WO2010049249A1 - Novel cementing fluid - Google Patents

Abstract

The present invention relates to cementing fluids for oil, gas, water, geothermal and similar wells. More precisely, the subject of the present invention is the use of silicone antifoam compositions in cementing fluids applicable for the cementing of such wells.

Description

 NEW CEMENT FLUID

TECHNICAL AREA

The present invention relates to cementation fluids for oil, gas, water, geothermal and similar wells. More specifically, the present invention relates to the use of silicone anti-foaming compositions in cementing fluids which are applicable to the cementing of such wells.

PRIOR ART

During the production of a particular oil well, drilling is carried out in the soil. A cementing of this drilling is necessary in order to consolidate the walls, to limit the movements of fluids between the different geological zones, to make it gas-tight and to protect it from corrosion.

To obtain good cementation, a casing is introduced into the borehole and a cement is injected via a pump into the annular space surrounding the casing. This cementing operation involves constraints on the cementing composition to be used. Firstly, the cement must be sufficiently fluid to be pumped over several meters and injected through thin-section tubes. In addition, the presence of air in the cement affects the quality of the cementation. Indeed, the mechanical properties of the cement are considerably modified by the presence of air bubbles which can, in particular affect its tightness and strength. Air bubbles are generated mainly during the brewing of the cement and its pumping, because of its low viscosity. To overcome the drawbacks associated with the presence of air bubbles, oil well operators have very quickly thought to integrate anti-foam compounds to cementing compositions.

In addition, the anti-foam compounds must be inert with respect to the other constituents of the cement. This is why silicone-based anti-foaming compounds are used by oil well operators when cementing their wells.

There are a large number of anti-foam formulations obtained from a mineral filler, most often silica particles, and a silicone oil adsorbed or physically and / or chemically bound to the mineral filler. This basic formulation can be emulsified with water in the presence of surfactants to give an emulsion antifoam. It is also possible to dilute these formulations in organic solvents such as olefins and paraffins, as described, for example, in patent application EP108354A1, in amines as described in the patent application published under the number WO2004 / 056445A1 and even in glycols as described in patent application EP0745648A1.

In the field of oil wells, it is the silicone emulsions which are most commonly used, as indicated in the French patent published under the number 2,787,105. The aqueous silicone emulsions have the advantage of being easily dispersible in the compositions cementing, which are essentially aqueous. Silicone emulsions are thus added during the manufacture of cementing fluids, without requiring a costly mixing operation in energy which would aim to ensure their dispersion.

One of the most commonly used silicone antifoam emulsions in cementing fluids is an oil-in-water silicone emulsion, which is described in patent application DE19620405A1. The oily phase is based on polydimethylsiloxane silicone oil, a silica filler and optionally a silicone resin. The aqueous phase contains water and ethoxylated surfactants as well as other surfactants such as glycerol monostearate or sorbitan monostearate, for example described in US5080828B or polyethylene glycol stearyl ether as described for example in the application US2007 / 0112078A.

TECHNICAL PROBLEM

Silicone antifoam emulsions, however, have the disadvantage of being unstable from 50 ^° C. Most of the oil drilling takes place in hot countries where the storage conditions of the anti-foaming compositions do not make it possible to ensure that they are dry. maintaining at a temperature below 30 ^° C., which constitutes the guaranteed temperature limit for this type of product. In addition, the products undergo significant temperature variations between day and night, which leads to the degradation of the quality of the emulsion. A separation of the aqueous phase and the oily phase is then observed and the heterogeneity of the mixture makes it unusable for its application to oil well cements. Indeed, a mixture out of phase (heterogeneous) loses its qualities of dispersibility in the cement. The addition of a phase-shifted silicone composition that will therefore not disperse well within the cementing fluid does not effectively control the amount of air that enters the cementing fluid. High temperature leads inevitably to the acceleration of the phenomenon of evaporation of the water present in the emulsion, which modifies its equilibrium and accentuates the coalescence of the oil droplets.

In addition, the surfactants used in these emulsions (in particular glycerol monostearates, sorbitan or stearyl polyethylene glycol ethers) are fusible at a temperature close to 50 ^° C. Their change in viscosity alters the quality of the emulsion and contributes all the more because of its phase shift.

Finally, the antifoam compositions diluted in organic solvents have, for their part, cost disadvantages, environmental problems and pose, as for the emulsions, problems of volume of material to be transported.

GOALS

In this context, one of the essential objectives of the present invention is therefore to provide a new silicone antifoam composition without organic solvent which is stable at 50 ⁰ C and self-dispersible.

