Pulser
US6002643A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 1997 |
| Grant date | Dec 14, 1999 |
| Priority date | — |
| Expiry date | Aug 19, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/24
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A downhole tool containing instruments and a pulser is landed within a string of drill pipe. The pulser has a pulser body and an orifice on a lower end. A piston slides within a bore in the body and has a signal poppet on a lower end. In an extended position, the signal poppet extends into and obstructs the orifice to reduce the flow of drilling fluid. In an open position, the signal poppet does not obstruct the orifice to increase the flow of drilling fluid. A bidirectional solenoid valve is located above the piston and has upper and lower electromagnetic coils and an axially moveable rod. The rod is movable between a closed position in an opening in the body and an open position away from the opening. The rod is moved to both positions in response to the instruments which sends signals to the coils. The mud pulser also has an on/off flow switch which is actuated by the commencement of mud circulation. Initially, the rod is in the closed position. The instruments take various measurements which are communicated through the pulser to the surface in the form of mud pulses. A mud pulse is generated when a coil is energized to move the rod to the open position. This forces the piston …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.