Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/34—Arrangements for separating materials produced by the well
  • E21B43/35—Arrangements for separating materials produced by the well specially adapted for separating solids
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G1/00—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
  • C10G1/002—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal in combination with oil conversion- or refining processes
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G1/00—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
  • C10G1/02—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal by distillation
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G1/00—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
  • C10G1/04—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal by extraction
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G21/00—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G21/00—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents
  • C10G21/06—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents characterised by the solvent used
  • C10G21/12—Organic compounds only
  • C10G21/22—Compounds containing sulfur, selenium, or tellurium
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G29/00—Refining of hydrocarbon oils, in the absence of hydrogen, with other chemicals
  • C10G29/06—Metal salts, or metal salts deposited on a carrier
  • C10G29/10—Sulfides
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G29/00—Refining of hydrocarbon oils, in the absence of hydrogen, with other chemicals
  • C10G29/20—Organic compounds not containing metal atoms
  • C10G29/28—Organic compounds not containing metal atoms containing sulfur as the only hetero atom, e.g. mercaptans, or sulfur and oxygen as the only hetero atoms
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/10—Feedstock materials
  • C10G2300/1033—Oil well production fluids
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/20—Characteristics of the feedstock or the products
  • C10G2300/201—Impurities
  • C10G2300/205—Metal content
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/40—Characteristics of the process deviating from typical ways of processing
  • C10G2300/4037—In-situ processes

Definitions

• the invention relates generally to a process, method, and system for removing heavy metals including mercury from hydrocarbon fluids such as crude oil and gases.
• Heavy metals can be present in trace amounts in all types of produced fluids such as hydrocarbon gases and crude oils.
• the amount can range from below the analytical detection limit to several thousand ppbw (parts per billion by weight) depending on the source.
• US Patent Publication No. 2011/0253375 discloses an apparatus and related methods for removing mercury from reservoir effluent by placing materials designed to adsorb mercury into the vicinity of a formation at a downhole location, and letting the reservoir effluent flow through the volume of the adsorbing material.
• US Patent Publication No. 2012/0073811 discloses a method for mercury removal by injecting a solid sorbent into a wellbore intersecting a subterranean reservoir containing hydrocarbon products.
• Production of oil and gas is usually accompanied by the production of water.
• the produced water may consist of formation water (water present naturally in the reservoir), or water previously injected into the formation. As exploited reservoirs mature, the quantity of water produced increases. Produced water is the largest single fluid stream in exploration and production operations. Every day, U.S. oil and gas producers bring to the surface 60 million barrels of produced water.
• the invention relates to a method for recovering hydrocarbons from a subterranean hydrocarbon-bearing formation while simultaneously removing heavy metals from the hydrocarbons.
• the method comprises: exposing the heavy metals in the hydrocarbons to a fixing agent in a dilution fluid for the fixing agent to react with the heavy metals forming heavy metal complexes in the dilution fluid; and recovering the hydrocarbons and the dilution fluid containing the heavy metal complexes from the formation via a production well as a mixture.
• the invention relates to a method for recovering
• the method comprises: exposing the heavy metals in the hydrocarbons to a fixing agent in a dilution fluid for the fixing agent to react with the heavy metals forming insoluble heavy metal complexes that precipitate and remain in the reservoir; and recovering the hydrocarbons and the dilution fluid containing the heavy metal complexes from the formation via a production well as a mixture.
• the invention in another aspect, relates to another method for recovering hydrocarbons from a subterranean hydrocarbon-bearing formation while simultaneously removing heavy metals from the hydrocarbons.
• the method comprises: fracturing the formation to generate fractures; providing a dilution fluid containing a fixing agent for the fixing agent to react with the heavy metals in the formation, forming heavy metal complexes in the dilution fluid; recovering the dilution fluid containing the heavy metal complexes; and recovering hydrocarbons having a reduced concentration of heavy metals from the formation via a production well.
• the invention in another aspect, relates to an in-situ method for removing heavy metals from the hydrocarbons while recovering the hydrocarbons from a subterranean hydrocarbon-bearing formation.
• the method comprises: fracturing the formation to generate fractures; providing a dilution fluid containing a fixing agent for at least a portion of the fixing agent to be adsorbed into fractures and rocks in the formation; reducing the pressure for the dilution fluid to flow back through a well bore; allowing the hydrocarbons to pass through the fractures and rocks having the fixing agent adsorbed thereon, wherein heavy metals in the hydrocarbons react with the fixing agent forming heavy metal complexes; and recovering the hydrocarbons from the formation via a well bore.
