Downhole surge pressure reduction system and method of use
US5960881A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 22, 1997 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Apr 22, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/16
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A system for reducing pressure while running a casing liner, hanging a casing liner from a casing and cementing the liner in a borehole during a single trip downhole is disclosed. Some of the components of the system are 1.) a bypass or diverter sub for reducing surge pressure having either an incremental breakaway seat or a yieldable seat, 2.) a container or manifold for launching a smaller ball used to close the bypass, a larger ball used to hang the liner in the casing, and a drill pipe wiper dart for cementing, and 3.) a guide shoe with multiple openings and no float valve to provide proper flow of drilling fluid up the liner and out the port of the bypass to reduce surge pressure and to provide for proper cementation. Advantageously, methods for operation of this surge pressure reduction system and its components are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.