Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEMS AND METHODS FOR PRODUCING OIL AND/OR GAS
Field of the Invention
The present disclosure relates to systems and methods for producing oil
and/or gas.
Background of the Invention
Substantial amounts of sour natural gas are currently being produced from
natural gas wells, oil wells (for example, as associated gas), and from
natural gas
storage reservoirs that have been infected with hydrogen sulfide -producing
bacteria. The presence of hydrogen sulfide and other sulfur compounds in fuel
and other gases has long been of concern for both the users and the producers
of
such gases. In addition to the corrosive and other adverse effects that such
impurities have upon equipment and processes, noxious emissions are commonly
produced from combustion of the natural gas as a result of oxidation of the
sulfur
compounds. The resulting sulfur oxides can be a major contributor to air
pollution
and may have detrimental impact upon the environment. Increasingly stringent
federal and state regulations have accordingly been promulgated in an effort
to
reduce or eliminate sulfurous emissions, and a concomitant interest exists in
efficiently removing from natural gas and the like the hydrogen sulfide that
comprises a significant precursor of noxious emissions. In addition, one
method of
disposing of hydrogen sulfide has been to convert it into solid sulfur, for
storage.
Due to environmental and aesthetic concerns, many countries are now outlawing
the formation of such sulfur stores.
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.
Thermal enhanced recovery works by adding heat to the reservoir. The
most widely practised 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 gas injection works in a similar way to
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chemical flooding. By injecting a fluid that is miscible with the oil, trapped
residual
oil can be recovered.
Referring to Figure 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. Gas in gas storage 116 may contain hydrogen
sulfide, which must be processed, transported, disposed of, or stored.
Co-Pending Patent Application Publication U.S. 2006/0254769 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.
Publication U.S. 2006/0254769 is herein incorporated by reference in its
entirety.
There is a need in the art for improved systems and methods for
processing, transportation, disposal, or storage of hydrogen sulfide from a
liquid
and/or gas. There is a need in the art for improved systems and methods for
processing, transportation, disposal, or storage of sulfur from a liquid
and/or gas.
There is a further 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 sulfur compound, for example through
viscosity
reduction, chemical effects, and miscible flooding. There is a further need in
the
art for improved systems and methods for making sulfur containing enhanced oil
recovery agents.
In addition, carbon disulfide is a common chemical with applications ranging
from use as a commercial solvent for the production of rayon, to a raw
material for
the production of agricultural insecticides. The carbon disulfide
manufacturing
process involves the purchase and transport of both solid sulfur and natural
gas
(or another carbon source), often from long distances, to the manufacturing
site
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and produces carbon disulfide at very high purity. These two factors - the
high
purchase and shipping costs of the raw materials, and the high purity of the
final
product - result in a relatively high production cost for carbon disulfide.
The manufacturing process for converting sour gas into solid sulfur involves
a solvent unit to first remove hydrogen sulfide, other sulfur compounds, and
contaminants such as carbon dioxide from the natural gas stream, followed by a
Claus unit to convert the hydrogen sulfide into sulfur, which is then allowed
to
solidify prior to transport or transported as a liquid. The manufacturing
process for
manufacturing carbon disulfide, on the other hand, entails the heating,
melting,
and vaporization of solid or liquid sulfur and reacting its vapors with heated
natural
gas or another carbon source.
There is a need in the art for improved systems and methods for carbon
disulfide manufacturing. There is a need in the art for improved systems and
methods for more energy efficient carbon disulfide manufacturing. There is a
need
in the art for improved systems and methods for removing carbon disulfide from
a
reservoir at the conclusion of an FOR process.
Summary of the Invention
In one aspect, the invention provides a system for producing oil and/or gas
comprising a formation comprising a mixture of oil and/or gas and a carbon
disulfide formulation and/or a carbon oxysulfide formulation; a mechanism for
releasing a separating agent into the formation, the separating agent adapted
to
separate the oil and/or gas from the carbon disulfide formulation and/or the
carbon
oxysulfide formulation.
In another aspect, the invention provides a method for producing oil and/or
gas comprising providing a formation comprising a mixture of oil and/or gas
and a
carbon disulfide formulation and/or a carbon oxysulfide formulation; releasing
a
separating agent into a formation; and separating the oil and/or gas from the
carbon disulfide formulation and/or the carbon oxysulfide formulation.
