PROCESS FOR TREATING PRODUCTION WATER FROM A PROCESS FOR ASSISTED OIL AND / OR GAS RECOVERY

专利摘要:
The present invention relates to a process for the treatment of production water from assisted hydrocarbon recovery, and containing Fe2 + ions, of at least partially oxidizing the Fe2 + ions by introducing at least one reaction activator and oxygen in said production water, the molar ratio introduced oxygen / Fe2 + ions being less than or equal to 0.25.
公开号:FR3054543A1
申请号:FR1657327
申请日:2016-07-28
公开日:2018-02-02
发明作者:Cedrick Favero；Ludwing Gil
申请人:SNF SA；
IPC主号:

专利说明:

® FRENCH REPUBLIC
NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number: 3,054,543 (to be used only for reproduction orders)
©) National registration number: 16 57327
COURBEVOIE © IntCI ⁸
C 02 F1 / 72 (2017.01), C 02 F 1/24
A1 PATENT APPLICATION
(§) Date of filing: 28.07.16. (© Applicant (s): SNF SAS Société par actions simpli- (30) Priority: trusted - FR. @ Inventor (s): FAVERO CEDRICK and GIL LUDWING. (© Date of public availability of the request: 02.02.18 Bulletin 18/05. (© List of documents cited in the preliminary search report: See the end of this brochure (© References to other related national documents: (© Holder (s): SNF SAS Simplified joint-stock company. ©) Extension request (s): @ Agent (s): LAURENT AND CHARRAS CABINET.
PROCESS FOR TREATING PRODUCTION WATER FROM AN ASSISTED RECOVERY OF OIL AND / OR GAS.
The present invention relates to a process for the treatment of production water originating from the enhanced recovery of hydrocarbons, and containing Fe ions, comprising at least partially oxidizing the Fe ²⁺ ions by introducing at least one reaction activator and of oxygen in said production water, the molar ratio of oxygen introduced / Fe ²⁺ ions being less than or equal to 0.25.
FR 3 054 543 - A1
PROCESS FOR TREATING PRODUCTION WATER FROM
ASSISTED RECOVERY OF OIL AND / OR GAS
FIELD OF THE INVENTION
The present invention relates to the technical field of enhanced recovery of hydrocarbons (oil and / or gas) in a deposit. More specifically, the present invention relates to the technical field of the treatment of production water from the enhanced recovery of hydrocarbons (oil and / or gas).
PRIOR STATE OF THE ART
Water treatment in the petroleum industry is a topic of primary importance as it is estimated that for every barrel of oil (oil) produced in the world, three barrels of water are generally co-produced. This co-production of water can reach 9 to 99 barrels of water per barrel of oil in mature fields which are often affected by enhanced chemical recovery of oil.
The recovery of crude oil contained in the deposits is generally carried out in several stages.
The production results initially from the natural energy of the fluids and the rock which decompresses. At the end of this depletion phase, the amount of oil recovered on the surface represents on average 5 to 15% of the initial reserve. It is therefore necessary, in a second step, to employ techniques aimed at increasing the recovery yield while maintaining the field pressure.
The most frequently used method is to inject water, and more generally brine, into the deposit through dedicated injection wells. This is called secondary recovery. This second phase stops when the water content in the mixture produced by the producing wells is too high. The gain here in terms of recovery rate of additional oil is around 5 to 20%.
The other usable techniques are grouped under the name of enhanced oil recovery (RAP or EOR for the English acronym for "Enhanced Oil Recovery"). Their goal is to recover between 10 and 35% of additional oil compared to the initial quantity. Various thermal techniques are known under the term of “enhanced oil recovery”, or not such as the so-called electric, miscible, steam or chemical techniques for improved recovery of the oil remaining in place (see “Oil & gas science and technology” - IFP review, vol 63 (2008) n ° l, pp 9-19). By petroleum is meant any type of oil, namely light oil as heavy oil, even bituminous. It is a mixture of hydrocarbons. The terms petroleum and oil are equivalent and both refer to this mixture of hydrocarbons.
The invention relates more specifically to the technique of enhanced recovery of hydrocarbons (petroleum and / or gas) by chemical means involving at least the injection into the deposit of an aqueous fluid containing one or more water-soluble polymers.
A distinction is made between enhanced oil recovery techniques (EOR) and reservoir stimulation operations. The latter are characterized by injections limited in volume of polymer solution in order to create a phenomenon localized in the reservoir, namely for the conformity a blockage of the zones of high permeabilities, for the "water shutt off" prevention or blockage of coming from water. The injections are generally made either by an injector well or by a producing well over fairly short periods of a few days and always less than a month, and with volumes representing less than 5% of the pore volume of the reservoir. The pore volume corresponds to the volume not occupied by the rock in the reservoir which is a permeable zone.
