Misaligning wellhead system
US5878812A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1997 |
| Grant date | Mar 9, 1999 |
| Priority date | — |
| Expiry date | May 13, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B34/02
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A misaligning wellhead system for use on the surface end of well production tubing in a well produced by a pump driven by a pumping unit operated polished rod extending through the wellhead to the pump. The wellhead system includes a flange for connection of the system to the surface end of the production tubing, a blowout preventer above the flange, a flow tee above the blowout preventer for directing well fluids into a flowline, and a floating tubular body supporting a stuffing box and a flapper valve for torsional and lateral movement relative to the longitudinal axis through the wellhead body as the polished rod reciprocates to compensate for misalignment of the pumping unit relative to the wellbore centerline.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.