Advantages of the invention include one or more of the following:
Improved systems and methods for disposing of hydrogen sulfide, sulfur,
and/or other sulfur based compounds.
Improved systems and methods for enhanced recovery of hydrocarbons
from a formation with a carbon disulfide formulation.
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Improved systems and methods for enhanced recovery of hydrocarbons
from a formation with a fluid containing a carbon disulfide formulation.
Improved systems and methods for producing a carbon disulfide
formulation.
Improved carbon disulfide containing compositions for secondary recovery
of hydrocarbons.
Improved systems and methods for processing, transportation, disposal, or
storage of a sulfur compound from a liquid and/or gas.
Improved systems and methods for enhanced oil recovery.
Improved systems and methods for enhanced oil recovery using a sulfur
compound.
Improved systems and methods for enhanced oil recovery using a
compound which is miscible with oil in place.
Improved systems and methods for making and/or using sulfur containing
enhanced oil recovery agents.
Improved systems and methods for removing carbon disulfide from a
formation at the conclusion of an enhanced oil recovery process.
Brief Description of the Drawings
Figure 1 illustrates an oil and/or gas production system.
Figure 2 illustrates an oil and/or gas production process.
Figures 3a-3e illustrate oil and/or gas production systems.
Figure 4 illustrates a carbon disulfide formulation production process.
Detailed Description of the Invention
Figure 2:
Referring now to Figure 2, in one embodiment of the invention, process A
for producing oil and/or gas, which includes disposing of a sulfur compound is
illustrated. Process A includes step 1 where sulfur and/or a sulfur-containing
compound is obtained, and optionally released into a formation. In step 2, at
least
a portion of the sulfur compound is converted into a carbon disulfide
formulation
and/or a carbon oxysulfide formulation, optionally within the formation. In
step 3,
at the conclusion of an FOR operation, oil and/or gas may be separated from
the
carbon disulfide formulation and/or the carbon oxysulfide formulation, and the
oil
recovered from the underground formation, and the carbon disulfide formulation
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and/or a carbon oxysulfide formulation may be converted into another compound
within the formation.
Step 1:
The obtaining of the sulfur containing compound may be accomplished by
any known method. Suitable methods include purchasing gaseous, liquid and/or
solid elemental sulfur or sulfur containing compounds; recovering such
compounds
from an underground formation; and/or recovering such compounds as a stream
from surface processes. The selection of the method used to obtain the sulfur
containing compound into the underground formation is not critical.
Such compounds may be injected into a formation with any known method.
Suitable methods include vertical and horizontal wells, perforating the
formation,
injecting liquid and/or vaporized elemental sulfur, or other methods for
injecting
liquids and gases into a formation as are known in the art. The selection of
the
method used to release the sulfur containing compound into the underground
formation is not critical.
In some embodiments of the invention, the sulfur compound may include
elemental sulfur, 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.
Releasing at least a portion of the sulfur containing compound and/or other
liquids and/or gases may be accomplished by any known method. One suitable
method is injecting sulfur containing compound into a single conduit in a
single
well, allowing sulfur containing compound to soak, and then pumping out at
least a
portion of the gases and/or liquids. Another suitable method is injecting
sulfur
containing compound into a first conduit in a single well, and pumping out at
least
a portion of the gases and/or liquids through a second conduit in the single
well.
Another suitable method is injecting sulfur containing compound into a first
well,
and pumping out at least a portion of the gases and/or liquids through a
second
well. The selection of the method used to inject at least a portion of the
sulfur
containing compound and/or other liquids and/or gases is not critical.
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Alternatively, the order of injection and conversion may be reversed. The
sulfur containing compound may be converted into another compound in a surface
process, and then the other compound injected into the formation. The other
compound may be injected by any known method, for example those discussed
above or other methods as are known in the art.
A sulfur containing compound and/or other liquids and/or gases, such as a
solvent or a liquid or gas miscible with the oil in place, may be left to soak
in a
formation for a period of time from about 1 hour to about 15 days, for example
from about 5 to about 50 hours.
In some embodiments, sulfur containing compound and/or other liquids
and/or gases may be pumped into a formation at a pressure above the fracture
pressure of the formation.
