Method and apparatus for surge reduction
US6520257B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 20, 2001 |
| Grant date | Feb 18, 2003 |
| Priority date | — |
| Expiry date | Mar 20, 2021 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B34/102
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Improvements are disclosed in surge reduction tools for running in casings or casing liners downhole with the ability to restore circulation in the event a tight hole condition is encountered. The improved tool includes among other features 1.) an axial indexing apparatus which allows the valving sleeve to be moved downward in predetermined increments to allow alternate closing and opening of the vent ports, 2.) a camming sleeve and Bellville spring washers which provide the surge reduction tool with a more predictable release pressure than has heretofore been available, 3.) a dart directing sleeve which has a smaller, smoother bore than the drill string and provides the important function of aligning the dart before it lands in the seat so that the dart resistance when passing through the seat is minimized, and 4.) chevron seals arranged in the housing above and below the vent port which reduces the potential for hydraulic lock and provides a seal mechanism that is more reliable while running in downhole conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.