U.S. patent application number 12/743314 was filed with the patent office on 2011-05-12 for systems and methods for producing oil and/or gas.
Invention is credited to Carolus Matthias Anna Maria Mesters, Patrick Guy Monin, Gerard Mulder, Raul Valdez, Claudia Van Den Berg, Kees Van Gelder, Dean Chien Wang.
Application Number | 20110108269 12/743314 |
Document ID | / |
Family ID | 40470034 |
Filed Date | 2011-05-12 |
United States Patent
Application |
20110108269 |
Kind Code |
A1 |
Van Den Berg; Claudia ; et
al. |
May 12, 2011 |
SYSTEMS AND METHODS FOR PRODUCING OIL AND/OR GAS
Abstract
A system for producing oil and/or gas from an underground
formation comprising a first array of wells dispersed above the
formation; a second array of wells dispersed above the formation;
wherein the first array of wells comprises a mechanism to inject a
miscible enhanced oil recovery formulation into the formation while
the second array of wells comprises a mechanism to produce oil
and/or gas from the formation for a first time period; a means to
convert at least a portion of the miscible enhanced oil recovery
formulation within the formation into another compound during a
second time period; and a means to recover at least a portion of
the another compound during a third time period.
Inventors: |
Van Den Berg; Claudia;
(Hazerswoude Rijndijk, NL) ; Van Gelder; Kees;
(Rijswijk, NL) ; Mesters; Carolus Matthias Anna
Maria; (Amsterdam, NL) ; Monin; Patrick Guy;
(Den Haag, FR) ; Mulder; Gerard; (The Hague,
NL) ; Valdez; Raul; (Bellaire, TX) ; Wang;
Dean Chien; (Missouri City, TX) |
Family ID: |
40470034 |
Appl. No.: |
12/743314 |
Filed: |
November 18, 2008 |
PCT Filed: |
November 18, 2008 |
PCT NO: |
PCT/US08/83843 |
371 Date: |
December 16, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60988844 |
Nov 19, 2007 |
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Current U.S.
Class: |
166/266 ;
166/52 |
Current CPC
Class: |
E21B 43/30 20130101;
C09K 8/594 20130101; E21B 43/16 20130101 |
Class at
Publication: |
166/266 ;
166/52 |
International
Class: |
E21B 43/34 20060101
E21B043/34; E21B 43/00 20060101 E21B043/00 |
Claims
1. A system for producing oil and/or gas from an underground
formation comprising: a first array of wells dispersed above the
formation; and a second array of wells dispersed above the
formation; wherein the first array of wells comprises a mechanism
to inject a miscible enhanced oil recovery formulation into the
formation while the second array of wells comprises a mechanism to
produce oil and/or gas from the formation for a first time period;
a means to convert at least a portion of the miscible enhanced oil
recovery formulation within the formation into another compound
during a second time period; and a means to recover at least a
portion of the another compound during a third time period.
2. The system of claim 1, wherein a well in the first array of
wells is at a distance of 10 meters to 1 kilometer from one or more
adjacent wells in the second array of wells.
3. The system of claim 1, wherein the underground formation is
beneath a body of water.
4. The system of claim 1, further comprising a mechanism for
injecting an immiscible enhanced oil recovery formulation into the
formation, after the miscible enhanced oil recovery formulation has
been released into the formation.
5. The system of claim 1 further comprising a miscible enhanced oil
recovery formulation selected from the group consisting of a carbon
disulfide formulation, hydrogen sulfide, carbon dioxide, octane,
pentane, LPG, C2-C6 aliphatic hydrocarbons, nitrogen, diesel,
mineral spirits, naptha solvent, asphalt solvent, kerosene,
acetone, xylene, trichloroethane, and mixtures thereof.
6. The system of claim 1, further comprising an immiscible enhanced
oil recovery formulation selected from the group consisting of
water in gas or liquid form, air, and mixtures thereof.
7. The system of claim 1, wherein the first array of wells
comprises from 5 to 500 wells, and the second array of wells
comprises from 5 to 500 wells.
8. The system of claim 1, further comprising a miscible enhanced
oil recovery formulation comprising a carbon disulfide
formulation.
9. The system of claim 1, further comprising a mechanism for
producing a carbon disulfide formulation.
10. The system of claim 1, wherein the underground formation
comprises an oil having a viscosity from 100 to 5,000,000
centipoise.
11. The system of claim 1, wherein the first array of wells
comprises a miscible enhanced oil recovery formulation profile in
the formation, and the second array of wells comprises an oil
recovery profile in the formation, the system further comprising an
overlap between the miscible enhanced oil recovery formulation
profile and the oil recovery profile.
12. The system of claim 1, wherein the miscible enhanced oil
recovery formulation comprises carbon disulfide.
13. The system of claim 1, wherein the another compound comprises
hydrogen sulfide.
14. The system of claim 1, wherein the means to recover at least a
portion of the another compound comprises a well to collect the
another compound and convey the another compound from within the
formation to a position above the formation.
15. The system of claim 1, wherein the means to recover at least a
portion of the another compound comprises a well to inject a
remediation agent into the formation to displace the another
compound from within the formation towards one or more other
wells.
16. A method for producing oil and/or gas comprising: injecting a
carbon disulfide formulation into a formation for a first time
period from a first well; producing oil and/or gas from the
formation from a second well for the first time period; converting
at least a portion of the carbon disulfide formulation into another
compound in situ at a conclusion of the producing oil and/or gas
from the formation; and recovering at least a portion of the
another compound from the formation.