In some embodiments, sulfur containing compound or sulfur containing
compound mixed with other components may be miscible in oil (or other liquids)
and/or gases in a formation. In some embodiments, sulfur containing compound
or sulfur containing compound mixed with other components may be immiscible in
oil and/or gas in formation.
In some embodiments, sulfur containing compound 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.
In some embodiments, sulfur containing compound 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 sulfur containing compound in
the
formation. Alternatively, a nonaqueous fluid could be substituted for steam or
hot
water as the heat medium to heat sulfur containing compound, for example a
heavy aromatic solvent which may have its own solubilizing effect on reservoir
hydrocarbons.
In some embodiments of the invention, in addition to injecting a sulfur
containing compound into the formation, one or more catalysts for example as a
slurry or suspension, oxygen or an oxygen containing gas, and one or more
hydrocarbons may also be injected into the formation. Suitable catalysts,
gases,
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and hydrocarbons which may be used in reactions within the formation are set
forth below with regard to Step 2.
Step 2:
The conversion of at least a portion of the sulfur compound into a carbon
disulfide and/or carbon oxysulfide formulation may be accomplished by any
known
method. Suitable methods may include an 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.
In some embodiments of the invention, the carbon disulfide and/or carbon
oxysulfide formulation may include carbon disulfide, carbon oxysulfide, 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.
In some embodiments of the invention, a carbon disulfide formulation is
defined as a formulation having a molar ratio of carbon disulfide to carbon
oxysulfide of greater than about 1.
In some embodiments of the invention, a carbon oxysulfide formulation is
defined as a formulation having a molar ratio of carbon disulfide to carbon
oxysulfide of about 1 or less.
In some embodiments of the invention, a carbon disulfide formulation may
be used interchangeably with a carbon oxysulfide formulation, as the terms are
defined above. For example, where the production, storage, and/or use of a
carbon disulfide formulation are described below, the carbon disulfide
formulation
may be substituted with a carbon oxysulfide formulation.
In some embodiments of the invention, carbon disulfide formulation and/or
carbon oxysulfide formulation production may have an input of a sulfur
compound,
for example injected directly into the formation.
In some embodiments of the invention, the sulfur compound may be
converted into sulfur dioxide and/or sulfur by an oxidation reaction, for
example by
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the Claus process, catalytic selective oxidation reaction, or by reaction with
a
metal as described hereinafter.
In some embodiments of the invention, the oxidation reaction may include
reacting a sulfur compound with an oxygen containing gas in a reaction zone to
yield sulfur dioxide and/or sulfur, among other components.
In some embodiments of the invention, the oxygen containing gas may be
oxygen, air, oxygen-enriched air, or oxygen depleted air.
In some embodiments of the invention, the sulfur compound may be
oxidized in the presence of a catalyst. Suitable catalysts may be present
within or
as part of the formation, including mineral compounds of elements such as
aluminum, antimony, barium, bismuth, calcium, cerium, chromium, cobalt,
copper,
gallium, germanium, hafnium, iridium, iron, lanthanum, lead, magnesium,
manganese, molybdenum, neodymium, nickel, niobium, osmium, palladium,
platinum, praseodymium, rhenium, rhodium, ruthenium, samarium, scandium,
silicon, silver, tantalum, tin, titanium, tungsten, vanadium, yttrium, zinc,
zirconium,
like oxides, sulfides, or carbides of these elements, and/or combinations or
mixtures of two or more of the above.
In some embodiments, suitable catalysts, or precursors thereof, might be
added to the formation or used in a surface conversion process. Suitable
delivery
methods to add catalyst precursors to the formation are via fluid injection,
the fluid
containing the catalyst precursor. The catalyst precursor can be part of the
injection fluid as a liquid, a solution, a slurry, or a gas. Suitable catalyst
precursors
may contain elements such as titanium, vanadium, chromium, manganese, iron,
cobalt, nickel, copper, zirconium, niobium, molybdenum or mixtures thereof.
Suitable gaseous catalyst precursors may be compounds of the elements above
such as halides and carbonyls or mixtures thereof. Suitable liquids include
molten
salts of carbonates, hydroxides and or halides or mixtures thereof such as
eutectic
melts. Suitable solutions may be aqueous solutions of the water-soluble salts
of
the elements above as nitrates, sulfates, and halides.
