초록 ▼

Sintered, spherical composite pellets or particles comprising one or more clays as a major component and bauxite, alumina, or mixtures thereof, are described, along with the process for their manufacture. The pellets may have an alumina-silica (Al2O3-SiO2) ratio from about 9:1 to about 1:1 by weight

Sintered, spherical composite pellets or particles comprising one or more clays as a major component and bauxite, alumina, or mixtures thereof, are described, along with the process for their manufacture. The pellets may have an alumina-silica (Al2O3-SiO2) ratio from about 9:1 to about 1:1 by weight. The use of such pellets in hydraulic fracturing of subterranean formations is also described.

대표청구항 ▼

A gas and oil well proppant comprising a plurality of composite, sintered, spherical pellets having a permeability to brine at about 200°F. (93.3°C.) which decreases not more than about three-fourths when the applied pressure on said pellets is increased from 2,000 to 10,000 psi (140 to 700 kg/cm2),

A gas and oil well proppant comprising a plurality of composite, sintered, spherical pellets having a permeability to brine at about 200°F. (93.3°C.) which decreases not more than about three-fourths when the applied pressure on said pellets is increased from 2,000 to 10,000 psi (140 to 700 kg/cm2), said pellets being prepared from a mixture of calcined clay and calcined bauxite, said mixture containing at least 40% clay on a dry weight basis, and said pellets having an alumina to silicia ratio on a dry weight basis of from about 8.28:1 to 1.17:1, more than 6.12 wt. % of other than alumina and silicia, a diameter of between 0.1 and about 2.5 mm, an apparent specific gravity of less than 3.40 but greater than 2.75 g/cc and a bulk density greater than 88 lbs./cubic ft., said pellets being made by a process including the steps of: (a) forming a particular mixture of calcined clay and calcined bauxite, having an average particle size of less than 15 microns in a high intensity mixture; (b) while stirring the mixture adding sufficient water to cause formation of composite spherical pellets from the mixture; (c) drying the pellets at a temperature ranging from about 100°C. to about 300°C.; and (d) furnacing the dried pellets at a furnace temperature ranging from about 1350°C. to about 1550°C. for a period sufficient to enable recovery of sintered spherical pellets.