Note: Descriptions are shown in the official language in which they were submitted.
1S16.1 193
PATENT APPLICATION
WELL STEAM INJECTION WITH FLOW CONTROL
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present document is based on and claims priority to US
Provisional
Application Serial No.: 62/395462, filed September 16, 2016, and US
Provisional
Application Serial No.: 62/395462, filed September 16, 2016, which are
incorporated
herein by reference in their entirety.
BACKGROUND
[0002] Hydrocarbon fluids such as oil and natural gas are obtained
from a
subterranean geologic formation, referred to as a reservoir, by drilling a
well that
penetrates the hydrocarbon bearing formation. Once a wellbore is drilled,
various forms
of well completion components may be installed to enable control over fluid
flow and to
enhance efficiency of producing the various fluids from the reservoir. In some
areas,
thermal stimulation may be implemented to heat and mobilize the oil by
lowering its
viscosity.
SUMMARY
[0003] In general, the present disclosure provides a system and
methodology for
enhancing hydrocarbon fluid production. A well is formed in a subterranean
region by
drilling a borehole, e.g. a wellbore, which may have a lateral section. The
lateral section
facilitates thermal stimulation of the hydrocarbon fluids via injection of a
hot fluid, e.g.
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steam, which lowers the viscosity of the desired hydrocarbon production fluid,
e.g. oil.
To facilitate production, a completion system is deployed into the borehole
and
comprises a screen combined with a base pipe and a sleeve body. The sleeve
body
comprises grooves and orifices which accommodate fluid flow. A sleeve, e.g. a
thermal
sliding sleeve, may be combined with the sleeve body and may be actuated to
either
block or allow fluid flow through the orifices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Certain embodiments will hereafter be described with
reference to the
accompanying drawings, wherein like reference numerals denote like elements.
It should
be understood, however, that the accompanying figures illustrate various
implementations described herein and are not meant to limit the scope of
various
technologies described herein, and:
[0005] Figure 1 is a schematic illustration of an example of a well
system having
a borehole with a lateral section and a completion deployed in the borehole,
according to
an embodiment of the disclosure;
[0006] Figure 2 is a cross-sectional illustration of a portion of
the completion
having a screen assembly, according to an embodiment of the disclosure; and
[0007] Figure 3 is a cross-sectional illustration of a portion of
another example of
the completion having a screen assembly, according to an embodiment of the
disclosure.
DETAILED DESCRIPTION
[0008] In the following description, numerous details are set forth
to provide an
understanding of some illustrative embodiments of the present disclosure.
However, it
will be understood by those of ordinary skill in the art that the system
and/or
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1S16.1 193
methodology may be practiced without these details and that numerous
variations or
modifications from the described embodiments may be possible.
[0009] The disclosure herein generally relates to a system and
methodology for
enhancing hydrocarbon fluid production. The system and methodology may be used
in
wells which undergo thermal stimulation such as steam assisted gravity
drainage
(SAGD). By way of example, SAGD involves injecting steam into the formation
through
injection wells at a constant operating pressure in a steam chamber. The oil
then flows
via gravity into a production well. Operation of this type of thermally
stimulated well
and other types of thermally stimulated wells may be enhanced by utilizing
completions
as described herein.
100101 According to an embodiment, a well may be formed in a
subterranean
region by drilling a borehole, e.g. a wellbore, which has a lateral section.
For example,
the wellbore may be drilled from the surface along a generally vertical
section and then
turned laterally and drilled to form a lateral section in the subterranean
region having a
reservoir of hydrocarbon fluid. In some applications, the lateral section may
generally be
a horizontal section although the horizontal section may have curved sections,
inclined
sections, declined sections, and/or other sections which deviate from
generally horizontal.
[0011] In various well applications, the lateral section
facilitates thermal
stimulation of the hydrocarbon fluids via injection of a hot fluid, e.g.
steam, which lowers
the viscosity of the desired hydrocarbon production fluid, e.g. oil. To
facilitate
production, a completion system is deployed into the borehole and comprises a
screen
combined with a base pipe and a sleeve body. The sleeve body may comprise
grooves
and orifices which accommodate fluid flow. A sleeve, e.g. a thermal sliding
sleeve, may
be combined with the sleeve body and may be actuated to either block or allow
fluid flow
through the orifices according to the parameters of a given stimulation and
production
operation.
