Multi Channel Seismic (MCS) System

 

Modern marine geoscience requires accurate and detailed subsurface information for the mapping of geologic structures and sedimentary sequences beneath the continental margin. In order to acquire this information NIWA purchased a Multi Channel Seismic system (MCS) in December 1996, consisting of a 24 channel streamer, seismic source and acquisition hardware.

Since then the MCS system has evolved to meet the tight specifications that NIWA science and industry have demanded. Improvements include provision for real-time streamer depth control, better data quality control, greater data acquisition capability (increased to 48 channels), extended streamer length and improved logging facilities. With this substantial investment in hardware and software, NIWA now has the potential to acquire shallow penetration seismic data of excellent quality.

The MCS system has been successfully deployed in numerous scientific voyages and commercial contracts.

Contact

Steve Wilcox
steve.wilcox@niwa.co.nz

Specifications

Array

Manufacturer Geometrics Inc.
Type Geoeel 42mm Digital Streamer
Specifications 48 channel
12.5m group spacing
16 hydrophones (Benthos Geopoint)/ group
Group Sensitivity 20v / bar
30m deck cable
200m lead in
2 x 25m elastic section
7 x 100m active sections
Total Length 825m
A/D Converters 5 – 8000hz bandwidth
24 bit A/D
120db dynamic range
0.0625 – 4ms sample rate
QC Checks Hydrophone Capacitance and leakage, Pulse, Oscillator, timing and DC Offset

Recorder

Manufacturer Geometrics Inc.
Type CNT-1
Specifications Pentium IV Windows XP Operating system
2 x 20 Gbyte external DLT drive
QC Displays Log, Shot, Spectra, Noise, Gather, Trigger, Tape.
Output SCSI upto 4 Tape drives
Real time gather (selected streamer channel)
Data Cycle time < 1 second for 5 second record
Data Format SEG2, SEG Y, SEG D

Energy Source

Manufacturer Seismic Systems Inc.
Type GI Gun 210 cu.in.
Specifications 105 / 150 / 250 cu.in. Generator
105 cu.in. Injector
Configurations
  1. GI Mode no bubble pulse
  2. Harmonic Mode reduced bubble pulse
  3. 600 cu.in array (150/105 and 250/105)

Compressors

Manufacturer Compair Ltd.
Type Reavell 5436
Specifications 128 cu.m /hr
Electric motor, water cooled
housed in 10ft shipping container



Manufacturer Price
Type SA35-AC
Specifications 272 cu.m /hr @ 25°C
Electric motor, water cooled
housed in 20ft shipping container

Streamer Depth Control

Manufacturer Digicourse
Type 7 x 5010 depth birds
3 x 5011 compass birds
Model 272 control Unit
System 3 control system 
Dual Gun being lowered into the water. Credit: John Mitchell
48 Channel Seismic Streamer and winch. Credit: Richard Wysoczanski
Streamer Depth Control “Bird”. Credit: John Mitchell
A Processed Seismic section. Credit: Geoffroy Lamarche