In contrast, enhanced oil recovery (EOR) techniques using polymers involve continuous and prolonged injection of polymer solution in order to sweep the reservoir from an injector well to a producing well. The goal is not to treat an area of the reservoir but its entirety in order to recover a maximum of oil (oil). For this, it is necessary to inject a much larger volume of aqueous solution generally between 50% and 500%, or even more, of the pore volume. At the level of the producing well (s), an aqueous, oily and sometimes gaseous mixture is then recovered which may contain the residues of the injected polymer.
The injection of a viscous polymer fluid according to the technique used is done alone or in combination with other chemical compounds useful for the improved recovery of petroleum.
In all of these techniques, the addition of water-soluble polymers makes it possible to improve the efficiency of sweeping by injection of water. The expected and proven benefits of using polymers, through the "viscosification" of the injected water, are improved sweeping and control of mobility in the field in order to recover the oil quickly and efficiently. These polymers increase the viscosity of the injection water.
It is known to those skilled in the art that synthetic water-soluble polymers and in particular based on acrylamide are very advantageous polymers for increasing the viscosity of aqueous solutions and are in fact, mainly used in enhanced recovery of hydrocarbons (petroleum and / or gas).
The polymers derived from acrylamides used are predominantly anionic and can in particular be obtained by:
• homopolymerization or copolymerization of acrylamide, ATBS, acrylic acid, • co-hydrolysis or post-hydrolysis of a polyacrylamide, • copolymerization or terpolymerization of acrylamide with other functional monomers, ionic or not.
Polyacrylamides are already widely used in enhanced recovery of hydrocarbons (petroleum and / or gas) in so-called "polymer", "surfactant polymer", "alkaline surfactant polymer" (P, SP, ASP) techniques.
The injected polymer goes during its injection, and its propagation in an underground formation undergo various mechanical, chemical and biological degradations. He will also see his concentration decrease. On leaving the well, the polymer is therefore not identical in quantity and in quality with respect to the injected polymer and can therefore give the aqueous part of the fluid produced a lower viscosity. In addition, the fluid (water + hydrocarbons), when the tank is swept, or when passing through the equipment, will be loaded with metals and / or H ₂ S.
The production fluid is treated so as to separate the production water and the hydrocarbons (oil and / or gas). The production water contains these possible metals and sulfur compounds such as H ₂ S. The production water also contains any degraded polymers and residual hydrocarbons, generally less than 10,000 ppm of residual hydrocarbons (petroleum and / or gas ).
The chemical degradation of polymers corresponds to the most difficult predictable and quantifiable mechanism because it can occur according to multiple mechanisms during the storage of the fluid, during the injection of the fluid, or within the reservoir.
The presence of viscosity in the production water affects the treatment of the aqueous phase. Treatment is necessary to allow, depending on the configuration, either a discharge into the environment or a reinjection into a tank.
Conversely, the presence of polymer is not troublesome if it does not generate excessive viscosity, generally not more than 2 centipoise. It is therefore not necessary to remove the polymer, but it is necessary to limit the viscosity which its presence in this aqueous part gives.
Various techniques for treating production water have been proposed. The simplest technique for small-scale, so-called "pilot" operations is to mix the produced fluid containing polymer with other fluids not including it. The viscosity of a polymer solution is a function, among other things, of its concentration. By the dilution effect of the aqueous phases, the viscosity will therefore be lower. This solution is only viable for small operations.
In large operations, the fluid must then be treated to reduce its viscosity. One of the solutions consists in removing the polymer by precipitation or by filtration.
The precipitation techniques consist in using cationic compounds which in interaction with the anionic charges of the polymer will cause its autocoagulation. As cationic compounds commonly used we can cite metallic salts such as aluminum or iron, cationic polymers with high charge density and low molecular weight such as polyDADMAC, EPI / DMA, DEC, or even mineral particles such as bentonites. , the kaolins.
Filtration techniques involve the use of membranes, such as ultrafiltration.
Removal of the polymer by precipitation or filtration is not desirable since it is generally difficult to selectively separate the polymer from the residual oil. In addition, existing techniques require multiple expensive steps and do not allow the recovery of residual oil.
The most suitable solution is to degrade the polymer chain to lower its molecular weight. Indeed, the interchain interactions of a polymer which generate viscosity are due to the molecular weight of the polymer. A polymer with a lower molecular weight will have less interchain interactions and therefore a lower viscosity. Three main types of degradation have been studied in order to reduce the molecular weight of the polymer.
