Borehole seismic recorder SCOUT-MSK

Intended use and field of application

The Seismic recorder is intended for engineering seismics by near-surface section study based on up-hole velocity survey and vertical seismic profiling in the open hole at a depth of up to100 m.

The Seismic recorder can be used with various types of seismic impulse sources and vibrators. SCOUT-MSK provides digital seismic data recording in field conditions and monitoring of the main data acquisition channel specifications by means of in-built diagnostic facilities.

scout-msk

Configuration of the Seismic recorder includes

    three-component borehole seismic surveying module with cable;
  • pressure-control unit;
  • recorder (BAR3-2);
  • hand winch with ratchet;
  • winch cable;
  • guide with roller.

Brief functional characteristics of the recorder’s components

Borehole seismic surveying module with tree built-in electrodynamic geophones is intended for geophones displacement inside the borehole and their fixation at selected depths of up to100 m. Pressing of the borehole seismic surveying module to the sidewall of the borehole for more close contact is provided with the in-built controllable electromechanical device. Earth mechanical oscillations are transformed by geophones into electrical signals and are transmitted via the cable to autonomous recorder BAR3-2 for their digitization and recording.

The guide with roller, winch cable and hand winch with ratchet provide borehole seismic surveying module displacement inside the borehole at selected depths.

Pressure control unit (PCU) is intended for borehole module’s electric motor power management.

scou-msk0

scou-msk2

Downhole module

scou-msk3

Recorder BAR3-2

 

Technical specifications:

 

                                                                Downhole module

Number of seismic channels

3

Geophone type

Electrodynamic

Geophone brand name

HT-5 (vertical)

HT-H-5 (horizontal)

Geophones layout

Three-component  orthogonal with rigid fixation in relation to the downhole module case

Holding down device type

Electromechanical with direct current motor

Holding down device supply voltage

(27±3) V

No-load current

(200 – 500) mA

Latching current

(1±0,2) A

Holding down device full opening time

In less than 40 s

Holding down device dimensions:

Diameter

Length

Connecting cable length

57 mm

630 mm

125 m

Downhole module weight (without the cable)

No more than 6 kg

Downhole module operating temperature range

- 40 ?C  ? +85 ?C

Sealing protection level according to GOST 14254-96 (MEC 529-89 CEI 70-1 EN 60529)

IP68

                                                             Recorder BAR3-2

Number of channels                                                                      

3

Sample rate

0,25, 0.5, 1.0, 2.0, 4,0 msec

Timing accuracy

1 mcs

Maximum input signal

No less  than 2500 mV

Frequency range

From 0 up to 1600 Hz

Common mode rejection

 100 dB       

Cross feed isolation   

-120 dB

Dynamic range

140 dB

Total harmonic distortion

0,00035%

Maximum continuous autonomous recording

capability supported by on-board memory 32 Gb

640 h

Maximum continuous autonomous recording

capability supported by two on-board batteries

670 h

Gain constants

0, 12, 24, 36 dB

Input noise (10 – 125 Hz band)

No more than 0,17 mcV

Output data formats

SEG Y, SEG

Operating temperature range                                                         

40?C to +70?C

                                                          Geophone

Natural frequency

5 (±10%) Hz

 

Conversion ratio

98 (±5%) V/m/s

 

Open circuit damping

0,7 (±5%)

 

Coil resistance

1800 (±5%) Ohm

 

Distortion

No more than 0,2%

 

 Frequency factor upper limit

No less than 250 Hz

 

Moving mass

15,8 g

 

Diameter

27,3 mm

 

Height

33,5 mm

 

Mass

105 g

 

Operating temperature

- 40 ?C  ? +80 ?C

 

Pressure control unit

 

Input voltage

12 V

 

Output voltage

27 V

 

Peak current

2 A

 

Electrocution protection class

III

 

Seal rating

IPO50 (full dust protection, but  moisture unprotected)