Hollow proppants and a process for their manufacture
US4547468A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1983 |
| Grant date | Oct 15, 1985 |
| Priority date | — |
| Expiry date | Jun 30, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/94
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Hollow, fine-grained ceramic proppants are less expensive and improve fracture control when compared to conventional proppants (dense alumina, mullite, bauxite, zirconia, etc.). Hollow proppants of the present invention have been fabricated by spray drying, followed by sintering in order to obtain a dense case and a hollow core. These proppants generally have high sphericity and roundness (Krumbein sphericity and roundness greater than 0.8), have diameters on average between 2250 and 125 .mu.m, depending on proppant size required, and have strength equal to or greater than that of sand. The hollow core, the size of which can be controlled, permits better fracture control in hydraulic fracturing treatments since the proppant can be transported in lower viscosity fluids. Hollow proppants produced at the same cost/weight as conventional proppants also provide for lower costs, since less weight is required to fill the same volume. The fine-grained (preferably less than 5 .mu.m in diameter) ceramic case provides the strength necessary to withstand closure stresses and prevent crushing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.