FR2736846A1 - Gel compsn., esp. for preparing water-based or foamed drilling fluids - comprises non-polar medium, multi-catenary surfactant which is soluble in medium, neutraliser and water with opt. addn. of emulsifier and solid filler - Google Patents

Abstract

Gel compsns. comprise: (a) a non-polar medium; (b) a liq. "multicaternary surfactant" (disclosed as having at least two hydrophobic chains attached to a hydrophilic head) which is in acid form and is soluble or dispersible in the medium; (c) neutralising agent present in amt. which is 2-30 (pref. 4-20) times the amt. required to neutralise the surfactant; (d) water in amt. of 0.2-5 (pref. 0.3-3) moles per mole of surfactant, at least part of the water being introduced with surfactant and/or neutralising agent; (e) opt. emulsifier capable of emulsifying the gel to aq. medium; and (f) opt. solid filler that is opt. soluble in medium.

Description

FOAMING AGENT BASED ON A SURFACTANT AGENT AND
FROM A SYSTEM IN APOLARY MIDDLE,
USE FOR THE EXCAVATION OF TUNNELS
The present invention relates to a foaming agent that can be used for the excavation of a tunnel.

 When excavating tunnels in different types of terrain, it is generally used devices called digging shields This type of device is composed of a metal cylinder or cutting disc1 driven in rotation about its axis, whose diameter corresponds to that of the tunnel to be excavated. This cutting disc carries slaughtering tools and / or crushing wheels allowing the excavation of the ground.

 When using this technique, a problem arises to avoid the collapse of the ground and especially the face as the excavation progresses.

 In order to stabilize the face of the face several solutions have been envisaged. In general, the stabilization is carried out using the pressure of the excavated earth and confined in a cutting chamber called containment chamber disposed at the rear of the cutting cylinder. The latter is provided with slots of openings allowing the passage of the cuttings towards the confinement chamber. The cuttings accumulated in the containment chamber can be removed by means of an extraction screw, usually arranged in a tubular body, and in which they form a movable plug. The quantities of excavated materials entering the containment chamber and the materials discharged from said chamber are generally carefully balanced to maintain a predetermined overpressure in the containment chamber.

 During the implementation of this type of technique, the cuttings are usually mixed with heavy sludge, in particular to facilitate their evacuation. However, these heavy sludges cause many disadvantages: in particular the need to implement a high capacity sludge production plant and the subsequent treatment of mud made muddy. To avoid these drawbacks, it is known to inject foam-generated foams at the front of the cutting disk by activating a solution of a surfactant. These mixtures of sludge and moss avoid the aforementioned drawbacks, but moreover these foams are deemed to reduce the friction of the cutting disk on the face of size, and give the cuttings a fluidity improving their evacuation.

 An object of the present invention is to provide a new foaming agent for the excavation of a tunnel.

Another object of the present invention is to provide a novel foaming agent
for the excavation of a tunnel to improve the fluidity of the cuttings, in particular
when excavating compact clays.

Another goal is to reduce the energy needed to evacuate
cuttings, particularly at the end of the extraction auger.

For these purposes, the invention relates to a foaming agent obtained by setting
solution in water:
at least one surfactant (TA),
and at least one preformed system (S) comprising:
at least one apolar medium (MApo),
. at least one zmulticatenary liquid surfactant in acid form (ATMC),
soluble or dispersible in said apolar medium,
. at least one neutralization agent (AN) of said multi-stranded surfactant ",
present in an amount corresponding to about 2 to 30 times, preferably 4 to 20 times
the quantity stoichiometrically necessary for the neutralization of said surfactant
active "multicatenary" in acid form (ATMC),
in the range of 0.2 to 5, preferably in the range of 0.3 to 3 molecules of water per
multicatenary liquid surfactant molecule in acid form (ATMC),
The water being introduced at least partly through said surfactant
in the acid form (ATMC) or via said
neutralization (AN),
and at least one hydrocolloid capable of thickening aqueous media, said surfactant (TA) being chosen from those capable of forming a foam with said system (S) in an aqueous medium.

 The process for preparing the foaming agent according to the invention first uses a surfactant (TA) which may be chosen from any type of surfactant that is soluble in water and compatible with the hydrocolloids capable of thickening the aqueous media forming part of the system (S). These surfactants must make it possible to form a foam and be chemically and thermally stable under the storage conditions. It may be a cationic surfactant, anionic or ionic.

