SERVICES        DIRECTIONAL DRILLING SERVICES - NORTH SEEKING GYRO [High Accuracy]
 

 

The Target INS offers unparalleled performance, the most advanced technology and a unique design. The Target INS is available from Flexit – the leader in advanced wellbore surveying instrumentation.
 

Unparalleled Performance

Flexit’s Target INS is an inertial navigation system especially designed for wellbore surveying. The instrument utilises modern strapped-down gyros and accelerometers adapted from aerospace applications, together with advanced signal processing techniques. The Target INS has been designed for all oilfield conditions and is protected by a robust pressure housing.
 

Features & Benefits

The most compact and versatile oilfield inertial navigation system - only 1.75 inches in diameter.

• High-speed and extremely accurate surveying and orientation services for a wide range of oilfield situations.

• Position and orientation data is determined in real time without making assumptions about the trajectory of the wellbore.

• The instrument runs continuously through the wellbore at speeds of up to 500 ft/min. - inclination has no affect on survey accuracy.

 

Advanced Technology

Strapped-down gyros and accelerometers.

• Advanced sensor error compensation techniques.

• Down hole signal processing in a state-of-the art micro-processor.

• In-run inertial sensor calibration using sophisticated Kalman filter techniques.

• Fuzzy decision logics.

• High-bandwidth long-distance communication between the downhole INS and the surface host computer through a single conductor wireline and modems.

 

Unique Design

The Target INS consists of three principal components:

• The down hole probe;

• Real time surface computer and interface; and

• Cable measuring device.

The down hole probe contains sensors, a processor and support electronics. Sensor outputs are acquired by the down hole processor which performs positioning calculations. Data is transmitted digitally to the surface computer through the wireline which also supplies power on the same single-conductor wireline.

The real time computer and interface incorporates the system power supply and the host computer that performs data recording and probe control operations.

Unique Design

The Target INS consists of three principal components:

• The down hole probe;

• Real time surface computer and interface; and

• Cable measuring device.

The down hole probe contains sensors, a processor and support electronics. Sensor outputs are acquired by the down hole processor which performs positioning calculations. Data is transmitted digitally to the surface computer through the wireline which also supplies power on the same single-conductor wireline.

The real time computer and interface incorporates the system power supply and the host computer that performs data recording and probe control operations.

  

Target INS Technical Specifications
Performance Accuracy of the 3D Probe Location (vs. staring point)
Inclination +/- 0.1° (1σ)
Azimuth

+/- 0.5° (1σ), |ϕ| < 50° (ϕ = latitude)

+/- 0.5°/cosϕ (1σ) 50 ° |ϕ| ≤ 70°
Roll/Gyro Tool Face +/- 0.5° (1σ)
Position

+/- 0,5 % distance travelled (1σ) |ϕ| < 50°

+/- 0,5 %/cosϕ distance travelled (1σ) 50° ≤ |ϕ| ≤ 70°
Temperature Range
Operating

-4° F to +257° F (-20° C to +125° C) without heat shield.

+347° F (+175° C) with heat shield.
Storage -29.2° F to 247° F (-34° C to + 125° C)
Surface Calibration and Alignment
Run-up Time 15 sec
Alignment Time 5 min
Calibration Time 60 mins
Operating Range
Angular rate 75°/s
Velocity Up to 500 ft/min (152.4 metres / min)
Cable Length Max. 30,000 ft. (9144 metres)
Cable Resistance Max. 600 Ω
Physical Characteristics
Physical size INS 1.75” (45 mm) diameter x 7 ft. (1,8 m) without centralizers
Physical size Surface Control Box 21” (534 mm) x 17.7” (450 mm) x 8.6” (217 mm)
Pressure Rating 15,000 PSI (1034 bar)
INS Shock, Non-Operating

500 g, half sine, 5 msec, each axis

INS Vibration, Operating

20 g rms random, 5 to 500 Hz

INS geodetic latitude, Operating -70° (southern hemisphere) to +70° (northern hemisphere)
Cable Head Plug “GO” type single conductor receptical
Centralizer Roller wheel expanding type. Upper-feed through with “GO” receptical. Lower- to accept 1 1/4 -8 shock absorber or mule shoe orienting alignment shock absorber, subject to customer specification
Swivel Head Feed through type swivel with “GO” connection.
Inertial Sensor
Length 68.33” / (173.56 cm)
Outside Diameter 1.75” / (4.45 cm)
Weight 40.9 lbs / (18.6 kg)
Power and power consumption
Input Voltage 90 V AC to 240 V AC, 50 to 60 Hz
Output Voltage 300 VDC ± 10 %, short circuit proof, to IMU probe through up to 30,000 ft. (9144 metres) of single conductor double armor cable, max. resistance 600 Ω
INS Power 20 to 37 W
Communication Capability
RS232 format, 2400 baud rate to send and receive data over 30,000 ft. (9144 metres) max. of single conductor armor cable
Real time analysis and computation of all subsurface data, including temperature compensation and calibration of inertial grade sensors
Output Data Operating mode, status, quality and accuracy parameters | Attitude angles, Cable length | Horizontal and vertical position co-ordinates | Body-fixed accelerations and angular rates. Configurable - Table Reports and Plots to Printer | CSV Data Export