Drill-Tek Twin EM Systems

Drilltek EM Systems


Drill-Tek offers a new EM technology that runs pulse and EM technology solutions simultaneously, without requiring the operator to trip and switch systems. The operator also has the option of running pulse or EM separately. Drill-Tek's Twin Telemetry solution is power-efficient, offering an incredible 400 hours on low power for running twin systems simultaneously, or 200 hours on high power. Twin Telemetry is field-proven and reliable. This system connects seamlessly with tensor based MWD.

How the Drill-Tek Twin EM System Works

  • The EM Telemetry system is based on electromagnetic wave technology used to transmit drilling data uphole.
  • It encodes downhole MWD/LWD data into low frequency electromagnetic waves.
  • Signal is transmitted from the tool through the drill pipe and formation and detected on surface as lowvoltage potential between the wellhead and remote electrode (antennae).
  • Waves are decoded and processed by surface receiver and displayed on driller’s display.
  • It operates in environments where mud pulse may not be optimal or possible, under-balanced drilling for example:
    • Drilling with air and foam
    • Drilling with high concentrations of lost circulation material in mud
    • Fast horizontal drilling
    • Shallow gas/oil drilling.

Twin Telemetry EM/MP MWD:

EM Transmitter for Tensor based MWD systems.

EM Twin Telemetry offers:

  • True Twin™ operation, mud pulse and EM to send information simultaneously.
  • Software runs on existing computers and rig floor displays.
  • Unmatched Battery conservation.
  • No modifications required to existing MWD.
  • Fluid independent, LCM tolerant.
  • Operator select-able frequency 2-10 Hz.
  • Two power modes; Economy, High.
  • Pumps down survey.
  • Constant lithology compensation allows for extended battery life.
  • Low signal to noise requirement.
  • Wireless design eliminates rig noise.
  • Many options to connect to rig system.
  • Technologically advanced.
  • Low noise electronics.
  • Active noise cancellation.
  • Most data throughput and energy efficient tool on the market.
  • 165c operation with reversible shut down.


  • Designed and tested to be Qbus and XXbus compatible.
  • No modifications required to connect to industry standard equipment.
  • Uses common MWD spares for repair and maintenance.

System Specifications


Transmission ModeContinuous Wave
Wireline RetrievabilityFully retrievable
Operating Depth (no repeater)10,000 ft (3,000 m) Maximum depth down to over 12,000 ft
Data Rate10 bps
Operating Pulse Width0.2-0.6 seconds
Battery2 standard Lithium batteries
Typical Battery LifeOver 150 hours per battery
Maximum Power Output20 W
Gap Sub OD available8”, 61/2”, 43/4”, 31/2”
Tool ProgrammingFully surface programmable
Pump-control:EM power and frequency downhole-programmable


Operating Temperature165C (329F)
Maximum Pressure20,000 psi (137,9 MPa)
Vibration30-500Hz 20g all axes


Operating Temperature-23 to 52C (-9 to 126F)
Storage Temperature-40 to 52C (-40 to 126F)


Directional Sensor Specifications *

Parameters AccuracyRepeatabilityResolution
Azimuth (Degrees)+/- 0.5+/- 0.50.1
Inclination (Degrees)+/- 0.05+/- 0.050.1
Operating Temperature (°C)+/- 2.0+/- 1.00.1
Local Magnetic Field (Total Magnetic Field, microTeslas)+/- 0.1 mT+/- 0.1 mT0.05mT
Gravitational Position - front of the unit (Highside Toolface, Degrees)+/- 0.5+/- 0.50.1
Magnetic Position - front of the unit (Magnetic Toolface, Degrees)+/- 1.0+/- 1.00.1
Azimuth Position - front of the unit (Magnetic Toolface referenced to Grid or True North, Degrees)+/- 1.0+/- 1.00.1
Transmission Resolution:Selectable
Speed (Data Rate):0.625 bits/sec nominal


EM Systems Drilltek



EM Transmitter & Gap Sub

The EM transmitter is the only one to simultaneously transmit data alongside our standard DC motor driven pulser for added data security. The transmitter also works faster and deeper than any comparable system. The highly efficient electroncis do this by generating almost zero noise which translates into very low

power consumption. The Gap Sub provides electrical isolation between the transmitter and the drillstring using extremely robust ceramic insulators.