The least effective is biological degradation because it requires several hours or several days to be significant. This type of treatment is not in line with the flow rates and residence times observed in the context of enhanced recovery of hydrocarbons (oil and / or gas).
The second technique is mechanical degradation of the fluid by shearing. This technique can be performed on a grid, slits or orifices, by rapid depressurization, by cavitation, by ultrasound ... The polymer is then broken into fragments of lower molecular weights. These treatments are effective but lead to a harmful reduction in the diameter of the oil drops to be purified afterwards. In addition, mechanical degradation can be restrictive because it requires high electrical power.
The third technique studied is chemical degradation. This degradation generally involves the generation of free radicals which will react with the main chain of the polymer and cause a drop in its molecular weight. This then results in a drop in viscosity of the injection fluid linked to a reduction in the hydrodynamic volume.
Free radicals can come from different sources. They can be generated by the cleavage of weak bonds in the polymer chain under the effect of heating / friction or by initiator residues or impurities from by-products. Red / ox systems also generate free radicals.
Application EP 2 450 314 proposes a process for treating production water in which the aim is to degrade the residual polymer present in the water resulting from an enhanced oil recovery process, by adding an agent excess oxidant to degrade the polymer, then add a sufficient amount of reducing agent to neutralize all of the excess oxidant.
Be that as it may, the various processes known to date do not make it possible to obtain a safe and effective treatment which reduces the residual viscosity while allowing the reuse of the production water thus treated without massive use of chemicals.
The Applicant has solved this technical problem by developing a process for treating water from the enhanced recovery of hydrocarbons (petroleum and / or gas) by introducing a specific quantity of oxidant in the presence of Fe ions. ²⁺ . This process thus makes it possible to obtain a suitable viscosity reduction for the different stages of the treatment of production water.
STATEMENT OF THE INVENTION
The present invention relates to a process for treating produced water from the enhanced recovery of hydrocarbons (oil and / or gas).
“Production water” means all salted or unsalted water, brines, seawater, aquifer water which can come from a hydrocarbon tank but also from any source of aqueous polymeric solution. Due to the presence of possibly degraded polymers, the production water generally has a viscosity called residual viscosity at the outlet of the production well.
As already indicated, the subject of the present invention is the treatment of this production water, and in particular the reduction of its viscosity.
More specifically, the subject of the present invention is a process for the treatment of production water originating from the enhanced recovery of hydrocarbons, and containing Fe ²⁺ ions, consisting in at least partially oxidizing the Fe ²⁺ ions by introduction of 'at least one reaction activator and oxygen in said production water. The molar ratio of oxygen introduced / Fe ²⁺ ions is less than or equal to 0.25.
As indicated, the production water comes from an enhanced hydrocarbon recovery process. The reaction activator activates the reaction of oxidation of Fe ²⁺ ions by oxygen and degradation of the polymer.
The reaction activator can be introduced before and / or during and / or after the introduction of oxygen. In other words, it can be introduced in one of the following modes of introduction:
before the introduction of oxygen; or during the introduction of oxygen; or after the introduction of oxygen; or before and during the introduction of oxygen; or before and after the introduction of oxygen; or during and after the introduction of oxygen; or before, during and after the introduction of oxygen.
Generally, the production water directly from the treatment of the production fluid (water + hydrocarbons) contains between 0 and 500 ppm of Fe ²⁺ .
When the amount of Fe ²⁺ initially present in the production water is zero or insufficient, Fe ²⁺ ions are added prior to the introduction of oxygen and optionally before, during or after the reaction activator. In this case, the Fe ²⁺ ions are added according to the means known to those skilled in the art. By way of example, it may be the introduction of the ferrous chloride or ferrous sulfate or Mohr salt compound.
Preferably the production water treated according to the process which is the subject of the invention contains at least 1 ppm (by weight relative to the weight of the production water) of Fe ²⁺ , advantageously between 1 and 300 ppm of Fe ^{2 +} , and more preferably between 5 and 50 ppm of Fe ²⁺ . These Fe ²⁺ ions can come directly from the production water. They may also have been introduced before implementing the process which is the subject of the invention.
Thus, according to a particular embodiment, the concentration of Fe ²⁺ ions is at least 1 ppm relative to the weight of the production water, the Fe ²⁺ ions being, where appropriate, introduced prior to introduction of oxygen and possibly activator. This embodiment is particularly suitable for the case where the production water naturally contains 0 ppm or less than 1 ppm of Fe ²⁺ ions.
