U.S. patent application number 13/934580 was filed with the patent office on 2014-02-20 for preconditioning for bitumen displacement.
The applicant listed for this patent is CONOCOPHILLIPS COMPANY. Invention is credited to Wendell P. Menard.
Application Number | 20140048259 13/934580 |
Document ID | / |
Family ID | 50099245 |
Filed Date | 2014-02-20 |
United States Patent
Application |
20140048259 |
Kind Code |
A1 |
Menard; Wendell P. |
February 20, 2014 |
PRECONDITIONING FOR BITUMEN DISPLACEMENT
Abstract
Methods and systems produce petroleum products with multiple
horizontal wells through which injection processes precondition and
displace the hydrocarbons in a formation. The wells extend through
the formation spaced apart from one another in a lateral direction.
Before fluid communication is established between the wells, cyclic
injections and production of resulting backflow initiates
conditioning of immobile products. Alternating between injection
and production at adjacent wells may then facilitate establishing
the fluid communication. After the fluid communication is
established, a displacement procedure sweeps the hydrocarbons from
one of the wells used for injection toward an adjacent one of the
wells used for production.
Inventors: |
Menard; Wendell P.; (Katy,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CONOCOPHILLIPS COMPANY |
Houston |
TX |
US |
|
|
Family ID: |
50099245 |
Appl. No.: |
13/934580 |
Filed: |
July 3, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61683373 |
Aug 15, 2012 |
|
|
|
Current U.S.
Class: |
166/272.3 ;
166/268 |
Current CPC
Class: |
E21B 43/16 20130101;
E21B 43/24 20130101; E21B 43/20 20130101 |
Class at
Publication: |
166/272.3 ;
166/268 |
International
Class: |
E21B 43/24 20060101
E21B043/24; E21B 43/16 20060101 E21B043/16 |
Claims
1. A method of recovering hydrocarbons, comprising: injecting
during a first time a conditioning fluid through first and second
wells and into a formation along lateral spaced apart and parallel
horizontal lengths of the first and second wells; producing the
hydrocarbons recovered as backflow along the lengths of the first
and second wells during a second time after the first time; then
alternating between injecting the conditioning fluid into the
formation along the length of the second well while producing the
hydrocarbons along the length of the first well and injecting the
conditioning fluid into the formation along the length of the first
well while producing the hydrocarbons along the length of the
second well, thereby establishing fluid communication between the
first well and the second well; and then injecting a displacement
fluid into the formation along the length of the first well to
sweep the hydrocarbons toward the second well and while producing,
along the length of the second well, the hydrocarbons being
displaced.
2. The method according to claim 1, further comprising cycling
during additional time intervals between the injecting of the
conditioning fluid and the producing of the hydrocarbons recovered
as backflow.
3. The method according to claim 1, wherein the conditioning fluid
includes a solvent for the hydrocarbons.
4. The method according to claim 1, wherein the conditioning fluid
includes a solvent for the hydrocarbons that includes a liquid
component under reservoir conditions and a gaseous component under
reservoir conditions.
5. The method according to claim 1, wherein the displacement fluid
includes steam.
6. The method according to claim 1, wherein the conditioning fluid
includes a hydrocarbon solvent with between one and twenty carbon
atoms per molecule and the displacement fluid contains steam.
7. The method according to claim 1, wherein the displacement fluid
includes at least one constituent selected from solvent for the
hydrocarbons, water, steam, emulsifiers, air, oxygen and carbon
dioxide.
8. The method according to claim 1, wherein the conditioning fluid
and the displacement fluid contain like constituents.
9. The method according to claim 1, wherein the first and second
wells are spaced between 5 meters and 50 meters apart in a common
horizontal plane without intervening wells between the first and
second wells.
10. A method of recovering hydrocarbons, comprising: injecting a
conditioning fluid through first and second wells and into a
formation at dispersed locations along parallel horizontal lengths
of the first and second wells such that the injecting via the first
well is offset in a lateral direction from the second well and
aligned between the dispersed locations of the second well across
from portions of the second well without fluid communication to the
formation; producing the hydrocarbons recovered as backflow at the
dispersed locations along the first and second wells after the
injecting of the conditioning fluid; and then injecting a
displacement fluid into the formation via the dispersed locations
along the first well to sweep the hydrocarbons toward the second
well and while producing, at the dispersed locations along the
second well, the hydrocarbons being displaced.
