be used as an isolation element 114. A non-limiting
example of an inflatable isolation element is an inflatable bladder.
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A joint 201 can have any length suitable for installation in a tubing string
108. One non-limiting example can include a joint length of five feet. Another
non-limifing example can include a joint length of forty feet.
Multiple ports or other inflow points can be included between two
5 connection points of a joint 201. Multiple ports or other inflow points included in a
joint 201 can be individually isolated.
Although Figure 2 depicts a single inflow control device on each side of an
isolation element, multiple inflow control devices can additionally or alternatively
be included between two isolation elements.
10 In additional or alternative aspects, the isolation element can include an
extrusion prevention mechanism. The extrusion prevention mechanism can apply a
force to an isolation element, thereby preventing the isolation element from
expanding axially. Axial expansion of the isolation element can obstruct, damage,
or otherwise interfere with the operation of the inflow control devices and or the
15 filtering elements. Non-limiting examples of an extrusion prevention mechanism
can include a bonded steel ring or a metal protrusion of the end rings.
Figures 3 and 4 depict an example of an extrusion prevention mechanism
304. Figure 3 depicts a longitudinal cross-sectional view of an isolation element
114' having an extrusion prevention mechanism 304.
20 The isolation element 114' can be a swellable isolation element, such as a
rubber or chemical compound that expands in response to pressure in the wellbore
102 or in response to contact with hydrocarbons from the formation 110 or contact
with other fluids present in wellbore or circulated into the wellbore. The isolation
element 114' can be retained by a retaining structure 302. An example of a
25 retaining structure 302 may include multiple end rings circumferentially
surrounding a joint 201 on opposite sides of the isolation element 114'.
The retaining structure 302 can include an extrusion prevention mechanism
304 that includes one or more metal protrusions overlaying the isolation element
114.' The metal protrusions can extend over the isolation element 114'. The radial
30 expansion of the isolation element 114' can apply force to the metal protrusions.
The force applied to the metal protrusions can cause the metal protrusions to extend
-11 -
10
15
radially, as depicted by the dashed lines of extrusion prevention mechanism 304'.
The metal protrusions of the extrusion prevention mechanism 304' can contact a
rigid surface 306. Examples of the rigid surface 306 can include the formation 110
or an outer casing circumferentially surrounding the joint 201. The metal
protrusions of the extrusion prevention mechanism 304' contacting a rigid surface
306 can form a barrier preventing the isolation element 114' from expanding axially
along the length of the joint 201.
Figure 4 depicts a vertical view of the outer diameter of a joint 201 having
extrusion prevention mechanisms 304. As depicted in Figure 4, each of the
isolation elements 114' can be overlaid by the protrusions of the extrusion
prevention mechanisms 304.
The foregoing description of the aspects, including illustrated examples, of
the invention has been presented only for the purpose of illustration and description
and is not intended to be exhaustive or to limit the invention to the precise forms
disclosed. Numerous modifications, adaptations, and uses thereof will be apparent
to those skilled in the art without departing from the scope of this invention.
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WE CLAIM:
1. An isolation assembly for inflow control device, configured to be disposed
in a wellbore through a fluid-producing formation, comprising:
5 one joint of a tubing section comprising at least two ports;
at least two inflow control devices, wherein each inflow control device is
coupled to the tubing section at a respective port of the at least two ports; and
an isolation element positioned between the at least two inflow control
devices, the isolation element being configured to fluidly isolate the at least two
10 ports from each other.
2. An isolation assembly of claim 1, wherein the isolation element comprises
a swellable solid material configured to expand radially.
15 3. An isolation assembly as claimed in claim 2, wherein the swellable solid
material comprises a rubber element.
4. An isolation assembly as claimed in claim 1, wherein the isolation element
comprises a chemical compound configured to expand radially in response to
20 pressure in a wellbore in which the tubing section is disposed.
5. An isolation assembly as claimed in claim 4, wherein the chemical
compound comprises an epoxy.
25 6. An isolation assembly as claimed in claim 1, wherein the isolation element
comprises a mechanical isolation element.
7. An isolation assembly as claimed in claim 1, wherein the mechanical
isolation element comprises a packer.
30
8. An isolation assembly as claimed in claim 1, wherein the isolation element
13
comprises an inflatable material.
9. An isolation assembly as claimed in claim 1, wherein each inflow control
device comprises an autonomous inflow control device configured to restrict a
5 first production fluid differently from a second production fluid.
10. An isolation assembly as claimed in claim 1, wherein each inflow control
device is positioned external to the tubing section at a respective port of the at
least two ports.
10
11. An isolation assembly as claimed in claim 1, further comprising at least
two filtering elements, wherein each filtering element is positioned external to the
tubing section at a respective inflow control device.
15 12. An isolation assembly configured to be disposed in a wellbore through a
fluid-producing formation, comprising:
a joint of a tubing section comprising at least two ports;
at least two inflow control devices, wherein each inflow control device is
coupled to the tubing section at a respective port;
20 at least two filtering elements, wherein each filtering element is coupled to the
tubing section at a respective inflow control device; and
an isolation element positioned between the at least two inflow control
devices, the isolation element being configured to fluidly isolate the at least two
ports from each other.
25
13. An isolation assembly as claimed in claim 12, wherein each filtering
element comprises a wire wrap screen.
14. An isolation assembly as claimed in claim 12, wherein each filtering
30 element comprises a mesh screen.
up
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, i . ^ v *
30
^ t ^ » : ^ \ , ^_ r^ ^ i /^ 0
15. An isolation assembly as claimed in claim 12, wherein each filtering
element comprises a porous medium, wherein the porous medium comprises a
material having one or more pores adapted to allow a fluid to flow through the
porous medium and to prevent one or more particles from flowing through the
5 porous medium.
16. An isolation assembly as claimed in claim 12, wherein each inflow control
device comprises an autonomous inflow control device configured to restrict a
first production fluid differently fi"om a second production fluid.
10
17. An isolation assembly configured to be disposed in a wellbore through a
fluid-producing formation, comprising:
a joint of a tubing section comprising at least two ports;
at least two autonomous inflow control devices, wherein each autonomous
15 inflow control device is coupled to the tubing section at a respective port;
at least two filtering elements, wherein each filtering element is coupled to the
tubing section at a respective inflow control device; and
an isolation element positioned between the at least two autonomous
inflow control devices, the isolation element being configured to fluidly isolate
20 the at least two ports from each other.
18. An isolation assembly as claimed in claim 17, wherein each autonomous
inflow control device is configured to restrict a flow of a first production fluid or a
second production fluid through the respective port, wherein the restriction of the
25 first production fluid is different from the restriction of the second production
fluid.
19. An isolation assembly as claimed in claim 17, fiirther comprising at least
one end ring configured to prevent axial expansion of the filtering element.
20. An isolation assembly as claimed in claim 19, wherein the at least one end
15
,iocv^«^/^* *- -"'0'^ 9.TZ-i r^ \4
ring is adapted to provide a protrusion, wherein the protrusion is positioned
external to the isolation element and is adapted to extend radially in response to
force applied by a radial expansion of the isolation element.
Dated this 17 day of October, 2014.
(VD GULWANI)
10 Applicant's Patent Attorney
Dua Associates
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