According to a particular embodiment, the Fe ²⁺ ions are added before, during or after the optional activator but before the introduction of oxygen.
According to the invention, the production water initially contains between 0 and 500 ppb of oxygen, preferably between 0 and 300 ppb, more preferably between 0 and 50 ppb of oxygen. However, this possible quantity of oxygen naturally present in the production water is not sufficient to oxidize the iron II ions so as to cause the viscosity of the production water to decrease.
This is the reason why, the present invention cannot be implemented inherently. It is the voluntary addition of a controlled quantity of oxygen which makes it possible to solve the technical problem which is that of reducing the viscosity of the production water by controlled oxidation of Fe ²⁺ ion so as to degrade the polymers present in the production water and responsible for its residual viscosity.
Indeed, controlling the amount of oxygen introduced into the water makes it possible to limit the residual amount, and consequently the possible negative effects. These negative effects can notably concern the quality:
residual hydrocarbons which can be separated from the production water; and the water-soluble polymer solution used when the produced water is recycled for injection into an enhanced oil recovery process.
According to the invention, the oxygen is brought into contact with the production water by means known to those skilled in the art. This contacting is advantageously carried out in a hermetic manner, so that only the desired quantity of oxygen is introduced.
The quantity of oxygen introduced is defined as a function of the quantity of Fe ²⁺ ions present in the production water, in particular as a function of the following reaction:
Fe ²⁺ + 4 H ⁺ + O2 * 4 Fe ³⁺ + 2 H2O
Thus, according to a particular embodiment, the method according to the invention can comprise a step of assaying the Fe ²⁺ ions present in the production water.
The titration methods for ferrous iron (Fe ²⁺ ) are based on ASTM D 1068-77, Iron in Water. The principle of this measurement method is to react ferrous iron with 1,10-phenanthroline to form an orange complex making it possible to determine the concentration of Fe ²⁺ ions either comparatively compared to a preset concentration range or by spectrophotometric measurement compared to a white. The titration apparatus and the reagents are available from Hach or Chemetrics.
In known manner, the production water generally contains residual hydrocarbons, the amount of which is typically less than 10,000 ppm. The produced water can therefore be treated in order to extract these residual hydrocarbons (oil and / or gas).
Thus, according to a preferred embodiment, oxygen can be added at the start of the production water treatment process, that is to say after the separation between the hydrocarbons and the production water contained in the production fluid. This introduction of oxygen at this stage makes it possible to reduce the impact of viscosity as early as possible in the water purification process.
Thus, according to a particular embodiment of the invention, the production water is treated by separation of the production water with residual hydrocarbons, by flotation and / or decantation and / or coalescence and / or centrifugation and / or filtration advantageously carried out by passing over a filtering medium (sand, activated carbon, nut shells, etc.).
According to this particular embodiment, oxygen can in particular be introduced: during the separation step; or between the steps of separation and flotation and / or decantation and / or coalescence and / or centrifugation and / or filtration; or during the flotation and / or decantation and / or coalescence and / or centrifugation and / or filtration stage.
According to a particular embodiment of the invention, the introduction of oxygen can be carried out in a partial diversion of the production water.
Advantageously, between 0.25 and 7 ppm of oxygen is introduced into the production water, relative to the weight of the production water.
In addition, and optionally, a compressor can be used in order to increase the oxygen saturation, advantageously in the deviated fraction of the production water.
According to a particular embodiment, the production water is treated successively by:
separation of produced water and residual hydrocarbons; flotation of production water and / or decantation of production water and / or coalescence of production water and / or centrifugation of production water; filtration of production water;
and oxygen is advantageously introduced during the separation step.
According to another particular embodiment, the production water is treated successively by:
separation of produced water and residual hydrocarbons; flotation of production water and / or decantation of production water and / or coalescence of production water and / or centrifugation of production water; filtration of production water;
and oxygen is advantageously introduced between the separation and flotation and / or decantation and / or coalescence and / or centrifugation steps.
According to another particular embodiment, the production water is treated successively by:
