Electromagnetic Repeater
The most efficient way to extend the depth capability of downhole EM telemetry.
The EM Repeater can restore full EM telemetry strength even when signal to noise ratio on surface from the downhole transmitter goes as low as 2-3. Recovered signal strength gain with Twin EM repeater can be over 10,000, effectively doubling EM operational range.
With downhole power proportional to the square of EM output, the EM repeater is an excellent alternative to simply increasing the power of a single downhole transmitter, which would require megawatts of power and is practically impossible.
The EM Repeater delivers a significantly more efficient power gain than a mud turbine generator.
Advantages
- Significantly reduced gap sub current leakage when drilling with highly conductive brine mud
- Covers wide range of formation resistivities, including highly resistive rock formations
- Constant current automatic lithology compensation – power conservation during operation and signal reliably in challenging formations
Features
- Plug and play compatible with Twin EM
- Advanced embedded efficient decoding – Fast data rate up to 10 bit per second
- Power economy: high voltage output with typical 200 hours per battery
- Effectively doubles maximum Twin EM depth, with signal gain over 10,000
- Ultra low-noise downhole receiver technology (intrinsic noise under 0.2μV)
- Mechanically robust: no moving mechanical parts
- Surface-programmable
- High MTBF 3000+ hrs 100
Specifications
Operating Principle | Mid-sting decoding and retransmission to surface |
Transmission Mode | Continuous Wave |
Placement depth | Mid-string, when Twin signal to noise ratio approaches 2-3 |
System Operating Depth after Placement (varies depending on formation) | Up to 32,000 ft (10 km) |
Carrier Frequency | 5 Hz standard, 2-10 Hz programmable |
Carrier frequency : Data rate ratio | 1:1 |
Effective Data Throughput | 2-10 bps programmable |
Retrievability | Non-retrievable |
Current Output | 6A |
Voltage Output to Formation | Up to 30V |
Full Load Energy Efficiency | Over 90% |
Battery | 1x or 2x standard 29V, 29 A-h lithium batteries (user provided) |
Battery Life (varies depending on formation) | Up to 580 hours/battery pack |
Gap Sub OD available | 8”, 6 ½”, 4 ¾”, 3 ½” |
Flow Switch | Vibration |
Tool Programming | Surface programmable carrier frequency |
Operating Temperature | 175C (350F) |
Maximum Pressure | 1,000g 0.5ms |
Vibration | 30-500Hz 20g all axes |