Among the surfactants, there may be mentioned:
alkylsulphates of formula ROSO3M, where R represents a C5-C24, preferably C10-C18, allyl or hydroxyalkyl radical, M representing a hydrogen atom or an alkaline cation (sodium, potassium, lithium), substituted or unsubstituted ammonium (methyl-, dimethyl-, trimethyl-, tetramethylammonium, dimethylpiperidinium ...) or derived from an alkanolamine (monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, ...). Ammonium alkylsulphates prepared from lauric alcohol, especially natural lauric alcohol obtained by distillation of coconut alcohols, are preferably used.

betaines, aikybétaines, alkyidiméthylbétaines, alkylamidobétaines including those containing a C4-C18 alkyl radical such as alkylbetaines and alkylamidobétaines prepared from a fatty chain derived from coconut oil as well as alkylamidopropyldiméthylbétaines, alkyltriméthylsulfobétaines;
mixtures of alkylamidobetaines and of sodium alkylsulfosuccinates in which the alkyl radical is C4-C18 and in particular those derived from coconut oil;
the alkyl ether sulphates RO (CH 2 CHR 10) n SO 3 M where n is between 0.5 and 30, preferably between 0.5 and 10, where R 1 is a C 4 -C 18 alkyl group and having on average from 0.5 to 30 units, preferably from 0.5 to 10 oxyethylene and / or oxypropylene units, M representing a hydrogen atom or a cation of the same definition as above. Alkyl ether fillers prepared from lauric alcohol are preferably used.

. alpha olefin sulfonates;
. alkylpolyglycosides of formula R (OCH2CH2) n (G) m, where R is a hydrocarbon radical, linear or branched, saturated or unsaturated C8-C24, G is a reducing sugar Cs-C6 such as galactose, glucose or fructose, n being between 0 and 20 and m between 1 and 10.

 The process for preparing the foaming agent according to the invention then uses a preformed system (S) in an apolar medium.

By apolar medium is meant "(MApo) any liquid component at the preparation temperature of said system, which, located in the solubility space of Hansen (Handbook of solubility parameters and other cohesion parameters - Allan FM BARTON, CRC
Press Inc., 1983 -), presents the following parameters:
. d'P of Keesom interactions less than 1O (Jlcm3) 1R
. Hydrogen binding less than 10 (J / cm 3) 112
. ôD of London interactions greater than 15 (Jlom3) 112
By way of example of an apolar medium (MApo), mention may be made of:
. triglycerides of saturated or unsaturated fatty acids having at least 12 carbon atoms and preferably 14 to 20 carbon atoms; they may be synthetic or preferably natural triglycerides, such as vegetable oils such as rapeseed oil, soybean oil, peanut oil, butter oil, cottonseed oil, linseed oil, coconut, olive oil, palm oil, grapeseed oil, fish oil, castor oil, coconut oil,
. aromatic oil cuts,
the terpene compounds (D-limonene, L-limonene, etc.),
mixtures of diesters succinateladipatelglutarate dimethyl, dipropyl, diisobutyl, dibutyl ...

 aliphatic hydrocarbons containing at least 6 carbon atoms (isooctane, kerosene, gasoline, diesel oil, mineral oils, lubricating oils, etc.).

. aromatic solvents (anisole, toluene ...)
. chlorinated solvents (trichloro-1, 1, 1 ethane)
. essential oils.

 The preformed system (S) comprises a multi-stranded surfactant (ATMC).

The term "multi-stranded surfactant" (ATMC) is understood to mean any liquid surfactant consisting of at least two hydrophobic chains connected via a hydrophilic head, said surfactant being in acid form.

 By way of examples, there may be mentioned surfactants based on diester phosphates of saturated or unsaturated aliphatic alcohols, linear or branched C6-C, preferably C6-C20, or alkylphenols whose radical alkyl is preferably C6-C20, alkoxylated having from 2 to 20, preferably from 4 to 10 oxyalkylene units, preferably oxyethylene.

 The preformed system (S) comprises at least one neutralizing agent (AN) of said "multi-stranded" surfactant (ATMC), which is preferably liquid and non-soluble in said apolar suspension medium.

 Among these may be mentioned primary, secondary or tertiary amines, alkanolamines. By way of examples, mention may be made of triethanolamine, aminomethylpropanol, cocoamine, butylamine, etc.

 The amounts of zmulticatenary surfactant (ATMC) are generally of the order of 0.5 to 10%, preferably of the order of 1 to 6% by weight relative to the weight of said system.

