Oil and Gas
Oil and Gas | Carbonates
Business Impact: Success depends on getting the basics right the first time, and this course is designed to provide the frameworks for practitioners in the industry to develop new, and critically evaluate existing, geological models for carbonate reservoirs, based on the latest ideas and techniques. This enables meaningful assessments of risk and uncertainty to be made as well as the best decision making regarding well planning and reservoir modelling, all with clear business implications.
Carbonate rocks contain over 40% of the world’s hydrocarbon reserves. Most earth science specialists have only had a rudimentary introduction to the topic at the first degree level and there seems to be a mystique in the oil industry that carbonates are “too complicated”. The aim of this course is to provide an up-to-date introduction to practical carbonate sedimentology. Carbonate rocks are complex and there are many gaps in our understanding, but there are basic principles taught in this course that provide a framework in which the complexity may be made understandable, improving exploration success and reducing the risk of inappropriate strategies being devised during appraisal and development of the reservoir.
The course provides a thorough grounding in the concepts, terminology and models used to interpret, assess and predict carbonate reservoirs. It will take the student from the seismic scale through to reservoir issues relating to dynamic simulations.
Duration and Training Method
This is a classroom or virtual classroom course comprising a mixture of lectures, discussion, case studies, and practical exercises.
Participants will learn to:
- Distinguish the principal carbonate sediment components, textures and systems of carbonate classification.
- Examine the primary controls on carbonate deposition temporally and spatially. Compare and contrast with siliciclastic deposition.
- Differentiate the main types of carbonate platform, their variability, scale and distribution of likely reservoir units.
- Demonstrate sequence stratigraphic aspects of carbonate build-ups, their differing response to sea level change compared to clastic sediments and discuss their seismic characters.
- Categorise the principal types of reservoir facies (platform interior, carbonate sands, reefs, slope systems and chalks), their recognition, architecture, sequence stratigraphy and porosity types.
- Differentiate the development of primary and secondary porosity through the combination of sedimentological, chemical and diagenetic processes.
- Compare and contrast carbonate pore systems and their reservoir characteristics with those developed in clastic sediments.
- Compare how the variety of diagenetic environments affect primary porosity in carbonate rocks and understand the implications for reservoir quality.
- Distinguish the principal modes of formation of dolomites and compare their reservoir properties with other carbonates.
The course will commence with an examination of the principles of carbonate deposition and the factors that control the formation of carbonate systems. The main structure of the course falls into three parts with all aspects being firmly set in a sequence stratigraphic framework:
Part 1 outlines the seismic scale of carbonate systems. This will include a discussion of the types of carbonate platforms, modern and ancient analogues, platform architecture, seismic recognition, play types and exercises.
Part 2 will summarise the reservoir scale of carbonates. The subjects covered will include all the key depositional systems including platform interiors, shoal belts, reefs, slopes and chalks. Criteria for recognition, key reservoir properties and common play associations will be distilled for each facies type. There will also be discussions of key reservoir types for “reefs” such as rudists, Miocene buildups, buildups of late Paleozoic age. Reservoir case studies and exercises will be integrated into the webinar sessions. This section ends by studying sequence stratigraphic aspects and also drowned platforms.
Part 3 focuses on the origins of porosity, diagenetic environments, reservoir aspects, layering issues and techniques used to examine carbonate reservoirs. Two reservoir types are studied in detail – dolomite reservoirs, and palaeokarsts.
The key topics are:
- An Introduction to Carbonate Systems
- Carbonate Sediment and Limestone Components
- Limestone Classification
- Carbonate Platforms
- Carbonate Shelves - Sequence Stratigraphy of Flat-topped Platforms
- Carbonate Ramps
- Carbonate, Evaporite and Siliciclastic Sediment Partitioning
- Platform Interior Carbonates
- Sandbodies on Platform Margins and Ramps
- Carbonate Slope Systems
- Pelagic Systems and Chalk Reservoirs
- Platform Drowning and Tethyan Carbonate-dominated Passive Margin of the Alps
- Facies Belts
- Introduction to Porosity in Carbonates
- Carbonate Porosity and Rock Fabrics
- Introduction to Diagenesis and Sequence Stratigraphy
- Upper Jurassic, Corallian Reefs of the Weald
- Porosity Development, Diagenesis and Diagenetic Environments
- Marine Diagenetic Environments - Western Canada Basin
- Meteoric Diagenesis
- Porosity Development During Burial Diagenesis
- Dolomites - Dolostones
- Palaeokarst and Karstic Porosity Systems
- Rudist-rich Formations
- Carbonates and Tectonics
Who Should Attend and Prerequisites
The course is structured to appeal to all geoscientists who wish to broaden and deepen their knowledge of carbonate reservoirs.
Paul Wright has worked on carbonates for over 40 years, holding positions at the universities of Bristol and Reading as well as the BG Chair in Applied Sedimentology at Cardiff University for ten years. For over five years from 2007 Paul was principal consultant sedimentologist and group technical authority for carbonates at BG Group. He has worked extensively on carbonate reservoirs in North Africa, offshore India, Kazakhstan and offshore Brazil, as well as in the Paris Basin, Abu Dhabi and West Africa. He has conducted field work widely in UK, Spain, Portugal, Oman and USA.
Paul has written over 140 research papers, and co-authored or edited several books including the main text book in carbonate sedimentology. He has supervised over 20 PhD students, most of whom work in the oil and gas industry. He has served on the editorial boards of several international journals.
He is now director of PW Carbonate Geoscience Ltd, specializing in consulting, training and mentoring in applied carbonate sedimentology. He is an honorary fellow at the National Museum of Wales, Cardiff.
Paul is the 2016 recipient of the Pettijohn medal for outstanding contributions to sedimentology and stratigraphy, awarded by SEPM (Society for Sedimentary Geology), and also recipient of the 2015 AAPG Grover E Murray Distinguished Educator Award.
N020: Carbonate Depositional Systems: Reservoir Sedimentology & Diagenesis
N143: Advanced Concepts in Carbonate Exploration and Reservoir Characterization (Northern Spain)
N245: Sedimentology and stratigraphy of Lacustrine Systems: Reservoir and Source Rocks (Utah & Colorado, USA)
N336: Carbonate Reservoir Description Based on Core and Well Data (Nottinghamshire, UK)