In some embodiments of the invention, the oxidation reaction may take
place in the formation or a surface process in a reaction zone having a
temperature of less than about 500 C, for example from about 150 to about 500
C,
or from about 200 to about 300 C, or above the dew point of sulfur, for given
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process conditions, so that sulfur does not condense onto the catalyst or in
the
reaction zone.
In some embodiments of the invention, the oxidation reaction may take
place in the formation or in a surface process in a reaction zone having a
pressure
from about 100 to about 1000 kilopascals, for example from about 200 to about
500 kilopascals (absolute).
In some embodiments, a sulfur compound may be converted to sulfur
and/or sulfur dioxide, for which processes are disclosed in U.S. patent
application
publication numbers 2004/0096381, 2004/0022721, 2004/0159583,
2003/0194366, 2001/0008619, 2002/0134706, 2004/0096381, 2004/0022721,
2004/0159583, and 2001/0008619, the disclosures of which are herein
incorporated by reference in their entirety.
Sulfur and/or sulfur dioxide may be reacted with carbon or a carbon
containing compound in the formation or in a surface process in a reaction
zone to
produce a carbon disulfide or carbon oxysulfide formulation.
In some embodiments, the carbon compound comprises carbon in any
form, for example graphite, coal, charcoal, carbon monoxide, hydrocarbons for
example natural gas, methane, ethane, propane, or heavier hydrocarbons, such
as
heavy oil, tar, tar sands, shales, asphaltenes, and/or bitumen.
In some embodiments, sulfur and/or sulfur dioxide may be combined with a
carbon compound at temperatures from about 500 to about 900 C, for example
from about 550 to 700 C.
In some embodiments, sulfur and/or sulfur dioxide may be combined with a
carbon compound at a pressure from about 100 to about 500 kilopascals.
In some embodiments, sulfur and/or sulfur dioxide may be combined with a
carbon compound in the presence of a catalyst. Suitable catalysts include
silica-
alumina catalysts, for example those containing from 2 to 10 per cent by
weight of
silica; silica gel; bauxite; activated alumina; and in general those types of
clay
which are effective in the removal of color bodies and gum forming bodies from
petroleum oils. The catalysts may additionally comprise one or more of
vanadium,
niobium, tantalum, chromium, molybdenum, tungsten, manganese, technetium,
rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium,
and/or platinum; in their elemental form, as compounds of the metals, or as
oxides
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and sulfides. For example, oxides and sulfides of iron, vanadium, chromium,
molybdenum, and manganese may be used as promoters in combination with
silica gel, fuller's earth and/or activated alumina catalysts.
In some embodiments, a carbon disulfide formulation may be produced by
reacting carbon with sulfur. The carbon may be obtained from hydrocarbons
within the formation such as natural gas, crude oil, heavy oils, shale, tar
sands, tar,
asphalt, bitumen, and/or other hydrocarbons within the formation. Sulfur may
be
reacted with the carbon so as to produce carbon disulfide formulation, for
example,
sulfur in the liquid or vapor phase may be used for this reaction.
In some embodiments, sulfur and/or sulfur dioxide and a carbon compound
may be converted to carbon disulfide formulation, processes for which are
disclosed in U.S. patent numbers 4,963,340, 2,636,810, 3,927,185, 4,057,613,
and
4,822,938, and U.S. patent application publication number 2004/0146450, the
disclosures of which are herein incorporated by reference in their entirety.
One suitable method of converting liquid sulfur and a hydrocarbon into a
carbon disulfide formulation in the absence of oxygen is disclosed in WO
2007/131976. WO 2007/131976 is herein incorporated by reference in its
entirety.
One suitable method of converting liquid sulfur and a hydrocarbon into a
carbon disulfide formulation in the presence of oxygen is disclosed in WO
2007/131977. WO 2007/131977 is herein incorporated by reference in its
entirety.