 The hydrocolloids capable of thickening the aqueous media may be chosen from polysaccharides of bacterial origin, galactomannans, carrageenans, alginates, carboxymethylcelluloses, methylcelluloses, hydroxypropylcelluloses, hydroxyethylcelluloses, alkali metal polyacrylates and polyvinyl alcohols. polyethylene glycols, polyvinylpyrrolidones, alone or in combination with one another.

 Preferably, the hydrocolloids capable of thickening the aqueous media are chosen from guar gum and xanthan gum.

 The preformed system (S) may further optionally comprise an agent capable of emulsifying said system in water or in an aqueous medium.

 As an example of agent capable of emulsifying said system (S) in water or in an aqueous medium, mention may be made of ethoxylated tristyrylphenols, sulphates or phosphates of ethoxylated and / or propoxylated tristyrylphenols, ethoxylated and / or propoxylated acids or fatty alcohols. ethoxylated propoxylated block copolymers, sodium dodecylbenzene sulfonate.

According to a preferred embodiment of the invention, the preformed system (S) comprises:
- 100- (a + b + c + d) parts by weight of at least one apolar medium (MApo),
a quantity (a) of the order of 0.5 to 6, preferably of the order of 1 to 4 parts by weight of at least one "multicatenary" liquid surfactant in acid form (ATMC), soluble or dispersible in said apolar medium,
an amount (b) of at least one neutralization agent (AN) of said "multicatenary" surfactant, corresponding to about 2 to 30 times, preferably 4 to 20 times the amount stoichiometrically necessary for the neutralization of said surfactant; active "multicatenary" in acid form (ATMC),
a quantity (c) of water corresponding to approximately 0.2 to 5, preferably approximately 0.3 to 3, molecules of water per molecule of multicatenary liquid surfactant in acid form (ATMC), water being introduced at least partly through said "multicatenary" surfactant in acid form (ATMC) and / or through said neutralizing agent (AN),
and an amount (d) of the order of 10 to 50, preferably of the order of 20 to 40 parts by weight of at least one hydrocolloid capable of thickening the aqueous media.

The system (S) can be obtained by mixing its various constituents,
The neutralization agent (AN) and the "multi-stranded" surfactant (ATMC) are each introduced separately into the apolar medium (MApo). The neutralization agent (AN) is preferably introduced after the surfactant. multicenter (ATMC).

 A method of preparation of the system (S) consists in introducing, with mechanical stirring, the "multi-stranded" surfactant (ATMC) in the apolar medium (MApo) brought to a temperature of the order of 15 to 50.degree. 25-35 ° C, followed by the optional emulsifying agent, the neutralizing agent (AN) and the hydrocolloid.

 According to a variant of the invention, solid charges are also introduced into the water during the preparation of the foaming agent.

These solid charges can be chosen from:
. natural silica (sand, diatom, ...) or synthetic (precipitation, ...),
. calcium carbonate, magnesium carbonate,
. metal oxides such as iron oxide (hematite, magnetite, etc.),
. natural (ocher, ...) or synthetic pigments,
. foam regulators such as aluminum stearate, hydrophobic silica, ethylene bis stearamide,
. natural lime, extinct, hydro, ...

gypsum (anhydrite, hemihydrate),
. active ingredients such as phytosanitary compounds,
. basic compounds soluble in water such as sodium metasilicates, polysilicates, clays (kaolin, smectite, illite), talcs, mica, etc.

 The solid charges may represent at most 50% by weight of the surfactant mixture CTA) + system (S) + charges, preferably at most 20%, even more preferably at most 15%.

 The particle size is in general between 0.1 μm and 1 mm, preferably between 0.2 μm and 200 μm.

 These solid charges may be introduced for all or part in the water through the preformed system (S).

 Indeed, the system (S) used in the preparation of the foaming agent according to the invention may optionally comprise solid charges of the type defined above. They can be introduced into the system (S) once it has been prepared. Thus all or part of the desired amount of solid charges can be introduced through the system (S).

 In general, when a low rate of solid particles is introduced into the water, these are fully introduced through the preformed system (S).

 The solid charges can also be introduced into the water separately from the preformed system (S).

 In general, the introduction into the water of the preformed system (S), the surfactant (TA) and optionally the solid charges is followed by gentle stirring.

