EP3820963A1

EP3820963A1 - Sulphonated internal ketone-based formulations for assisted recovery of oil

Info

Publication number: EP3820963A1
Application number: EP19734440.1A
Authority: EP
Inventors: Mikel Morvan; Pascal Pitiot; Loïc BAUSSARON; Roberto COMPANY
Original assignee: IFP Energies Nouvelles IFPEN; Rhodia Operations SAS
Current assignee: IFP Energies Nouvelles IFPEN; Rhodia Operations SAS
Priority date: 2018-07-09
Filing date: 2019-07-05
Publication date: 2021-05-19
Also published as: FR3083562A1; US12006470B2; WO2020016025A1; CN112567002A; WO2020016025A8; CN112567002B; US20210269703A1; CA3105567A1

Abstract

The present invention relates to compositions for assisted recovery of oil, comprising: (A) alpha-sulphonated internal ketones of the ketone group; and (B) non-sulphonated internal ketones, with a molar ratio B/(A+B) greater than or equal to the limit molar concentration of non-sulphonated ketones, from which a stabilisation of the reduction in mobility is observed when the mixture of said ketones is introduced into a porous medium.

Description

Formulations based on sulfonated internal ketones

for enhanced oil recovery

The present invention relates to the field of petroleum extraction, and more particularly to techniques known as enhanced oil recovery.

During the extraction of petroleum from a hydrocarbon reservoir (petroleum reservoir such as a rock formation, consolidated or not, or a sand, for example), according to a first stage called "primary recovery", the petroleum is entrained out of a production well by the overpressure prevailing naturally within the reservoir. This primary recovery only gives access to a small quantity of the oil contained in the reservoir, typically of the order of 10 to 15% at most.

To allow further extraction of the oil following this primary recovery, secondary production methods are used, when the reservoir pressure becomes insufficient to move the oil still in place. Typically, a fluid is injected (re-injection of the water produced diluted or not, injection of sea or river water, or injection of gas, for example) into the hydrocarbon tank, with a view to exerting within the tank, an overpressure capable of entraining the oil towards the production well (s). A common technique in this context is the injection of water (also known as flooding or “waterflooding”), in which large volumes of water are injected under pressure into the reservoir via injector wells. The injected water entrains part of the oil it encounters and pushes it towards one or more producing wells. Secondary production methods such as water injection, however, only allow a relatively small portion of the hydrocarbons in place to be extracted (typically around 30%). This partial sweeping is due in particular to the trapping of the oil by the capillary forces, to the differences in viscosity and density existing between the injected fluid and the hydrocarbons in place, as well as to heterogeneities. at micro- or macroscopic scales (pore scale and also reservoir scale).

To try to recover the rest of the oil, which remains in the underground formations at the end of the implementation of the primary and secondary methods of production, it has been proposed different techniques called "enhanced oil recovery" (or enhanced recovery (or improved) of RAH hydrocarbons), or even "EOR" (for English "Enhanced OR Recovery"). Among these techniques, mention may be made of techniques akin to the aforementioned injection of water (flooding), but employing water comprising additives such as, for example, water-soluble surfactants (this is typically referred to as of "surfactant flooding"). The use of such surfactants in particular induces a reduction in the water / oil interfacial tension, which is capable of ensuring a more effective entrainment of the oil trapped in the pore constrictions.

The surfactants usually recommended for EOR are typically anionic surfactants, generally of the sulfate or sulfonate type. In particular, there has been described in application WO 2016/177817 compositions useful for EOR which comprise particular sulfonates, namely internal ketones sulfonated in alpha of the ketone group, more precisely mixtures of mono-sulfonated ketones (c that is to say sulfonated on only one of the alpha positions of the carbonyl group) and di-sulfonated (sulfonated on both positions). The compositions of WO 2016/177817 are typically obtained by sulfonation of internal ketones.

In the context of the work which led to the present invention, the inventors have now demonstrated that, in the most general case, mixtures of the type described in WO 2016/177817, and in particular the mixtures of the examples of this application patent, have a drawback in terms of transport in porous medium. More specifically, it turns out that the injection of mixtures of WO 2016/177817 leads to a constant increase in the reduction in mobility during the injection of the mixture, which translates into damage to the porous medium.

