Fully electronic magnetic survey systems offering enhanced accuracy, speed and reliability–plus all-angle operation, horizontal steering, long and short radius with gamma and pressure.

System Design

Gyrodata’s GEMS survey system provides a vast improvement in the accuracy and reliability of magnetic survey instrumentation by employing the latest technology including:

  • Tri-axial magnetic and gravity force-field sensors.
  • Solid-state electronic data acquisition and processing.
  • Special data verification and performance modeling procedures and techniques.


GEMS consists of a downhole sensor and electronics package, powered by a battery pack for continuous coring operations. Survey data is downloaded at surface to a laptop computer. GEMS has numerous advantages over the older film-based systems. Most importantly, GEMS allows for data to be provided every single foot.

GEMS eliminates

  • Film-reading and human-interpretation errors.
  • Limited angle operation and poor resolution of photo-angle units.
  • Reliability problems associated with film, mechanical camera operation, and temperature sensitivity.
  • Time consuming downhole survey operation and lengthy film-reading procedures.



  • Single/multishot surveys in drillstring.
  • Wireline steering tool operation for kick-ofs and horizontal drilling. Wet-connect available.
  • Continuous core-barrel orientation.


GEMS II Steering System with Gamma and Pressure

GEMS II is the latest evolution of Gyrodata’s electronic magnetic survey instrumentation. In addition, gamma and pressure detection sensors can be run in conjunction with GEMS II, providing realtime readout at surface of the three instruments. An interconnect flex-joint between the survey and gamma probes allows the longer system to negotiate short-radius drilling curves.

Key applications include:

  • Kick-off / Sidetracks
  • Horizontal / Short-Radius Drilling
  • Re-entry / Multi-lateral Projects
  • Air Drilling / Underbalanced Drilling Operations
  • Coiled Tubing Guidance


Float Wet-Connect

A unique float wet-connect system eliminates the side-door sub and allows rotating while drilling.

Specifications (GEMS)

  • Downhole probe with power pack: 1.38″ OD x 73″ long, 8 lbs.
  • Protective housing: 1.75″ OD x 8′, 41 lbs.
  • Standard magnetic single/multishot running gear
  • Programmable delay setting, 1-530 minutes
  • Memory storage: 1020 survey records
  • Survey shot interval, 5 seconds to 530 minutes
  • Pressure rating: 20,000 psi
  • Temperature: 32° – 257° F / 0° – 125° C
  • 2.125-inch diameter system, 500°F(260°C)
  • Surface computer
  • Resolution: azimuth, inclination, toolface – 0.01°
  • Readings: inclination, azimuth, toolface, magnetic field strength, dip angle, gravity field strength, temperature

Specifications (GEMS II)

  • GEMS II steering probe: 1.75″ OD x 76″ long, 25 lbs.
  • Temperature: 150°C/300°F, 20,000 psi
  • Gamma probe: 1.75″ OD x 27″ long
  • 150°C/300°F, 15,000 psi
  • API standard calibration
  • Pressure probe: 1.75″ OD x 37″ long
  • Annular/drillpipe pressure/temp.
  • Total System Capability
  • Probe length: 17 feet
  • Short radius: 0 to 90 in 40 feet