17. The method of claim 16, further comprising recovering carbon
disulfide formulation from the oil and/or gas, if present, and then
injecting at least a portion of the recovered carbon disulfide
formulation into the formation.
18. The method of claim 16, wherein injecting the carbon disulfide
formulation comprises injecting at least a portion of the carbon
disulfide formulation into the formation in a mixture with one or
more of hydrocarbons; sulfur compounds other than carbon disulfide;
carbon dioxide; carbon monoxide; or mixtures thereof.
19. The methods of claim 16, further comprising heating the carbon
disulfide formulation prior to injecting the carbon disulfide
formulation into the formation, or while within the formation.
20. The method of claim 16, wherein the carbon disulfide
formulation is injected at a pressure from 0 to 37,000 kilopascals
above the initial reservoir pressure, measured prior to when carbon
disulfide injection begins.
21. The method of claim 16, wherein the underground formation
comprises a permeability from 0.0001 to 15 Darcies, for example a
permeability from 0.001 to 1 Darcy.
22. The method of claim 16, wherein any oil, as present in the
underground formation prior to the injecting the carbon disulfide
formulation, has a sulfur content from 0.5% to 5%, for example from
1% to 3%.
23. The method of claim 16, further comprising converting at least
a portion of the recovered oil and/or gas into a material selected
from the group consisting of transportation fuels such as gasoline
and diesel, heating fuel, lubricants, chemicals, and/or
polymers.
24. The method of claim 16, further comprising: injecting a
remediation agent into the formation for a second time period from
the second well; and producing the another compound from the
formation from the first well for the second time period.
25. The method of claim 24, wherein the remediation agent comprises
a material selected from the group consisting of water, water and a
surfactant, carbon dioxide, air, and natural gas.
26. The method of claim 24, wherein the remediation agent comprises
water and a polymer dissolved in the water.
27. The method of claim 16, wherein converting at least a portion
of the carbon disulfide formulation into another compound comprises
injecting at least one of steam, water, and peroxide into the
formation.
28. A method for producing oil and/or gas comprising: injecting a
miscible enhanced oil recovery formulation into a formation for a
first time period from a first well; producing oil and/or gas from
the formation from a second well for the first time period;
converting at least a portion of the miscible enhanced oil recovery
formulation into another compound within the formation after a
conclusion of the producing oil and/or gas from the formation; and
producing at least a portion of the another compound from the
formation.
29. The method of claim 28, further comprising: injecting an
immiscible enhanced oil recovery formulation into the formation for
a time period after the first time period from the first well, to
push the miscible enhanced oil recovery formulation through the
formation.
30. The method of claim 28, wherein the produced oil and/or gas
comprises a sulfur compound, further comprising converting at least
a portion of the sulfur compound into a miscible enhanced oil
recovery formulation.
31. The method of claim 28, wherein the miscible enhanced oil
recovery formulation comprises a carbon disulfide formulation.
32. The method of claim 28, wherein the another compound comprises
hydrogen sulfide.
33. The method of claim 28, further comprising heating the miscible
enhanced oil recovery formulation.
34. The method of claim 28, further comprising: injecting a
remediation agent into the formation for a second time period from
the second well; and producing the another compound from the
formation from the first well for the second time period.
35. The method of claim 34, wherein the remediation agent comprises
at least one of water and carbon dioxide.
Description
FIELD OF THE INVENTION
[0001] The present disclosure relates to systems and methods for
producing oil and/or gas.
BACKGROUND OF THE INVENTION
[0002] Enhanced Oil Recovery (EOR) may be used to increase oil
recovery in fields worldwide. There are three main types of EOR,
thermal, chemical/polymer and gas injection, which may be used to
increase oil recovery from a reservoir, beyond what can be achieved
by conventional means--possibly extending the life of a field and
boosting the oil recovery factor.
[0003] Thermal enhanced recovery works by adding heat to the
reservoir. The most widely practiced form is a steamdrive, which
reduces oil viscosity so that it can flow to the producing wells.
Chemical flooding increases recovery by reducing the capillary
forces that trap residual oil. Polymer flooding improves the sweep
efficiency of injected water. Miscible injection works in a similar
way to chemical flooding. By injecting a fluid that is miscible
with the oil, trapped residual oil can be recovered.
[0004] Referring to FIG. 1, there is illustrated prior art system
100. System 100 includes underground formation 102, underground
formation 104, underground formation 106, and underground formation
108. Production facility 110 is provided at the surface. Well 112
traverses formations 102 and 104, and terminates in formation 106.
The portion of formation 106 is shown at 114. Oil and gas are
produced from formation 106 through well 112, to production
facility 110. Gas and liquid are separated from each other, gas is
stored in gas storage 116 and liquid is stored in liquid storage
118.
[0005] U.S. Pat. No. 5,826,656 discloses a method for recovering
waterflood residual oil from a waterflooded oil-bearing
subterranean formation penetrated from an earth surface by at least
one well by injecting an oil miscible solvent into a waterflood
residual oil-bearing lower portion of the oil-bearing subterranean
formation through a well completed for injection of the oil
miscible solvent into the lower portion of the oil-bearing
formation; continuing the injection of the oil miscible solvent
into the lower portion of the oil-bearing formation for a period of
time equal to at least one week; recompleting the well for
production of quantities of the oil miscible solvent and quantities
of waterflood residual oil from an upper portion of the oil-bearing
formation; and producing quantities of the oil miscible solvent and
waterflood residual oil from the upper portion of the oil-bearing
formation. The formation may have previously been both waterflooded
and oil miscible solvent flooded. The solvent may be injected
through a horizontal well and solvent and oil may be recovered
through a plurality of wells completed to produce oil and solvent
from the upper portion of the oil-bearing formation. U.S. Pat. No.
