Seismic Interpretation and Mapping

Gerhard Diephuis  Maarten Wiemer 
5 days

Business context

This course is specifically designed for senior exploration geoscientists currently active in prospect mapping.  Due to current routines of seismic interpretation dominated by automated mapping processes, seismic interpretation can easily become mechanical and lacking in solid geophysical and geological conceptual underpinning. The lack of coherent geological- and geophysical story lines underpinning the prospect evaluation is often apparent in volumetric assessment and well placing review sessions.

Who should attend

Senior geoscientists with (ca. 6-8 years' work experience) in geoscience fields and well-versed in seismic interpretation projects.

Course content

The course is designed to assist participants to optimise conceptual geoscience input into technical evaluation: link interpretation to fundamentals of geology and geophysics and produce technically coherent models, with particular attention to an understanding of structural styles and evolution, depositional systems and their implication to sedimentary basinfill. Attention is paid to a thorough understanding of the merits of geophysical techniques in prospect evaluation.

Learning, methods and tools

Participants will be exposed to hands-on extraction of geological and geophysical information from variable data types and integration of this information in order to produce a consistent subsurface model to support their work at regional, prospect or reservoir scale. "Let the data tell their story" is the key learning theme in this course. 

The exercises are table-top and generally executed in team mode.

Report-out and discussion is a key learning tool.

Day by day programme

DAY ONE                    

1.0 Course Introduction                                                        

Introduction of course instructors and delegates.

Course objectives and way of learning.

1.1 Plate Margins and Basins                                  

Link plate margins and sedimentary basins; tectonic activity map; Tethys reconstruction example; Exercise - Arabian Plate.      

1.2 Team Exercise: Basin Settings and Trap Styles

Selection of regional lines for team evaluation and discussion.

1.3 Petroleum Systems, Hc Plays and Prospects

Petroleum systems definition; hc play and prospect definition; play and prospect elements; event chart; basic volume equation; prospect volumetric uncertainties; PBE; play maps.

Exercise - prospect risk ranking.                                 

1.4 Madagascar RL poster discussion                                               

Megasequences and link with plate tectonic phases; hc plays - what happened?

 

DAY TWO

Recap day 1                  

2.1 Principles of Rock Physics and DHI's

Objectives, elastic moduli, fluid properties, Biot-Gassmann.

Exercise on fluid replacement

2.2 Principles of QI: Seismic Inversion

Application & advantages, acoustic vs elastic impedance, various approaches

Discussion on techniques for shale exploration/exploitatation

2.3 Seismic Stratigraphy 

Seismic reflections what do they represent; some pitfalls; seismic strat. nomenclature; depositional sequences and systems tracts; sand distribution.

Exercise - Ebro Delta RL seismic stratigraphic interpretation and play evaluation

 

DAY THREE 

Recap day 2             

3.1 Divergent Margins

Examples of extensional regimes.

Exercise - North SeaGullfaks: basement induced normal faulting; alternative Interpretations.

Exercise - Niger delta growth fault setting

3.2 Depositional Systems in Passive Margin Deltaic & Rift-fill Settings

Delta processes and classification; sand body geometry; structural controls; stacking patterns and seismic facies.

Exercise - well correlation and pitfalls

Rift Settings and basin fill; alluvial stacking patterns.

Exercise - Nova Scotia RL; key horizons and faults; evaluate structural and stratigraphic history.

Exercise - Madagascar Graben-fill - review core, log and seismic data.

 

DAY FOUR                     

Recap day 3

4.1 Convergent Margins

Compressional settings; toe-thrust settings.       

Exercise NW Borneo.

N. Tarim (W. China) foredeep case history.

Exercise: Pyrenees - outcrop, RG profile, wells & seismic

4.2 Oblique Convergent and Strike Slip Margins

Oblique convergent settings - examples from California, Egypt Western Desert and Levant.

Exercise - Central Atlantic.

Exercise - Bohai Sina farm-out opportunity.

4.3 Inversion & Wrenching Structures

Examples.

Exercise - Broad Fourteens lines - plenary discussions.

 

DAY FIVE                       

Recap day 4

5.1 Salt Basins

Ebro Basin Cordona example; depositional environment of salt; salt basin settings; major salt basins examples; deformation styles; why is salt important in exploration.

Exercise - North Sea Permian Salt Basin structuration.

Exercise thermal conductivity impact.

5.2 L05 End of Course Interpretation Exercise

Guided team exercise with plenary report-out per team

North Sea L05 structure -

1)    Lower Cretaceous play, volume calculation,

2)    Triassic DHI and discussion trapping mechanism,

3)    Permian prospect assessment of strengths and weaknesses.