Oil and Gas

Oil and Gas | Basin Analysis

Integrated Charge Access Evaluation: The Key to Successful Exploration

Course Code: N522
Instructors:  Leon DzouMark Thompson
Course Outline:  Download
Format and Duration:
3 days
5 sessions

Next Event

Location: Virtual
Date:  2nd - 6th Dec 2024
Start Time: 14:00 GMT
Event Code: N522a24V
Fee From: GBP £2,595 (exc. Tax)


Charge access considers the journey of expelled hydrocarbon from the source rock into the reservoir of a prospect. It is often a critical, if not the critical, risk to the success of any exploration well. Often the seismic interpreter hands over their maps to the petroleum systems analyst at the last minute, giving no time for the necessary integration. This integration of the geological framework with petroleum systems modelling is key to avoiding drilling dry holes and is the focus of this course. The course presents a rich series of global examples and case histories, taught by two industry experts with over 80 years of experience between them. Participants in this course will learn to integrate the basin-wide regional understanding with prospect evaluation principles in order to more accurately quantify resource estimates and risk in any prospect, ultimately drilling fewer dry holes or underfilled traps.

Business Impact: Does your company drill numerous failures with no shows? Do you consider faults as the main migration route into your prospect? Do you make complex 3D basin models that don’t predict the next well result? If so, we have a useful course for you!


"The course instructors have a lot of experience and show many global case studies covering different aspects of the complexity of Charge Access. A very useful course for people (like me) that need to improve their understanding of charge access."


Event Code: N522a24V
Sessions: 5 sessions
Instructors: Mark Thompson, Leon Dzou
Dates: 2nd - 6th Dec 2024
Start Time: 14:00 GMT
Location: Virtual
Fee From
GBP £2,595 (exc. Tax)
Good Availability
Please login to book.

Duration and Training Method

This is a classroom or virtual classroom course comprising a mixture of lectures, discussion, case studies, and practical exercises.

Course Overview

Participants will learn to:
  1. Understand the science that underpins petroleum migration and accumulation.
  2. Understand the impact of the overall tectonic style in different mega-sequence settings, structural relief, and the role of faults and fractures in migration and trapping.
  3. Apply the principles to make better predictions of charge access in prospect evaluation.
  4. Appreciate a rich variety of case histories from basins worldwide and how they can be applied to your prospect to help understand the risk.

The course will consider four key factors in charge access:

  1. Source rock potential and distribution;
  2. Carrier bed extent and distribution;
  3. Structural focusing;
  4. Structural relief and seal capacity;

The following shows the anticipated schedule of content, which may vary according to the pace of your course and focus of the participants, as well as if any new case studies arise.

Part 1: Source Rock Potential

An overview of the controls on source presence and quality.

  • Case history: Gulf of Mexico -  the nature and distribution of the various petroleum systems (organo-facies A and B);
    • Exercise: Mensa gas field - did we miss thermogenic oil charge in the mature GoM basin or is the Tithonian source rock not present?
    • Exercise: Are the Gulf of Mexico Norphlet fields sourced from the Smackover?
  • Case history discussion: Cooper Basin, Australia (organo-facies D/E);
  • Biogenic gas generation processes: An overview of the biological and chemical processes involved;

Part 2: Geological Models (Source-Carrier-Seal Systems)

An overview of secondary petroleum migration principles.

  • GDE mapping (clastics and carbonate systems).
    • Exercise: Zohr gas field, Nile Delta Egypt;
  • Case history: Pearl River Mouth Basin, South China Sea;
    • Exercise: Where’s the oil charge in the South PRMB?
    • Exercise: Liuhua 11-1 field, what are the main factors favouring long-distance transport of petroleum?

Part 3: Migration and Entrapment

  • Focussed vs dispersive migration on a basin scale. Downwards vs upwards migration.
    • Case history: (Lateral drainage coupled systems) foreland basin North Slope Alaska;
    • Exercise: Migration blind spots Bintuni Basin, Papua New Guinea;
    • Case history and discussion: (Vertical drainage) petroleum system Marco Polo Field, Gulf of Mexico (charge focus, structural relief and seal capacity, migration time lag);
    • Exercise: W Shetlands Basin Palaeocene discoveries;
  • Roles of faults and fractures.
    • Case history: Thunder Horse;
    • Trap configuration concept: Evaluation of the capillary sealing capacity of all the seal rocks (top, bottom, lateral, and fault seal);
    • Case history: Columbus Basin, offshore Trinidad - use of fault-seal analysis in understanding petroleum migration in a complexly faulted anticlinal trap;

Part 4a: Post-Well Evaluation

  • Case history: Mexican Ridge undercharged systems v poor regional top seal;
  • Case history: Exploration results on the Equatorial Margin. Good discovery rate, but very limited commercial success;
  • Case history: Brigadier Trend NW Shelf Australia, followed by a discussion of Ironbark well failure mode;
  • Exercise: Good luck, Bad luck and Mukluk;
  • Case Histories: Using shows as a smoking gun (Buzzard and Marconi fields, North Sea);

Part 4b: 3D Petroleum Migration Modelling

  • Case History: 3D modelling study of the low-permeability petroleum system of the Bakken Formation, Williston basin;
  • Discussion: The use of 3D petroleum migration modelling in exploration; How useful are these models in exploration risking and decision making?
  • Alternative workflow for petroleum migration modelling: Thinking processes to draw schematic charge cartoon and then test with appropriate software (percolation modelling).