5,826,656 is herein incorporated by reference in its entirety.
[0006] Co-pending U.S. Patent Application Publication Number
2006/0254769, published Nov. 16, 2006, and having attorney docket
number TH2616, discloses a system including a mechanism for
recovering oil and/or gas from an underground formation, the oil
and/or gas comprising one or more sulfur compounds; a mechanism for
converting at least a portion of the sulfur compounds from the
recovered oil and/or gas into a carbon disulfide formulation; and a
mechanism for releasing at least a portion of the carbon disulfide
formulation into a formation. U.S. Patent Application Publication
Number 2006/0254769 is herein incorporated by reference in its
entirety.
[0007] WO International Publication Number 03/095118 A1 discloses
methods of remediating carbon disulfide contaminated soil by
contacting the soil with iron.
[0008] WO International Publication Number 03/095118 A1 is herein
incorporated by reference in its entirety.
[0009] There is a need in the art for improved systems and methods
for enhanced oil recovery. There is a further need in the art for
improved systems and methods for enhanced oil recovery using a
solvent, for example through viscosity reduction, chemical effects,
and miscible flooding. There is a further need in the art for
improved systems and methods for solvent miscible flooding. There
is a further need in the art for improved systems and methods for
recovering a solvent after miscible flooding. There is a need in
the art for remediation of a formation after a miscible solvent
flooding operation.
SUMMARY OF THE INVENTION
[0010] In one aspect, the invention provides a system for producing
oil and/or gas from an underground formation comprising a first
array of wells dispersed above the formation; a second array of
wells dispersed above the formation; wherein the first array of
wells comprises a mechanism to inject a miscible enhanced oil
recovery formulation into the formation while the second array of
wells comprises a mechanism to produce oil and/or gas from the
formation for a first time period; a means to convert at least a
portion of the miscible enhanced oil recovery formulation within
the formation into another compound during a second time period;
and a means to recover at least a portion of the another compound
during a third time period.
[0011] In another aspect, the invention provides a method for
producing oil and/or gas comprising injecting a carbon disulfide
formulation into a formation for a first time period from a first
well; producing oil and/or gas from the formation from a second
well for the first time period; converting at least a portion of
the carbon disulfide formulation into another compound in situ at a
conclusion of the producing oil and/or gas from the formation; and
recovering at least a portion of the another compound from the
formation.
[0012] In another aspect, the invention provides a method for
producing oil and/or gas comprising injecting a miscible enhanced
oil recovery formulation into a formation for a first time period
from a first well; producing oil and/or gas from the formation from
a second well for the first time period; converting at least a
portion of the miscible enhanced oil recovery formulation into
another compound within the formation after a conclusion of the
producing oil and/or gas from the formation; and producing at least
a portion of the another compound from the formation.
[0013] Advantages of the invention include one or more of the
following:
[0014] Improved systems and methods for enhanced recovery of
hydrocarbons from a formation with a solvent.
[0015] Improved systems and methods for enhanced recovery of
hydrocarbons from a formation with a fluid containing a miscible
solvent.
[0016] Improved compositions and/or techniques for secondary
recovery of hydrocarbons.
[0017] Improved systems and methods for enhanced oil recovery.
[0018] Improved systems and methods for enhanced oil recovery using
a miscible solvent.
[0019] Improved systems and methods for enhanced oil recovery using
a compound which may be miscible with oil in place.
[0020] Improved systems and methods for recovering a compound which
may be miscible with oil in place.
[0021] Improved systems and methods for remediation of a formation
which has been flooded with a compound which may be miscible with
oil in place
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 illustrates an oil and/or gas production system.
[0023] FIG. 2a illustrates a well pattern.
[0024] FIGS. 2b and 2c illustrate the well pattern of FIG. 2a
during enhanced oil recovery processes.
[0025] FIGS. 3a-3c illustrate oil and/or gas production
systems.
DETAILED DESCRIPTION OF THE INVENTION
[0026] FIG. 2a:
[0027] Referring now to FIG. 2a, in some embodiments, an array of
wells 200 is illustrated. Array 200 includes well group 202
(denoted by horizontal lines) and well group 204 (denoted by
diagonal lines).
[0028] Each well in well group 202 has horizontal distance 230 from
the adjacent well in well group 202. Each well in well group 202
has vertical distance 232 from the adjacent well in well group
202.
[0029] Each well in well group 204 has horizontal distance 236 from
the adjacent well in well group 204. Each well in well group 204
has vertical distance 238 from the adjacent well in well group
204.
[0030] Each well in well group 202 is distance 234 from the
adjacent wells in well group 204. Each well in well group 204 is
distance 234 from the adjacent wells in well group 202.
[0031] Each well in well group 202 may be surrounded by four wells
in well group 204. Each well in well group 204 may be surrounded by
four wells in well group 202.
[0032] Horizontal distance 230 is from about 5 to about 1000
meters, or from about 10 to about 500 meters, or from about 20 to
about 250 meters, or from about 30 to about 200 meters, or from
about 50 to about 150 meters, or from about 90 to about 120 meters,
or about 100 meters.