The “Mobility Reduction” (noted Rm), to which reference is made in the present description, is a well-known parameter in the field of petroleum extraction, and it is applied here to the injection of an aqueous solution surfactant. For a given aqueous solution of surfactant comprising at least one surfactant and an aqueous solvent medium (which can typically be water or brine), the value of the reduction in mobility is obtained from the Darcy relation: it corresponds the ratio between the value of the pressure drop measured during the injection of the aqueous solution of surfactants considered at a given flow rate (DR solution) compared to the value of the pressure drop measured, before injection of the surfactant solution, during the injection of the aqueous solvent medium without the surfactants (DR solvent):

Rm = DR solution / DR solvent In the case of a laminar flow of liquid in a porous section medium

S and of length L, Darcy's law is written: or :

Q represents the flow rate of a fluid of viscosity h,

DR represents the pressure drop caused by the fluid flow

k represents the permeability which can be defined as the hydraulic conductivity of the porous medium, which is expressed in Darcy (1 D "0.987 pm ² ). The reduction in mobility Rm defined above corresponds to the effective viscosity of the surfactant solution in the porous medium and it is by definition greater than 1. A surfactant solution proves to be all the more difficult to inject as its value of Rm is high.

Unless the ratio Rm is unduly high, the existence of an Rm does not in itself reflect a particular problem in terms of propagation of the fluid. On the other hand, an increase in the value of the reduction in mobility as the injection is continued reflects another problem, namely damage to the porous medium over time during the injection. It can typically be a clogging phenomenon of the porous structure. It is this problem which is encountered in the most general case with the compositions of the type described in WO 2016/177817. This problem is particularly marked for the relatively low flow rates which are obtained de facto within the porous formation.

An object of the present invention is to provide compositions based on sulfonated internal ketones, but not leading to this phenomenon of amplification of the reduction in mobility over time.

To this end, the inventors have demonstrated an original technical solution: it turns out that the effect of increasing the reduction in mobility can be counteracted by using the internal sulfonated ketones together with a sufficient quantity of non-internal ketones. sulfonated.

This result is all the more surprising since one would have expected, a priori, that the presence of compounds of the internal ketone type would induce an increase in the reduction in mobility: in fact, the internal ketones are similar to hydrophobic compounds, and it was therefore more logical to think that their use would induce the opposite phenomenon to that obtained. Even more remarkable, it turns out that the internal, unsulfonated ketones provide their inhibitory effect on the increase in the reduction in mobility only when they are used in a sufficient content. In other words, and contrary to what one could have intuitively supposed, the solution put forward by the inventors to avoid the increase in the reduction of mobility does not consist only in using additives which, in themselves, are rather likely to induce an increase, but also to use these additives in a significant proportion.

More specifically, and without wishing to be bound to a particular theory, the work carried out by the inventors in the context of the present invention shows that, if non-sulfonated internal ketones are added to a composition based on sulfonated internal ketones, there is a limit value of the molar concentration of non-sulphonated ketones (defined by the ratio of the quantity of non-sulphonated ketones compared to the total quantity of sulphonated and non-sulphonated ketones), hereinafter called "limit molar concentration" such that:

- for mixtures based on sulfonated and non-sulfonated ketones with a molar concentration of non-sulfonated ketones below the limit molar concentration, an increase in the reduction in mobility is observed over time when the mixture is injected into a porous medium;

- for mixtures based on sulphonated and non-sulphonated ketones with a molar concentration of non-sulphonated ketones greater than or equal to that of the limit molar concentration, the reduction in mobility reaches a limit value after a short stabilization period, and the reduction mobility then remains substantially stable over time.

For a given composition of sulfonated ketones and non-sulfonated ketones, the limiting molar concentration of non-sulfonated ketones can vary to a large extent depending on the sulfonated ketones and non-sulfonated ketones used. For a given composition, based on sulfonated ketones and specific non-sulfonated ketones, the limit molar concentration can be established experimentally by iteration, by testing a molar concentration of non-sulfonated ketones and by observing for this concentration the evolution obtained for the reduction mobility. If the reduction in mobility stabilizes, the molar concentration tested is greater than or equal to the limit ratio, otherwise it is lower. By testing several molar concentrations, it is thus possible to easily determine the limit molar concentration of non-sulphonated ketones for a given sulphonated ketone / non-sulphonated ketone system, by framing it by successive approaches.