Part 5: Prospect Charge Analysis

  • Impact of DHI’s on charge access risking;
  • Hydrocarbon charge assessment: Procedures for estimating amounts of oil and gas generated, migrated, and trapped in prospects;
  • Case history: Great White Field, Gulf of Mexico.
    • Exercise: Biogenic gas charge assessment
  • Case history: Frade and Roncador Fields, Campos Basin.
    • Exercise: Using seismic lines to assess Southern Mexico offshore exploratory wells charge access risk.

Concluding remarks and summary of best practice.

This course is aimed at geoscientists working on basin, play fairway, and prospect evaluation with 5 years or more experience working frontier to mature basins. This is an applied and integrated course involving all geoscience disciplines.

Leon Dzou

Dr Leon Dzou works as a Consultant for ADNOC in Abu Dhabi, UAE. He has more than 30 years’ experience with a variety of companies across the spectrum of petroleum systems, with a strong background in geochemistry, source rock depositional environments, petroleum generation and migration, as well as pressure and seal analysis. He has experience of both conventional and unconventional plays across the value chain of Exploration, Development and Production. As well as teaching courses on the Nautilus programme, Leon has been deeply involved in delivering training courses as part of a cohesive exploration capability development programme for a national oil company.

Dr Dzou completed a PhD at the University of Texas at Dallas, with the title ‘Quantitative study of biomarkers in coals and vitrinite concentrates of different maturity and a geochemical study of oils and condensates from K Field, offshore Taiwan’. Most recently, Dr Dzou was a Senior Advisor in Petroleum Systems Analysis with BP and a member of the global Exploration Assurance team. He was passionate about developing discipline health at BP and dedicated a lot of energy to training, advising, and mentoring less experienced petroleum systems specialists and practitioners. He derived great satisfaction from coaching, teaching and generally stimulating staff in the Petroleum Systems arena at BP.

Research interests include generation/expulsion/migration processes, especially secondary migration appears to be the key technical issue, mostly because the movement of petroleum in the subsurface is so poorly understood. Leon believes that young geoscientists should be taught to become skeptics who search for data that does not fit existing paradigms; They must go back to basics and challenge conventional wisdom. 

Affiliations and Accreditation
PhD University of Texas at Dallas - Organic Geochemistry
MSc University of Texas at Dallas - Organic Geochemistry
BSc National Taiwan University - Geology
American Association of Petroleum Geologists, USA - Member

Courses Taught
N425: Play Analysis for Targeted Prospect Identification
N491: Play and Prospect Assessment
N522: Integrated Charge Access Evaluation: The Key to Successful Exploration

Mark Thompson

Mark is Director of Lurch Oil Consultation Limited and is an Associate member of RPS Nautilus. As well as teaching courses on the Nautilus programme, Mark has been deeply involved in delivering training courses as part of a cohesive exploration capability development programme for a national oil company.

Mark is from Staffordshire in the British Midlands. He went to Cambridge University 1974 to 1977 to do a Natural Sciences degree, specialising in Geology. Mark joined BP straight out of University and successfully developed a career in both exploration and development geology, attaining the position of Senior Exploration Advisor before leaving BP at the end of 2014. He has been involved in many hydrocarbon discoveries worldwide in numerous basins. He was for many years a global coach in BP, where he prepared and taught many internal courses.

Mark’s career has taken him on many postings including Brazil, Egypt, Indonesia and Norway. His main interests include basin analysis, play fairway and prospect analysis. He has published on a wide variety of topics including alternative explanations for depth dependent stretching, heat flow associated with underplating and play fairway analysis. Interests outside geology include walking and orienteering.

Affiliations and Accreditation
MA University of Cambridge - Natural Science, Geology

Courses Taught
N005: Tectonic Controls on Basin Development and Petroleum Systems
N378: Basin Analysis for Petroleum Geoscientists
N380: Seismic Interpretation Workshop: Play Recognition on Passive Margins
N425: Play Analysis for Targeted Prospect Identification
N477: A Systematic Approach to Defining and Evaluating Stratigraphic and Subtle Combination Traps
N522: Integrated Charge Access Evaluation: The Key to Successful Exploration

CEU: 2.1 Continuing Education Units
PDH: 21 Professional Development Hours
Certificate: Certificate Issued Upon Completion
RPS is accredited by the International Association for Continuing Education and Training (IACET) and is authorized to issue the IACET CEU. We comply with the ANSI/IACET Standard, which is recognised internationally as a standard of excellence in instructional practices.
We issue a Certificate of Attendance which verifies the number of training hours attended. Our courses are generally accepted by most professional licensing boards/associations towards continuing education credits. Please check with your licensing board to determine if the courses and certificate of attendance meet their specific criteria.