[0033] Vertical distance 232 may be from about 5 to about 1000
meters, or from about 10 to about 500 meters, or from about 20 to
about 250 meters, or from about 30 to about 200 meters, or from
about 50 to about 150 meters, or from about 90 to about 120 meters,
or about 100 meters.
[0034] Horizontal distance 236 may be from about 5 to about 1000
meters, or from about 10 to about 500 meters, or from about 20 to
about 250 meters, or from about 30 to about 200 meters, or from
about 50 to about 150 meters, or from about 90 to about 120 meters,
or about 100 meters.
[0035] Vertical distance 238 may be from about 5 to about 1000
meters, or from about 10 to about 500 meters, or from about 20 to
about 250 meters, or from about 30 to about 200 meters, or from
about 50 to about 150 meters, or from about 90 to about 120 meters,
or about 100 meters.
[0036] Distance 234 may be from about 5 to about 1000 meters, or
from about 10 to about 500 meters, or from about 20 to about 250
meters, or from about 30 to about 200 meters, or from about 50 to
about 150 meters, or from about 90 to about 120 meters, or about
100 meters.
[0037] Array of wells 200 may have from about 10 to about 1000
wells, for example from about 5 to about 500 wells in well group
202, and from about 5 to about 500 wells in well group 204.
[0038] Array of wells 200 may be seen as a top view with well group
202 and well group 204 being vertical wells spaced on a piece of
land. Array of wells 200 may be seen as a cross-sectional side view
with well group 202 and well group 204 being horizontal wells
spaced within a formation.
[0039] The recovery of oil and/or gas with array of wells 200 from
an underground formation may be accomplished by any known method.
Suitable methods include subsea production, surface production,
primary, secondary, or tertiary production. The selection of the
method used to recover the oil and/or gas from the underground
formation is not critical.
[0040] FIG. 2b:
[0041] Referring now to FIG. 2b, in some embodiments, array of
wells 200 is illustrated. Array 200 includes well group 202
(denoted by horizontal lines) and well group 204 (denoted by
diagonal lines).
[0042] In some embodiments, a miscible enhanced oil recovery agent
may be injected into well group 204, and oil may be recovered from
well group 202. As illustrated, the miscible enhanced oil recovery
agent has injection profile 208, and oil recovery profile 206 is
being produced to well group 202.
[0043] A miscible enhanced oil recovery agent may be injected into
well group 202, and oil may be recovered from well group 204. As
illustrated, the miscible enhanced oil recovery agent has injection
profile 206, and oil recovery profile 208 is being produced to well
group 204.
[0044] Well group 202 may be used for injecting a miscible enhanced
oil recovery agent, and well group 204 may be used for producing
oil and/or gas from the formation for a first time period; then
well group 204 may be used for injecting a miscible enhanced oil
recovery agent, and well group 202 may be used for producing oil
and/or gas from the formation for a second time period, where the
first and second time periods comprise a cycle.
[0045] Multiple cycles may be conducted which include alternating
well groups 202 and 204 between injecting a miscible enhanced oil
recovery agent, and producing oil and/or gas from the formation,
where one well group may be injecting and the other may be
producing for a first time period, and then they are switched for a
second time period.
[0046] A cycle may be from about 12 hours to about 1 year, or from
about 3 days to about 6 months, or from about 5 days to about 3
months. Each cycle may increase in time, for example each cycle may
be from about 5% to about 10% longer than the previous cycle, for
example about 8% longer.
[0047] A miscible enhanced oil recovery agent or a mixture
including a miscible enhanced oil recovery agent may be injected at
the beginning of a cycle, and an immiscible enhanced oil recovery
agent or a mixture including an immiscible enhanced oil recovery
agent may be injected at the end of the cycle. The beginning of a
cycle may be the first 10% to about 80% of a cycle, or the first
20% to about 60% of a cycle, the first 25% to about 40% of a cycle,
and the end may be the remainder of the cycle.
[0048] FIG. 2c:
[0049] Referring now to FIG. 2c, in some embodiments, array of
wells 200 is illustrated. Array 200 includes well group 202
(denoted by horizontal lines) and well group 204 (denoted by
diagonal lines).
[0050] A miscible enhanced oil recovery agent may be injected into
well group 204, and oil may be recovered from well group 202. As
illustrated, the miscible enhanced oil recovery agent has injection
profile 208 with overlap 210 with oil recovery profile 206, which
is being produced to well group 202.
[0051] A miscible enhanced oil recovery agent may be injected into
well group 202, and oil may be recovered from well group 204. As
illustrated, the miscible enhanced oil recovery agent has injection
profile 206 with overlap 210 with oil recovery profile 208, which
is being produced to well group 204.
[0052] In order to recover miscible enhanced oil recovery agent
from injection profile 206 back to well group 202, a remediation
agent may be injected into well group 204, after the oil recovery
from well group 204 has been completed. Suitable remediation agents
are discussed below.
[0053] In order to clean the formation after a miscible oil flood,
the miscible enhanced oil recovery agent may be converted in situ
within injection profile 206 into another compound, and then the
other compound may be recovered. Suitable methods for the
conversion of the miscible enhanced oil recovery agent are
discussed below.
[0054] FIGS. 3a and 3b:
[0055] Referring now to FIGS. 3a and 3b, in some embodiments of the
invention, system 300 is illustrated. System 300 includes
underground formation 302, underground formation 304, underground
formation 306, and underground formation 308. Facility 310 may be
provided at the surface. Well 312 traverses formations 302 and 304,
and has openings in formation 306. Portions 314 of formation 306
may be optionally fractured and/or perforated. During primary
production, oil and gas from formation 306 may be produced into
portions 314, into well 312, and travels up to facility 310.
