Borehole receivers

BHC4 | Hydrophone String

The hydrophone string BHC4 is used to receive P-waves in water filled boreholes. The BHC4 consists of a downhole cable containing a Kevlar tension string and a number of moulded hydrophones at pre-defined intervals. Each hydrophone consists of a sensor with a pre-amplification board. The electronic boards are powered from the surface by a bank of rechargeable AA cells. The cable is terminated by a connector to the seismograph.

bhc4

Hydrophone sensor: SQ54 or AQ2000
Frequency response: Flat from 1 to 10.000 Hz
Pre-Amplification: 4 or 10 x
Power supply: AA cells (battery box on surface)
Operational depth: Up to 500 m
Number of hydrophones: 24 (others on request)
Hydrophone interval: 1 m (others on request)
Hydrophone diameter: 38 mm
Cable weight per metre: 200 g
Cable strength: 4700 N
Borehole diameter: Min. 50 mm
Depth indicator: Cable marking every 2 m
Connector: To any seismograph
Storage: On drum

 

BGK5 | Borehole Geophone

The borehole geophone BGK5 is used to receive P- and S-waves in dry or water filled boreholes. The borehole geophone BGK5 consists of four horizontal sensors, separated by 45° intervals, and one vertical sensor. The geophone is coupled to the borehole wall by a pneumatic clamping system (inflatable bladder). Air is supplied to the BGK5 through an electro-pneumatic hybrid cable with a Kevlar tension string. The cable is terminated by a connector to the seismograph.

bgk5

Natural sensor frequency:

10 Hz (others on request)

Sensor arrangement:

4 horizontal (45°)/1 vertical

Operational depth:

Up to 100 m

Receiver length:

600 mm

Receiver diameter:

51 mm

Receiver weight:

2.8 kg

Cable weight per metre:

145 g

Cable strength:

2150 N

Borehole diameter:

75 mm (or larger if spacers are used)

Clamping system:

Inflatable bladder

Depth indicator:

Cable marking every 2 m

Connector:

To any seismograph

Storage:

On drum

 

BGK3/7 | Borehole Geophone

The borehole geophone BGK3 is used to receive P- and S-waves in dry or water filled boreholes. The borehole geophone BGK3 consists of a tri-axial sensor whereas the BGK7 consists of six horizontal sensors, separated by 30° intervals, and one vertical sensor. The geophone is coupled to the borehole wall by a pneumatic clamping system (inflatable bladder). Air is supplied to the BGK3/7 through an electro-pneumatic hybrid cable with a Kevlar tension string. A magnetic compass shows azimuthal deviation to North and can be used to get the orientation of the geophone in the borehole. The cable is terminated by a connector to the seismograph.

bgk3 7

Natural sensor frequency:

10 Hz (others on request)

Sensor arrangement:

Tri-axial (BGK3) or 6 horizontal (30°)/1 vertical (BGK7)

Operational depth:

Up to 100 m

Receiver length:

705 mm

Receiver diameter:

50 mm

Receiver weight:

3 kg

Cable weight per metre:

145 g

Cable strength:

2150 N

Borehole diameter:

75 mm (or larger if spacers are used)

Clamping system:

Inflatable bladder

Orientation:

Magnetic compass (+/-2.5°)

Depth indicator:

Cable marking every 2 m

Connector:

To any seismograph

Storage:

On drum

 

BGK1000 | Borehole Geophone

The BGK1000 is a digital borehole geophone used to receive P- and S-waves in dry and water filled boreholes. It is manufactured by Hinz Messtechnik GmbH and exclusively distributed by Geotomographie. The borehole geophone BGK1000 consists of a downhole probe with a tri-axial geophone sensor and a surface communication unit connected to the USB port of a laptop. Optionally, a hydrophone sensor can be added. An auxiliary channel can be connected to the surface unit to record an external seismic signal, i.e. a pilot vibrator sweep. Triggering is made via the surface unit allowing TTL pulse, geophone or contact triggering. The borehole geophone is designed to run on a winch equipped with a 4-conductor cable and a Gearhart Owen cable head. The geophone is coupled to the borehole wall by a mechanical clamping system (motor-driven arm). A magnetic compass is used to get the sensor orientation in the borehole. Seismic data are stored in SEG2 format by the acquisition software. A seismograph is not required. 