separation of produced water and residual hydrocarbons; flotation of production water and / or decantation of production water and / or coalescence of production water and / or centrifugation of production water; filtration of production water;
and oxygen is advantageously introduced during the flotation and / or decantation and / or coalescence and / or centrifugation step.
The reaction activator (oxidation of iron II and degradation of the polymer) can in particular be chosen from the group comprising: stearyl citrate, monoammonic citrate, calcium citrate, disodium calcium ethylenediaminetetraacetate, monocalcium phosphate, tricalcium phosphate, calcium phytate, citric acid, ethylenediaminetetraacetate disodium, glycine, sodium tripolyphosphate, phosphoric acid, monopotassium phosphate, tetrapotassium pyrophosphate, dipotassium phosphate, sodium acid pyrophosphate, sodium citrate, tetrasodium pyrophosphate, monosodium phosphate, disodium phosphate, hexametaphosphate '-bis (2-hydroxybenzyl) -ethylenediamineΝ, Ν'-diacetic, N- (l, 2-dicarboxyethyl) -D, L aspartic, diethylene triamine pentacetic acid, humic acid, fulvic acid, polyacrylate, polyitaconate, polymaleate, and polyaspartate.
As already indicated, the activator can be introduced into the production water before and / or during and / or after the introduction of oxygen.
The amount of activator introduced into the production water is advantageously between 1 and 30 ppm, more advantageously between 5 and 20 ppm, relative to the weight of the production water.
Without wishing to formulate any theory, it would seem that the activator accelerates the decrease in the residual viscosity of the production water by accelerating the generation of the flow of radicals resulting from the reaction between the Fe ²⁺ ions and the oxygen O2.
In addition, and optionally, a deoxygenating agent may be added in order to remove the residual oxygen, in the last step, and therefore after the introduction of oxygen and the reduction in the viscosity of the production water.
This embodiment is optional since the quantity of oxygen resulting does not generally require the introduction of a reducing agent. The process which is the subject of the present invention is therefore preferably carried out in the absence of the addition of a reducing agent capable of eliminating any residual oxygen.
Anyway, this deoxygenating agent can in particular be chosen from the group comprising sulfite, bisulfite, metabisulfite, dithionite, hydrazine and hydrazine hydroxylamine derivatives. Document US 3,343,601 describes in particular the use of this type of agent for deoxygenating a polyacrylamide solution.
This deoxygenating agent acts as a reducing agent modifying the redox potential of the aqueous formulation. They may especially be organic sulfites such as alkyl sulfites, alkyl hydrosulfites, sulfmate, sulfoxylate, phosphites but also oxalic or formic acid, erythorbate salts, carbohydrazides.
These compounds are generally used to remove traces of oxygen present in the injection fluid / water and typically allow dissolved oxygen contents of less than 200 ppb (part per billion) to be achieved. Preferably, in accordance with the physico-chemical, toxicological and industrial criteria, the oxygen scavenging compounds of organic and inorganic sulfite type are particularly advantageous. Examples include Na2SO ₃ (sodium sulfite) and NaDT (sodium dithionite) or ammonium bisulfite.
At the end of this process for treating the production water according to the present invention, the production water advantageously contains less than 500 ppb of oxygen, preferably less than 300 ppb of oxygen, and even more preferably less than 100 ppb of oxygen.
There are online and point-in-time dissolved oxygen measurement methods. Online methods measure dissolved oxygen according to two principles, electrochemical and optical. The equipment is available from suppliers such as Presens, Mettler Toledo, Hach, WTW. Spot measurement methods are colorimetric methods using the oxidation of compounds such as indigo carmine and rhodazine D. Measuring equipment is available from Chemetrics.
In addition, at the end of this process for treating the production water according to the present invention, the production water advantageously contains less than 5 ppm of Fe ²⁺ , preferably less than 1 ppm of Fe ²⁺ , and even more preferably less than 0.5 ppm of Fe ²⁺ .
Furthermore, at the end of this process for treating the production water according to the present invention, the production water advantageously contains less than 100 ppm of Fe ³⁺ , preferably less than 10 ppm of Fe ³⁺ , and even more preferably less than 5 ppm of Fe ³⁺ .
Without wishing to formulate any theory, the Applicant considers that the oxidation of Fe ²⁺ ions leads to the formation of Fe ³⁺ ions and of radicals. Fe ³⁺ ions appear to degrade polymers much less. The formation of radicals during the oxidation of Fe ²⁺ ions makes it possible to reduce the residual viscosity by degrading the polymer. The treatment process therefore makes it possible to facilitate the formation of Fe ³⁺ while reducing the residual viscosity of the production water, the phenomenon being accelerated or even amplified by the presence of an activator.