Another essential objective of the present invention is to provide a cementing fluid which is pumpable over several meters and which does not contain air bubbles.

Another essential objective of the invention is to provide a new method of cementing a well, in particular a tanker.

All these objectives, among others, are achieved by the present invention which relates to a new cementing fluid characterized in that it comprises at least one anti-foam composition A autodispersible, stable at 50 ⁰ C and consisting of a phase continuous silicone, said composition comprising: from 78 to 99%, by weight relative to the total amount of said antifoam composition A, of at least one mixture B consisting of:

70 to 99.5% by weight, relative to the total amount of said mixture B, of at least one silicone oil whose viscosity is between 500 and 30,000 mPa.s,

0.5 to 10% by weight, relative to the total amount of said mixture B, of at least one particulate filler, 0 to 15% by weight, based on the total amount of said mixture B, of at least one silicone resin, optionally diluted in a silicone oil, and

0 to 1% by weight, based on the total amount of said mixture B, of at least one polycondensation catalyst of 0 to 5%, by weight relative to the total amount of said antifoam composition A, of an anti-foam additive, from 0.1 to 2%, by weight relative to the total amount of said antifoam composition A, of at least one dispersing agent chosen from the group of polyalkylene glycols, preferably a polyethylene glycol and,

from 1 to 15%, by weight relative to the total amount of said antifoam composition A, of at least one liquid surfactant or a solid surfactant with a melting temperature greater than 55 ° C.

All these objectives, among others, are achieved by the present invention which relates to a new cementing fluid characterized in that it comprises an effective amount of a self-dispersing anti-foam composition A, stable at 50 ^° C. and consisting of a continuous silicone phase, said composition comprising:

from 78 to 99%, by weight relative to the total amount of said antifoam composition A, of at least one mixture B consisting of:

70 to 99.5% by weight, relative to the total amount of said mixture B, of at least one silicone oil whose viscosity is between 500 and 30,000 mPa.s,

0.5 to 10% by weight, relative to the total amount of said mixture B, of at least one particulate filler,

0 to 15% by weight, based on the total amount of said mixture B, of at least one silicone resin, optionally diluted in a silicone oil, and

0 to 1% by weight, based on the total amount of said mixture B, of at least one polycondensation catalyst

from 0 to 5%, by weight relative to the total amount of said antifoam composition A, of an anti-foam additive,

from 0.1 to 2%, by weight relative to the total amount of said antifoam composition A, of at least one dispersing agent chosen from the group of polyalkylene glycols, preferably a polyethylene glycol, and from 1 to 15% by weight, based on the total amount of said antifoam composition A, of at least one liquid surfactant or a solid surfactant with a melting point above 55 ° C.

To achieve this objective, the inventors have had the merit of highlighting, quite surprisingly and unexpectedly, that a concentrated silicone composition does not need to be diluted in an organic or aqueous solvent, in order to be able to disperse in water without the aid of specific equipment (such as an Ultra-Turrax). It is important to note that the group of polyalkylene glycols here acts as a dispersing additive and they are added at a maximum of 2% by weight in the silicone antifoam compositions according to the invention.

The anti-foam compositions thus obtained can be stored at 50 ^° C. without losing their effectiveness. They also have the advantage of not containing solvents.

According to a preferred embodiment, the cementing fluid further comprises at least one hydraulic binder, water, optionally at least one latex and at least one autodispersible anti-foam composition A according to the invention and described above.

According to a preferred embodiment, the cementing fluid comprises at least one hydraulic binder, water, optionally at least one latex and an effective amount of a self-dispersible anti-foam composition A according to the invention and described above. .

For the purposes of the present invention, the term "effective amount" is understood to mean an amount of between 0.01 and 10% by weight, preferably between 0.05 and 1%, in particular between 0.05 and 0.5%, and even more preferably between 0.08 and 0.3%.

According to a preferred embodiment of the invention, the hydraulic binder is a cement, preferably selected from the following group: plaster, lime, pozzolan, prompt cement, Portland cement and mixtures thereof.

Preferred cements for the implementation of the invention are for example based on Portland cements conforming to classes A, B, C, G and H as defined by section 10 of the standards of the American Petroleum Institute (API). . Class G Portland cements are more particularly preferred, but other known cements of this art may be used profitably. By way of example of a latex useful according to the invention, mention may be made, without limitation, of the latices prepared by the emulsion polymerization technique, for example the styrene-butadiene copolymer-based latices, possibly with the presence of a latex. third monomer carboxylate type, sulfate or sulfonate, commercially available under many names.

