Low-density ball sealer for use as a diverting agent in hostile environment wells
US5485882A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1994 |
| Grant date | Jan 23, 1996 |
| Priority date | — |
| Expiry date | Oct 27, 2014 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/138
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The invention is a rigid, hollow core, low-density ball sealer designed to perform effectively in hostile well environments. It temporarily seals perforations inside cased wells at temperatures up to 400.degree. F. (204.degree. C.), at hydrostatic pressures up to 20,000 psi (137 Mpa), and at differential pressures across the perforations up to 1,500 psi. Ball densities may range from 0.80 to 1.3 gm/cc (or higher). It can withstand the degradation effects of solvents common to oil and gas wells during a workover. Nominal changes in ball density occur during a 24-hour period when exposed to a hostile well environment. The ball sealer is comprised of two pieces made of a high strength material that snap together to form a hollow-core sphere. If necessary, adjustments to ball density can occur subsequent to manufacturing of the ball pieces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.