SEISMIC DATA

1. SEISMIC DATA ACQUISITION
ONSHORE & OFFSHORE

2. As Geoscientists
1. An anticlinal trap 2. A fault bound trap

3. Geophysical Methods of
Exploration
• Gravity
• Magnetic
• Electrical
• Seismic

4. Why Seismic?
• Seismic forms the backbone of hydrocarbon
exploration.
• The predominance over other geophysical
methods is due to:
– High accuracy
– High resolution
– Penetration to a great depth.

5. Seismic Data Acquisition in Oil
Exploration
• Refraction Survey
• Reflection Survey

6. What are we looking for
We are looking for sub surface conditions, suitable for accumulation of
hydrocarbons

7. What are we looking for

8. Fundamentals .....
Geophones record the movement of the ground due to the propagation of
seismic energy as seismograms or seismic traces. Seismograms are frequently
displayed as "wiggle traces."

9. Components of Data Acquisition
• Energy source with adequate power
• Sensors to detect the signal
• Recording instrument to record data
• Positioning (and Navigation)

10. Land Seismic
Data Acquisition
1 2
3
4 5
Detonators
Explosives

11. Energy Source
• Explosive
• Non Explosive
– Weight Dropping
– Vibroseis

12. Non-explosive Source
• Weight Dropping
• Vibroseis

13. Sensor
• Geophone

14. Seismic Survey Methods
• 2D Seismic
• 3D Seismic
• 4D Seismic
• OBC (Ocean Bottom Cable) - can be of any
type like 2D, 3D or 4D
• VSP Survey (bore-hole seismic)

15. 2D Seismic Data Acquisition
Source
Geophones
Seismic Waves
Recording

16. Seismic data is digitally recorded in the field along a predefined line,
using appropriate shot and receiver geometries.
Layer-1
Layer-2
Layer-3
Shots
Receivers
SEISMIC DATA ACQUISITION - 2D

17. Shot Line
Receiver
Layout
3D Survey
Improves imaging of complex subsurface
Data is acquired on a aerial grid. Position of each trace (shot receiver combination) is important

18. OFFSHORE SEISMIC
DATA ACQUISITION

19. • Source - Airguns
• Receiver - Hydrophone
• Recording instruments - Similar
• Positioning - DGPS/Gyro
Acoustics,Compass
Land vs Marine Acquisition

20. 2D Data Acquisition

21. Seismic API
Acquisition, Processing & Interpretation
Acquisition:
Acquiring data
Processing:
Correction & enhancement of
Signal to noise
Interpretation:
converting to Geological
meaning

22. THANK YOU !