In the most general case, the limit molar concentration of non-sulfonated ketones for a given sulfonated ketone / non-sulfonated ketone system is typically greater than 10% (it is for example of the order of 15% for the composition of the example illustrative described in more detail at the end of this description). Furthermore, in the context of the present invention, non-sulfonated ketones are preferably used as an additive, with a molar concentration of ketones not preferably less than 50%, typically less than or equal to 30%, or even 25 %.

According to a first aspect, the subject of the present invention is the advantageous compositions identified by the inventors, namely the compositions of sulfonated internal ketones comprising non-sulfonated ketones in an amount greater than or equal to the limit value allowing stabilization of the reduced mobility.

More specifically, the subject of the present invention is compositions comprising:

(A) internal ketones sulfonated in alpha of the ketone group; and

(B) non-sulfonated internal ketones, with a molar ratio B / (A + B), corresponding to the molar concentration of non-sulfonated ketones, which is greater than or equal to the limit molar concentration of non-sulfonated ketones from which a stabilization of the reduction in mobility is observed when injecting the mixture of said sulfonated internal ketones and said non-sulfonated internal ketones into a porous medium.

Typically, in a composition according to the invention, the molar ratio B / (A + B) is between 10% and 50%, and it is preferably less than 50%, in particular between 10 and

30%.

According to another aspect, the invention relates to the use of the aforementioned compositions for enhanced oil recovery.

In this context, the invention more specifically relates to an enhanced oil recovery process from an underground formation, in which:

- Is injected into said underground formation, by at least one injection well, a composition of the aforementioned type; and - recovering, by at least one production well, a fluid carrying the oil leaving the underground formation.

Various particular characteristics and embodiments of the invention will now be described in more detail. The internal ketones sulfonated in alpha of the ketone group

(compounds A)

The compounds A of the sulfonated internal ketone type which are present in the compositions of the invention are advantageously present in the form of a mixture including (i) mono-sulfonated internal ketones (that is to say sulfonated on a single alpha positions of the carbonyl group C = 0); and (ii) internal di-sulfonated ketones (ie sulfonated at the two alpha positions of the carbonyl group).

The ratio of mono-sulfonated internal ketones / internal di-sulfonated ketones is advantageously between 1: 99 and 99: 1, for example between 3: 97 and 97: 3; especially between 5: 95 and 95: 5

According to an interesting embodiment, the compounds A present in the composition of the invention comprise a mixture of at least one mono-sulfonate and at least one disulfonate corresponding respectively to formulas (1) and (2) below :

or :

each of Ri, R ₃ and R ₅ , identical or different, is, independently, a hydrogen or a linear or branched alkyl chain having from 1 to 20 carbon atoms;

each of R ₂ and R ₄ , which may be identical or different, is independently a linear alkyl chain or having from 4 to 24 carbon atoms, said alkyl chain possibly comprising cycloaliphatic groups; and

X is H; or -S0 ₃ X is a sulfonate salt formed with 1 / n mole of a cation X ^{n +} where n is the valence of the cation, this cation being advantageously chosen from the group consisting of ammonium cations NH and metal cations, especially alkaline and alkaline earth metals such as sodium, potassium, calcium and magnesium cations.

Preferably, each of R _1; R ₃ and R ₅ is hydrogen or an alkyl group having 1 to 6 carbon atoms, and it is preferred that each of R _1; R ₃ and R ₅ denote hydrogen, methyl, ethyl, propyl, butyl, pentyl or hexyl groups; and advantageously hydrogen.

Each of R ₂ and R ₄ preferably contains from 6 to 18 carbon atoms and more preferably from 6 to 14 carbon atoms.

The compounds of formula (1) and (2) are preferably obtained by sulfonation of internal ketones obtained from fatty acids or else from a mixture of fatty acids, typically using the Piria reaction. Fatty acids well suited as a starting point for the synthesis of the compounds of formula (1) and (2) include caprylic, capric, lauric, myristic, palmitic, stearic, arachidic, behenic, lignoceric, cerotic acids and their mixtures. One can also start from some of their derivatives, such as their esters and their anhydrides. Preferred fatty acids are caprylic, capric, lauric, myristic, palmitic, stearic, naphthenic, isostearic acids and their mixtures. One can in particular start from mixtures of fatty acids in the form of "cuts" obtained from vegetable or animal oils, in particular by saponification or alcoholysis. Good candidates are fatty acids from coconut oil or palm oil, which include fatty acids with 8 to 18 carbon atoms. The starting fatty acids can optionally comprise one or more ethylenic unsaturations, as is the case for example with oleic, linolenic or erucic acids. In general, however, it is preferred to avoid the presence of such unsaturations in view of the fact that the double bonds are subjected to sulfonation and therefore lead to mixtures of less defined structures than with alkyl chains devoid of double Nasions.