• the invention in another aspect, relates to a method for recovering hydrocarbons from a subterranean hydrocarbon-bearing formation while simultaneously removing heavy metals from the hydrocarbons.
• the method comprises: fracturing the formation to generate fractures; providing a dilution fluid containing a fixing agent for the fixing agent to diffuse into fractures and rocks in the formation to react with the heavy metals in the hydrocarbons; recovering the dilution fluid containing the heavy metal complexes; and recovering hydrocarbons having a reduced concentration of heavy metals from the formation via a production well.
• the invention relates to a system for the in-situ removal of heavy metals hydrocarbons in recovering the hydrocarbons from a subterranean hydrocarbon-bearing formation.
• the system comprises: a well drilled into an underground formation comprising hydrocarbons and a topside production facility.
• the topside production facility is for the storage and treatment of produced water recovered from a subterranean formation, and the injection of the treated produced water containing the fixing agent into the well.
• FIG. 1 is a diagram of an embodiment of an in-situ system for the removal of heavy metals from a produced fluid.
• FIG. 2 is a diagram of a second embodiment of an in-situ system for the simultaneous recovery of oil and removal of heavy metals from the recovered oil.
• Hydrocarbons refers to hydrocarbon streams such as crude oils and / or natural gases.
• Produced fluids refers hydrocarbon gases and / or crude oil. Produced fluids may be used interchangeably with hydrocarbons.
• “Crude oil” refers to a hydrocarbon material, including to both crude oil and condensate, which is typically in liquid form. Under some formation conditions of temperature and/or pressure, the crude may be in a solid phase. Under some conditions, the oil may be in a very viscous liquid phase that flows slowly, if at all.
• “Production well” is a well through which produced fluids are carried from an oil-bearing geological formation to the earth's surface, whether the surface is water or land. Surface facilities are provided for handling and processing the crude from the formation as it arrives on the surface.
• Topic production facility refers to the surface hardware on an offshore oil platform or connected group of platforms, such as the oil production plant and the drilling rig.
• injection well is a well through which at least a treatment agent is passed from the surface facilities into the geological formation.
• a well is alternatively employed in a producing and an injection mode.
• the well is alternatively employed for injecting a material into the formation for some period of time.
• the process conditions within the well are then adjusted to permit crude to flow into the well, from where it is withdrawn to surface facilities.
• Race amount refers to the amount of heavy metals in a produced fluid. The amount varies depending on the source of the fluid and the type of heavy metal, for example, ranging from a few ppb to up to 30,000 ppb for mercury and arsenic.
• Heavy metals refers to gold, silver, mercury, osmium, ruthenium, uranium, cadmium, tin, lead, selenium, and arsenic. While the description described herein refers to mercury removal, in one embodiment, the treatment removes one or more of the heavy metals.
• Flow-back water refers to water that flows back to the surface after being placed into a subterranean formation as part of an enhanced oil recovery operation, e.g., a hydraulic fracturing operation.
• Produced water refers to the water generated in the production of oil and gas, including formation water (water present naturally in a reservoir), as well as water previously injected into a formation either by matrix or fracture injection, which can be any of connate water, aquifer water, seawater, desalinated water, flow-back water, industrial byproduct water, and combinations thereof.
• Mercury sulfide may be used interchangeably with HgS, referring to mercurous sulfide, mercuric sulfide, or mixtures thereof, which can be in any common phases of cinnabar, meta-cinnabar, hyper-cinnabar and combinations thereof.
• Mercury sulfide is typically present as mercuric sulfide with a stoichiometric equivalent of one mole of sulfide ion per mole of mercury ion.
• the invention relates to a method for the in-situ removal of heavy metals such as mercury, arsenic, etc., from produced fluids such as gases and crudes from a subterranean hydrocarbon bearing formation.
• a fixing agent is injected in the formation, which reacts with the heavy metals and forms precipitates and / or soluble heavy metal compounds.
• the amount of precipitates or soluble heavy metal compounds formed depends on the type of mercury present in the formation, as well as well as the amount and type of fixing agent(s) employed.
• Heavy metals such as lead, zinc, mercury, silver, selenium, arsenic and the like can be present in trace amounts in all types of hydrocarbon streams such as crude oils and natural gases. Producers may desire to remove heavy metals such as mercury and lead from crude oil. The amount of mercury and / or arsenic can range from below the analytical detection limit to several thousand ppb depending on the feed source.
