Oil and Gas
Oil and Gas | Structure and Tectonics
A Systematic Approach to Defining and Evaluating Stratigraphic and Subtle Combination Traps
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.
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Schedule
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
Learning Outcomes
Participants will learn to:
- Apply a methodical approach, through a systematic workflow, to identify stratigraphic and subtle combination traps within the appropriate tectonic and sequence stratigraphic context.
- 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.
- Evaluate prospects involving stratigraphic and subtle combination traps in terms of risk and resource estimation uncertainties.
- Work to deliver an efficient exploration screening result in a “learning by doing” scenario, applying the workflow taught on the course.
Course Content
Introduction:
- 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
Full day 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.
Course summary
Who Should Attend and Prerequisites
This Skilled Application 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.
Instructors
Mike Mayall
Background
Mike Mayall is a consultant for the oil industry and has also helped develop and deliver industry training courses on ‘Passive margin play concepts’ and ‘Maximising the impact of analogues across the E&P cycle’. He is a Visiting Professor at Imperial College London with a research program on sedimentation and tectonics in slope systems. He also teaches on the Petroleum Geology MSc course. Mike works with the Aberdeen University deep-water PRAXS consortia on developing workflows for interpreting deep-water slope systems. He has numerous publications particularly on deep-water sediments.
Mike started at BP as a sedimentologist in the International group in London and worked on numerous projects from all over the world, particularly in Indonesia, Ireland, Norway and Alaska. He later became manager of the International Sedimentology group and subsequently moved to Houston as manager of an Integrated Reservoir Description group. Mike spent four years in Houston where he was involved in many projects including early exploration and appraisal of the deepwater Gulf of Mexico. On returning to London Mike worked on major projects in the NW shelf of Australia and on clastic and carbonate reservoirs offshore Vietnam. When new giant discoveries were made in deepwater offshore Angola Mike was part of the small BP team which evaluated the discoveries and took them through the BP sanctioning process. During this time Mike was able to interpret the fabulous seismic data, integrate with small multidiscipline teams and work with, and learn from, the operating teams in other major companies. Through this thrilling and exhilarating period Mike was involved in the appraisal and sanctioning of ten major projects in deepwater reservoirs. Thirty four years after starting with BP, Mike retired to become an independent consultant.
Mike’s key skills are in reducing complex technical issues to practical and pragmatic value focused on important element of a project. He is an energetic and passionate advocate of technical quality, teaching and coaching of both young and more experienced professionals. Mike has taught many field and classroom training courses ranging from basic sedimentology and petroleum geology to conducting advanced workshops. Mike has always had strong links with academia and he is enthusiastic about applying research results to industry subsurface problems. Mike has published papers on clay mineralogy, Devonian limestones, shelf edge deltas, tufted algal mats, Miocene carbonates and earthquake beds. His more recent work has been focussed on deepwater reservoirs and he has published a number of papers with colleagues from industry and academia.
Affiliations and Accreditation
PhD Reading University - The late Triassic (Rhaetian) transgression in SW Britain
MSc Reading University - Sedimentology and it’s Applications
BSc Cardiff University - Geology, Honors
Courses Taught
N533: Deepwater Deposiitional Systems (Virtual Outcrops)
N372: Integrated Subsurface Description in a Working Petroleum System (North Derbyshire, UK)
N477: A Systematic Approach to Defining and Evaluating Stratigraphic and Subtle Combination Traps
N483: Deepwater Stratigraphy and Facies Analysis from Seismic, Well Data and Outcrops
Mark Thompson
Background
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