The cementing fluids according to the invention may also comprise other additives common to most cementing compositions, such as, for example, dispersants, suspending agents, retarders or accelerators for setting the cement or agents for controlling the filtrate.

According to another preferred embodiment of the invention, the silicone oil is chosen from α, ω-bis (trialkyl) -polydialkylsiloxane oils, preferably α, ω-bis (trimethyl) polydimethylsiloxane oils.

According to an even more preferred embodiment of the invention, the α, ω-bis (trimethyl) polydimethylsiloxane oils are chosen from those having a viscosity of between 500 and 10,000 mPa.s, preferably of 500 to 5000 mPa.s. .

All viscosities referred to herein correspond to a dynamic viscosity quantity which is measured, in a manner known per se, at 25 ^° C. The viscosities are measured using a BROOKFIELD viscometer according to the indications of US Pat. AFNOR NFT 76 106 of May 1982. These viscosities correspond to a dynamic viscosity variable at 25 ^° C., known as "Newtonian", ie the dynamic viscosity which is measured, in a manner known per se, with a Shear rate gradient sufficiently low that the measured viscosity is independent of the velocity gradient.

The particulate filler is preferably selected from treated or untreated precipitated silicas, treated or untreated fumed silicas and mixtures thereof.

By way of illustration, the resin may be an organopolysiloxane resin comprising siloxyl units (CH3) 3SiOi / ₂ (M units) _and SiO _4Z2 (Q units), optionally diluted in a silicone oil, for example an α, co-bis oil. (trialkyl) -polydimethylsiloxane. The presence of hydroxyl units in the organopolysiloxane resin is not excluded.

As an example of a polycondensation catalyst, mention may be made of a potassium silanolate having a KOH alkalinity level of 15% by weight. According to another preferred embodiment of the invention, the antifoam additive is an alkylene oxide copolymer chosen from ethylene oxide and propylene oxide copolymers and their mixtures, preferably the block copolymers of ethylene oxide and propylene oxide.

According to a preferred variant of the invention, the surfactant is a liquid surfactant chosen from linear or branched polyalkoxylated fatty alcohols, preferably a polyethoxylated fatty alcohol. These fatty alcohols promote the dispersion of the antifoam composition according to the invention in aqueous media, such as the cementing fluid.

According to another of its aspects, the present invention relates to a self-dispersing antifoam composition A, stable at 50 ^° C. and consisting of a continuous silicone phase comprising: from 78% to 99%, by weight relative to the total amount of said antifoam composition A, at least one mixture B consisting of:

70 to 99.5% by weight, based on the total amount of said mixture B, of at least one silicone oil having a viscosity of between 500 and 30,000 mPa · s, 0.5 to 10% by weight , with respect to the total amount of said mixture B, of at least one particulate filler,

0 to 15% by weight, based on the total amount of said mixture B, of at least one silicone resin, optionally diluted in a silicone oil, and 0 to 1% by weight, based on the total amount of said mixture B, at least one polycondensation catalyst

from 0 to 5%, by weight relative to the total amount of said defoaming composition A, of an anti-foaming additive, of from 0.1 to 2%, by weight relative to the total amount of said composition antifoam A, at least one dispersing agent selected from the group of polyalkylene glycols, preferably a polyethylene glycol, and

from 1 to 15%, by weight relative to the total amount of said antifoam composition A, of at least one liquid surfactant or a solid surfactant with a melting temperature greater than 55 ° C. The anti-foaming compositions thus obtained can be stored at 50 ^° C. without losing their effectiveness. These compositions do not contain an organic or aqueous solvent. It should be noted that the polyalkylene glyco Is here act as a dispersing additive and they are added at a maximum of 2% by weight in the silicone anti-foaming compositions according to the invention.

According to a preferred embodiment of the invention, the silicone oil is chosen from α, ω-bis (trialkyl) -polydialkylsiloxane oils, preferably α, ω-bis (trimethyl) polydimethylsiloxane oils.

It is advantageous to choose the α, ω-bis (trimethyl) polydimethylsiloxane oils from those having a viscosity of between 500 and 10,000 mPa.s, preferably of 500 to 5000 mPa.s.

The particulate filler is preferably selected from treated or untreated precipitated silicas, treated or untreated fumed silicas and mixtures thereof.