• Arsenic species can be present in produced fluids in various forms including but not limited to triphenylarsine (Ph 3 As), triphenylarsine oxide (Ph 3 AsO), arsenic sulfide minerals (e.g., AS4S4 or AsS or As 2 S 3 ), metal arsenic sulfide minerals (e.g., FeAsS; (Co, Ni, Fe)AsS; (Fe, Co)AsS), arsenic selenide (e.g., As 2 Se 5 , As 2 Se 3 ), arsenic-reactive sulfur species, organo-arsenic species, and inorganic arsenic held in small water droplets.
• triphenylarsine Ph 3 As
• triphenylarsine oxide Ph 3 AsO
• arsenic sulfide minerals e.g., AS4S4 or AsS or As 2 S 3
• metal arsenic sulfide minerals e.
• Mercury can be present in produced fluids as elemental mercury Hg°, ionic mercury, inorganic mercury compounds, and / or organic mercury compounds. Examples include but are not limited to: mercuric halides, mercurous halides, mercuric oxides, mercuric sulfide, mercuric sulfate, mercurous sulfate, mercury selenide, mercury hydroxides, organo-mercury compounds and mixtures of thereof.
• Mercury can be present as particulate mercury, which can be removed from hydrocarbons by filtration or centrifugation. The particulate mercury in one embodiment is predominantly non-volatile.
• the produced fluid is a crude oil containing at least 50 ppbw mercury.
• the mercury level is at least 100 ppbw.
• less than 50% of the mercury can be removed by stripping (or more than 50% of the mercury is non- volatile).
• at least 65% of the mercury in the crude is non-volatile.
• at least 75% of the mercury is of the particulate or non-volatile type.
• In-situ Removal of Heavy Metals In one embodiment, the removal of heavy metals such as mercury and arsenic is simultaneous with the recovery of a produced fluid in a subterranean reservoir with the injection of a dilution fluid. In this method, a sufficient amount of fixing agent is added to the formation for the removal of heavy metals as oil and / or gas is being produced in the well.
• the in-situ removal occurs simultaneously with a water flooding in one embodiment, and with a fracturing process in another embodiment. Fracturing is a method for increasing the production of crude oil and gas from a fractured reservoir.
• Fractures can be generated in formations by means known in the art, e.g., pulsed power energy, gas fracturing, explosion, plasma stimulation, hydraulic fracturing, etc.
• Water injection or waterflooding is a widely applied method of improved oil recovery, wherein water is used as the dilution fluid for injecting into the rock formation through a system of injection boreholes to facilitate recovery of hydrocarbons from subsurface formations.
• a fracturing fluid is injected into the well at a rate and pressure sufficient to propagate a fracture adjacent to or in the well.
• the fracturing fluid is allowed to soak into the formation rock for a period of time, ranging from hours to days.
• the fracturing fluid is a dilution fluid which contains propping agents to maintain the fracture in a propped condition when the applied pressure is relieved, as well as a sufficient amount of a fixing agent for the removal of heavy metals.
• the fracturing fluid can also be an acid, e.g., HC1, to etch the fracture faces in the formation to form conductive channels facilitating the oil recovery.
• the fixing agent diffuses into the formation fractures and reacts with the heavy metals embedded in the formation, forming heavy metal complexes in the fracturing (dilution) fluid.
• the fluid containing extracted heavy metals flows back to the surface for recovery and subsequent treatment to remove extracted heavy metals and other contaminants.
• at least a portion of the fixing agent adsorbs onto the reservoir rock in the soaking process, for "treated rock" with embedded fixing agent.
• the heavy metal reacts with the embedded fixing agent forming heavy metal complexes.
• the heavy metal complexes are embedded and stay in the formation fractures for a produced fluid when recovered from the production well to effectively have a lower heavy metal concentration than a produced fluid from a well without the fixing agent in the fracture fluid.
• At least 25% of the heavy metal complexes stay in the formation fractures in one embodiment, at least 50% of the heavy metal complexes remain in the formation fractures in a second embodiment; and at least 75% in a third embodiment.
• the fixing reagent is exhausted from the formation, increasing amounts of heavy metals will be detected in the recovered produced fluids so that a new supply of fixing agent can be injected into the formation.
• the amount of heavy metals such as mercury remaining in the formation can be determined by measuring concentration of in-situ formation material before and after drilling and coring. The amount can be determined by analyses of adsorption on samples from the formation, e.g., core samples, cutting waste, produced water from the formation, etc.