11. The method according to claim 10, further comprising injecting
the conditioning fluid into the formation via the dispersed
locations along the second well while producing the hydrocarbons at
the dispersed locations along the first well.
12. The method according to claim 10, further comprising, following
simultaneous injection through the first and second wells and
simultaneous production through the first and second wells and
until fluid communication is established between the first well and
the second well, alternating between: injecting the conditioning
fluid into the formation via the dispersed locations along the
second well while producing the hydrocarbons at the dispersed
locations along the first well; and injecting the conditioning
fluid into the formation via the dispersed locations along the
first well while producing the hydrocarbons at the dispersed
locations along the second well.
13. The method according to claim 10, further comprising cycling
multiple times between the injecting of the conditioning fluid and
the producing the hydrocarbons recovered at the dispersed locations
along the first and second wells.
14. The method according to claim 10, wherein the injecting of the
conditioning fluid occurs simultaneously through the first and
second wells and the producing the hydrocarbons recovered as
backflow occurs simultaneously through the first and second
wells.
15. The method according to claim 10, wherein the first and second
wells lack fluid communication with one another across the
formation upon initiating the injecting of the conditioning
fluid.
16. The method according to claim 10, wherein the displacement
fluid includes steam.
17. The method according to claim 10, wherein the displacement
fluid includes at least one constituent selected from solvent for
the hydrocarbons, water, steam, emulsifiers, air, oxygen and carbon
dioxide.
18. The method according to claim 10, wherein the conditioning
fluid is injected alone and consists of a solvent for the
hydrocarbons.
19. The method according to claim 10, wherein the conditioning
fluid includes a solvent for the hydrocarbons that includes a
liquid component under reservoir conditions and a gaseous component
under reservoir conditions.
20. The method according to claim 10, wherein the first and second
wells are spaced between 5 meters and 50 meters apart.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application which
claims benefit under 35 USC .sctn.119(e) to U.S. Provisional
Application Ser. No. 61/683,373 filed Aug. 15, 2012, entitled
"PRECONDITIONING FOR BITUMEN DISPLACEMENT," which is incorporated
herein in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] None.
FIELD OF THE INVENTION
[0003] Embodiments of the invention relate to producing
hydrocarbons with multiple horizontal wells through which injection
processes precondition and displace the hydrocarbons.
BACKGROUND OF THE INVENTION
[0004] Bitumen recovery from oil sands presents technical and
economic challenges due to high viscosity of the bitumen at
reservoir conditions. Steam assisted gravity drainage (SAGD)
provides one process for producing the bitumen from a reservoir.
During SAGD operations, steam introduced into the reservoir through
a horizontal injector well transfers heat upon condensation and
develops a steam chamber in the reservoir. The bitumen with reduced
viscosity due to this heating drains together with steam condensate
along a boundary of the steam chamber and is recovered via a
producer well placed parallel and beneath the injector well.
[0005] However, costs associated with energy requirements for the
SAGD operations limit economic returns and can make thin pay zones
uneconomic to recover. Other past processes proposed to rely on
cyclic injections but failed to recover enough of the bitumen for
commercial success. Further, prior displacement methods utilized in
reservoirs containing mobile hydrocarbons cannot enable recovery of
the bitumen where immobile since the bitumen provides a barrier to
flow between wells.
[0006] Therefore, a need exists for methods and systems for
recovering hydrocarbons from oil sands including thin pay zones of
immobile bitumen.
BRIEF SUMMARY OF THE DISCLOSURE
[0007] In one embodiment, a method of recovering hydrocarbons
includes injecting during a first time a conditioning fluid through
first and second wells and into a formation along lateral spaced
apart and parallel horizontal lengths of the first and second
wells. The method further includes producing the hydrocarbons
recovered as backflow along the lengths of the first and second
wells during a second time after the first time. Then, injecting
the conditioning fluid into the formation along the length of the
second well while producing the hydrocarbons along the length of
the first well alternates with injecting the conditioning fluid
into the formation along the length of the first well while
producing the hydrocarbons along the length of the second well,
thereby establishing fluid communication between the first and
second wells. Next, injecting a displacement fluid into the
formation along the length of the first well sweeps the
hydrocarbons toward the second well and occurs while producing,
along the length of the second well, the hydrocarbons being
displaced.