Other suitable methods for converting sulfur compounds into a carbon
disulfide formulation and/or a carbon oxysulfide formulation are disclosed in
co-
pending patent applications: U.S. Patent Publication 2006/0254769 having
attorney docket number TH2616; U.S. Provisional Application 61/031,832 having
attorney docket number TH3448; U.S. Provisional Application 61/024,694 having
attorney docket number TH3443; PCT Patent Publication WO 2007/131976 having
attorney docket number TS1 746; PCT Patent Publication WO 2008/003732 having
attorney docket number TS1 818; PCT Patent Publication WO 2007/131977 having
attorney docket number TS1 833; and PCT Patent Application
PCT/EP2007/059746 having attorney docket number TS9597, which are all herein
incorporated by reference in their entirety.
As discussed above, the reaction inputs and/or catalysts may be used in a
surface process or found within the formation or injected into the formation
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to convert a sulfur containing compound into a carbon disulfide formulation
and/or
a carbon oxysulfide formulation.
Step 3:
Carbon disulfide formulation and/or a carbon oxysulfide formulation may be
produced in a surface process and/or produced within a formation. The carbon
disulfide formulation and/or a carbon oxysulfide formulation may then be used
in
an enhanced oil recovery (EOR) process to boost the production of oil from the
formation, for example as disclosed in co-pending patent application TH2616,
which is herein incorporated by reference in its entirety. A mixture of oil
and the
carbon disulfide formulation may be produced to the surface, the carbon
disulfide
formulation separated, and optionally recycled to be injected into the
formation or
into another formation. At the conclusion of the FOR process, there will be a
volume of carbon disulfide formulation within the formation. The carbon
disulfide
formulation may be separated from oil, the oil produced to the surface, and
the
carbon disulfide formulation converted into another sulfur containing
compound.
The separation of oil and/or gas from a carbon disulfide and/or carbon
oxysulfide formulation may be accomplished by any known method. Suitable
methods include boiling off the carbon disulfide and/or carbon oxysulfide
formulation, by increasing the temperature of the oil mixture. This will leave
behind an elevated temperature oil with an increased mobility and lower
viscosity
to be produced. The temperature of the mixture can be increased by injecting
steam or hot water, the use of in-situ heaters, or injecting another hot
substance
such as a liquid or a gas.
Another suitable method to separate the oil mixture is to hydrolyze the
carbon disulfide and/or carbon oxysulfide formulation. This can be
accomplished
by injecting steam and/or hot water into contact with the oil mixture. This
will leave
behind an elevated temperature oil with an increased mobility and lower
viscosity
to be produced. In some embodiments, the steam and/or hot water may be basic
or alkaline, for example by adding amines or ammonia or other bases to the
water
or steam.
Another suitable method to separate the oil mixture is to oxidize the carbon
disulfide and/or carbon oxysulfide formulation. This can be accomplished by
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injecting oxygen, air, or other oxygen containing gases into contact with the
oil
mixture. This will leave behind an elevated temperature oil with an increased
mobility and lower viscosity to be produced.
Another suitable method to separate the oil mixture is to strip the carbon
disulfide and/or carbon oxysulfide formulation from the oil. This can be
accomplished by injecting nitrogen or other suitable stripping gases or
liquids into
contact with the oil mixture. This will leave behind an oil to be produced.
The recovery of oil and/or gas 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.
In one embodiment, 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, may be used to increase the flow of oil and/or gas from the
formation.
Sulfide Conversion:
Any carbon disulfide and/or carbon oxysulfide present in the formation may
be converted into another compound while within the formation by any suitable
method. The selection of the method to convert the carbon disulfide and/or
carbon
oxysulfide is not critical. Suitable methods to convert the carbon disulfide
and/or
carbon oxysulfide include the formation of hydrogen sulfide and oxidation,
which
are set forth below.
Hydrogen Sulfide Formation:
In one example, the miscible solvent may include a carbon disulfide and/or
carbon oxysulfide formulation. The carbon disulfide may be hydrolyzed within
the
formation into hydrogen sulfide and/or carbon oxysulfide formulation, for
example
by reaction with water and/or steam. Optionally, one or more catalysts such as
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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.
The carbon disulfide can be hydrolyzed to hydrogen sulfide and/or carbon
oxysulfide 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:
CS2 + H2O -* H2S + COS (Formula 1)
The carbon disulfide may be hydrolyzed further within the formation into
carbon dioxide and hydrogen sulfide, for example by reaction with water or
steam.