The antifoam additive is preferably an alkylene oxide copolymer selected from ethylene oxide and propylene oxide copolymers and mixtures thereof, preferably ethylene oxide and ethylene oxide block copolymers. propylene oxide.

A surfactant useful according to the invention is a liquid surfactant chosen from linear or branched polyalkoxylated fatty alcohols, preferably a polyethoxylated fatty alcohol. These fatty alcohols promote the dispersion of the antifoam composition in aqueous media.

The other components of the autodispersible anti-foam composition A are as described above for the cementing fluid according to the invention.

The present invention also relates to the use of an anti-foam composition

A self-dispersible as defined above in cementing fluids and in particular in well cementing fluids for the extraction of oil, gas, water or geothermal.

Finally, the last subject of the invention relates to a method for cementing oil, geothermal, gas and water wells and the like, characterized in that drilling of the soil, the cementing fluid is pumped as described above, and then said cementing fluid is injected along the walls of the borehole.

Other advantages and features of the present invention will appear on reading the following examples given by way of non-limiting illustration.

EXAMPLES

1) Preparation of anti-foam compositions

Mixture B-I:

Mixed in an IKA reactor:

93 parts by weight of polydimethylsiloxane oil with trimethylsiloxyl ends, viscosity 1000 mPa.s., and

7 parts by weight of hydrophobic combustion silica marketed by DEGUSSA under the name SIPERNAT D-10.

Then, it is heated for 1 hour at 80 ^° C.

Mixture B-2:

In an IKA reactor, 82 parts by weight of polydimethylsiloxane oil having trimethyl siloxy ends and having a viscosity of 12500 mPas were mixed.

13 parts by weight of a solution at 30% by weight of an organopolysiloxane resin containing (CH ₃₎ 3 SiO / ₂ (M units) _and SiO _4/2 (Q units) with a M / Q ratio of 0.7 / 1 (44% M and 56% Q) in a polydimethylsiloxane oil with trimethyl siloxy ends, 1 part by weight of polycondensation catalyst, and

4 parts by weight of hydrophobic combustion silica AEROSIL A200 sold by DEGUSSA. Then, heating for 3 hours at 15O ⁰ C.

Mixture B-3:

Mixed in an IKA reactor:

74.7 parts by weight of polydimethylsiloxane oil with trimethyl siloxy ends, viscosity 1000 mPa.s,

5.6 parts by weight of SIPERNAT D-10 silica and 19.7 parts by weight of the mixture B-2 described above.

Then, it is heated for 1 hour at 75 ^° C. Example 1 - Antifoam composition 1-1 according to the invention:

The anti-foam composition 1-1 according to the invention is obtained by mixing:

93 parts by weight of the mixture B-I,

1 part by weight of EMPILAN P7061 block copolymer of ethylene oxide and propylene oxide marketed by HUNTSMAN,

1 part by weight of PEG 400, polyethylene glycol of average molecular weight 400 g / mol, and

5 parts by weight of RHODIASURF ROX, 85% aqueous solution of an ethoxylated fatty alcohol sold by RHODIA.

Example 2 Anti-Foam Composition 1-2 According to the Invention

The anti-foam composition 1-2 according to the invention is obtained by mixing:

88 parts by weight of the mixture B-I,

1 part by weight of EMPILAN P7061, 1 part by weight of PEG 400, and

10 parts by weight of RHODIASURF ROX.

Example 3 - Anti-Foam Composition 1-3 According to the Invention

The antifoam composition 1-3 according to the invention is obtained by mixing: 93 parts by weight of the mixture B-2,

1 part by weight of EMPILAN P7061, 1 part by weight of PEG 400, and 5 parts by weight of RHODIASURF ROX.

EXAMPLE 4 Anti-Foam Composition 1-4 According to the Invention

The antifoam composition 1-4 according to the invention is obtained by mixing: 93 parts by weight of the mixture B-3, 1 part by weight of EMPILAN P7061, 1 part by weight of PEG 400 and 5 parts by weight of weight of RHODIASURF ROX.

Comparative C-I (oil-in-water emulsion - continuous water phase):

The anti-foam emulsion C-I is obtained by mixing:

30 parts by weight of the mixture 1, 3.1 parts by weight of PEG 40 stearate,

6.9 parts by weight of sorbitan monostearate, and 60 parts by weight of water. Comparative C-2 (with a polydimethylsiloxane oil of viscosity <500 mPa.s):

The anti-foaming composition C-2 is prepared by mixing and then heating for 1 hour at 80 ^° C., 84.6 parts by weight of polydimethylsiloxane oil with trimethylsiloxy ends, viscosity 100 mPa.s,

6.4 parts by weight of silica SIPERNAT D-10,

2 parts by weight of a fluidifying additive,

1 part by weight of EMPILAN P7061, 1 part by weight of PEG 400 and,

5 parts by weight of RHODIASURF ROX.