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[0012] Referring generally to Figure 1, an example of a well system
20 is
illustrated. In this embodiment, the well system 20 has a borehole 22, e.g. a
wellbore,
with a generally vertical section 24 and a lateral section 26, e.g. a
generally horizontal
section. In the illustrated example, the wellbore 22 is lined with a surface
casing 28
which extends down from a wellhead 30. An intermediate casing 32 is disposed
within
surface casing 28 to extend farther downhole and at least partially into
lateral section 26.
A completion 34 is deployed down through the intermediate casing 32 and may
comprise
a variety of features and components according to the parameters of a given
thermal
stimulation and/or production operation. By way of example, at least a portion
of the
completion 34 may extend into an open hole section 36 of lateral borehole
section 26.
[0013] By way of example, the completion 34 may comprise a
plurality of screen
assemblies 38 disposed along a base pipe 40. In Figure 1, a centerline or axis
of the
screen assemblies 38 is marked by reference numeral 42. The screen assemblies
38 may
comprise various components, such as sliding sleeves, e.g. thermal sliding
sleeves,
combined with screens. The screens allow the flow of production fluid to enter
the
completion 34 where it is directed through the sliding sleeve and into the
base pipe 40.
The sliding sleeves may work in cooperation with inflow control devices, e.g.
orifices, to
regulate the fluid flow. In other embodiments, the screens may not be used and
the flow
of hydrocarbons from the reservoir may be directed through the sliding sleeve
and into
the interior of base pipe 40.
100141 Referring generally to Figure 2, an embodiment of one of the
screen
assemblies 38 is partially illustrated in cross-section to provide an example
of screen
assembly components which may be utilized to facilitate thermal stimulation
and
production operations. In this example, the screen assembly 38 comprises a
screen 44
which restricts reservoir sands and other particles from entering the screen
assembly 38
and plugging a flow path. The screen assembly 38 also comprises a portion of
the base
pipe 40 which may include grooves 46, e.g. axial grooves, disposed along the
exterior
surface to increase flow area beneath the screen 44. By way of example, the
grooves 46
may be milled into the base pipe 40, e.g. casing base pipe, along the length
of the screen
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44 or along a different, desired axial portion of the base pipe. The grooves
46 serve to
enhance the flow area under the screen 44 so that the pressure drop is less
substantial
along the length of the screen 44, thus rendering the entire screen
functional.
[0015] In the embodiment illustrated, a sleeve body 48 is located
between
sections of base pipe 40 and may be sealably secured to the sections of base
pipe 40 via
welds 50 or other suitable attachment mechanisms. The sleeve body 48 contains
axial
grooves 52, e.g. passages, and corresponding orifices 54, e.g. flow ports,
positioned
through the wall of the sleeve body 48 and oriented toward an internal flow
region 56 of
base pipe 40. By way of example, the axial grooves 52 and orifices 54 may be
milled or
otherwise formed within sleeve body 48.
[0016] A sleeve 58 is slidably mounted along the interior of sleeve
body 48 to
enable blocking or opening of the orifices 54. Suitable seals 60, e.g. 0-ring
seals or other
types of seals, may be positioned between sleeve 58 and sleeve body 48. Use of
sleeve
58 provides flexibility over the control of fluids into and out of a thermal
wellbore and
enables the complete shut off of fluid flow.
[0017] By way of example, the sleeve 58 may be in the form of a
thermal
application sleeve. One example of such a thermal sliding sleeve is the
premiumportTM
thermal tool available from Absolute Completion Technologies, located in
Calgary
Canada. It should be noted other mechanisms may be used to provide access to
the
surrounding formation/reservoir, e.g. perforating a liner after a warmup phase
is
completed to initiate an SAGD phase or production phase.
[0018] In the example illustrated, the sleeve body 48 also is
combined with a
diverter insert 62 positioned proximate orifices 54 to direct fluid flow from
perpendicular
flow with respect base pipe 40, e.g. radial flow, to axial flow as fluid flows
through
orifices 54. By way of example, the diverter insert 62 may be in the form of a
tungsten
diverter insert or other suitable insert formed of an appropriate material for
use in thermal
stimulation operations. In some embodiments, the diverter insert 62 may be
positioned
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generally centrally within screen assembly 38 such that a screen 44 is located
at each
axial end.