[0008] For one embodiment, a method of recovering hydrocarbons
includes injecting a conditioning fluid through first and second
wells and into a formation at dispersed locations along parallel
horizontal lengths of the first and second wells such that the
injecting via the first well is offset in a lateral direction from
the second well and aligned between the dispersed locations of the
second well across from portions of the second well without fluid
communication to the formation. Producing the hydrocarbons
recovered as backflow at the dispersed locations along the first
and second wells occurs after the injecting of the conditioning
fluid. Then, injecting a displacement fluid into the formation via
the dispersed locations along the first well sweeps the
hydrocarbons toward the second well and occurs while producing, at
the dispersed locations along the second well, the hydrocarbons
being displaced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A more complete understanding of the present invention and
benefits thereof may be acquired by referring to the follow
description taken in conjunction with the accompanying
drawings.
[0010] FIG. 1 is a schematic of three horizontal wells as viewed
transverse to their horizontal length within a reservoir, according
to one embodiment of the invention.
[0011] FIG. 2 is a schematic top view of the wells with dispersed
flow control along their length and operated in an all injection
cycle as depicted by arrows indicating fluid flow direction,
according to one embodiment of the invention.
[0012] FIG. 3 is a schematic of the wells depicted in an all
production cycle subsequent to the all injection cycle, according
to one embodiment of the invention.
[0013] FIG. 4 is a schematic of the wells depicted in a first
alternating injection and production cycle subsequent to the all
injection and the all production cycles, according to one
embodiment of the invention.
[0014] FIG. 5 is a schematic of the wells depicted in a second
alternating injection and production cycle opposite and subsequent
to the first alternating injection and production cycle, according
to one embodiment of the invention.
[0015] FIG. 6 is a schematic of the wells depicted in a final
displacement operation once fluid communication is established
between the wells, according to one embodiment of the
invention.
[0016] FIG. 7 is a schematic of the wells with resulting sweep of
the reservoir by the final displacement operation shown by areas
within dashed lines, according to one embodiment of the
invention.
DETAILED DESCRIPTION
[0017] Turning now to the detailed description of the preferred
arrangement or arrangements of the present invention, it should be
understood that the inventive features and concepts may be
manifested in other arrangements and that the scope of the
invention is not limited to the embodiments described or
illustrated. The scope of the invention is intended only to be
limited by the scope of the claims that follow.
[0018] For some embodiments, methods and systems produce petroleum
products with multiple horizontal wells through which injection
processes precondition and displace the hydrocarbons in a
formation. The wells extend through the formation spaced apart from
one another in a lateral direction. Before fluid communication is
established between the wells, cyclic injections and production of
resulting backflow initiates conditioning of immobile products.
Alternating between injection and production at adjacent wells may
then facilitate establishing the fluid communication. After the
fluid communication is established, a displacement procedure sweeps
the hydrocarbons from one of the wells used for injection toward an
adjacent one of the wells used for production.
[0019] FIG. 1 illustrates a formation 100 defining a hydrocarbon
reservoir bounded between a bottom layer 101 and a top layer 102.
While methods disclosed herein are applicable even if the formation
100 is greater than 15 meters, the formation 100 in some
embodiments extends in height less than 15 meters, thereby limiting
commercial applications of processes such as steam assisted gravity
drainage. A first well 111, a second well 112 and a third well 113
each include horizontal lengths that pass through the formation
100.
[0020] As shown viewed transverse to the horizontal lengths, all
the wells 111, 112, 113 in some embodiments align in a common
horizontal plane or otherwise have the horizontal length in
substantial horizontal alignment with one another. A lateral
distance of between 5 and 50 meters may separate the wells 111,
112, 113 from one another. Costs of cycling depicted and described
with respect to FIGS. 2 and 3 and accompanying revenue may
influence duration of such cycling with longer durations enabling
wider lateral separation, even greater than 50 meters, between the
wells 111, 112, 113. The second well 112 extends between and is
adjacent the first well 111 and the third well 113 without any
additional intervening wells disposed between any of the wells 111,
112, 113. As visible in FIGS. 2-7, the horizontal lengths of the
wells 111, 112, 113 may extend parallel to one another.
