Oil and Gas
This course defines the processes of carbonate sediment accumulation in carbonate platforms in different tectonic settings and identifies target depositional facies that commonly form reservoirs. The diagenetic changes that carbonate rocks undergo during their burial history are reviewed through a series of informative classroom lectures, including a review of the commonly occurring carbonate reservoir types.
Duration and Training Method
This is a classroom course.
Participants will learn to:
- Compare carbonate rocks, minerals and their pore systems.
- Illustrate the formation of limestones and dolomites.
- Contrast carbonate facies from rimmed shelves and ramps.
- Analyse the diagenetic changes that affect carbonate rocks; mineralogy, textures and porosity evolution.
- Interpret the evolution of porosity and permeability in carbonates.
- Illustrate the classification of carbonate reservoir types; depositional versus diagenetic controls.
- Sketch the major changes that have taken place in carbonate depositional systems through geological time.
Despite hosting around 60% of the world’s hydrocarbon reserves, carbonate rocks form reservoirs that are often viewed as complex and unpredictable. The study of carbonates requires additional skills to those needed to understand clastic sytems. The application of modern facies models and facies patterns to subsurface carbonate systems allows some predictions to be made about the occurrence of different facies and their likely reservoir potential. Similarly, some basic rules and principles can be used to predict the diagenetic changes that carbonate rocks undergo with burial and how this affects their quality as hydrocarbon reservoirs.
The course will be divided into four parts:
Part 1 will introduce the building blocks of carbonate rocks; carbonate minerals, carbonate grain types, rock textures, and the different environments in which they form. Carbonate depositional processes will be studied using case studies from present-day humid and arid sedimentary environments. Facies models will be developed that aid in the prediction of potential reservoir facies. Practical work on a range of carbonate facies will be integrated with the lectures.
Part 2 focuses on diagenetic changes such as recrystallisation and dissolution that affect carbonate sediments from the time of their deposition through to burial and hydrocarbon charge. These changes may fundamentally alter the porosity and permeability of carbonate rocks and therefore have an important, sometimes overriding, control on reservoir quality. Images of various diagenetic textures and structures will be studied and their relationship to porosity and permeability discussed.
Part 3 will integrate the skills learnt in parts 1 and 2 to achieve an understanding of carbonate reservoirs. These are often said to form three main types; those controlled by the occurrence of particular sedimentary facies, those controlled by particular diagenetic fabrics and those controlled by fracture systems. Case studies of different reservoir types will be studied as well the different schemes that are used to classify different carbonate reservoir rock types.
- Introduction to carbonate minerals and carbonate rocks
- Classification of limestones and their pore systems
- Introduction to carbonate depositional systems and reservoirs
- Carbonate sedimentation in a modern, humid climate setting; south Florida and the Bahamas
- Rimmed carbonate shelves and carbonate platforms
- Facies models for rimmed shelves
- Carbonate and evaporite sedimentation in a modern arid climate setting; Arabian Gulf
- Ramp facies models
- Major controls on occurrence of carbonate platforms (climate, tectonic, oceanographic etc.)
- Principles and models of carbonate sequence stratigraphy and comparision with clastic systems
- Application of seismic carbonate sequence stratigraphy (worked examples)
- Near surface diagenetic environments of limestones and dolomites and relation to depositional sequences
- Burial diagenetic environments of limestones and dolomites. Diagenetic trends with burial and uplift
- Porosity and permeability of carbonate rocks
- Carbonate reservoir types; depositional and diagenetic controls
- Carbonate platforms, facies and reservoirs through time
Who Should Attend and Prerequisites
This course is aimed at geoscientists who require a fundamental understanding of carbonate depositional systems, diagenesis and modern facies models. The course will build from first principles and assumes no prior knowledge of carbonates but a basic understanding of geoscience is required.
Dan started his professional career with 30 years full-time teaching and research in the University of London. He currently divides his time between an Emeritus Chair in Carbonate Sedimentology, teaching professional courses in carbonate sedimentology and reservoirs, and consultancy projects on carbonate reservoirs for the hydrocarbons industry.
Dan’s research in carbonates started with studies on modern cool-water and tropical biogenic carbonates with a focus on carbonate producing communities and production rates. This work formed the foundation of subsequent numerical forward modelling of carbonate platform formation. Research on Cenozoic carbonate platforms and algal limestones of the Mediterranean area. Research at Royal Holloway featured a multidisciplinary study of rift basin evolution in the Red Sea and Gulf of Aden focusing on syn-rift carbonate platform formation. An interest in structural controls on carbonate platform evolution also led to studies of foreland basin platforms in Spain and platforms in convergent settings in Southeast Asia. These field-based studies led to a new classification of carbonate platforms based on their basinal setting. Current research focuses on new models to understand the origin of high-frequency cycles in shallow-water carbonates.
During his time in London, Dan supervised some 25 PhD students at London and many of these now have careers as petroleum geologists or as academics. He has published about 100 scientific papers and 5 books and edited volumes.
Classroom and field-based courses (Egypt and Oman) on carbonate facies, sequence stratigraphy and reservoirs are currently run for Shell, Schlumberger, Neftex, Roxar as well as for Nautilus.
Affiliations and Accreditation
PhD University of Reading, UK (Sedimentology)
N189: Concepts of Carbonate Depositional Systems and Reservoirs