1. Low-frequency hydrocarbon microtremors: Case studies around the world
Robert M. Habiger (Spectraseis AG, Zürich), Erik Saenger (Geologisches Institut, Switzerland), Stefan Schmalholz (Geologisches Institut, Switzerland)

2. Survey operations: on land
Spectraseis is operating in diverse locations around the world
Shown here: field operations on four continents
Put list down side of all places we have acquired and/or processed data; or perhaps some statistics on how much data we have acquired or processed

3. Outline Project workflow Project examples Summary and Conclusions
Acquisition
Processing & Analysis
Interpretation
Project examples
Objectives
Enviornments and operatonal challenges
Processing & Analysis issues
Results
Summary and Conclusions
Acknowledgements
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4. Spectraseis surveys around the world
___ surveys have been acquired aournd the world in 7 countries
I will be talking talking about operations and data from the 4 shown by the red dots

5. Outline Project workflow Project examples Summary and Conclusions
Acquisition
Processing & Analysis
Interpretation
Project examples
Objectives
Enviornments and operatonal challenges
Processing & Analysis issues
Results
Summary and Conclusions
Acknowledgements
ttktjkjt

6. Acquisition: field operations (site preparation)
Tripod N
Sensors are buried to reduce environmental noise.
An aluminum tripod system allows for quick orientation & leveling.
Leveling

7. Acquisition: field operations (equipment)
Broadband seismometers are used for sensitivity, noise floor, and bandwidth
Sensor
Handheld
control
Batteries
Güralp Seismometer
Freq. Range: 0.03 – 50 Hz
Sampling rate: 100Hz
Sensitivity: 1500 V/m/s
Weight: 15 kg

8. Acquisition: field operations (installed station)
GPS antenna
Position
Marker
Completed field setup at measurement point (station).
All equipment is buried for nominally 24hrs - except GPS antenna.

9. Acquisition: survey design
Possible survey designs include:
3D grids
dense lines
staggered synchronized swaths
combinations
reference stations

10. Processing & Analysis Workflow
Raw Data Characterization & QC
Reference Stations
Spectral Analysis
Noise
Amplitude vs. Time
Synchrogram
Earthquakes
Time Stability
Spectrogram
Weather
Prepare clean, comparable data
Data Conditioning and Processing
The workflow supports a systematic analysis. It has taken us several years to develop this workflow and the tools needed to carry it out. It remains active research and development.
Range Setting
Parameter setting
Spectra/Attributes
Reservoir Localization
PSD-IZ
V/H
Time Reverse Modeling
PSD-IN
Soil Effects
PSD-IE
Polarization
Analysis & Interpretation

11. Data from northern Africa
Different colors are data acquired on different days. This is daytime data. The main observations:
The data is complex
The data is variable
Calculated PSD for synchronized lines 4, 5 and 6 taken in Block 186 using “day” data range. There has been no range setting. Each color represents a different line, acquired on a different day. The multiple lines for a given color represent different time intervals.

12. Data from northern Africa
Night data
1st minimum shifts
anthropogenic noise is less
anomaly band is better defined
Calculated PSD for synchronized lines 4, 5 and 6 taken in Block 186 using “night” data range. There has been no range setting. Each color represents a different line, acquired on a different day. The multiple lines for a given color represent different time intervals.

13. Processing & Analysis (statistical spectral analysis)
Deep gas example of weak anomaly

14. Processing & Analysis (synchrograms)
Observations
regional events
local events
night/day variation
Synchrogram for all points on the line A and PS-01, recording period on 26-27th June with a common local time axis. Day/night signal variations are clearly visible. Note strong perturbing broadband noises (first at 0.20AM and event at 3.10AM). LF anomaly at around 3Hz is visible. PS-01 (at the bottom of the picture) recorded a lot of noise, which differs in character from the rest of the data.

15. Data cleaning and signal conditioning
The top row of composite spectra are raw data
The bottom row is “range set” data
: SDA plots for each point on Line B (Z component on full raw dataset, 24 hours, no ranges applied). Note the strong bimodal signal distribution due to day/night variation
SDA plots for all points on Line B (Z component on night data: 07.00PM-04.00AM local time subset, ranges applied). Note that spectra for all points are quieter and better defined at night time compare to day time.

16. Outline Project workflow Project examples Summary and Conclusions
Acquisition
Processing & Analysis
Interpretation
Project examples
Objectives
Enviornments and operatonal challenges
Processing & Analysis issues
Results
Summary and Conclusions
Acknowledgements
ttktjkjt

17. North American case study
The technology was confirmed over an existing field and then extended into an exploration area

18. North America case study
A very good correlation over a known reservoir and hydrocarbon potential map

19. South American case study
A limited test for the first application to heavy oil
Mapa de Tierras – Cinturón de crudo pesado – Campo Rubiales

20. South American case study
Two major attributes provided a consistent relationship with the expected reservoir for this limited study

21. Outline Project workflow Project examples Summary and Conclusions
Acquisition
Processing & Analysis
Interpretation
Project examples
Objectives
Enviornments and operatonal challenges
Processing & Analysis issues
Results
Summary and Conclusions
Acknowledgements
ttktjkjt

22. Conclusion Off the shelf sensors provide good qualitydata
A rich set of workflow processing & anlaysis tools are needed for data conditioning and attribute calculation
LF passive seismic technology has been applied to ___ survey in ___ different locations
Remaining challenges
Theory relating to the mechanisms causing the LF micro tremors
Noise analysis and mitigation

23. Acknowledgements Permission to show data
StatoilHydro
EniRepSa
Pemex
Ecopetrol
Spectraseis staff in acquisition, processing and analysis

25. Instruments used during the survey
First raw data QC in FO
Block 186
Preliminary QC of raw data in Field Office