The carbon oxysulfide can be hydrolyzed to hydrogen sulfide and carbon
dioxide by any reaction or mechanism. The selection of the reaction or
mechanism is not critical. One suitable mechanism by which the carbon
oxysulfide
is hydrolyzed to hydrogen sulfide is a known reaction, which has the formula:
COS + H2O -* H2S + CO2 (Formula 2)
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.
Oxidation Reactions:
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.
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 and/or carbon dioxide, for example by the
addition of
oxygen, peroxides, and/or heat.
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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:
CS2 + 3 02 -* 2SO2 + CO2 (Formula 3)
The sulfur dioxide may then be recovered from one or more wells, or left in
place within the formation. 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.
Figure 3a:
Referring now to Figure 3a, in one embodiment of the invention, system 200
is illustrated. System 200 includes underground formation 202, underground
formation 204, underground formation 206, and underground formation 208.
Production facility 210 is provided at the surface. Well 212 traverses
formations
202 and 204, and has openings in formation 206. Portions 214 of formation 206
may optionally be fractured and/or perforated. Oil and gas from formation 206
is
produced into portions 214, into well 212, and travels up to production
facility 210.
Production facility may then separate gas, which is sent to gas processing
216,
and liquid, which is sent to liquid storage 218. Production facility also
includes
carbon disulfide formulation storage 230. Carbon disulfide, hydrogen sulfide
and/or other sulfur containing compounds produced from well 212 may be sent to
carbon disulfide formulation production 230. Carbon disulfide, hydrogen
sulfide
and/or other sulfur containing compounds may be pumped down well 212 that is
shown by the down arrow and is pumped into formation 206, and is then
separated
and the oil and gas produced back up well 212 to production facility 210.
Figures 3b & 3c:
Referring now to Figures 3b and 3c, in some embodiments of the invention,
system 200 is illustrated. System 200 includes underground formation 202,
underground formation 204, underground formation 206, and underground
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formation 208. Production facility 210 is provided at the surface. Well 212
traverses formations 202 and 204, and has openings in formation 206. Portions
214 of formation 206 may be optionally fractured and/or perforated. During
primary production, oil and gas from formation 206 is produced into portions
214,
into well 212, and travels up to production facility 210. Production facility
then
separates gas, which is sent to gas processing 216, and liquid, which is sent
to
liquid storage 218. Production facility also includes carbon disulfide
formulation
storage 230. Carbon disulfide formulation, hydrogen sulfide and/or other
sulfur
containing compounds may be separated from oil and/or gas within the
formation,
before the oil and/or gas is produced into well 212, or after the oil and/or
gas is
produced into well 212 and to a surface facility. As shown in Figure 3b,
sulfur
containing compound, other liquids, gases, and/or catalysts may be pumped down
well 212 that is shown by the down arrow and pumped into formation 206. Sulfur
containing compound 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, in order to react with hydrocarbons to form a miscible sulfur compound -
oil
formulation.
After the soaking / reaction period, as shown in Figure 3c, carbon disulfide
formulation may be produced with the oil and/or gas, back up well 212 to
production facility 210.
In some embodiments, sulfur containing compound may be pumped into
formation 206 above the fracture pressure of the formation, for example from
about 120% to about 200% of the fracture pressure.
Sulfur containing compound may be pumped into formation 206 at a
temperature from about 200 to about 1000 C, for example from about 400 to
about
800 C, or from about 500 to about 700 C.
Sulfur containing compound may be pumped into formation 206 at a
pressure from about 2 to about 200 bars, for example from about 3 to about 100
bars, or from about 5 to about 50 bars.
Figure 3d:
Referring now to Figure 3d, in some embodiments of the invention, system
300 is illustrated. System 300 includes underground formation 302, formation
304,
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formation 306, and formation 308. Production facility 310 is provided at the
surface. Well 312 traverses formation 302 and 304 has openings at formation
306. Portions of formation 314 may be optionally fractured and/or perforated.
As
oil and gas is produced from formation 306 it enters portions 314, and travels
up
well 312 to production facility 310. Gas and liquid may be separated, and gas
may
be sent to gas storage 316, and liquid may be sent to liquid storage 318.
Production facility 310 is able to store and/or produce carbon disulfide
formulation,
which may be produced and stored in carbon disulfide formulation production
330.
