Night School – Depth Conversion (Virtual Course)

High quality training to boost professional development. Courses are exclusive to PESGB members only.

5-26 August 2020

Ticket Type Price Qty*

Member Ticket

£85.00 (GBP)

Course Description

This is a practical course for geoscientists tasked with creating depth maps for volumetrics and well planning, with an emphasis on understanding and modelling the geological controls on velocity. Velocity analysis techniques designed to extract full value from velocity data will be taught, along with velocity modelling methods including powerful ‘Vok’ linear functions and seismic velocity calibrated to wells. The theory and practice of tying maps to wells will be covered, as well as highlighting common pitfalls in the depth conversion process. Spreadsheet exercises to illustrate concepts and techniques will be demonstrated and provided to attendees. A wide range of experience will be catered for in the course. Attendees will leave with an awareness of techniques necessary to undertake defendable depth conversions.
Please note that 1 of the sessions will include pre-recorded material as a precaution to internet connectivity concerns. This is likely to be Session 2. Alan will be still be live to introduce the session and to answer any questions throughout the evening.

Part 1 | Velocity: geological controls and data sources
Facilitator: Alan Atkinson
Wednesday 5 August 2020
6:00pm – 8:00pm


  • Understand the relevance of depth conversion in the era of Pre Stack Depth Migration
  • Appreciate the impact of overburden velocity on reservoir depth structure

Geological factors influencing velocity

  • Learn the intrinsic properties of rocks which influence their velocity and anisotropy
  • Understand how diagenesis, overpressure and fluid fill modify these properties

Sources of velocity data and their problems

  • Be aware of the different sources of data providing a measure of velocity
  • Understand seismic velocity origins

Part 2 | Velocity data analysis techniques
Facilitator: Alan Atkinson
Wednesday 12 August 2020
6:00pm – 8:00pm

  • Learn data analysis techniques to determine the best approach to velocity modelling and depth conversion
  • Understand the importance of scale in displaying quantitative data, and learn tips to do it right
  • Appreciate the importance of looking at all of the data, including logs and seismic velocities

Part 3 | Velocity model building methods
Facilitator: Alan Atkinson
Date: Wednesday 19 August 2020
6:00pm – 8:00pm

  • Understand when one layer models (e.g. t-d polynomials, Vavg maps) can and can’t be used
  • Appreciate the benefits of layering even with simple velocity models
  • Know how to implement common velocity models, including linear velocity functions (‘Vok’)
  • Learn techniques to calibrate and condition seismic velocity
  • Reveal the hidden limitations of less standard velocity models (isochron-isochore etc)

Part 4 | Depth conversion & pitfalls
Facilitator: Alan Atkinson
Date: Wednesday 26 August 2020
6:00pm – 8:00pm

Tying to wells

  • Learn strategies for tying maps to wells, and when not to use restricted radius tying
  • Understand why tying in depth or velocity domains is different, and how to choose
  • Appreciate the implications and value of mapping Vo, learn how to do it, and when not to

Handling common pitfalls

  • Know when it is best not to tie, due to seismic imaging limitations
  • Understand when linear velocity modelling techniques require modification to account for commonly encountered problems

Who should attend:
Aspiring, future leaders in the oil and gas industry who want to acquire skills beyond the academic and technical and obtain insights into the commercially orientated analysis. Acquire the global perspectives essential to professional success.

Become a member:
If you want reduced ticket prices, access to exclusive free events, a monthly magazine and more you can apply  to become a member today from just £65* by visiting our membership page
*Standard membership fees from £65 + admin fee

This course will go ahead regardless of the number of attendees.

Speaker Biography - Alan Atkinson

Alan has over thirty years of exploration, field development, and production geoscience experience with operators in West Africa, South Asia and the North Sea.

Specialising in the application of high end geophysics to structural and stratigraphic seismic interpretation, his areas of expertise are reservoir characterisation (using pre-stack inversion, AVO analysis) and velocity modelling (pre-stack depth migration and depth conversion).

He started his career working the North Sea with Phillips Petroleum and Amerada Hess in London, and subsequently moved to CNR International, working Angola and Côte d’Ivoire. He then moved to Cairn Energy, living and working in India, and becoming Chief Geophysicist during their successful Rajasthan campaign. Here, he supervised several significant seismic acquisition and processing programmes, and managed a geophysical studies team undertaking, amongst other projects, AVO modelling work and pioneering 4D studies on India’s largest onshore fields.

He is now a partner in Rockflow Resources Ltd, a specialist technical and management consultancy serving the international petroleum industry, primarily advising on reserve evaluations for a variety of clients worldwide and providing services as an Expert Witness in oil and gas disputes. He is also an honorary lecturer at Imperial College London, contributing to the Petroleum Geoscience MSc.

Alan devised the ‘Depth Conversion Methods & Pitfalls’ course in 2009 and ‘Depth Conversion Methods & Petrel Workflows’ two years later. The courses have been delivered over 50 times to audiences across the world.

Venue Information

Venue information

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This course will be delivered online

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