High pressure downhole progressive cavity drilling apparatus with lubricating flow restrictor
US5096004A · kind A · utility
Inventor
Key dates
| Filing date | Aug 6, 1990 |
| Grant date | Mar 17, 1992 |
| Priority date | — |
| Expiry date | Aug 6, 2010 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B4/02
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A progressive cavity drilling apparatus which includes a drill bit, a drill bit driving shaft have a hollow bore formed therein and a progressive cavity drive train for driving the drilling shaft. A flow restrictor is provided to cause fluid leaving the progressive cavity drive train to enter the interior of the hollow drilling shaft and then to be exited therefrom through nozzles formed in the drill bit. The flow restrictor includes a groove to allow a small amount of fluid to flow in a path winding around the circumference of the flow restrictor and into a bearing assembly located below the flow restrictor. Because the flow path winds around the circumference of the flow restrictor, it is significantly longer than a straight longitudinal flow path. Consequently, the velocity of the high pressure fliud through the flow path is significantly reduced thus minimizing erosion and wear of the flow restrictor. The flow restrictor may also function as a radial support which can obviate the need for separate radial bearing. The radial support may be provided between the helical grooves or in a separate portion of the flow restrictor. The flow restrictor can also have an inner diameter whi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.