The Vibmon monitors downhole shock and vibration in three axes.

Real-time telemetry and display of downhole shock and vibration enables drillers to avoid costly downhole equipment failure and optimize ROP. Data is also recorded downhole for plotting and analysis on surface.

Directional Interface Module

The DIM provides a flexible, intelligent solution for the acquisition, formatting and telemetry of downhole data to surface. It is a drop-in downhole Directional Interface Module providing mud pulse telemetry compatible with industry standard Tensor systems.

Directional Sensor Module

The Directional Sensor, designed to API standards and specifications, incorporates the industry renowned JAE accelerometers and magnetometers. Incorporating Digital Head Module, the complete Directional Sensor assembly provides a temperature corrected plug-and-play solution using the most reliable aviation specification components.

Pulser Driver and DC Drive Pulser

The Pulser Driver and DC Drive Pulser is a rugged field proven unit with a highly efficient and reliable brushless DC motor.

The intelligent PDEM electronics optimizes telemetry rates and manages power consumption using an accelerometer flow switch.

The DC motor drive gives huge battery savings and higher MTBF than comparable solenoid-based units while being easy to service.


Drill-Tek manufactures a complete range of MWD and DD accessories including everything needed to run an MWD survey. Our product centre makes everything from spearpoints to muleshoes and all of the barrels and interconnects in between. We also supply larger accessories including the kit boxes, tools

racks and pipe screens.


Gamma Ray Sensor

An industry standard, natural Gamma Ray tool based around a highly ruggedized scintillation counter and photomultiplier tube. The GR data can be used in depth correlation and geosteering applications where radioactive uranium is associated with gas rich shales.

Resistivity Tool

Single and Multifrequency LWD tools available in a complete range of sizes including slim hole. These field proven tools deliver true reservoir saturation data from multiple depths of investigation. The wireline log quality output has been used by oil companies all over the world. The data can also be used for geostreering applications.


Advantages of Drill-Tek Twin EM System:

- Improved overall reliability with a combined mud pulse and EM telemetry system.

- Ability to slide out of casing shoe.

- Drill in discontinuous borehole fluid column.

- Drill in highly resistive formations.

- Faster MWD/LWD data-point update rates.

- No switch over needed between systems if one system encounters problems.

- Can be run as stand-alone EM system if the operating environment dictates.


Benefits of Drill-Tek Twin EM System:

- Twice as fast as older EM systems at same carrier frequency delivering faster updates.

- 20W output equivalent to 60W competitor output optimising battery length without compromising operational efficiency.

- Data rate up to 10 BPS. 10 x standard MWD mud pulse.

- Fully retrievable.

- 2-10 Hz adjustable carrier frequency.

- Transmit 4 global parameters: Gamma (including focused), Toolface, three generic variables including shock, vibration and resistivity.

- Updates at 15 second intervals compared to 120 seconds for mud pulse.

- Constant current mode enables automatic lithology compensation.

- Power efficient mode for signal transmission through formation (Example:10 ohm.m formation).

- Standard power mode (120 hours/battery).

- Power saving mode (240 hours/battery).

- 75% less power than other systems.

- Ultra low-noise receiver technology.

- Capable of detecting low/weak signal under 20nV amplitude meaning deeper operations (TVD in excess of 2500m and MD in excess of 4000m).

- Continuous wave (AC) transmission model.


Power Challenges

The logistical EM challenges previously associated with lithium cells and lack of power no longer apply. The Drill-Tek Twin EM System is more power efficient than any previous EM system with running costs similar to standard mud pulse meaning the system can be used economically anywhere in the world.