Facility 310 then separates gas, which may be sent to gas
processing 316, and liquid, which may be sent to liquid storage
318. Facility 310 also includes miscible enhanced oil recovery
formulation storage 330. As shown in FIG. 3a, miscible enhanced oil
recovery formulation may be pumped down well 312 that is shown by
the down arrow and pumped into formation 306. Miscible enhanced oil
recovery formulation may be left to soak in formation for a period
of time from about 1 hour to about 15 days, for example from about
5 to about 50 hours.
[0056] After the soaking period, as shown in FIG. 3b, miscible
enhanced oil recovery formulation and oil and/or gas may be then
produced back up well 312 to facility 310. Facility 310 may be
adapted to separate and/or recycle miscible enhanced oil recovery
formulation, for example by boiling the formulation, condensing it
or filtering or reacting it, then re-injecting the formulation into
well 312, for example by repeating the soaking cycle shown in FIGS.
3a and 3b from about 2 to about 5 times.
[0057] In some embodiments, miscible enhanced oil recovery
formulation may be pumped into formation 306 below the fracture
pressure of the formation, for example from about 40% to about 90%
of the fracture pressure.
[0058] Well 312, as shown in FIG. 3a, injecting into formation 306
may be representative of a well in well group 202, and well 312 as
shown in FIG. 3b producing from formation 306 may be representative
of a well in well group 204.
[0059] Well 312, as shown in FIG. 3a, injecting into formation 306
may be representative of a well in well group 204, and well 312 as
shown in FIG. 3b producing from formation 306 may be representative
of a well in well group 202.
[0060] In order to recover miscible enhanced oil recovery agent
from formation 306 back to well 312, a remediation agent may be
injected into another adjacent well (not shown), after the oil
recovery from formation 306 has been completed. Suitable
remediation agents are discussed below.
[0061] In order to clean the formation after a miscible oil flood,
the miscible enhanced oil recovery agent may be converted in situ
within formation 306 into another compound, and then the other
compound recovered from well 312. Suitable methods for the
conversion of the miscible enhanced oil recovery agent are
discussed below.
[0062] FIG. 3c:
[0063] Referring now to FIG. 3c, in some embodiments of the
invention, system 400 is illustrated. System 400 includes
underground formation 402, formation 404, formation 406, and
formation 408. Production facility 410 may be provided at the
surface. Well 412 traverses formation 402 and 404 has openings at
formation 406. Portions of formation 414 may be optionally
fractured and/or perforated. As oil and gas is produced from
formation 406 it enters portions 414, and travels up well 412 to
production facility 410. Gas and liquid may be separated, and gas
may be sent to gas storage 416, and liquid may be sent to liquid
storage 418. Production facility 410 may be able to produce and/or
store miscible enhanced oil recovery formulation, which may be
produced and stored in production/storage 430. Hydrogen sulfide
and/or other sulfur containing compounds from well 412 may be sent
to miscible enhanced oil recovery formulation production/storage
430. Miscible enhanced oil recovery formulation may be pumped down
well 432, to portions 434 of formation 406. Miscible enhanced oil
recovery formulation traverses formation 406 to aid in the
production of oil and gas, and then the miscible enhanced oil
recovery formulation, oil and/or gas may all be produced to well
412, to production facility 410. Miscible enhanced oil recovery
formulation may then be recycled, for example by boiling the
formulation, condensing it or filtering or reacting it, then
re-injecting the formulation into well 432.
[0064] In some embodiments, a quantity of miscible enhanced oil
recovery formulation or miscible enhanced oil recovery formulation
mixed with other components may be injected into well 432, followed
by another component to force miscible enhanced oil recovery
formulation or miscible enhanced oil recovery formulation mixed
with other components across formation 406, for example air; water
in gas or liquid form; water mixed with one or more salts,
polymers, and/or surfactants; carbon dioxide; other gases; other
liquids; and/or mixtures thereof.
[0065] In some embodiments, well 412 which is producing oil and/or
gas may be representative of a well in well group 202, and well 432
which is being used to inject miscible enhanced oil recovery
formulation may be representative of a well in well group 204.
[0066] In some embodiments, well 412 which is producing oil and/or
gas may be representative of a well in well group 204, and well 432
which is being used to inject miscible enhanced oil recovery
formulation may be representative of a well in well group 202.
[0067] In order to recover miscible enhanced oil recovery agent
from formation 406 back to well 432, a remediation agent may be
injected into well 412, after the oil recovery from formation 406
and well 412 has been completed. Suitable remediation agents are
discussed below.
[0068] In order to clean the formation after a miscible oil flood,
the miscible enhanced oil recovery agent may be converted in situ
within formation 406 into another compound, and then the other
compound recovered from the formation 406. Suitable methods for the
conversion of the miscible enhanced oil recovery agent are
discussed below.
[0069] Remediation Agents:
[0070] Suitable remediation agents include water in liquid or vapor
form, foams, aqueous surfactant solutions, aqueous polymer
solutions, carbon dioxide, natural gas, and/or other hydrocarbons,
and mixtures thereof.
[0071] In one embodiment, suitable remediation agents include
aqueous surfactant solutions. Suitable aqueous surfactant solutions
are disclosed in U.S. Pat. No. 3,943,160; U.S. Pat. No. 3,946,812;
U.S. Pat. No. 4,077,471; U.S. Pat. No. 4,216,079; U.S. Pat. No.
