CA1106587A - Microemulsions usable for the recovery of petroleum from high temperature deposits containing water with a high salt content - Google Patents

Abstract

Microemulsions usable for the recovery of petroleum from high temperature deposits and whose water contains more than 60 g / liter of mono or divalent salts characterized in that they are composed of deposit water, a hydrocarbon, d 'an amphoteric surfactant and cosurfactants. The amphoteric surfactant is an alkyl betaine.

Description

6S ~ 37 ~ The invention relates to new compositions of ~.
microemulsions or micellar solutions of hydrocarbon and water containing polyvalent cations, in particular mono and divalent, ~.
at concentrations above 60 g / liter of surfactants and co-surfactants.
These new compositions have been perfected and developed for the recovery of petroleum from high temperature and high salinity concentrations high in ions such as: Sodium, Potassium, Calcium and Magnesium.
It is known to use, in the processes of recovery of hydrocarbons by injecting water, additives reducing the interfacial tension between water injected and formation oil. It has already been proposed many surfactant compositions, which added with appropriate amounts of oil and water provide a solution homogeneous and stable oil and water., in which water or the oil is present in an extremely divided form, say in the form of droplets of a size included between 100 and 1400 ~, - We know how to make distilled water microemulsions.
and a hydrocarbon comprising at least one surfactant and -cotensio-active. These mlcroemulsions are characterized: by their clarity when they consist of a trans hydrocarbon ~
parent, a micelle size in the range of 100 to 1500 and an indefinite stability over time.
. On the other hand, the formulation of microemulsions from of water containing mono and especially di.valent ions is made difficult from salt concentrations above 30. : ~
g / Liter, as is the case, in reservoir waters, which `~:

can contain 500 to 15,000 parts per million ions;
Calcium and / or magnesium. In this case, certain surfactants:

- 1 - ~

~ 6 ~ i87 lose their solubility, the micelles get bigger, the microemulsion becomes a classic emulsion and by ~ ois, even surfactants precipitate. This precipitation is harmful to the porosity and capillarity of the formation which retains oil and prevents displacement of this oil by injection of water.
The known microemulsions are generally composed at least one anionic surfactant chosen from the group of alkyl- or alkylaryl - sulfates, sulfonates, sulfosuccinates, sulfosuccinamates as described in the patent application r ~ lbl; é ~ sO ~ ~
French ~. 2,273,328.
Other microemulsions include at least one tensio-cationic active. These cationic surfactants are chosen in the group of quaternary ammonium compounds, or, derivatives fatty amines.
But these two types of ionic surfactants react smells strongly salted, may precipitate, and, to be strongly adsorbed on the mineral matrix constituting reservoir rock.
Other surfactants, of the nonionic group type hydrophilic polyethylene oxide, are soluble in the presence of high concentrations of salts but do not resist heat, even mixed with the surfactants described previously.
This is why the microemulsions which are the subject of the invention are formulated from:
- of water containing mono or divalent ions at a -concentration greater than 60 g / Liter.
- a hydrocarbon: crude oil - petroleum cut -Diesel - Kerosene, or refined fractions of crude oil, or liquefied petroleum gas - at least one surfactant ~ mphoteric - cosurfactants made up of alcohols.

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Amphoteric surfactants can be represented by the general formula:
R ~

Cn H2n + l- 1 - (CH2) m X

Where m is an integer ranging from 1 to 5 inclusive.
Rl and R2 are h ~ drocarbon groups containing 1 to 22 carbon atoms.
n is an integer ranging from 1 to 22 inclusive.
X can be a COO or SO3 group.
Among these surfactants, mention may be made of the families "
beta-sines, taurines and those of aminopropionic derivatives what ~
Amphoteric surfactants belonging to the ~ 'family beta`ines, and in particular to alkyl betaines are represented by the following general formula ~
1 ~ 3 D ~ ~
Rl - N CH2-C