[0021] FIG. 2 shows the wells 111, 112, 113 operated in an all
injection cycle as depicted by arrows indicating fluid flow
direction. The all injection cycle may initiate while the wells
111, 112, 113 lack fluid communication with one another across the
formation and may be an initial operation of the wells 111, 112,
113. The arrows in the all injection cycle indicate simultaneous
injection of a conditioning fluid into the formation along the
horizontal lengths of each of the wells 111, 112, 113.
[0022] For some embodiments, flow control devices 200 dispersed
along the horizontal lengths of the wells 111, 112, 113 facilitate
uniform or patterned injection and/or production along the
horizontal lengths of the wells 111, 112, 113. The flow control
devices 200 provide fluid communication from inside the wells 111,
112, 113 to the formation and can include orifices, perforations or
slots in tubing or liner, well screen or other tortuous flow path
assemblies. Valves or other metering devices may control inflow
and/or outflow from the flow control devices 200.
[0023] Solid wall lined portions 201 of the horizontal lengths of
the wells 111, 112, 113 may prevent fluid communication from inside
the wells 111, 112, 113 to the formation. The lined portions 201
without fluid communication to the formation may separate the flow
control devices 200 from one another along the horizontal lengths
of the wells 111, 112, 113. In some embodiments, the flow control
devices 200 of the first well 111 align between the flow control
devices 200 of the second well 112 and across from the lined
portions 201 of the second well 112. The flow control devices 200
of the third well 113 may also align across from the flow control
devices 200 of the first well 111.
[0024] In some embodiments, the conditioning fluid as referred to
herein and used in the all injection cycle can be any fluid capable
of reducing viscosity or increasing mobility of the hydrocarbons by
dissolving into the hydrocarbons and/or transferring heat to the
hydrocarbons. The conditioning fluid may however not rely on any
thermal application and may consist of only a solvent for the
hydrocarbons. Economics may not support applying heat to the
hydrocarbons with the conditioning fluid due to factors such
thickness or extent of the formation.
[0025] For example, the solvent may be a lighter hydrocarbon than
contained in the formation and may have 1 to 20 carbon atoms
(C.sub.1-C.sub.20) or 1 to 4 carbon atoms (C.sub.1-C.sub.4) per
molecule, or any mixture thereof. Examples of C.sub.1 to C.sub.4
hydrocarbon solvents include methane, ethane, propane and/or
butane. The hydrocarbon solvent used as the conditioning fluid can
be introduced into the formation as a gas or as a liquid regardless
of its phase under reservoir conditions.
[0026] Composition of the conditioning fluid may also transition
during any injection operation disclosed herein. For example, the
all injection cycle may first utilize a liquid hydrocarbon solvent
under reservoir conditions, such as diesel, for the conditioning
fluid followed by a gaseous solvent under reservoir conditions,
such as a mix of propane and carbon dioxide, for the conditioning
fluid. Injecting the propane as a liquid may further provide drive
energy upon flashing to gas in the formation to facilitate
subsequent recovery.
[0027] FIG. 3 illustrates the wells 111, 112, 113 operated in an
all production cycle during a subsequent time interval to the all
injection cycle shown in FIG. 2. The arrows in the all production
cycle indicate simultaneous recovery of the hydrocarbons along the
horizontal lengths of each of the wells 111, 112, 113. Since the
wells 111, 112, 113 still lack fluid communication with one
another, the hydrocarbons can only backflow along with accompanying
conditioning fluid to each of the wells 111, 112, 113.
[0028] The flow control devices 200 permit controlled inflow of the
hydrocarbons into the wells 111, 112, 113 at where dispersed along
the horizontal lengths of the wells 111, 112, 113. Processing the
hydrocarbons produced to surface during the all production cycle
may separate out the conditioning fluid for recycle. In some
embodiments, cycling during additional time intervals between the
all injection cycle shown in FIG. 2 and the all production cycle
illustrated in FIG. 3 continues for multiple times and facilitates
even distribution of the conditioning fluid injected into the
formation.
