Electromagnetic pulse downhole telemetry
US9995134B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 2014 |
| Grant date | Jun 12, 2018 |
| Priority date | — |
| Expiry date | Feb 24, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/04
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An apparatus for transmitting electromagnetic (EM) telemetry data from a downhole location to surface comprising: an EM signal transmitter configured to generate positive and negative polarity EM pulses corresponding to a telemetry signal; and an electronics subassembly communicative with the EM signal transmitter and comprising a processor and a memory having encoded thereon program code executable by the processor to perform a method comprising encoding measurement data into an EM telemetry signal using a modulation scheme comprising mapping a symbol set to at least one positive polarity EM pulse and one negative polarity EM pulse; and sending a control signal to the EM signal transmitter to generate EM pulses corresponding to the EM telemetry signal. The EM signal transmitter can comprise an H-bridge circuit electrically coupled to positive and negative ends of a gap sub such that applying a voltage across a positive pathway of the H-bridge circuit generates the positive polarity EM pulse, and applying a voltage across a negative pathway of the H-bridge circuit generates the negative polarity EM pulse.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.