Hydraulic shock absorbing method
US4171025A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 1977 |
| Grant date | Oct 16, 1979 |
| Priority date | — |
| Expiry date | Dec 14, 1997 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/07
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hydraulic shock absorbing method for protecting the drill bit and drill pipe in rotary earth drilling comprising the steps of slidably moving an anvil connected to a drilling bit in a casing in response to increased down weight on the drill bit and sequentially transmitting further increases in the down weight and shocks from the anvil to a plurality of independently operating hydraulic pistons slidably mounted within the casing when down weight on the drill bit exceeds increasing predetermined amounts to activate the pistons in sequence. The drilling fluid within the casing is transmitted to first pressure areas on the anvil and the plurality of pistons and the drilling fluid is passed through the drilling bit to provide a pressure drop and then communicated to second pressure areas on the plurality of pistons.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.