• the fixing agent is added to a dilution fluid such as water for injection into the well, during any stage of the recovery, and on a continuous or intermittent basis. It can be added to the dilution fluid along with other additives, e.g., proppants, surfactants, electrolytes, etc.
• the fixing agent can also be added to the production well as a separate feed from the dilution fluid. It can be injected into the production well within less than thirty days of the injection of the dilution fluid or periodically over a period of a few months to allow for the soaking of the reservoir.
• the fixing agent can be provided in a dispenser with perforations positioned in the production tubing for continuous slow dissolution into the injected dilution fluid, as disclosed in US Patent Publication No.
• the well after the injection of the fixing agent into the reservoir, the well can be shut-in for some period of time to allow the fixing agent and optionally, other additives such as surfactants, etc., to imbibe into the matrix rock and thereby react with the heavy metals present in the oil, as the dilution fluid displaces the oil into the fracture system.
• the shut-in time can range from 2 hours to hundreds of days in one embodiment, and 2-10 days in another embodiment, and less than 30 days in a third embodiment.
• the fixing agent as dissolved in the injected dilution fluid flows through the subsurface or formation
• the injected dilution fluid such as water contains a sufficient amount of fixing agent, so as the water flows through subsurface or formation passageways may include pores in the formation matrix, fractures, voids, cavities, perforations and fluid passages through the wells, including cased and uncased wells, tubings and other fluid paths in the wells, causing the hydrocarbons trapped in the formation to move toward the production well.
• the fixing agent in the injected water reacts and extracts the heavy metals from the produced fluids into the injected water.
• the injected water travels through the rock formation at a speed of 0.1 to 20 m/day in one embodiment. In another embodiment, the water is heated while within the formation which facilitates the in-situ removal of heavy metals.
• the wastewater containing the heavy metal complexes is separated from the crude in a phase separation device known in the art, resulting in a crude oil with a significantly reduced level of heavy metals and a wastewater stream.
• additional chemical reagents such as complexing agents can be added to the mixture to facilitate the oil / water separation.
• the water phase after separation is diverted to treatment systems before re-injection back into the same reservoir or a different reservoir (after depletion), re-used for drilling or stimulation, or discharged where applicable or feasible.
• the water treatment is carried out to control any of excessive solids, dissolved oil, corrosion, chemical reactions, or growth of microbes.
• the wastewater can be treated to remove oil and followed by discharge to the sea in compliance with relevant regulations.
• Recovery of the treated crude oil with reduced levels of heavy metals, and treatment of the recovered water phase can be carried out using processes and equipment known in the art, including separators, hydroclone, mesh coalescer, filter, membrane, centrifuge and the like for the oil / water separation; ion exchange, electrodialysis, electrodialysis reversal, electrochemical, deionization, evaporation, electro-deionization, reverse osmosis, membrane separation, oxidation reactor, filtration, and combinations thereof can be used for the treatment of recovered water.
• Diluent Fluid for the In-situ Reaction The diluent fluid to be used for the in- situ reaction depends on the production fluids to be recovered, the state of the production, the location of the production well, amongst other factors.
• the dilution fluid is a lighter hydrocarbon, e.g., pentane, diesel oil, gas oil, kerosene, gasoline, benzene, toluene, heptane, and the like.
• the dilution fluid is non-potable water, e.g., connate water, aquifer water, seawater, desalinated water, oil field produced water, industrial by-product water, or combinations thereof.
• the dilution fluid may be a mixture comprising a mixture of an oil phase in water.
• the dilution fluid may be augmented with other additives such as scale inhibitors, surfactants, proppants, etc.
• the dilution fluid is from a water storage / treatment facility connected to a topside production facility, wherein produced water, seawater, etc., is recovered and prepared with the addition of additives, e.g., fixing agents needed for the removal of the heavy metals.
• the dilution fluid may be injected into the production well at cold, heated, or ambient temperature.
• the produced fluid such as crude oil is recovered in the same injection well for the dilution fluid and / or the fixing agent.
• the recovery is through a second well located some distance from the injection well referred to above.
• at least a portion of fixing agent may adsorb to the rock downhole or packing materials around the well. When hydrocarbons pass over the treated rock or the packing material, the fixing agent reacts with and extracts the heavy metals into the passing the dilution fluid for subsequent removal from the same production well, or a second well located some distance from the injection well. Dilution fluids are driven to the production well by formation re-compaction, fluid expansion and gravity.