Other internal ketones suitable for the preparation of internal sulfonated ketones according to the invention are those derived from naphthenic acids.

The sulfonates of formula (1) or (2) can be obtained from a single internal ketone of well defined composition. Most often, the sulfonates of formula (1) or (2) are obtained from a mixture of several distinct internal ketones, whereby the sulfonated internal ketones are mixtures comprising several compounds of formula (1) and (2 ) with separate chain lengths.

Non-sulfonated internal ketones

(compounds B)

According to an advantageous embodiment, the compounds B present in a composition according to the invention correspond to the unsulfonated version of the compounds A present elsewhere. Thus, typically, when the compounds A are mono-sulfonate and di-sulfonate compounds corresponding respectively to the formulas (1) and (2) above, the compounds B preferably correspond to the formula (3) below:

or :

R _1; R _2, R ₃ , R ₄ and R ₅ have the abovementioned meanings; and

R ₆ is hydrogen or a linear or branched alkyl chain having from 1 to 20 carbon atoms, preferably hydrogen.

According to a particularly advantageous embodiment, a composition according to the invention is prepared by only partially sulfonating a compound of formula (3) or else a mixture of compounds of formula (3) using a sulfonating agent. A mixture of compounds of formulas (1) and (2) constituting the compounds A of the composition and residual compounds of formula (3) constituting the compounds B of the composition is then obtained.

According to this embodiment, the partial sulfonation of the compounds of formula (3) is advantageously carried out so that the molar concentration of non-sulfonated ketones at the end of the sulfonation is at least equal to the limit molar concentration ensuring stabilization reduced mobility. The partial sulfonation of the compounds of formula (3) can, in absolute terms, be carried out using any suitable sulfonating agent. For example by using a sulfonating agent, advantageously concentrated, chosen from sulfuric acid, sulfuric acid monohydrate, an oleum, chlorosulfonic acid, sulfamic acid and sulfur trioxide S0 ₃ .

According to an advantageous embodiment, the sulfonation is carried out using gaseous sulfur trioxide S0 ₃ as sulfonating agent, preferably using the falling film technique.

After the sulfonation, the reaction mixture can advantageously be subjected to ripening. Furthermore, it is generally advantageous to neutralize the reaction medium with a basic compound, typically NaOH, this neutralization being advantageously carried out with stirring, and preferably at a temperature of 40 to 100 ° C for 15 minutes to 5 hours, typically between 40 minutes and 3 hours.

Possible additives

A composition according to the invention can advantageously comprise a certain number of additives in addition to compounds A and B.

Thus, it is particularly advantageous for the composition according to the invention to comprise the compounds A and B within an aqueous medium comprising dissolved salts, typically a brine.

This aqueous medium containing dissolved salts preferably has a salinity similar to that of the underground formation in which the composition according to the invention is intended to be injected, which tends to improve the efficiency of the recovery of petroleum. Typically, the total salt content in a composition according to the invention is advantageously in the range between 1 to 200 g / L, preferably from 5 to 150 g / L.

As salts advantageously present in the composition of the invention, mention may in particular be made, without limitation, of the halides of alkali and alkaline-earth metals, such as NaCI, KCI, RbCI, CsCI, MgCI, BeCI2, CaCI ₂ .

A composition according to the invention generally comprises several distinct types of salt and the salt concentration to which reference is made corresponds to the total amount of all the salts present. Typically, in a composition according to the invention comprising a saline aqueous medium of the aforementioned type, the total concentration of compounds A and B within said saline aqueous medium is between 0.5 and 50 g / L, preferably between 1 and 30 g / L, for example between 2 and 20 g / L.

Furthermore, a composition according to the invention can advantageously comprise other additives, in particular additives improving the quality of oil recovery.