The present invention also relates to a process for the enhanced recovery of hydrocarbons (petroleum and / or gas) using the water resulting from the treatment process described above. This process involves injecting a polymer solution into an underground formation and recovering the hydrocarbons. The injected polymer solution contains water from the production water treatment process described above.
Thus, at the end of this process for treating production water according to the present invention, when the production water is reinjected into the reservoir, at least one water-soluble polymer is added before injection into the underground formation.
The polymer is in practice a polymer or advantageously a copolymer based on acrylamide, acrylic acid, 2-acrylamido-2-methylpropane sulfonic acid or N-vinyl pyrrolidone.
The invention and the advantages which result from it emerge clearly from the following exemplary embodiments given in order to illustrate the invention and not in a limiting manner.
FIGURES
FIG. 1 represents a particular embodiment of the invention implementing a compressor for introducing oxygen into a deviated fraction of the production water.
EXAMPLES OF EMBODIMENT OF THE INVENTION
The decrease in viscosity of an aqueous polymer solution has been studied over time.
Protocol
A synthetic brine is prepared based on deionized water and the following salts:
- NaCl: 3.3 g / L
- CaCl ₂ , 2H ₂ O: 0.1 g / L
- MgCl ₂ , 6H ₂ O: 0.1 g / L
- NaHCO ₃ : 1.5 g / L
- Na ₂ SO ₄ : 0.2 g / L
Part of the brine is then degassed by bubbling with nitrogen under an anoxic atmosphere (less than 50 ppb of oxygen) for one hour.
A polymer solution is prepared in the degassed brine under an anoxic atmosphere. The polymer used is an acrylamide / acrylic acid copolymer (70/30 by weight), having a molecular weight of 7 million g / mol.
During the various tests, ferrous chloride, an activator (EDTA - Ethylene Diamine Tetra-Acetic) and non-degassed brine are added sequentially (oxygen content = 7 ppm) to the polymer solution so as to obtain a polymer concentration of 600 ppm.
The solution is kept stirring and the residual viscosity is measured at 5 minutes and 30 minutes (Brookfield viscometer, UL module at 6 rpm at 25 ° C; rpm = revolution per minute). At 30 minutes the residual oxygen content is measured.
All tests are carried out under an anoxic atmosphere (less than 50 ppb of oxygen).
CE-1 CE-2 CE-3 CE-4 CE-5 CE-6 INV-1 INV-2 Oxygen(PPm) 0 7 1 7 7 7 1 1 Iron II(PPm) 0 10 10 0 0 10 10 10 Activator(PPm) 0 0 0 0 20 15 20 5
Table 1: Quantities of oxygen, of Fe ²⁺ ions and of activator used in the counter examples (CE) and examples according to the invention (INV).
CE-1 CE-2 CE-3 CE-4 CE-5 CE-6 Viscosityinitial 10 10 10 10 10 10 Viscosity at5 minutes 10 7.5 10 10 9.5 6 Viscosity at30 minutes 10 5.5 8.5 10 9.5 6 Oxygenresidual30 minutes(ppm) 0 6 0.8 7 7 6
Table 2: Decrease in viscosity (cps) as a function of time for a solution according to the counter examples CE-1 to CE-6.
INV-1 INV-2 Viscosityinitial 10 10 Viscosity at5 minutes 6 7 Viscosity at30 minutes 5 5.5 Residual oxygen30 minutes(PPm) 0.1 0.3
Table 3: Decrease in viscosity (cps) as a function of time for a solution according to the examples according to the invention INV-1 to INV-2.
Acceptable viscosity degradation is achieved at high concentrations of oxygen and iron (CE-2 and CE-6) as well as at high concentrations of oxygen, iron and activator. In these two cases, the residual oxygen content remains high, which is a drawback in the process used due to the corrosion caused. A major advance is the use of an activator which combined with iron and a lower oxygen concentration (INV-1 and INV-2) will lead to a lowering of the viscosity and to a residual oxygen concentration of between 100 and 500 ppb. This low oxygen concentration can be reduced by a post addition of a reducing agent to maintain low oxygen contents.
In the following 3 counterexamples, the oxygen is replaced by another oxidant, sodium hypochlorite, as in document FR 2 966 820.
CE-7 CE-8 CE-9 Hypochloritesodium (ppm) 1 1 1 Fe II (ppm) 0 10 10 Activator (ppm) 0 0 5
Table 4: Quantities (in weight) of sodium hypochlorite, of Fe ²⁺ ions and of activator used in the counterexamples CE-7 to CE-9.
CE-7 CE-8 CE-9 Viscosityinitial 10 10 10 Viscosity5 minutes 10 8 8.5 Viscosity30 minutes 9.5 7.5 8.5
Table 5: Decrease in viscosity (cps) as a function of time for a solution according to the counterexamples CE-7 to CE-9.
Although using an oxidant described in the prior art, the drop in viscosity is not sufficient for this assay.
The reuse of treated water for dissolving a "new" polymer has been studied.
Two solutions containing 1000 ppm of an acrylamide / acrylic acid copolymer (70/30 by weight), having a molecular weight of 18 Million g / mol, are prepared. Each solution is prepared respectively with the treated water of the counterexample CE3 and of the example INV-1 according to the invention.
The viscosity of the solutions is measured at 20 ° C after 3 days after staying in an oven at 55 ° C.
The viscosity of the solution prepared with the treated water of the CE-3 counterexample is 16.5 cps.
The viscosity of the solution prepared with the treated water of example INV-1 according to the invention is 26.5 cps.
The results clearly demonstrate that the process according to the invention makes it possible to obtain water suitable for the dissolution of the polymer.