[0019] Additionally, the diverter insert 62 may comprise curved
regions 64
constructed with a curvature such that flow from internal flow region 56
through orifices
54 is split in each axial direction, e.g. equally split in each axial
direction. The curvature
of curved regions 64 also may be selected to change the flow of fluid from a
perpendicular flow, e.g. radial flow, to an axial flow in a manner which
reduces the
chances of erosion of an outer sleeve 66.
[0020] According to the embodiment illustrated, a nozzle ring 68
may be fixed to
the base pipe 40 via a weld 70 or other suitable attachment mechanism. The
nozzle ring
68 contains nozzles 72 which function to choke flow into or out of the
surrounding
formation/reservoir. The outer sleeve 66 may be affixed to nozzle ring 68 via
a weld 74
or other suitable attachment mechanism so as to contain pressure integrity
around the
nozzle ring 68 and to ensure proper function of nozzles 72. The welds 70, 74
(or other
suitable attachment mechanisms) create a pressure seal which causes the entire
fluid flow
to pass through nozzles 72.
[0021] A nozzle access sleeve 76 may be releasably secured between
nozzle ring
68 and an end ring 78 via, for example, threaded engagement or other
releasable
engagement mechanism. The nozzle access sleeve 76 allows access to the nozzle
ring 68
so that nozzles 72 may be changed out to provide a different size/choke. For
example,
the nozzle access sleeve 76 may be removed to enable last-minute changes in
the flow
profile of the well based on factors such as temperature data and reservoir
characteristics.
The end ring 78 may be constructed to facilitate flow along grooves 46. For
example, the
end ring 78 may be welded to the base pipe 40 in a stitch pattern which allows
fluid flow
to move between it and the base pipe 40 within grooves 46.
[0022] Referring generally to Figure 3, another embodiment of one
of the screen
assemblies 38 is partially illustrated in cross-section to provide an example
of screen
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assembly components which may be utilized to facilitate thermal stimulation
and
production operations. In this example, the screen assembly 38 may have many
components similar to that described above with reference to Figure 2. For
example, this
embodiment may utilize components similar to screen 44, base pipe 40 with
axial
grooves 46, sleeve body 48 with axial grooves/passages 52 and orifices 54,
sleeve 58, and
outer sleeve 66. The form and arrangement of these components may vary
somewhat
according to the parameters of a given operation.
[0023] The embodiment illustrated in Figure 3, however, utilizes a
portion 80 of
base pipe 40 having a plurality of holes 82 oriented generally radially
therethrough to
direct fluid, e.g. steam, from the internal passage 56 toward the
nozzles/chokes 72. In
this example, the nozzles/chokes 72 may be inserted into or built into the
sleeve body 48
along the flow path therethrough. The plurality of holes 82 enable a smooth
transition of
fluid from internal region 56 to the area of nozzles/chokes 72. In some
applications, fluid
also may be flowed in reverse of the injection/thermal stimulation direction
as indicated
by arrows 84.
[0024] According to an operational example, the completion 34 is
run downhole
with the flow ports/orifices 54 closed off via thermal sliding sleeves 58.
Steam or other
hot fluid is then injected at a toe of the well but it does not enter the
surrounding
formation/reservoir. The heat is transferred to the reservoir via conduction.
The well is
then transitioned to a circulation phase or directly to the SAGD phase by
opening the
sliding sleeves 58. When the well is at a suitable temperature, production may
be
commenced.
[0025] Depending on the parameters of a given application, the
wellbore
geometries described herein may be adjusted according to the type, size,
orientation, and
other features of the well system 20. Additionally, the size, location and
configuration of
various components of completion 34 may be changed. The flow patterns,
coupling
mechanisms, orifices, screen arrangements, and other components and features
also may
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be changed according to parameters of a given thermal stimulation and
production
operation.
100261 Although a few embodiments of the system and methodology
have been
described in detail above, those of ordinary skill in the art will readily
appreciate that
many modifications are possible without materially departing from the
teachings of this
disclosure. Accordingly, such modifications are intended to be included within
the scope
of this disclosure as defined in the claims.
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