D477 A Systematic Approach to Defining and Evaluating Stratigraphic and Subtle Combination Traps

Course Facts

Course Code:
4 days
Virtual Classroom
3.2 Continuing Education Units
32 Professional Development Hours
Certificate Issued Upon Completion


Business Impact: Many stratigraphic and combination traps are discovered serendipitously, throughout a basin’s exploration history. They are often perceived as high risk and volumes are commonly underestimated, especially where the column height is larger than the structural spill.  In this course we will develop a consistent and systematic workflow for the deliberate identification and evaluation of such traps.  This is important as these subtle traps often get risked in an inconsistent manner across organisations but they can contain significant resources. Course participants will acquire the necessary skills to enhance value for their employers by identifying new prospects, performing robust geological risk assessments, and generating more accurate resource volume assessments

Topics include classification schemes; defining a regional framework; formulation of a geological model; trap domains; regional angular unconformities; stratigraphic edges; risking and volumetrics. Case histories and exercises are taken from a rich variety of tectonic settings and a large variety of depositional environments, both for carbonates and clastics.

Duration and Training Method

A virtual classroom course divided into 8 webinar sessions (equivalent to a four-day classroom course), comprising lectures, discussion, case studies, and practical exercises to be completed by participants during and between sessions.

Participants will learn to:
  1. Apply a methodical  approach, through a systematic workflow, to identify stratigraphic and subtle combination traps within the appropriate tectonic and sequence stratigraphic context. 
  2. Appreciate the rich set of analogue fields world-wide in various plate tectonic and mega-sequence settings for both carbonates and clastic reservoirs.  Deploy these analogues to help guide exploration in similar basins.
  3. Evaluate prospects involving stratigraphic and subtle combination traps in terms of risk and resource estimation uncertainties.
  4. Work to deliver an efficient exploration screening result in a “learning by doing” scenario, applying the workflow taught on the course.


  • Classification schemes; The importance of stratigraphic and subtle combination traps, globally. Review the track record over last few decades;
  • Exercise: Trap description methodology in terms of trap edges

Regional framework:

  • Megasequences
  • Location of analogue traps in extensional settings
  • Location of analogue traps in compressional settings
  • Description by systems tracts
  • Trap identification and classification
  • Exercise: N Slope Alaska

Integrated geological model:

  • Formulation of a geological model: 
    • Role of pre-existing and syn-depositional topography on reservoir GDE’s; Growth structures; The importance of sediment entry points and dispersal;
    • Impact of top seal thickness and environment of deposition
    • Effects of early hydrocarbon generation synchronous with quartz cementation
    • Concept of the first carrier; Coupled systems;
    • Migration foci - importance of chasing the molecules
    • Seal effectiveness vs available charge
  • Trap domains maps talk

Regional angular unconformities:

  • Super-crop and sub-crop maps, case history North Slope.
  • Exercises: SNS and Gippsland.

Stratigraphic edges – pinch-outs and erosional truncation:

  • Defining play-scale pinch out geometries on seismic data
  • Exercise: Sergipe
  • Defining paralic prospect scale stratigraphic traps
  • Exercise: Brookian N Slope
  • Defining deep-water prospect-scale stratigraphic traps. Including lobes, channels, MTC’s and ‘waste zones’
  • Exercises: Various basins worldwide
  • Defining carbonate prospect-scale stratigraphic traps

Aspects of risking and volumetrics:

  • Use of seismic attributes and direct hydrocarbon indicators (DHI’s)
  • Exercise: 3 cases for discussion
  • Risking guidelines and pitfalls
  • BRV criteria: Importance of defining the geological model(s)
  • Exercise: Dependency between column height and available charge volumes
  • Learning from well failures using a ‘failure criteria lookback methodology’ - North Sea case histories
  • Exercise: West of Shetland
  • Exercise: Portfolio Management

 “The edges of the wedges”: a suggested workflow

Kopervik exercise:

  • Participants will apply the work flow and lessons from the previous part of the course on a seismic dataset from the North Sea.
  • Define the regional setting, construct a play cartoon, draw a trap domain map, and discuss risking and portfolio management of identified stratigraphic traps.

Overview of North Sea stratigraphic traps

Course summary

Who should attend

This Skilled level course is aimed at exploration geoscientists with experience of seismic interpretation and a firm grasp of stratigraphic concepts and the fundamentals of petroleum systems. Team leaders and managers of exploration teams could also benefit from participation in this course.

Prerequisites and linking courses

There are no specific prerequisites for this course, although familiarity with seismic interpretation would be beneficial, such as that acquired on D085 (Introduction to Seismic Interpretation (Distance Learning)).

Click on a name to learn more about the instructor

Mike Mayall

Mark Thompson

Dates for this Course



12 Oct. 2021
Event Code:
GBP £2,990 (Exclusive of tax)

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