5,318,709; U.S. Pat. No. 5,723,423; U.S. Pat. No. 6,022,834; U.S.
Pat. No. 6,269,881; and by Wellington, et al. in "Low Surfactant
Concentration Enhanced Waterflooding," Society of Petroleum
Engineers, 1995; all of which are incorporated by reference
herein.
[0072] As discussed above, a remediation agent may be introduced
into the formation after the completion of the miscible solvent
flooding process in order to produce as much of the miscible
solvent as possible.
[0073] In Situ Conversion
[0074] In some embodiments, any miscible solvent remaining within
the formation after the completion of the enhanced oil recovery
operation, and after an optional remediation agent flooding
operation, may be converted in situ (within the formation) into a
different compound.
[0075] Hydrogen Sulfide Formation:
[0076] In one example, the miscible solvent may include a carbon
disulfide formulation. The carbon disulfide may be hydrolyzed
within the formation into hydrogen sulfide, for example by the
addition of oxygen, water, steam, peroxides, and/or heat.
Optionally, one or more catalysts such as alumina and/or titania,
for example in a solution, as a powder, or as a suspension in water
or other fluids may be introduced into the formation in order to
catalyze the reaction from carbon disulfide to hydrogen
sulfide.
[0077] The carbon disulfide can be converted to hydrogen sulfide by
any reaction or mechanism. The selection of the reaction or
mechanism is not critical. One suitable mechanism by which the
carbon disulfide is hydrolyzed to hydrogen sulfide is a known
reaction, which has the formula:
CS.sub.2+2H.sub.2O.fwdarw.2H.sub.2S+CO.sub.2 (Formula 1)
[0078] The hydrogen sulfide may then be recovered from one or more
wells. In order to recover the hydrogen sulfide from the formation,
water, air, carbon dioxide, or one or more other liquids or gases
or remediation agents may be injected into the formation to aid in
the recovery of the hydrogen sulfide from a well.
[0079] Oxidation Reactions:
[0080] In one example, the miscible solvent may include an alcohol
and/or hydrocarbon such as natural gas, propane, butane, and/or
pentane. The miscible solvent may be burned in place within the
formation into primarily water and carbon dioxide, for example by
the addition of oxygen, steam, peroxides, and/or heat.
[0081] In another example, the miscible solvent may include a
carbon disulfide formulation. The carbon disulfide may be combusted
or oxidized within the formation into sulfur dioxide, for example
by the addition of oxygen, peroxides, and/or heat.
[0082] The carbon disulfide can be oxidized by any reaction or
mechanism. The selection of the reaction or mechanism is not
critical. One suitable mechanism by which the carbon disulfide is
oxidized to sulfur dioxide is a known reaction, which has the
formula:
CS.sub.2+3O.sub.2.fwdarw.2SO.sub.2+CO.sub.2 (Formula 2)
[0083] The sulfur dioxide may then be recovered from one or more
wells. In order to recover the sulfur dioxide from the formation,
water, air, carbon dioxide, or one or more other liquids or gases
or remediation agents may be injected into the formation to aid in
the recovery of the sulfur dioxide from a well.
Alternative Embodiments
[0084] In some embodiments, oil and/or gas may be recovered from a
formation into a well, and flow through the well and flowline to a
facility. In some embodiments, enhanced oil recovery, with the use
of an agent for example steam, water, a surfactant, a polymer
flood, and/or a miscible agent such as a carbon disulfide
formulation or carbon dioxide, may be used to increase the flow of
oil and/or gas from the formation.
[0085] In some embodiments, oil and/or gas recovered from a
formation may include a sulfur compound. The sulfur compound may
include hydrogen sulfide, mercaptans, sulfides and disulfides other
than hydrogen disulfide, or heterocyclic sulfur compounds for
example thiophenes, benzothiophenes, or substituted and condensed
ring dibenzothiophenes, or mixtures thereof.
[0086] In some embodiments, a sulfur compound from the formation
may be converted into a carbon disulfide formulation. The
conversion of at least a portion of the sulfur compound into a
carbon disulfide formulation may be accomplished by any known
method. Suitable methods may include oxidation reaction of the
sulfur compound to sulfur and/or sulfur dioxides, and by reaction
of sulfur and/or sulfur dioxide with carbon and/or a carbon
containing compound to form the carbon disulfide formulation. The
selection of the method used to convert at least a portion of the
sulfur compound into a carbon disulfide formulation is not
critical.
[0087] In some embodiments, a suitable miscible enhanced oil
recovery agent may be a carbon disulfide formulation. The carbon
disulfide formulation may include carbon disulfide and/or carbon
disulfide derivatives for example, thiocarbonates, xanthates and
mixtures thereof; and optionally one or more of the following:
hydrogen sulfide, sulfur, carbon dioxide, hydrocarbons, and
mixtures thereof.
[0088] In some embodiments, a suitable method of producing a carbon
disulfide formulation is disclosed in copending U.S. patent
application having Ser. No. 11/409,436, filed on Apr. 19, 2006,
having attorney docket number TH2616. U.S. patent application
having Ser. No. 11/409,436 is herein incorporated by reference in
its entirety.