Carbon disulfide formulation, hydrogen sulfide and/or other sulfur containing
compounds may be separated from oil and/or gas, after the oil and/or gas is
produced to well 312 and to surface facilities. Carbon disulfide formulation
may
also be optionally recycled back to the formation, or to another formation.
A carbon disulfide and/or a carbon oxysulfide formulation, and optionally
other liquids, gases, and/or catalysts may be pumped down well 332, to
portions
334 of formation 306. The carbon disulfide and/or the carbon oxysulfide
formulation traverses formation 306 and reacts with one or more hydrocarbons
to
make a miscible oil mixture with the carbon disulfide and/or carbon oxysulfide
formulation, which aids in the production of oil and gas, and then the mixture
may
be produced to well 312 and to production facilities 310, and then the carbon
disulfide formulation and oil and/or gas may be separated. Carbon disulfide
formulation may then be recycled and reinjected into the formation or to
another
target formation.
In some embodiments, carbon disulfide formulation or carbon disulfide
formulation mixed with other components may be miscible in oil and/or gas in
formation 306.
In some embodiments, carbon disulfide formulation or carbon disulfide
formulation mixed with other components may be mixed in with oil and/or gas in
formation 306 to form a miscible mixture. The mixture may then be produced to
well 312, then separated.
In some embodiments, carbon disulfide formulation or carbon disulfide
formulation mixed with other components may not mix in with oil and/or gas in
formation 306, so that carbon disulfide formulation or carbon disulfide
formulation
mixed with other components travels as a plug across formation 306 to force
oil
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and/or gas to well 312. In some embodiments, a quantity of carbon disulfide
formulation or carbon disulfide formulation mixed with other components may be
injected into well 332, followed by another component to force carbon
disulfide
formulation or carbon disulfide formulation mixed with other components across
formation 306, 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.
Figure 3e:
Figure 3e illustrates the system of Figure 3d at the conclusion of an FOR
process. There is a volume of carbon disulfide formulation mixed with oil
and/or
gas within underground formation 302. System 300 may be used to separate
and/or convert carbon disulfide formulation within underground formation 302.
System 300 includes underground formation 302, formation 304, formation
306, and formation 308. Production facility 310 is provided at the surface.
Well
312 traverses formation 302 and 304 has openings at formation 306. Portions of
formation 314 may be optionally fractured and/or perforated.
A separating agent may be injected into well 332 and into formation 306 as
shown by the arrows. A separating agent may also be injected into well portion
332 and out of the bottom of well portion 332 as shown by the arrows and into
formation 306. As discussed above, the separating agent may act to separate
the
oil and/or gas from the carbon disulfide formulation, and/or to raise the
temperature and mobility of the oil. Suitable separating agents include steam,
water, air, oxygen containing gases, nitrogen, amines, and other liquids and
gases
known in the art to separate oil / carbon disulfide formulation mixtures.
After the separating agent has been injected for a period of time, separated
oil and/or gas 344 may be produced to well potion 312 as shown by arrows, for
example at a point in the well above where the separating agent was injected.
In
addition, carbon disulfide formulation, separating agent, converted carbon
disulfide
formulation, and/or a mixture thereof may form a lower density blanket 342
above
oil and/or gas 344. Blanket 342 may be used to force oil and/or gas 344
towards
well portion 312.
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After the oil and/or gas 344 is produced, blanket 342 may be produced to
well portion 312 or left in formation 306.
In some embodiments, well 312 may be used to inject separating agent for
a first time period, and then well 312 may be used to produce oil and/or gas
for a
second time period. In some embodiments, well 312 may be alternatively cycled
between injecting the separating agent and producing oil and/or gas, for
example
from about 2 to about 100 cycles, for example from about 5 to about 10 cycles.
Figure 4:
Referring now to Figure 4, in some embodiments of the invention, carbon
disulfide formulation production 430 is illustrated. Carbon disulfide
formulation
production 430 has an input of hydrogen sulfide and/or other sulfur containing
compounds. Hydrogen sulfide may be converted into sulfur dioxide by oxidation
reaction 432. Hydrogen sulfide and sulfur dioxide may be converted to sulfur
at
434. Sulfur may be combined with a carbon compound to produce carbon
disulfide formulation at 436. The carbon disulfide formulation and hydrogen
sulfide
produced at 436 may be the output. Carbon disulfide formulation and/or a
carbon
disulfide formulation containing mixture may be the output from carbon
disulfide
formulation production 430.