权利要求:
Claims (5)
[1" id="c-fr-0001]
Process for the treatment of production water originating from the enhanced recovery of hydrocarbons, and containing Fe ²⁺ ions, comprising at least partially oxidizing the Fe ²⁺ ions by introducing at least one reaction activator and oxygen in said production water, the molar ratio of oxygen introduced / Fe ²⁺ ions being less than or equal to 0.25.
Method according to claim 1, characterized in that the activator is introduced into the production water according to one of the following methods of introduction:
- before the introduction of oxygen;
- during the introduction of oxygen;
- after the introduction of oxygen;
- before and during the introduction of oxygen;
- before and after the introduction of oxygen;
- during and after the introduction of oxygen;
- before, during and after the introduction of oxygen.
Method according to claim 1 or
[2" id="c-fr-0002]
2, characterized in that the activator is chosen from the group comprising: stearyl citrate, monoammonic citrate, calcium citrate, disodium calcium ethylenediaminetetraacetate, monocalcium phosphate, tricalcium phosphate, calcium phytate, citric acid, ethylenediaminetetraacetate disodium, glycine, sodium tripolyphosphate, phosphoric acid, monopotassium phosphate, tetrapotassium pyrophosphate, dipotassium phosphate, sodium acid pyrophosphate, sodium citrate, tetrasodium pyrophosphate, monosodium phosphate, disodium phosphate, sodium hexametaphosphate, N acid, N'-bis (2-hydroxybenzyl) ethylenediamine-N, N'-diacetic, N- (1,2-dicarboxyethyl) -D, L aspartic, diethylene triamine pentacetic acid, humic acid, fulvic acid, polyacrylate, polyitaconate, polyaleate, and polyaspartate.
Method according to one of claims 1 to
[3" id="c-fr-0003]
3, characterized in that between 1 and 30 ppm of activator are introduced into the production water, relative to the weight of the production water.
5.
5 6.
7.
8.
9.
Method according to one of claims 1 to
[4" id="c-fr-0004]
4, characterized in that between 0.25 and 7 ppm of oxygen is introduced into the production water, relative to the weight of the production water.
Method according to one of claims 1 to 5, characterized in that the production water is treated successively by:
- separation of production water and residual hydrocarbons;
- flotation of production water and / or decantation of production water and / or coalescence of production water and / or centrifugation of production water;
- filtration of production water;
and that oxygen is introduced during the separation step.
Method according to one of claims 1 to 5, characterized in that the production water is treated successively by:
- separation of production water and residual hydrocarbons;
- flotation of production water and / or decantation of production water and / or coalescence of production water and / or centrifugation of production water;
- filtration of production water;
and in that oxygen is introduced between the separation and flotation and / or decantation and / or coalescence and / or centrifugation steps.
Method according to one of claims 1 to 5, characterized in that the production water is treated successively by:
- separation of production water and residual hydrocarbons;
- flotation of production water and / or decantation of production water and / or coalescence of production water and / or centrifugation of production water;
- filtration of production water;
and in that oxygen is introduced during the flotation and / or decantation and / or coalescence and / or centrifugation step.
Method according to one of claims 1 to 8, characterized in that the concentration of Fe ²⁺ ions is at least 1 ppm relative to the weight of the production water; and in that, if appropriate, Fe ²⁺ ions are introduced prior to the introduction of oxygen.
10. Process for the enhanced recovery of hydrocarbons consisting in injecting a polymer solution into an underground formation and in recovering the hydrocarbons, characterized in that the polymer solution contains water
[5" id="c-fr-0005]
5 resulting from the process which is the subject of one of claims 1 to 9.
1/1
Compressor oxygen
Polymer (s)
Production water
JL

