Carousel well rig
US5174389A · kind A · utility
Inventor
Key dates
| Filing date | Jul 12, 1991 |
| Grant date | Dec 29, 1992 |
| Priority date | — |
| Expiry date | Jul 12, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B19/146
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A well work-over drilling rig uses a single cylindrical column forming a mast for assembly and disassembly of a casing, pipe or rod forming a well string in a well bore. The mast supports a hydraulic ram for elevating a crown block having arms radially extending equal distances from the axis of the ram. Cables are supported by sheaves at the outer ends of the arms to permit equal and opposite forces (moments) to be applied to the column by the weight of pipe sections or the complete well string. The column is stabilized by racking pipe sections, including up to the full length of a well string, annularly around the column mast on a rotatable fingerboard, with substantially the full weight of pipe sections on the lower annular support. This avoids the need for lateral guy wires to stabilize the column mast.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.