[0089] In some embodiments, suitable miscible enhanced oil recovery
agents include carbon disulfide, hydrogen sulfide, carbon dioxide,
octane, pentane, LPG, C2-C6 aliphatic hydrocarbons, nitrogen,
diesel, mineral spirits, naptha solvent, asphalt solvent, kerosene,
acetone, xylene, trichloroethane, or mixtures of two or more of the
preceding, or other miscible enhanced oil recovery agents as are
known in the art. In some embodiments, suitable miscible enhanced
oil recovery agents are first contact miscible or multiple contact
miscible with oil in the formation.
[0090] In some embodiments, suitable immiscible enhanced oil
recovery agents include water in gas or liquid form, air, mixtures
of two or more of the preceding, or other immiscible enhanced oil
recovery agents as are known in the art. In some embodiments,
suitable immiscible enhanced oil recovery agents are not first
contact miscible or multiple contact miscible with oil in the
formation.
[0091] In some embodiments, immiscible and/or miscible enhanced oil
recovery agents injected into the formation may be recovered from
the produced oil and/or gas and re-injected into the formation.
[0092] In some embodiments, oil as present in the formation prior
to the injection of any enhanced oil recovery agents has a
viscosity of at least about 100 centipoise, or at least about 500
centipoise, or at least about 1000 centipoise, or at least about
2000 centipoise, or at least about 5000 centipoise, or at least
about 10,000 centipoise. In some embodiments, oil as present in the
formation prior to the injection of any enhanced oil recovery
agents has a viscosity of up to about 5,000,000 centipoise, or up
to about 2,000,000 centipoise, or up to about 1,000,000 centipoise,
or up to about 500,000 centipoise.
[0093] Releasing at least a portion of the miscible enhanced oil
recovery agent and/or other liquids and/or gases may be
accomplished by any known method. One suitable method is injecting
the miscible enhanced oil recovery formulation into a single
conduit in a single well, allowing carbon disulfide formulation to
soak, and then pumping out at least a portion of the carbon
disulfide formulation with gas and/or liquids. Another suitable
method is injecting the miscible enhanced oil recovery formulation
into a first well, and pumping out at least a portion of the
miscible enhanced oil recovery formulation with gas and/or liquids
through a second well. The selection of the method used to inject
at least a portion of the miscible enhanced oil recovery
formulation and/or other liquids and/or gases is not critical.
[0094] In some embodiments, the miscible enhanced oil recovery
formulation and/or other liquids and/or gases may be pumped into a
formation at a pressure up to the fracture pressure of the
formation.
[0095] In some embodiments, the miscible enhanced oil recovery
formulation may be mixed in with oil and/or gas in a formation to
form a mixture which may be recovered from a well. In some
embodiments, a quantity of the miscible enhanced oil recovery
formulation may be injected into a well, followed by another
component to force carbon the formulation across the formation. For
example air, water in liquid or vapor form, carbon dioxide, other
gases, other liquids, and/or mixtures thereof may be used to force
the miscible enhanced oil recovery formulation across the
formation.
[0096] In some embodiments, the miscible enhanced oil recovery
formulation may be heated prior to being injected into the
formation to lower the viscosity of fluids in the formation, for
example heavy oils, paraffins, asphaltenes, etc.
[0097] In some embodiments, the miscible enhanced oil recovery
formulation may be heated and/or boiled while within the formation,
with the use of a heated fluid or a heater, to lower the viscosity
of fluids in the formation. In some embodiments, heated water
and/or steam may be used to heat and/or vaporize the miscible
enhanced oil recovery formulation in the formation.
[0098] In some embodiments, the miscible enhanced oil recovery
formulation may be heated and/or boiled while within the formation,
with the use of a heater. One suitable heater is disclosed in
copending U.S. patent application having Ser. No. 10/693,816, filed
on Oct. 24, 2003, and having attorney docket number TH2557. U.S.
patent application having Ser. No. 10/693,816 is herein
incorporated by reference in its entirety.
[0099] In some embodiments, oil and/or gas produced may be
transported to a refinery and/or a treatment facility. The oil
and/or gas may be processed to produced to produce commercial
products such as transportation fuels such as gasoline and diesel,
heating fuel, lubricants, chemicals, and/or polymers. Processing
may include distilling and/or fractionally distilling the oil
and/or gas to produce one or more distillate fractions. In some
embodiments, the oil and/or gas, and/or the one or more distillate
fractions may be subjected to a process of one or more of the
following: catalytic cracking, hydrocracking, hydrotreating,
coking, thermal cracking, distilling, reforming, polymerization,
isomerization, alkylation, blending, and dewaxing.
Illustrative Embodiments
[0100] In one embodiment of the invention, there is disclosed a
system for producing oil and/or gas from an underground formation
comprising a first array of wells dispersed above the formation; a
second array of wells dispersed above the formation; wherein the
first array of wells comprises a mechanism to inject a miscible
enhanced oil recovery formulation into the formation while the
second array of wells comprises a mechanism to produce oil and/or
gas from the formation for a first time period; a means to convert
at least a portion of the miscible enhanced oil recovery
formulation within the formation into another compound during a
second time period; and a means to recover at least a portion of
the another compound during a third time period. In some
embodiments, a well in the first array of wells is at a distance of
10 meters to 1 kilometer from one or more adjacent wells in the
second array of wells. In some embodiments, the underground
formation is beneath a body of water. In some embodiments, the
system also includes a mechanism for injecting an immiscible
enhanced oil recovery formulation into the formation, after the
miscible enhanced oil recovery formulation has been released into
the formation. In some embodiments, the system also includes a
miscible enhanced oil recovery formulation selected from the group
consisting of a carbon disulfide formulation, hydrogen sulfide,
carbon dioxide, octane, pentane, LPG, C2-C6 aliphatic hydrocarbons,
nitrogen, diesel, mineral spirits, naptha solvent, asphalt solvent,
kerosene, acetone, xylene, trichloroethane, and mixtures thereof.