• the well-servicing amount of injected dilution fluid depends on a number of factors including but not limited to the composition and salinity of the dilution fluid employed, the properties of the produced fluid to be recovered, the amount of produced fluids to be recovered, the characteristics of the formation rock, and the maturity of the field.
• the well-servicing amount as the volume ratio of dilution fluid to produced fluid ranges from 1 :3 to 60: 1 in on embodiment, from 2: 1 to 40: 1 in a second embodiment, and from 10: 1 to 30: 1 in a third embodiment.
• the fixing agent is a sulfur-based compound for forming sulfur complexes with the heavy metals.
• the fixing agent includes organic and inorganic sulfide materials (including polysulfides), which in some embodiments, convert the heavy metal complexes into a form which is more soluble in an aqueous dilution fluid than in a produced fluid such as shale oil.
• the fixing agent is a water-soluble monatomic sulfur species, e.g., sodium sulfides and alkaline sulfides such as ammonium sulfides and hydrosulfides, for the extract of mercury into an aqueous dilution fluid as soluble mercury sulfur complexes, such as HgS 2 2 ⁇ .
• the sulfur-based compound is any of hydrogen sulfide, bisulfide salt, or a polysulfide, for the formation of precipitates which require separated from the treated produced fluid by filtration, centrifugation, and the like.
• the fixing agent is an organic polysulfide such as di-tertiary-nonyl-polysulfide.
• the sulfur-based compound is an organic compound containing at least a sulfur atom that is reactive with mercury as disclosed in US Patent No. 6,685,824, the relevant disclosure is included herein by reference.
• Examples include but are not limited to dithiocarbamates, sulfurized olefins, mercaptans, thiophenes, thiophenols, mono and dithio organic acids, and mono and dithiesters.
• the fixing agent is an oxidizing agent which converts the heavy metal to an oxidation state that is soluble in water.
• Examplary fixing agents include elemental halogens or halogen containing compounds, e.g., chlorine, iodine, fluorine or bromine, alkali metal salts of halogens, e.g., halides, chlorine dioxide, etc; iodide of a heavy metal cation; ammonium iodide; iodine-potassium iodide; an alkaline metal iodide; etheylenediamine dihydroiodide; hypochlorite ions (OCl ⁇ such as NaOCl, NaOCl 2 , NaOCl 3 , NaOCl 4 , Ca(OCl) 2 , NaC10 3, NaC10 2 , etc.); vanadium oxytrichloride; Fenton's reagent;
• the fixing agent is selected from KMn0 4 , K 2 S 2 0g, K 2 Cr0 7 , and Cl 2 .
• the fixing agent is selected from the group of persulfates.
• the fixing agent is selected from the group of sodium perborate, potassium perborate, sodium carbonate perhydrate, potassium peroxymonosulfate, sodium peroxocarbonate, sodium peroxodicarbonate, and mixtures thereof.
• a complexing agent is also added to the fixing agent to form strong complexes with the heavy metal cations in the produced fluids, e.g., Hg 2+ , extracting heavy metal complexes from the oil phase and / or the interface phase of the oil-water emulsion into the dilution fluid by forming soluble complexes.
• complexing agents to be added to an oxidizing fixing agent examples include hydrazines, sodium metabisulfite (Na 2 S 2 0 5 ), sodium thiosulfate (Na 2 S 2 0 3 ), thiourea, thiosulfates (such as Na 2 S 2 0 3 ), ethylenediaminetetraacetic acid, and combinations thereof.
• the fixing agent is added to the dilution fluid for injection into formation first to oxidize the heavy metal, then the complexing agent is subsequently added to form a complex that is soluble in water.
• the complexing agent can be injected at intervals into the formation, or it can be subsequently added after the introduction of the fixing agent to the formation for the in-situ reaction.
• the fixing agent reacts with heavy metals such mercury, forming insoluble heavy metal complexes, e.g., mercury sulfide, which precipitate out of the hydrocarbons and dilution fluid and at least a portion remains in the reservoir.
• heavy metals such as mercury
• insoluble heavy metal complexes e.g., mercury sulfide
• fixing agents of this type may include sodium polysulfide, or polymeric compounds containing sulfide functional groups.