Comparative C-3 (without polyalkylene glvcol):

The anti-foaming composition C-3 is prepared by mixing, then heating for 1 hour at 80 ^° C., of:

88.2 parts by weight of polydimethylsiloxane oil with trimethyl siloxy ends, viscosity 100 mPa.s,

2 parts by weight of hydroxyl ends polydimethylsiloxane oil of viscosity 50 mPa.s, 3.7 parts by weight of AEROSIL A200 silica and,

4.9 parts by weight of a nonionic liquid surfactant ALCODET 218 marketed by RHODIA.

2) Evaluation of anti-foam compositions

2-a-Stability of antifoaming compositions

The stability of the antifoaming compositions is evaluated visually on two criteria:

• Presence of phase shift: the phase shift is proven when one observes a supernatant layer of oil without silica on the surface of the silicone composition. The phase shift of the antifoam composition is unacceptable because the heterogeneity of the mixture does not ensure the anti-foaming properties.

• Gelling and caking of the antifoam composition that makes it unfit for use.

Table 1 summarizes the appearance (noted "yes" in Table 1 below) or not (noted "no" in the following Table 1) of a phase shift after different storage times at room temperature and at 50 ⁰ C . Table 1: Evolution of the appearance of anti-foam compositions after different storage conditions

The antifoam compositions described in the examples according to the invention have excellent stability at room temperature and at 50 ^° C. No phase shift or bulking of the antifoam compositions has been observed. On the other hand, the anti-foam composition according to the comparative CI (oil-in-water emulsion) expands at 50 ^° C. and takes up as much as one week at this temperature. For the antifoam compositions according to Comparative C-2 (formulated with a polydimethylsiloxane oil of viscosity <500 mPa.s) and C-3 (formulated without polyethylene glycol), the appearance of an oil layer is observed at ambient temperature. surface.

2-b-Evaluation of anti-foam compositions in cementing fluids.

Description of the test

In a stirred reactor are added:

• 337 g of water

• a variable amount of silicone antifoam

2.1 g of naphthalene sulfonate

• 36 g of styrene-butadiene latex • 198 g of API cement, hydraulic binder.

The mixture is mixed for 35 seconds at a speed of 13000 rpm. The mixture is then poured into a 1-liter graduated container and the total volume of slurry obtained is measured which is directly related to the effectiveness of the antifoam. More Panti-mousse is effective, more this volume of slurry will be weak. In the absence of antifoam, the amount of air present in the cement in the form of bubbles is very important and leads to a total measured slurry volume of 870 ml. Table 2 presents the volumes of cement slurry obtained after the addition of 0.6 g of antifoam.

Table 2:

Volume of cement slurry measured after the addition of 0.6 g of the different anti-foam compositions

The addition of 0.6 g of the antifoam composition according to the comparative C-1 (oil-in-water emulsion) leads to a measured volume of cement slurry of 630 ml. The various anti-foam compositions according to the invention lead to cement slurry volumes of 520 to 590 ml, ie a decrease of 6 to 20%.

Table 3:

Amount of anti-foam composition needed to obtain a volume of cement slurry of 510 to 530 ml

To reduce the slurry of cement from 870 to 510 ml it is necessary to add 1.6 g of the antifoam composition according to the comparative CI (oil-in-water emulsion). On the other hand, in order to obtain a comparable cement slurry volume, 0.6 g of the antifoam compositions according to the invention I-1 and 1-2 suffice, ie a 63% reduction in the amount of antifoam used. Table 4:

Quantity of antifoam composition necessary to obtain a volume of 470 ml cement slurry (optimum deaeration)

To reduce the slurry of cement from 870 to 470 ml it is necessary to add 2.3 g of the antifoam composition according to the comparative C-I (emulsion oil in water). On the other hand, to obtain the same volume of cement slurry, 1.2 g of the antifoam compositions according to the invention I-1 and 1-2 suffice to be a reduction of 48% of the amount of antifoam used.