Alternatives:
In some embodiments, carbon disulfide derived salts can be dissolved in
water, and the resulting solution pumped into formations 206 and/or 306. The
dissolved carbon disulfide formulations may decompose, yielding carbon
disulfide
in formations 206 and/or 306.
In some embodiments of the invention, gas and liquid produced from well
212 and/or 312 may be separated, for example with a gravity separator or a
centrifuge, or with other methods known in the art. The gas portion may be
sent to
carbon disulfide formulation production 230 and/or 330.
In some embodiments of the invention, all of the components of system 200
and/or system 300 may be within about 10 km of each other, for example about
5,
3, or 1 km.
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In some embodiments, oil and/or gas produced from well 212 and/or 312
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.
It is to be appreciated that any of the embodiments to complete Step 1 may
be combined with any of the embodiments to complete Step 2, which may be
combined with any of the embodiments to complete Step 3.
The selection of a method to complete any of Steps 1-3 is not critical.
Illustrative Embodiments:
In one embodiment of the invention, there is disclosed a system for
producing oil and/or gas comprising a formation comprising a mixture of oil
and/or
gas and a carbon disulfide formulation and/or a carbon oxysulfide formulation;
a
mechanism for releasing a separating agent into the formation, the separating
agent adapted to separate the oil and/or gas from the carbon disulfide
formulation
and/or the carbon oxysulfide formulation. In some embodiments, the system also
includes a mechanism for recovering the oil and/or gas from the formation. In
some embodiments, the mechanism for recovering comprises a well in the
underground formation and a recovery facility at a topside of the well. In
some
embodiments, the mechanism for recovering comprises a first well drilled in
the
underground formation for recovering the oil and/or gas, and a production
facility at
a topside of the first well; and the mechanism for releasing the separating
agent
comprises a second well in the underground formation for releasing the
separating
agent into the formation. In some embodiments, the mechanism for recovering
comprises a first well drilled in the underground formation for recovering the
oil
and/or gas, and a production facility at a topside of the first well; and the
mechanism for releasing the separating agent comprises the first well in the
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underground formation for releasing the separating agent into the formation.
In
some embodiments, the the first well comprises a first portion for recovering
the oil
and/or gas, and a second portion for releasing the separating agent. In some
embodiments, the first well is used for releasing the separating agent for a
first
time period, and then used for recovering the oil and/or gas for a second time
period. In some embodiments, the system also includes a heater within the
formation adapted to heat at least one of the separating agent, oil, and/or
gas. In
some embodiments, the system also includes a mechanism adapted to convert the
carbon disulfide formulation and/or the carbon oxysulfide formulation into
another
compound within the formation. In some embodiments, the mechanism to convert
comprises a mechanism to produce hydrogen sulfide and/or a mechanism to
oxidize. In some embodiments, the separating agent is selected from the group
of
air, oxygen, oxygen containing gases, nitrogen, amines, steam, water, and
mixtures thereof.
In one embodiment of the invention, there is disclosed a method for
producing oil and/or gas comprising providing a formation comprising a mixture
of
oil and/or gas and a carbon disulfide formulation and/or a carbon oxysulfide
formulation; releasing a separating agent into a formation; and separating the
oil
and/or gas from the carbon disulfide formulation and/or the carbon oxysulfide
formulation. In some embodiments, the method also includes recovering oil
and/or
gas from the underground formation. In some embodiments, the recovering is
done from a first well and the releasing the separating agent is done from the
first
well. In some embodiments, the recovering is done from a first well and the
releasing the separating agent is done from a second well. In some
embodiments,
the recovering is done from a higher point in the formation, and the releasing
the
separating agent is done from a lower point in the formation. In some
embodiments, the method also includes heating the separating agent prior to
injecting the separating agent into the formation, or while within the
formation. In
some embodiments, the method also includes converting the carbon disulfide
formulation and/or a carbon oxysulfide formulation into another compound
within
the formation. In some embodiments, the method also includes converting at
least
a portion of a recovered oil and/or gas from the formation into a material
selected
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from the group consisting of transportation fuels such as gasoline and diesel,
heating fuel, lubricants, chemicals, and/or polymers.
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.
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