• the fixing agent can be added as in a solid form, or slurried / dissolved in a diluent, e.g., water, alcohol (such as methanol, ethanol, propanol), a light hydrocarbon diluent, or combinations thereof, in an amount sufficient for a molar ratio of fixing agent to heavy metals ranging from 1 : 1 to 20,000: 1 in one embodiment; from 50: 1 to 10,000: 1 in a second embodiment; from 100: 1 to 5,000: 1 in a third embodiment; and from 150: 1 to 500: 1 in a fourth embodiment.
• a diluent e.g., water, alcohol (such as methanol, ethanol, propanol), a light hydrocarbon diluent, or combinations thereof, in an amount sufficient for a molar ratio of fixing agent to heavy metals ranging from 1 : 1 to 20,000: 1 in one embodiment; from 50: 1 to 10,000: 1 in a second embodiment; from 100: 1 to 5,000: 1
• the amount as molar ratio of complexing agent to soluble mercury ranges from 2: 1 to about 3,000: 1 from one embodiment; from 5:1 to about 1,000: 1 in a second
• In-situ system 200 includes body of water 202, formation 204, formation 206, and formation 208.
• Production facility including processing equipment for the separation of water containing mercury complexes from the treated crude may be provided at the surface of body of water 202.
• Dilution fluid such as water containing a fixing agent is pumped down well 232, to fractured portions 234 of formation 206.
• Water containing a fixing agent traverses formation 206 to aid the in-situ removal of mercury and the production of oil and gas going to well 212 and subsequently to production facility 210.
• Well 212 traverses body of water 202 and formation 204, and has openings at formation 206. Portions of formation may be fractured and/or perforated as shown at 214.
• Water containing fixing agent(s) may be injected under pressure into injection zones 234 formed in the subsurface formation 206 to stimulate hydrocarbon production through the production wells in a field, and facilitate the mixing of the produced fluids with the fixing agent for the in-situ removal of mercury.
• sea water for offshore wells
• brine produced from the same or nearby formations for onshore wells
• Produced fluids from the earth's subsurface formation 206 can be recovered through production wellbore 212 with perforations 206 that penetrate hydrocarbon-bearing formations or reservoirs, facilitating the flow of the "treated" produced fluids as well from the hydrocarbon- bearing formations to the production wellbores.
• water production facility includes equipment to process water, for example from body of produced water 202 and/or waste water containing extracted mercury from well 212.
• the recycled water may be processed and stored in water storage 230 for recycle, for example by re -injection into well 232.
• FIG. 2 illustrates a second embodiment of a system 100 for the in-situ removal of heavy metals from a produced fluid.
• a vertical wellbore 101 comprising an outer sleeve 102 and an inner bore 103 driven into reservoir 105 is connected to a bottom wellbore portion 106.
• the bottom wellbore portion 106 comprises a perforated liner section 107 and an inner bore 108.
• dilution fluid e.g., produced water from water source 109 and the fixing agent is pumped down outer sleeve 102 to perforated liner section 107, where the injected water percolates into reservoir 105 and penetrates reservoir materials to yield a reservoir penetration zone.
• Crude oil in the formation flows down and collects at or around the toe 11 1 and may be pumped by a surface pump through inner bores 108 and 103 through a motor at the wellhead 114 to a production tank 115 where oil and the water mixture containing extracted heavy metal complexes are separated.
• the wastewater may be treated and recycled back into the reservoir as shown.
• Example 1 100 gram sample of formation material obtained from a drilling operation is crushed to 8-16 mesh and soaked in a solution of 1 wt% sodium sulfide

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• Chemical & Material Sciences (AREA)
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• Oil, Petroleum & Natural Gas (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Mining & Mineral Resources (AREA)
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• Geochemistry & Mineralogy (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Removal Of Specific Substances (AREA)

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• 2013
  • 2013-05-16 EP EP13791572.4A patent/EP2850157A4/de not_active Withdrawn
  • 2013-05-16 AR ARP130101704A patent/AR093279A1/es unknown
  • 2013-05-16 CN CN201380025179.XA patent/CN104583372A/zh active Pending
  • 2013-05-16 WO PCT/US2013/041433 patent/WO2013173634A1/en active Application Filing
  • 2013-05-16 AU AU2013262645A patent/AU2013262645A1/en not_active Abandoned
  • 2013-05-16 BR BR112014026597A patent/BR112014026597A2/pt not_active IP Right Cessation
  • 2013-05-16 CA CA2872808A patent/CA2872808A1/en not_active Abandoned
• 2014
  • 2014-11-13 CL CL2014003083A patent/CL2014003083A1/es unknown

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