Claims

1. Cementing fluid characterized in that it comprises at least one anti-foam composition A autodispersible, stable at 50 ⁰ C and consisting of a continuous silicone phase, said composition comprising: from 78 to 99% by weight relative to to the total amount of said antifoam composition A, at least one mixture B consisting of: 70 to 99.5% by weight, relative to the total amount of said mixture B, of at least one silicone oil whose viscosity is between 500 and 30,000 mPa.s, 0.5 to 10% by weight, relative to the total amount of said mixture B, of at least one particulate filler, 0 to 15% by weight, based on the total amount of said mixture B, of at least one silicone resin, optionally diluted in a silicone oil, and 0 to 1% by weight, based on the total amount of said mixture B, of at least one polycondensation catalyst of 0 to 5%, by weight relative to the total amount of said antifoam composition A, an anti-foam additive, from 0.1 to 2%, by weight based on the total amount of said antifoam composition A, at least one dispersing agent selected from the group of polyalkylene glycols, preferably polyethylene glycol, and - from 1 to 15% by weight relative to the total amount of said antifoam composition A, at least one liquid surfactant or a solid surfactant with a melting temperature greater than 55 ° C. 2. Cementing fluid according to claim 1 further comprising at least one hydraulic binder, water and optionally at least one latex. 3. Cementation fluid according to any one of claims 1 or 2, characterized in that the silicone oil is selected from α, ω-bis (trialkyl) polydialkylsiloxane oils, preferably α, ω-bis oils ( trimethyl) polydimethylsiloxane. 4. Cementation fluid according to any one of claims 1 or 2, characterized in that the particulate filler is selected from treated precipitation silicas or not, the treated or untreated silicas combustion and mixtures thereof. 5. The cementing fluid as claimed in claim 1, wherein the antifoam additive is an alkylene oxide copolymer chosen from ethylene oxide and propylene and mixtures thereof, preferably block copolymers of ethylene oxide and propylene oxide. 6. Cementation fluid according to any one of claims 1 or 2, characterized in that the surfactant is a liquid surfactant selected from linear or branched polyaloxylated fatty alcohols, preferably a polyethoxylated fatty alcohol. 7. Cementing fluid according to claim 2, wherein the hydraulic binder is a cement, preferably selected from the following group: plaster, lime, pozzolan, prompt cement, Portland cement and mixtures thereof. 8. Anti-foam composition A autodispersible, stable at 50 ⁰ C and consisting of a continuous silicone phase comprising: from 78 to 99%, by weight relative to the total amount of said antifoam composition A, of at least one mixture B consisting of: 70 to 99.5% by weight, relative to the total amount of said mixture B, of at least one silicone oil whose viscosity is between 500 and 30,000 mPa.s, 0.5 to 10% by weight, relative to the total amount of said mixture B, of at least one particulate filler, 0 to 15% by weight, based on the total amount of said mixture B, of at least one silicone resin, optionally diluted in a silicone oil, and 0 to 1% by weight, based on the total amount of said mixture B, of at least one polycondensation catalyst from 0 to 5%, by weight relative to the total amount of said antifoam composition A, an antifoam additive, from 0.1 to 2%, by weight relative to the total amount of said an antifoam composition A, at least one dispersing agent selected from the group of polyalkylene glycols, preferably a polyethylene glycol, and from 1 to 15% by weight relative to the total amount of said antifoam composition A of at least one liquid surfactant or a solid surfactant with a melting temperature above 55 ° C. Anti-foam composition A according to claim 8, characterized in that the silicone oil is chosen from α, ω-bis (trialkyl) -polydialkylsiloxane oils, preferably α, ω-bis (trimethyl) polydimethylsiloxane oils. 10. antifoam composition A according to claim 8, characterized in that the particulate filler is selected from treated precipitation silicas or not, the treated or untreated silicas combustion and mixtures thereof. Antifoaming composition A according to claim 8, characterized in that the antifoam additive is an alkylene oxide copolymer selected from ethylene oxide and propylene oxide copolymers and mixtures thereof. , preferably block copolymers of ethylene oxide and propylene oxide. 12. antifoam composition A according to claim 8, characterized in that the surfactant is a liquid surfactant selected from linear or branched polyaloxylated fatty alcohols, preferably a polyethoxylated fatty alcohol. 13. Use of a self-dispersible anti-foam composition A as defined in any one of claims 8 to 12 in cementing fluids. 14. Use of a self-dispersible anti-foam composition A according to claim 13 in well cementing fluids for extraction of oil, gas, water, geothermal, and the like. 15. A process for cementing oil, geothermal, gas and water wells and the like, characterized in that drilling of the soil, the cementing fluid as defined in one of claims 1 to 7 is pumped, then said cementing fluid is injected along the walls of the borehole.