Well cementing material

Abstract

The present invention relates to a formulation of a high-performance foamed cement material, comprising: at least one hydraulic binder, microparticles whose grain size ranges between 0.1 and 30 μm, whose proportion ranges between 15% and 50% by mass in relation to the mass of hydraulic binder, mineral particles whose grain size ranges between 1 and 500 μm, whose proportion ranges between 10% and 35% by mass in relation to the mass of hydraulic binder, the proportion of particles being lower than the proportion of microparticles, a hydrosoluble polymer thinning agent whose proportion ranges between 0.1% and 8% by mass in relation to the mass of hydraulic binder, water whose proportion is at most 40% by mass in relation to the mass of hydraulic binder, a foaming agent whose proportion ranges between 0.1% and 10% by mass in relation to the mass of hydraulic binder.

1 ) A cementing material comprising: 
 at least one hydraulic binder from the group consisting of class G Portland cements, class H Portland cements, aluminous cements whose alumina content is at least above 30% by mass, and sulfoaluminous cements,    microparticles from the group consisting of microsilica particles and silico-aluminate particles, whose grain size ranges between 0.1 and 30 μm, whose proportion ranges between 15% and 50% by mass in relation to the mass of hydraulic binder,    mineral particles whose grain size ranges between 1 and 500 μm, whose proportion ranges between 10% and 35% by mass in relation to the mass of hydraulic binder, the proportion of particles being lower than the proportion of microparticles,    a hydrosoluble polymer thinning agent whose proportion ranges between 0.1% and 8% by mass in relation to the mass of hydraulic binder,    water whose proportion is at most 40% by mass in relation to the mass of hydraulic binder,    a foaming agent whose proportion ranges between 0.1% and 10% by mass in relation to the mass of hydraulic binder.    
   
   
       2 ) A material as claimed in  claim 1 , further comprising a foam stabilizing additive whose proportion ranges between 0.1% and 2% by mass in relation to the mass of hydraulic binder, the additive being a hydrosoluble associative polymer comprising hydrophobic units.  
   
   
       3 ) A material as claimed in  claim 1 , wherein the foaming agent is a surfactant compound in a proportion ranging between 0.1% and 3% by mass in relation to the mass of hydraulic binder.  
   
   
       4 ) A material as claimed in  claim 3 , wherein the surfactant compound is selected from among the following products: abietic acid salts, sodium alkyl-aryl sulfonates, phenol-ethoxylates and perfluoroalkyl betaine.  
   
   
       5 ) A material as claimed in  claim 1 , wherein the foaming agent is a hydrosoluble associative polymer comprising hydrophobic chains, the polymer being in a proportion ranging between 0.1% and 10% by mass in relation to the mass of hydraulic binder.  
   
   
       6 ) A material as claimed in  claim 1 , wherein the associative polymer is a polymer with hydrophilic units Hy and hydrophobic units Hb containing C1 to C30 alkyl, aryl, alkyl-aryl groups.  
   
   
       7 ) A material as claimed in  claim 6 , wherein the associative polymer has a molecular mass of between 10 4  and 5×10 6  daltons and a proportion of hydrophobic units Hb ranging between 0.5% and 60%.  
   
   
       8 ) A material as claimed in  claim 1 , wherein the mass of microparticles ranges between 15% and 30% in relation to the mass of hydraulic binder.  
   
   
       9 ) A material as claimed in  claim 1 , wherein the proportion of water ranges between 20% and 35% by mass in relation to the mass of hydraulic binder.  
   
   
       10 ) A material as claimed in  claim 1 , wherein the hydrosoluble polymer thinning agent is selected from among the group consisting of: a polynaphthalene sulfonate, a polycarboxylate and a polyoxyethylene poly-carboxylate.  
   
   
       11 ) A material as claimed in  claim 1 , further comprising a retarding agent for controlling the setting time of the slurry.  
   
   
       12 ) A material as claimed in  claim 1 , further comprising an accelerating agent for controlling the setting time of the slurry.  
   
   
       13 ) A material as claimed in  claim 1 , used for cementing an oil well.  
   
   
       14 ) A method of producing a foamed cement slurry, wherein the following stages are carried out: 
 mixing a powder with water comprising a hydrosoluble polymer thinning agent so as to obtain a cement slurry, the powder comprising a hydraulic binder, microparticles and mineral particles, the hydraulic binder being selected from the group consisting of class G Portland cements, class H Portland cements, aluminous cements whose alumina content is at least above 30% by mass, and sulfoaluminous cements, the microparticles being selected from the group consisting of microsilica particles and silico-aluminate particles, of grain size ranging between 0.1 and 30 μm, whose proportion ranges between 15% and 50% by mass in relation to the mass of hydraulic binder, the mineral particles having a grain size ranging between 1 and 500 μm, with a proportion ranging between 10% and 35% by mass in relation to the mass of hydraulic binder, the proportion of particles being lower than the proportion of microparticles, the hydrosoluble polymer thinning agent having a proportion ranging between 0.1% and 8% by mass in relation to the mass of hydraulic binder,    introducing a foaming agent in the cement slurry, the proportion of foaming agent ranging between 0.1% and 10% by mass in relation to the mass of hydraulic binder,    pumping the cement slurry comprising the foaming agent, and    injecting a gas into the cement slurry comprising the foaming agent and stirring the mixture of slurry and of gas so as to foam the slurry and to obtain a foamed cement slurry.    
   
   
       15 ) A method as claimed in  claim 14 , wherein the foaming agent is a surfactant compound in a proportion ranging between 0.1% and 3% by mass in relation to the mass of hydraulic binder.  
   
   
       16 ) A method as claimed in  claim 15 , wherein the surfactant is introduced in powder form into the cement slurry.  
   
   
       17 ) A method as claimed in  claim 16 , wherein the foaming agent is a hydrosoluble associative polymer comprising hydrophobic chains, the polymer being in a proportion ranging between 0.1% and 10% by mass in relation to the mass of hydraulic binder.