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WO2018020175A1|2018-02-01|

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US20130213650A1|2010-07-06|2013-08-22|Jean-Francois Argillier|Optimized chemical enhanced recovery method|

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EP2450314A1|2010-11-03|2012-05-09|S.P.C.M. Sa|Method for treating production water produced at the end of a method for enhanced oil recovery using polymers|

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US20140072653A1|2012-09-07|2014-03-13|Clean Chemistry, Llc|System and method for generation of point of use reactive oxygen species|

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FR3012129A1|2013-10-23|2015-04-24|Total Sa|PROCESS AND UNIT FOR TREATING AN AQUEOUS COMPOSITION COMPRISING AT LEAST ONE POLYMER|

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CN102259993B|2011-06-27|2012-09-05|华南理工大学|Water treatment method utilizing complex-ferrous-activated persulfate oxidation|

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CN103011376A|2012-12-13|2013-04-03|同济大学|Method for oxidatively degrading chlorophenol substances by using EDTA -reinforced bimetal aluminum-iron system|

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US9267158B2|2013-03-14|2016-02-23|Intrexon Corporation|Biological production of multi-carbon compounds from methane|

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KR101549468B1|2013-11-29|2015-09-03|한국과학기술연구원|Curing hwangchil composition, preparing method for the same, and manufacturing method of hwangchil coating film|FR3064004B1|2017-03-20|2019-03-29|S.P.C.M. Sa|HYDRATED CRYSTALLINE FORM OF 2-ACRYLAMIDO-2-METHYLPROPANE SULFONIC ACID|

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US11046600B2|2018-07-11|2021-06-29|Kemira Oyj|Method for treating produced water|

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FR3088071B1|2018-11-06|2020-11-13|S N F Sa|ASSISTED OIL RECOVERY PROCESS BY INJECTION OF AN AQUEOUS POLYMERIC COMPOSITION|

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FR3088068B1|2018-11-06|2020-11-06|S N F Sa|AUTO INVERSIBLE REVERSE POLYMERIC EMULSION|

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FR3102482A1|2019-10-23|2021-04-30|IFP Energies Nouvelles|Process for treating aqueous fluid containing polymers using zirconium salts and alkali carboxylates|

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FR3102483A1|2019-10-23|2021-04-30|IFP Energies Nouvelles|Process for treating an aqueous fluid containing polymers using trivalent salts of iron and aluminum or divalent zinc and alkali carboxylates|

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FR3102484A1|2019-10-23|2021-04-30|IFP Energies Nouvelles|Process for the treatment of production water with alkali metal or metal citrates|

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FR3110912A1|2020-05-26|2021-12-03|S.P.C.M. Sa|Process for enhanced oil recovery in an underground carbonate formation|

法律状态:
2017-07-21| PLFP| Fee payment|Year of fee payment: 2 |

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2018-02-02| PLSC| Publication of the preliminary search report|Effective date: 20180202 |

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2018-07-28| PLFP| Fee payment|Year of fee payment: 3 |

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2018-11-09| TP| Transmission of property|Owner name: S.P.C.M. SA, FR Effective date: 20181009 |

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2019-07-23| PLFP| Fee payment|Year of fee payment: 4 |

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2020-07-27| PLFP| Fee payment|Year of fee payment: 5 |

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2021-07-29| PLFP| Fee payment|Year of fee payment: 6 |

优先权:

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申请号 | 申请日 | 专利标题

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FR1657327A|FR3054543B1|2016-07-28|2016-07-28|PROCESS FOR TREATING PRODUCTION WATER FROM A PROCESS FOR ASSISTED OIL AND / OR GAS RECOVERY|FR1657327A| FR3054543B1|2016-07-28|2016-07-28|PROCESS FOR TREATING PRODUCTION WATER FROM A PROCESS FOR ASSISTED OIL AND / OR GAS RECOVERY|

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US16/316,815| US11046601B2|2016-07-28|2017-07-27|Method for treating production water from a method for enhanced oil and/or gas recovery|

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PCT/FR2017/052117| WO2018020175A1|2016-07-28|2017-07-27|Method for treating production water from a method for enhanced oil and/or gas recovery|

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CN201780046927.0A| CN109641768A|2016-07-28|2017-07-27|The method that industrial water in the oil and/or Gas recovering method of enhancing is handled|

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CA3031387A| CA3031387A1|2016-07-28|2017-07-27|Method for treating production water from a method for enhanced oil and/or gas recovery|

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EP17754416.0A| EP3490940B1|2016-07-28|2017-07-27|Method for treating production water from a method for enhanced oil and/or gas recovery|