Thus, by way of nonlimiting example, a composition according to the invention may advantageously comprise additional surfactants, for example nonionic surfactants, chosen for example, if appropriate, from alkoxylated nonyl phenol, alkoxylated dinonylphenol, alkoxylates, in particular alcohol, branched at C8 to C20. Carboxylated, phosphated, sulfated surfactants, or other sulfonated surfactants than Compounds A. Surfactants of interest in the context of the present invention are the alkyl glyceryl ether sulfonates (AGES), for example obtained according to the methods described in US 3,024,273 or US 2,989,547.

AGES can be described by the following general formula:

R ₇ -0 - [- CH2-CH (0H) -CH2-0-] m-CH2CH (0H) -CH2-S0 ₃ Y (4) in which:

R ₇ represents a linear or branched alkyl or alkenyl chain typically having from 3 to 32 carbon atoms; m is equal to 0 or else m is an integer ranging from 1 to 20, preferably from 2 to 15; The cation is preferably chosen from the group consisting of sodium, potassium, ammonium, calcium or magnesium.

Other potentially useful additional surfactants in the context of the present invention are the alkoxylated alkyl glyceryl ether sulfonates or AAGES (for the alkoxylated alkyl glyceryl ether sulfonates) which correspond to the following formula (5):

R7-0 - [- CH2-CH (0H) -CH2-0-] _m - [- CH2-CH (CH3) -0] n - [- CH2-CH2-0] p-CH ₂ CH (0H) - H2-S03Y

(5) in which:

R ₇ , m and Y have the meanings given for the above formula (4); and each of n and p, identical or different, is an integer ranging from 0 to 20, preferably from 2 to 15, it being understood that n + p is not zero.

When compounds of AGES or AAGES type are present in a composition according to the invention, they are typically present at a content of between 0.5 and 50 g / L, preferably between 1 and 25 g / L.

According to a particular mode, AGES or AAGES can be used jointly, if necessary with an AGES / AAGES mass ratio between 1: 10 and 10: 1, preferably from 1: 5 to 5: 1.

Various aspects and advantages of the invention will be further illustrated by the example.

Illustrative given below

EXAMPLE

In this example, a mixture of ketones from the partial sulfonation of an internal ketone was used.

The internal ketone used is an internal C23-35 ketone which was obtained by Piria reaction catalyzed with magnetite.

Partial sulfonation was carried out using SO ₃ gas in a falling film reactor cooled by a double jacket with water, under the following conditions:

• S03 concentration in the air: 5% v / v

• sulfur feed rate: 1.5 kg S / h "assumed conversion S02 -> S03: 97%

• Internal ketone feed rate: 12.3 kg / h

At the end of the sulfonation, a mixture M of sulfonated and non-sulfonated internal ketones was obtained with the following concentrations (determined by NMR analyzes):

A. Internal sulfonated ketones Internal mono-sulfonated ketones: 43.7% by mole

Internal sulfonated ketones: 32.4% by mol

B. Residual non-sulfonated internal ketones:

24% by mole Part of the mixture M thus obtained was then treated according to the protocol below to remove the residual internal non-sulfonated ketones from it:

Dispersion of 30 g of mixture M on 70 g of silica in a solvent (CHCI3).

• Removal of the solvent using a rotary evaporator.

• Deposition on 330g silica column (flash chromatography) conditioned with 00% cyclohexanel.

• Elution of non-sulfonated residual internal ketones with

cyclohexane / AcOEt (80:20). After evaporation to dryness of this fraction, 4.4 g of orange wax are recovered (IK characterized in 1 H NMR)

• Elution of the rest of the sample with CH2CI2 / MeOH (80:20). After evaporation to dryness of this fraction, 24.1 g of a black oil are recovered.

• 23 g of this oil are introduced into a 500 ml flask and neutralized at 60 ° C with 2.2 equivalents of 2N sodium hydroxide based on the acidity of the sample measured in potentiometry.

• The neutralized crude is brought to room temperature and lyophilized to recover 26.3 g of brown solid.

