IESE Borehole Instrumentation
IESE-SONDI, the seismic service and borehole instrumentation arm of the Institute of Earth Science and Engineering has more than 30 years experience in designing, building and deploying long-term and permanent borehole seismic instruments. The seismometers are designed and manufactured at IESE's machining workshop at The University of Auckland, New Zealand.
IESE-SONDI was founded in 2007 when Auckland UniServices Ltd of The University of Auckland acquired SONDI and Consultants. Originally established in 1989, SONDI specialised in custom geophysical exploration projects and surface and borehole geophysical instruments.
We provide the following seismic services
A complete end-to-end service from seismic instrument design to scientific analysis. Our capability includes a team of readily deployable researchers, field technicians, data analysts and machinists for contracted projects.
- Custom borehole seismometer designs
- In-house manufacturing of instruments
- Borehole instrument installation and calibration
- Microearthquake network design, installation support and maintenance
- Data processing, and basis to advanced analysis
- Training in network operation
Custom Design
We work with clients to develop custom designed seismic tools to varying specifications and for extreme borehole conditions. Such innovations include:
- Cableless Seismometer: data recording is within the sonde to minimise the data loss due to transmission noise.
- Hydrid Seismometer: two sensor types in one sonde, featuring 2 Hz 3D sensors and MEMS 3D accelerometer. [S31f-2.0a PDF]
- Slim Hole Seismometer: high tilt, high temperature sensor, suitable for test well or behind casing installation. [S31f-15 PDF]
- GOES: a multi-purpose magnetotelluric, seismic and microseismic recording system that is self-contained, extremely rugged and can be handled like a large geophone. This tool as been developed with REFTEK.
Borehole seismometer models
We produce a range of standard, fully gimbaled 3- or 6- component deviated borehole seismometers (sondes) for use in microearthquake detection (as small as -2 below the Richter scale measurement). The primary sondes used in IESE's borehole seismic networks are the S21g-2.0 and S21g-4.5 models.
Our borehole seismometers feature passive sensors with the highest current performance level in sensitivity, reliability and longevity, for permanent or temporary installation in hostile borehole environments.
|
IESE Standard Models
|
S21g-4.5
|
S21g-2.0
|
S31f-2.0
|
|
Specifications
|
|
|
|
|
Sensor type
|
Triaxial, Orthogonal
|
Triaxial, Orthogonal
|
Triaxial, Orthogonal
|
|
Natural frequency
|
4.5 Hz
|
2.0 Hz
|
2.0 Hz
|
|
Operational Temperature
|
45° - 150°C
|
50°C
|
45° to 50°C
|
|
Operational Pressure
|
10,000 psi (69 Mpa)
|
10,000 psi (69 Mpa)
|
Up to 100 m
|
|
Tilt tolerance
|
±18° max
|
±18° max
|
1°
|
|
Gimbaled
|
Fully
|
Fully
|
Fixed
|
|
DC resistance
|
3810Ω
|
3810Ω
|
3810Ω
|
|
Sensitivity
|
2.0 V/in/sec
|
2.0 V/in/sec
|
2.0 V/in/sec
|
|
Open circuit damping
|
0.27
|
0.61
|
0.61
|
|
Moving mass
|
23 g
|
23 g
|
23 g
|
|
Max coil excursion p-p
|
>0.30 in (<0.8 cm)
|
0.30 in (<0.8 cm)
|
0.30 in (<0.8 cm)
|
|
Normalised transduction constant
|
0.032 √Rc V/in/sec
|
0.0317 √Rc V/in/sec
|
0.0317 √Rc V/in/sec
|
|
Permanent Installation
|
Yes
|
Yes
|
Yes
|
|
Temporary Installation
|
No
|
No
|
Yes
|
|
Deployment
|
Winch/Crane
|
Winch/Crane
|
Surface/Winch
|
|
Dimensions
|
|
|
|
|
Outer diameter
|
3.5 in (8.8 cm)
|
3.5 in (8.8 cm)
|
2.8 in (7.2 cm)
|
|
Wall thickness
|
0.213 in (0.5 cm)
|
0.213 in (0.5 cm)
|
0.213 in (0.5 cm)
|
|
Height
|
3.5 ft
|
3.5 ft
|
3.5 ft
|
|
Weight
|
19 kg
|
30 kg
|
11 kg
|
|
Casing Material
|
316 stainless steel
|
316 stainless steel
|
304 stainless steel
|
Enquiries
Please contact Marcos if you have a specialised requirement or would like to receive specialist advice about borehole instrumentation and microseismology.