In some embodiments, the system also includes an immiscible
enhanced oil recovery formulation selected from the group
consisting of water in gas or liquid form, air, and mixtures
thereof. In some embodiments, the first array of wells comprises
from 5 to 500 wells, and the second array of wells comprises from 5
to 500 wells. In some embodiments, the system also includes a
miscible enhanced oil recovery formulation comprising a carbon
disulfide formulation. In some embodiments, the system also
includes a mechanism for producing a carbon disulfide formulation.
In some embodiments, the underground formation comprises an oil
having a viscosity from 100 to 5,000,000 centipoise. In some
embodiments, the first array of wells comprises a miscible enhanced
oil recovery formulation profile in the formation, and the second
array of wells comprises an oil recovery profile in the formation,
the system further comprising an overlap between the miscible
enhanced oil recovery formulation profile and the oil recovery
profile. In some embodiments, the miscible enhanced oil recovery
formulation comprises carbon disulfide. In some embodiments, the
another compound comprises hydrogen sulfide. In some embodiments,
the means to recover at least a portion of the another compound
comprises a well to collect the another compound and convey the
another compound from within the formation to a position above the
formation. In some embodiments, the means to recover at least a
portion of the another compound comprises a well to inject a
remediation agent into the formation to displace the another
compound from within the formation towards one or more other
wells.
[0101] In one embodiment of the invention, there is disclosed a
method for producing oil and/or gas comprising injecting a carbon
disulfide formulation into a formation for a first time period from
a first well; producing oil and/or gas from the formation from a
second well for the first time period; converting at least a
portion of the carbon disulfide formulation into another compound
in situ at a conclusion of the producing oil and/or gas from the
formation; and recovering at least a portion of the another
compound from the formation. In some embodiments, the method also
includes recovering carbon disulfide formulation from the oil
and/or gas, if present, and then injecting at least a portion of
the recovered carbon disulfide formulation into the formation. In
some embodiments, injecting the carbon disulfide formulation
comprises injecting at least a portion of the carbon disulfide
formulation into the formation in a mixture with one or more of
hydrocarbons; sulfur compounds other than carbon disulfide; carbon
dioxide; carbon monoxide; or mixtures thereof. In some embodiments,
the method also includes further comprising heating the carbon
disulfide formulation prior to injecting the carbon disulfide
formulation into the formation, or while within the formation. In
some embodiments, the carbon disulfide formulation is injected at a
pressure from 0 to 37,000 kilopascals above the initial reservoir
pressure, measured prior to when carbon disulfide injection begins.
In some embodiments, the underground formation comprises a
permeability from 0.0001 to 15 Darcies, for example a permeability
from 0.001 to 1 Darcy. In some embodiments, any oil, as present in
the underground formation prior to the injecting the carbon
disulfide formulation, has a sulfur content from 0.5% to 5%, for
example from 1% to 3%. In some embodiments, the method also
includes converting at least a portion of the recovered oil and/or
gas into a material selected from the group consisting of
transportation fuels such as gasoline and diesel, heating fuel,
lubricants, chemicals, and/or polymers. In some embodiments, the
method also includes injecting a remediation agent into the
formation for a second time period from the second well; and
producing the another compound from the formation from the first
well for the second time period. In some embodiments, the
remediation agent comprises a material selected from the group
consisting of water, water and a surfactant, carbon dioxide, air,
and natural gas. In some embodiments, the remediation agent
comprises water and a polymer dissolved in the water. In some
embodiments, converting at least a portion of the carbon disulfide
formulation into another compound comprises injecting at least one
of steam, water, and peroxide into the formation.
[0102] In one embodiment of the invention, there is disclosed a
method for producing oil and/or gas comprising injecting a miscible
enhanced oil recovery formulation into a formation for a first time
period from a first well; producing oil and/or gas from the
formation from a second well for the first time period; converting
at least a portion of the miscible enhanced oil recovery
formulation into another compound within the formation after a
conclusion of the producing oil and/or gas from the formation; and
producing at least a portion of the another compound from the
formation. In some embodiments, the method also includes injecting
an immiscible enhanced oil recovery formulation into the formation
for a time period after the first time period from the first well,
to push the miscible enhanced oil recovery formulation through the
formation. In some embodiments, the produced oil and/or gas
comprises a sulfur compound, further comprising converting at least
a portion of the sulfur compound into a miscible enhanced oil
recovery formulation. In some embodiments, the miscible enhanced
oil recovery formulation comprises a carbon disulfide formulation.
In some embodiments, the another compound comprises hydrogen
sulfide. In some embodiments, the method also includes heating the
miscible enhanced oil recovery formulation. In some embodiments,
the method also includes injecting a remediation agent into the
formation for a second time period from the second well; and
producing the another compound from the formation from the first
well for the second time period. In some embodiments, the
remediation agent comprises at least one of water and carbon
dioxide.
[0103] Those of skill in the art will appreciate that many
modifications and variations are possible in terms of the disclosed
embodiments of the invention, configurations, materials and methods
without departing from their spirit and scope. Accordingly, the
scope of the claims appended hereafter and their functional
equivalents should not be limited by particular embodiments
described and illustrated herein, as these are merely exemplary in
nature.
* * * * *