At the end of the protocol, a MO mixture was obtained which is substantially free of residual internal ketones and essentially consists of the internal sulfonated ketones contained in the mixture M. From the mixtures M and MO, two compositions C and C0 were prepared for the tests. injection and having the formulations below:

Composition C: Composition CO: Mixture M: 2 g / l Mixture MO: 2 g / l

AGES Exx C13 7 PO 6 EO: 6 g / l AGES Exx C13 7 PO 6 EO: 6 g / l

NaCI: 81 g / l NaCI: 81 g / l

By mixing compositions C and CO in variable proportions, five Solutions 1 to 5 described in the table below were obtained, which have variable contents of residual internal ketones, reported in the column on the far right: the value reported , expressed as a percentage, corresponds to the molar concentration of compound A, namely the ratio A / (A + B).

Table 1 Composition of the solutions injected into the porous medium

Note: Solution 1 corresponds to composition C - Solution 2 corresponds to composition C0

The five solutions thus prepared were subjected to an injection test under the following conditions. Bentheimer-type rock samples of cylindrical shape and the characteristics of which are described in Table 2 were used as porous media to study the flow of the solutions described in Table 1.

Table 2 Characteristics of the porous medium

The test was carried out under the following conditions:

The system is maintained at 60 ° C in an oven. The fluid injection rate is 0.0165 ml / min (which corresponds to 15s ¹ shear suffered by the fluid during its propagation in the medium). Pressure sensors are used to measure the pressure difference across the porous medium. From the pressure measurements, the reduction in mobility Rm of the surfactant solution is determined.

The results of the Rm curves as a function of the volume of pore injected (VP) make it possible to establish for each solution the profile adopted for the evolution of the Rm.

These tests show that in this specific example, the value of the limit molar concentration of non-sulfonated internal ketones is of the order of 15% mol.

For solutions 1, 4 and 5 which correspond to compositions according to the present invention, and where the content of non-sulfonated residual internal ketones is sufficient, a stabilization of the value of Rm is obtained which rapidly ceases to diverge. On the contrary, for solutions 2 and 3, where the content is lower, the evolution profile is different, with a continuous increase in the reduction in mobility during the injection of the surfactant solution, which translates that the surfactant solution damages the porous medium.

Claims

1. A composition suitable for enhanced petroleum recovery, comprising: (A) alpha-sulfonated internal ketones of the ketone group; and

(B) non-sulfonated internal ketones, with a B / (A + B) molar ratio, corresponding to the molar concentration of non-sulfonated ketones, which is greater than or equal to the limit molar concentration of non-sulfonated ketones from which a stabilization of the reduction in mobility is observed when the mixture of said sulfonated internal ketones and of said non-sulfonated internal ketones is injected into a porous medium.

2. Composition according to claim 1, wherein the molar ratio B / (A + B) is between 10% and 50%.

3. Composition according to claim 1 or 2, in which the compounds A comprise a mixture of at least one mono-sulfonate and of at least one disulfonate corresponding respectively to formulas (1) and (2) below:

or :

each of R _1; R ₃ and R ₅ , which may be identical or different, is, independently, hydrogen or a linear or branched alkyl chain having from 1 to 20 carbon atoms;

X is H; or -S0 ₃ X is a sulfonate salt formed with 1 / n mole of a cation X ^{n +} where n is the valence of the cation.

4. Composition according to claim 3, in which the compounds B correspond to the formula

(3) below: or :

R _1; R _2, R ₃ , R ₄ and R ₅ are as defined in claim 3; and R ₆ is hydrogen or a linear or branched alkyl chain having from 1 to 20 carbon atoms.

5. Composition according to claim 4, which is prepared by only partially sulfonating a compound of formula (3) or a mixture of compounds of formula (3) as defined in claim 4, using a sulfonation.

6. Composition according to claim 5, in which the sulfonation is carried out using gaseous sulfur trioxide S0 ₃ as sulfonating agent.

7. The composition of claim 6, wherein the sulfonation is further conducted using the falling film technique.

8. Composition according to one of claims 1 to 7, which further comprises:

- an aqueous medium comprising dissolved salts; and / or an anionic surfactant, preferably an AGES or an AAGES

9. Use of a composition according to one of claims 1 to 8 for enhanced oil recovery.

10. Process for the enhanced recovery of petroleum from an underground formation, in which:

- Is injected into said underground formation, by at least one injection well, a composition according to one of claims 1 to 8; and

- Recovering, by at least one production well, a fluid carrying the oil leaving the underground formation.