 The respective amounts of surfactant (TA) and preformed system (S) dissolved in water can be very variable depending on the application of the foaming agent. The surfactant content can thus be between 1 and 2000% by weight relative to the weight of the preformed system (S).

 The final amount in water of the surfactant is generally between 0.05 and 25% by weight relative to water, preferably between 0.05 and 15%, even more preferably between 0, 2 and 1.5%.

 The invention also relates to the use of the foaming agent according to the invention for the excavation of a tunnel, in particular by means of a digging shield, such as a shield with earth pressure.

 The composition of the foaming agent, in particular the respective amounts of the surfactant (TA) and the system (S), vary according to the nature of the terrain in which a tunnel is excavated. The person skilled in the art knows how to adapt the amounts of surfactant (TA) and system (S) containing hydrocolloids as a function of the ground dug.

 The foam can then be generated conventionally by introducing a compressed gas such as air or nitrogen into the foaming agent.

Preferably, the foaming agent is activated so that the coefficient of expansion
K, measured at atmospheric pressure, is between 5 and 10, the coefficient K being determined by the following relation:
vm
Go
where Vm is the volume of the foam after activation of the foaming agent in solution, and Va is the volume of the foaming agent in solution before activation.

 The activation of the foaming agent can be carried out conventionally in a foam generator. This foam can be injected by suitable means, in front of the cutting disk and / or in the confinement chamber where it mixes with the cuttings.

 The foam resulting from the composition according to the invention has several advantages.

 It allows to significantly reduce the friction of the cutting disc on the face of size.

 It has good stability although it is subjected to pressures above atmospheric pressure and shear stresses on the front of the cutting cylinder, in the confinement chamber and at the worm.

 This foam is also easily pumpable because of these plastic properties.

 It improves the fluidity of clay-based cuttings.

 The following examples are given for illustrative purposes.

Example 1 Foaming Agent in Sandy-gravelly Medium
- Preparation of the system (S)
The apolar medium (MApo) is placed in a 1 liter container.

 The "multi-stranded" agent (ATMC) is introduced at ambient temperature, with stirring using a Raynerie deflocculating blade marketed by Rayneri, rotating at 400 revolutions; it is stirred for a further 5 minutes.

 The neutralization agent (AN) is then introduced and stirred for 5 minutes.

 Finally, the hydrocolloid is added.

 After stirring for 5 minutes, the medium is allowed to stand for about 2 hours.

The following system is prepared according to the above procedure:

<tb><SEP> InveredlnfS <SEP> pats <SEP> in <SEP> aoldg <SEP>% <SEP> eo <SEP> oolds
<tb><SEP> oil <SEP> of <SEP> rapeseed <SEP> 335 <SEP> 67
<tb> LUBRHOPHOS <SEP> LL550 <SEP> 6 <SEP> * <SEP> 10 <SEP> 2
<tb><SEP> aminomethyl <SEP> propanol <SEP> 5 <SEP> 1
<tb><SEP> RHODOPOL <SEP> 23 <SEP> n <SEP> 150 <SEP> 30
<Tb>
* "Multicatal" surfactant based on C8-C14 ethoxylated phosphate diester, having 5.5 oxyethylene units, containing water in an amount of less than 2% by weight, marketed by Rhône-Poulenc
xanthan gum marketed by Rhône-Poulenc
- Preparation of foaming agent and foam
We introduce in water:
. the system (S) at a rate of 1% by weight relative to the weight of water,
. Rhodapex ABV from Rhone-Poulenc as a surfactant (TA) at a rate of 0.5% by weight relative to the weight of water, then this mixture is stirred with a pale stirrer and let stand a few minutes the composition obtained.

- Use of the foam
The composition is then injected into a foam generator and mixed with a sandy-gravelly soil saturated with 15% water at a rate of 2% by weight relative to the weight of the ground and the water of said ground.

 In order to control the fluidity of the ground mixed with the foam, a measurement is made with the Abrams cone of the ground: this is 15 cm. This measurement reflects the plastic behavior of the soil containing the foaming agent. On the other hand, the environment does not sediment.

This ground is easily pumpable and evacuable unlike a sandy ground without adding foam that has a rapid sedimentation and no plastic behavior
It is also noted that the ground does not adhere to the steels: The foaming agent thus makes it possible to reduce the friction with the toothed wheel.

Example 2 Foaming Agent in a Sandy Environment
The same system (S) is used as that of Example 1.

