Geotomographie

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.

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 the 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.

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.

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.

BIS-SH S-Wave Source

The borehole source BIS-SH generates horizontally polarized shear waves (SH) and compressional waves (P). The seismic signals are highly repeatable. The source works in dry or water-filled boreholes and can be used in vertical or horizontal boreholes.
The energy released by the IPG5000 discharges through a system of electromagnetic coils adjacent to a copper plate. If the plate is rejected a mechanical impact to the borehole wall is generated. The borehole source is coupled to the borehole wall by a pneumatic clamping system (inflatable bladder). The orientation of the source is controlled from the surface by a torsionally stiff hose.

BIS-SH-DS S-Wave Source

The borehole source BIS-SH-DS generates horizontally polarized shear waves (SH) and compressional waves (P). The seismic signals are highly repeatable. The source works in dry or water-filled boreholes and can be used in vertical or horizontal boreholes. The energy released by the IPG800 discharges through a system of coupled coils. They generate a mechanical impact on the borehole wall that releases seismic waves.
The borehole source is coupled to the borehole wall by a pneumatic clamping system (inflatable bladder). The orientation of the source is controlled from the surface by a torsionally stiff hose.

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.

DevProbe1 Deviation Probe

The Deviation Probe DevProbe1 is used to measure the borehole deviation. A three-axis magnetometer measures the azimuthal direction of the borehole and a dual tilt sensor provides information about the inclination. The probe is sealed and temperature compensated. Borehole deviation is required to determine the precise XYZ location of a seismic source or geophone inside a borehole. A software is provided to visualize and store the deviation data.

IPG5000 Impulse Generator

The Impulse Generator IPG5000 (formerly named IPG1005) is the high voltage supply to the seismic borehole sources BIS-SH and SBS42. The energy is stored in a large capacitor bank which discharges through a mechanical switch.
The IPG5000 is controlled by a Remote Control Unit (RCU). The RCU allows the user to start the seismic survey by a single or continuous shot release. The repetition rate is freely selectable under continuous operation. The RCU is connected to the seismograph to send an accurate trigger signal.

IPG800 Impulse Generator

The Impulse Generator IPG800 is the high voltage supply to the seismic borehole source BIS-SH-DS. The energy is stored in capacitors which discharge through a mechanical switch. The lightweight IPG800 is incorporated in a robust PeliTM case.
The IPG800 is operated by a Remote Control Unit (RCU) which is used to start a pre-defined sequence of shots or to stop the operation. The RCU is connected to the seismograph to send an accurate trigger signal.

LS-24 Landstreamer

The Landstreamer LS-24 is used to record P-, S- or surface waves. It consists of a number of horizontally or vertically oriented sensors mounted on sledges which are attached to a robust belt. The belt can be hooked to a vehicle and moved along the profile. A landstreamer is used to collect a large volume of seismic data in a short time. The landstreamer is suitable for MASW or reflection seismic applications especially on paved ground.

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.

MBAS-A Analogue Multistation Borehole Acquisition System

The Analogue Multistation Borehole Acquisition System can be used for S-wave borehole tomography or downhole surveying. It consists of up to eight geophone stations each equipped with a triaxial sensor. The string is fully waterproof and can be used to receive P- and S-waves in dry or water-filled boreholes. All geophone stations are aligned and mechanically connected by a torsional stiff hose to ensure a correct sensor orientation. A magnetic compass placed in the lowest station shows the azimuth to the North. Compass values are displayed at a surface box. All geophone stations can be coupled to the borehole wall by a pneumatic clamping system (air packer). Air is supplied to the geophone stations through a separate air hose. The borehole geophone string is terminated by a seismograph connector.

MBAS-D Digital Multistation Borehole Acquisition System

The Digital Multistation Borehole Acquisition System (MBAS-D) 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.

SBS42 P-Wave Source

The borehole source SBS42 generates compressional waves (P) in water filled boreholes. The seismic signals are highly repeatable. Energy released by the IPG5000 discharges through a coaxial cable terminated by two adjacent spark electrodes. The spark discharge vaporizes water by a high-pressure plasma. This generates vapour bubbles which expand and collapse, thereby generating high-frequency seismic waves.

Sledge Hammer Surface Source

The Sledge Hammer is used to generate seismic waves (P or S-waves) at the surface. It is a suitable source for shallow downhole surveys up to a depth of 100 m.

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