Suspension of concentrated particulate additives containing oil for fracturing and other fluids

Abstract

The handling, transport and delivery of particulate materials, particularly fine particles, may be difficult. Alkaline earth metal oxide particles such as magnesium oxide (MgO) may be suspended in glycerin and/or alkylene glycols such as propylene glycol up to loadings of 51 wt %. Such suspensions or slurries make it easier to deliver MgO and similar agents into fluids, such as aqueous fluids gelled with viscoelastic surfactants (VES). These concentrated suspensions or slurries may be improved in their stability by the inclusion of minor amounts of a vegetable oil and/or a fish oil. The MgO serves as stabilizers and/or fluid loss control agents for VES-gelled fluids used to treat subterranean formations, e.g. for well completion or stimulation in hydrocarbon recovery operations. The particle size of the magnesium oxide or other agent may be between 1 nanometer to 0.4 millimeter.

1 . A concentrated slurry of particles comprising:
 particles having an average particle size of about 400 microns or less, selected from the group consisting of alkaline earth metal oxides, alkaline earth metal hydroxides, transition metal oxides, transition metal hydroxides, and mixtures thereof;   a non-aqueous fluid selected from the group consisting of alkylene glycols, glycerin and mixtures thereof; and   at least one oil selected from the group consisting of vegetable oil and fish oil, in an amount effective to improve the suspension of the particles in the non-aqueous fluid.   
   
   
       2 . The concentrated slurry of particles of  claim 1  where the particles are magnesium oxide particles of an average particle size of about 100 microns or less. 
   
   
       3 . The concentrated slurry of particles of  claim 1  where the non-aqueous fluid is propylene glycol. 
   
   
       4 . The concentrated slurry of particles of  claim 1  where the wt % of particles in the non-aqueous fluid ranges from about 5 to about 51 wt %. 
   
   
       5 . The concentrated slurry of particles of  claim 1  where the oil is present in the fluid loss control agent slurry in an amount up to about 15% by volume. 
   
   
       6 . A concentrated slurry of particles comprising:
 particles having an average particle size of about 100 microns or less, selected from the group consisting of alkaline earth metal oxides, alkaline earth metal hydroxides, transition metal oxides, transition metal hydroxides, and mixtures thereof; and   a non-aqueous fluid selected from the group consisting of alkylene glycols, glycerin and mixtures thereof;   an amount up to about 15% by volume in the fluid loss control agent slurry of at least one oil selected from the group consisting of vegetable oil and fish oil;   
     where the wt % of particles in the non-aqueous fluid ranges from about 5 to about 51 wt %. 
   
   
       7 . An aqueous viscoelastic treating fluid made by the process comprising:
 mixing an aqueous base fluid with a viscoelastic surfactant (VES) gelling agent, where the VES gelling agent is added in an amount effective to increase the viscosity of the aqueous base fluid, to form an aqueous treating fluid; and   adding to the aqueous treating fluid a concentrated slurry of particles comprising:
 particles having an average particle size of about 400 microns or less, selected from the group consisting of alkaline earth metal oxides, alkaline earth metal hydroxides, transition metal oxides, transition metal hydroxides, and mixtures thereof; 
 a non-aqueous fluid selected from the group consisting of alkylene glycols, glycerin and mixtures thereof; and 
 at least one oil selected from the group consisting of vegetable oil and fish oil, in an amount effective to improve the suspension of the particles in the non-aqueous fluid. 
   
   
   
       8 . The aqueous viscoelastic treating fluid of  claim 7  where the particles are magnesium oxide particles of an average particle size of about 100 microns or less. 
   
   
       9 . The aqueous viscoelastic treating fluid of  claim 7  where the wt % of particles in the non-aqueous fluid ranges from about 5 to about 51 wt %. 
   
   
       10 . The aqueous viscoelastic treating fluid of  claim 7  where the amount of the concentrated slurry of particles ranges from about 2 to about 200 pptg (about 0.2 to about 24 kg/m 3 ) based on aqueous viscoelastic treating fluid. 
   
   
       11 . The aqueous viscoelastic treating fluid of  claim 7  where the oil is present in the fluid loss control agent slurry in an amount up to about 15% by volume.