BGK1000

Natural geophone sensor frequency:

15 Hz (others on request)

Sensor arrangement:

Tri-axial

Power supply:

12 V input 72 V output

Operational depth:

Up to 2000 m

Max. pressure:

200 bar

Temperature range:

0 - 70 °C

Receiver length:

800 mm

Receiver diameter:

60 mm

Receiver weight:

8 kg

Borehole diameter:

75 - 200 mm

Clamping system:

Motor-driven clamping arm

Orientation:

Magnetic compass (+/- 2.5°)

Communication:

2 wire RS-485

Downhole electronics:

DSP = Blackfin 548, 64 MB SDRAM

Cable head:

GO-4

Digitization

Design:

Hinz Messtechnik GmbH

A/D conversion:

24 bit

Sampling frequencies:

250, 500, 1000, 2000, 4000, 8000, 16000, 48000 Hz

Trace length:

Max. 21 s

Trigger:

TTL, geophone, contact

Software:

SmartRec (Geotomographie)

 

DDS | Dual Downhole System

The Dual Downhole System (DDS) is used to receive P- and S-waves in dry and water filled boreholes in order to determine interval velocities. The DDS consists of two stations each equipped with tri-axial sensors. The stations are mechanically connected to each other to ensure the alignment of all horizontal sensors. Both stations are coupled to the borehole wall by a pneumatic clamping system (inflatable bladder). Air is supplied to the DDS through an electro-pneumatic hybrid cable with a Kevlar tension string. A magnetic compass shows azimuthal deviation to North and can be used to get the orientation of the DDS in the borehole. The cable is terminated by a connector to the seismograph.

dds

Natural sensor frequency:

28 Hz (others on request)

Sensor arrangement:

Tri-axial

Operational depth:

100 m

Number of stations:

2

Station interval:

2 m

Station length:

620 mm

Station diameter:

65 mm

Station weight:

2.5 kg

Cable weight per metre:

145 g

Cable strength:

2150 N

Borehole diameter:

75 mm

Clamping system:

Inflatable bladder

Orientation:

Magnetic compass (+/-2.5°)

Depth indicator:

Cable marking every 2 m

Connector:

To any seismograph

Storage:

On drum

 

MBAS | Multistation Borehole Geophone

The Multistation Borehole Acquisition System (MBAS) is a digital three-component geophone string used to receive P- and S-waves in dry or water filled boreholes. Up to ten individual stations with tri-axial sensors can be connected. The stations are aligned to ensure that all horizontal sensors are oriented in same direction. The system can be oriented from the surface by a torsionally stiff hose. Each station is clamped to the borehole wall by two pneumatic cylinders. An external trigger can be plugged into the USB interface on surface which is connected to a laptop. The operation is entirely controlled by the acquisition software. A separate seismograph is not required.

mbas

Natural sensor frequency:

10 Hz

Sensor arrangement:

Tri-axial

Operational depth:

Up to 100 m

Max. number of stations:

10

Station interval:

1 or 2 m

Station length:

735 mm

Station diameter:

65 mm

Station weight:

2.5 kg

Cable weight per metre:

460 g

Borehole diameter:

75 mm

Clamping system:

Pneumatic cylinders

Orientation:

Torsionally stiff hose

Depth indicator:

Cable marking every 2 m

Storage:

On drum and in

Digitization

Design:

MoHo s.r.l.

Power supply:

PC USB interface

A/D conversion:

24 bit

Sampling frequencies:

256 to 32768 Hz

Trace length:

Max. 4 s

Trigger:

TTL, geophone

Software:

Soilspy (MoHo s.r.l.)

 

M40 | Mini-Geophone

The Mini-Geophone M40 is used to receive P- and S-waves in horizontal boreholes. The borehole geophone consists of a tri-axial sensor. The geophone is coupled to the borehole wall by a pneumatic clamping system (inflatable bladder). Air is supplied to the M40 through the cable. The orientation of the M40 geophone is controlled from surface by a torsionally stiff hose. The cable is terminated by a connector to the seismograph.

M40

Geophone sensor:

GS14-L9

Natural sensor frequency:

28 Hz

Sensor arrangement:

Tri-axial

Operational depth:

Up to 10 m

Receiver length:

405 mm

Receiver diameter:

42 mm

Receiver weight:

3 kg

Cable weight per metre:

480 g

Borehole diameter:

50 mm (or larger if spacers are used)

Clamping system:

Inflatable bladder

Orientation:

Torsionally stiff hose

Depth indicator:

Cable marking every 2 m

Connector:

To any seismograph