[0029] FIG. 4 shows the wells 111, 112, 113 operated in a first
alternating injection and production cycle subsequent to the all
injection and the all production cycles. In the first alternating
injection and production cycle, injecting the conditioning fluid
through the second well 112 and out the flow control devices 200
along the horizontal length thereof occurs while producing the
hydrocarbons recovered through the flow control devices of the
first and third wells 111, 113. As evident, the third well 113
mirrors the first well 111 in function and arrangement and just
provides a more complete picture of how further alternating well
arrangements, i.e., the first well 111 and the second well 112,
could continue to be disposed across the formation.
[0030] FIG. 5 illustrates the wells 111, 112, 113 operated in a
second alternating injection and production cycle opposite and
subsequent to the first alternating injection and production cycle.
Specifically, injecting the conditioning fluid through the first
and third wells 111, 113 and out the flow control devices 200 along
the horizontal lengths thereof occurs while producing the
hydrocarbons recovered through the flow control devices of the
second well 112. For some embodiments, cycling during additional
time intervals between the alternating injection and production
cycles shown in FIGS. 4 and 5 continues for multiple times and
facilitates establishing fluid communication between the wells 111,
112, 113.
[0031] FIG. 6 shows the wells 111, 112, 113 operated in a final
displacement operation once fluid communication is established
between the wells subsequent to operations illustrated in FIGS.
2-5. The arrows for the displacement operation indicate injection
of a displacement fluid through the second well 112 and out the
flow control devices 200 along the horizontal length thereof while
producing the hydrocarbons recovered through the flow control
devices of the first and third wells 111, 113. While the second
well 112 for explanation purposes is selected for injection in the
final displacement operation, direction of the arrows in FIG. 6 may
match either FIG. 4 or FIG. 5.
[0032] Examples of the displacement fluid include gases or liquids
capable of pushing the hydrocarbons through the formation. The
displacement fluid may in some embodiments also facilitate recovery
by further decreasing viscosity of the hydrocarbons in the
formation. The displacement fluid may contain like constituents as
the conditioning fluid described herein and which may likewise
include any constituent described herein for use as the
displacement fluid.
[0033] For some embodiments, the displacement fluid includes any
combination of gaseous or liquid solvents for the hydrocarbons,
water, steam, emulsifiers (e.g., surfactants, alkalis, polymers),
air, oxygen and carbon dioxide. Heating any of the fluids used for
the displacement fluid enables heat transfer to the hydrocarbons
for viscosity reduction. Injection of combustibles, such as air or
oxygen, as the displacement fluid enables starting in situ
combustion during the displacement operation for recovery, which
depends on the fluid communication being established between the
wells 111, 112, 113.
[0034] FIG. 7 illustrates the wells 111, 112, 113 with resulting
sweep of the formation by the displacement operation shown by areas
within dashed lines. The displacement operation thus drives the
hydrocarbons that are now mobile toward the first and third wells
111, 113 for recovery. The displacement operation recovers the
hydrocarbons not produced during the operations shown in FIGS. 2-5
to gain desired cumulative recovery needed for commercial
success.
[0035] In closing, it should be noted that the discussion of any
reference is not an admission that it is prior art to the present
invention, especially any reference that may have a publication
date after the priority date of this application. At the same time,
each and every claim below is hereby incorporated into this
detailed description or specification as an additional embodiment
of the present invention.
[0036] Although the systems and processes described herein have
been described in detail, it should be understood that various
changes, substitutions, and alterations can be made without
departing from the spirit and scope of the invention as defined by
the following claims. Those skilled in the art may be able to study
the preferred embodiments and identify other ways to practice the
invention that are not exactly as described herein. It is the
intent of the inventors that variations and equivalents of the
invention are within the scope of the claims, while the
description, abstract and drawings are not to be used to limit the
scope of the invention. The invention is specifically intended to
be as broad as the claims below and their equivalents.
* * * * *