In which R1, R2, R3 are hydro-carbon containing from 1 ~ 22 Carbon atoms.
Co-surfactants are chosen from the group of alcohols having from 1 to 10 carbon atoms, depending on their partition coefficient between water and oil. The examples and the following diagrams, given for information only but not '' ~ '' limiting, illustrate the invention and appreciate it ~ ' advantages.
~ In Figures 1 to 4 corresponding to each of ' formulations of the examples, a ternary diagram has been represented:
C) Surfactant / Cotensioactive, E) Deposit water, (P) Hydro-carbide.
We have the curve appear for each formula _ 3 _ , 6 ~

separating the field of homogeneous solutions or microemulsions located above said curve, from the composition domain multiphase located below said curve ~
The surfactant preferably used in examples is acetyl dimethyldodecylammonium chloride under form of sodium salt, 35% solution. It belongs to the family of alkylbetaines sold under the brand AM2 ~ IOSOL * by the chemical industries of Voreppc, and corresponds to the formula next :

\ CH Cl CH2-COONa _ _ - ~:
R is an alkyl chain corresponding to the distribution carbon of coconut fatty acids, acids C10 to C14 EXAMPLE I
- The deposit water contains 200 g / Liter of Na Cl.
- The oil is dodecane - The surfactant is of the al ~ ylbétalne type, of which R
: is a Coprah radical in aqueous solution containing 25% of active ingredient and 18% isopropanol.
. ~.
- The cosurfactants are N-hexanol and N-octanol combined in a mixture 50 - 50 by volume. The volume report surfactant / Cotensio-active varies from 0.1 to 1.5 ~ t it is preferably between 0.5 and 1.0. :
The microemulsion is prepared by simple méLan ~ e. :.

- Deposit water ~ :.
- Dodecane as a hydrocarbon - Of surfactant-cosurfactants mixture.
The curve of diagram 1 shows that one can obtain a wide range of microemulsions with 200 g reservoir water * trade mark.

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~, ~
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Na Cl / liter and dodecane, stable over time and at 80C.
EXAMPLE II Di a ~ ramme N2 The ternary diagram N2 defines the domain of existence tence ~ of microemulsions formulated with water at 100 g / l Ca2Cl, dodecane as oil and the same systems surfactant and alcohols as those described in Example I.
The resistance over time and to heat is the same as in Example I.
EXE ~ PLE III
Diagram N3 defines the domain of existence of microemulsions formulated with: water from a medium deposit-salted ment containing: -:
- 60 g / liter of Na Cl and - 15 g / liter of Ca C12 - dodecane - a mix of :
Amphosol * in 35% aqueous solution, with iso-propanol and hexanol, combined in a respective proportion tive in volume of 1/3 - 2/3. ~
The surfactant / alcohol ratio can vary ~:
from 0.25 to 4.5 ~
The stability of the microemulsions obtained is also good than in previous cases.
EXAMPLE IV
Diagram N 4 defines the domain of existence of stable and heat resistant microemulsions as can be get with:
- Highly salted reservoir water containing:
. 100 g / liter NaCl . 20 g / liter CaC12 - Dodecane - The surfactant system - cosurfactants of * brand of heart.
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Example III.
The volume ratio of surfactant / alcohol being from 0.30 to 4.50 ~

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Claims (6)

The embodiments of the invention, about which an exclusive right of property or privilege is claimed, are defined as follows: 1. Microemulsions usable for recovery petroleum in high temperature deposits containing high salinity water, characterized in that they are obtained by simple mixing - water containing more than 60 g / l of mono ion salts and divalent;
- a hydrocarbon;
- an amphoteric surfactant of formula:

in which R1 and R2 are hydrocarbon groups containing from 1 to 22 carbon atoms, n is an integer ranging from 1 to 22 inclusive, m is an integer ranging from 1 to 5 inclusive, and X? is chosen in the group constituted by CO O- and S O3-; and - co-surfactants. 2. Microemulsions according to claim 1, charac-in that the surfactant is chosen from the family of alkylbetaines of formula:

in which R is an alkyl chain corresponding to the distribution carbon tition of copra fatty acids, C10 to C14 acids. 3. Microemulsions according to claim 1, character-laughed at in that the surfactant is a sodium salt of the chloride acetyldimethyldodecylammonium. 4. Microemulsions according to claim 1, character-laughs in that the co-surfactants are chosen in the group of C 10 alcohols and are used in mixture two together. 5. Microemulsions according to claim 4, character-laughs in that the cotensio-active are chosen from the group that are n-hexanol, n-octanol and isopropanol. 6. Microemulsions according to claims 1, 3 or 5, characterized in that the surfactant / cotensio-assets range from 0.1 to 4.5 by volume depending on the concentration and the composition of reservoir waters.