- Preparation of the foaming agent and the foam
We introduce in water:
. the system (S) at a rate of 1% by weight relative to the weight of water,
. Rhodapex ABV as surfactant (TA) at a rate of 0.8% by weight relative to the weight of water, then this mixture is stirred with a paddle stirrer and allowed to stand a few minutes the composition obtained.

- Use of the foam
The composition is then injected into a foam generator and mixed with sandy soil, having a large granular discontinuity of between 0.1 and 0.3 mm and a water content of 16%. The composition is introduced at a rate of 3% by weight relative to the weight of the ground and the water of said ground.

 In order to control the fluidity of the ground mixed with the foam, a measurement is made with the Abrams cone of the ground: it is 15 cm. This measurement reflects the plastic behavior of the soil containing the foaming agent. On the other hand, the environment does not sediment.

This ground is easily pumpable and evacuable unlike a sandy ground without adding foam that has a rapid sedimentation and no plastic behavior
It is also observed that the ground does not adhere to the steels: The foaming agent therefore makes it possible to reduce the friction with the toothed wheel.

Example 3 Foaming Agent in a Clay Medium
The same system (S) is used as that of Example 1.

- Prenaration of the foaming agent and the foam
We introduce in water:
. the system (S) at a rate of 0.1% by weight relative to the weight of water,
. Rhodapex ABV at a rate of 1.5% by weight relative to the weight of water, then this mixture is stirred using a paddle stirrer and the composition obtained is left for a few minutes.

- Use of the foam
The composition is then injected into a foam generator and mixed with a silty soil, having a clay content of between 15 and 18% and a water content of 15%. The composition is introduced at a rate of 10% by weight relative to the weight of the ground.

 In order to control the fluidity of the ground mixed with the foam, a measurement is made with the Abrams cone of the ground: it is 15 cm. This measurement reflects the plastic behavior of the soil containing the foaming agent. On the other hand, the environment does not sediment.

This ground is easily pumpable and evacuable unlike a sandy ground without adding foam that has a rapid sedimentation and no plastic behavior
It is also noted that the ground does not adhere to the steels: The foaming agent thus makes it possible to reduce the friction with the toothed wheel.

Claims (12)

1-foaming agent characterized in that it is obtained by dissolving in water: - at least one surfactant (TA), - and at least one preformed system (S) comprising:  at least one apolar medium (MApo),  at least one multicatenary liquid surfactant in acid form (ATMC),  soluble or dispersible in said apolar medium,  at least one neutralization agent (AN) of said "multicatenary" surfactant,  present in an amount corresponding to about 2 to 30 times, preferably 4 to 20 times  the quantity stoichiometrically necessary for the neutralization of said tensor agent  multi-stranded active acid (ATMC),  - from about 0.2 to 5, preferably from about 0.3 to 3 molecules of water per  molecule of "multicatenary" liquid surfactant in acid form (ATMC),  The water being introduced at least partly through said surfactant  "multicatenary" acid form (ATMC) and / or via said agent  neutralization (AN),  and at least one hydrocolloid capable of thickening the aqueous media, said surfactant (TA) being chosen from those capable of forming a foam in an aqueous medium with said system (S). 2- foaming agent according to claim 1 characterized in that the surfactant (TA) is selected from:  alkylsulphates of formula ROSO3M, where R represents a C5-C24, preferably C10-C18, allyl or hydroxyalkyl radical, M representing a hydrogen atom or an alkaline cation (sodium, potassium, lithium), substituted or unsubstituted ammonium (methyl-, dimethyl-, trimethyl-, tetramethylammonium, dimethylpiperidinium ...) or derived from an alkanolamine (monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, ...);  betaines, alkylbetaines, alkyldimethylbetaines, alkylamidobetaines, alkyltrimethylsulfobetaines;  mixtures of alkylamidobetaines and sodium alkylsulfosuccinates wherein the alkyl radical is C4-C18;  the alkyl ether sulphates RO (CH 2 CHR 10) n SO 3 M where n is between 0.5 and 30, preferably between 0.5 and 10, and where R 1 is a C 4 -C 18 alkyl group, and having on average from 0.5 to 30 units, preferably from 0.5 to 10 oxyethylene and / or oxypropylene units, M representing a hydrogen atom or an alkaline cation (sodium, potassium, lithium), substituted or unsubstituted ammonium (methyl-, dimethyl-, trimethyl-, tetramethylammonium, dimethylpiperidinium) , ...) or derivative of an alkanolamine (monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, ...);  alpha olefin sulfonates;  alkylpolyglycosides of formula R (OCH2CH2) n (G) m, where R is a linear or branched, saturated or unsaturated C8-C24 hydrocarbon radical, G is a C5-C6 reducing sugar, such as galactose, glucose or fructose, n being between 0 and 20 and m between 1 and 10. 3- foaming agent according to one of claims 1 or 2, characterized in that the apolar medium (MApo) is selected from triglycerides of saturated or unsaturated fatty acids having at least 12 carbon atoms and preferably from 14 to 20 carbon atoms, aromatic petroleum cuts, terpene compounds, mixtures of diester succinate / adipate / dimethyl glutarate, dipropyl, diisobutyl, dibutyl, aliphatic hydrocarbons containing at least 6 carbon atoms, aromatic solvents, chlorinated solvents and essential oils. 4. foaming agent according to one of claims 1 to 3, characterized in that the neutralization agent (AN) of said multi-stranded surfactant (ATMC) is liquid and insoluble in said apolar suspension medium. 5-foaming agent according to claim 4, characterized in that the surfactant wmulticaténaire (ATMC) is selected from surfactants based on diesters phosphates aliphatic alcohols saturated or unsaturated, linear or branched in / C6- C30, preferably C6-C20, or alkylphenols whose alkyl radical is C6-C30, preferably C6-C20, alkoxylated having from 2 to 20, preferably from 4 to 10 oxyalkylene units, preferably oxyethylene. 6. Foaming agent according to claim 5, characterized in that the neutralization agent (AN) is selected from primary amines, secondary or tertiary and alkanolamines. 7- foaming agent according to any one of the preceding claims, characterized in that the amount of "multicatenary" liquid surfactant (ATMC) is of the order of 0.5 to 10%, preferably of from 1 to 6% by weight relative to said system.  Foaming agent according to one of the preceding claims, characterized in that the hydrocolloid capable of thickening the aqueous media is chosen from polysaccharides of bacterial origin, galactomannans, carrageenans, alginates, carboxymethylcelluloses, methylcelluloses, hydroxypropylcelluloses, hydroxyethylcelluloses, polyacrylates of alkali metals, polyvinyl alcohols, polyethylene glycols, polyvinylpyrrolidones, alone or in combination with one another 9-foaming agent according to claim 9, characterized in that the hydrocolloid capable of thickening the media Aqueous is xanthan gum or guar gum. 10-foaming agent according to one of the preceding claims characterized in that the preformed system (S) further comprises an emulsifying agent capable of emulsifying said system in water or in an aqueous medium. 11. Foaming agent according to claim 10, characterized in that the agent capable of emulsifying said system in water or in an aqueous medium is chosen from ethoxylated tristyrylphenols, sulphates or phosphates of ethoxylated eticu propoxylated tnstyrylphenols, ethoxylated and / or propoxylated acids or fatty alcohols, ethoxylated / propoxylated block copolymers, sodium dodecylbenzene sulphonate. 12- foaming agent according to any one of claims 1 to 9, characterized in that the preformed system (S) comprises:  - 100 (a + b + c + d) parts by weight of at least one apolar medium (MApo)  a quantity (a) of the order of 0.5 to 6, preferably of the order of 1 to 4 parts by weight of at least one liquid surfactant Wmulticatenaire in acid form (ATMC), soluble or dispersible in said apolar medium  an amount (b) of at least one neutralization agent (AN) of said "multicatenary" surfactant, corresponding to about 2 to 30 times, preferably 4 to 20 times the amount stoichiometrically necessary for the neutralization of said surfactant; "multicatenary" in acid form (ATMC)  a quantity (c) of water corresponding to approximately 0.2 to 5, preferably approximately 0.3 to 3, molecules of water per molecule of multicatenary liquid surfactant in acid form (ATMC), water being introduced at least in part via said acid-bound multicatenary surfactant (ATMC) and / or through said neutralizing agent (AN)  and an amount (d) of the order of 10 to 50, preferably of the order of 20 to 40 parts by weight of at least one hydrocolloid capable of thickening the aqueous media. 13- foaming agent according to any one of the preceding claims, characterized in that is introduced further into the water solid charges. 14- foaming agent according to claim 13, characterized in that the solid charges are introduced for all or part in the water through the system (S). 15. Use of the foaming agent according to any one of the preceding claims for the excavation of a tunnel. 16. Use according to claim 15 for improving the fluidity of clay-based cuttings.