N201 Depositional Systems, Sequence Stratigraphy and Diagenesis of Carbonate Rocks

Course Facts

Course Code:
N201
Duration:
5 days
Type:
Classroom
CEU:
4.0 Continuing Education Units
PDH:
40 Professional Development Hours
Certificate:
Certificate Issued Upon Completion

Summary

This course examines the processes of the formation and accumulation of carbonate sediments with reference to examples from Asia-Pacific. Facies and facies models are described, including their variation in different tectonic settings. The principles and practical application of sequence stratigraphy are reviewed, together with discussion on how this improves our understanding of carbonate reservoirs. Diagenetic changes that carbonate rocks undergo are also analysed.

Duration and Training Method

A five-day course, comprising classroom lectures and paper and specimen based exercises.


Participants will learn to:

  1. Analyse the sedimentology of carbonate rocks: carbonate minerals, grain types, rock textures and the different environments in which they form.
  2. Interpret carbonate reservoir facies, using Cenozoic case studies from SE Asia and the Pacific region and published facies models.
  3. Categorise the diagenetic changes that affect limestones and dolomites and the evolution of their pore systems and potential reservoir quality.
  4. Apply carbonate sequence stratigraphy; systems tracts, parasequences, depositional sequences, marine flooding and drowning surfaces, sequence boundaries and other major surfaces.
  5. Use carbonate sequence stratigraphy to provide a conceptual and predictive understanding of carbonate stratigraphies and their early diagenesis.
  6. Examine formation and controls on the different types of carbonate reservoirs, with particular reference to Southeast Asia.
  7. Compare various reservoir types using selected case studies and explain the different schemes that are used to classify different carbonate reservoir rock types.
  8. Analyse the major changes that have taken place in carbonate depositional systems and carbonate mineralogy through geological time.

Despite hosting around 60% of the world’s hydrocarbon reserves carbonate rocks and reservoirs are often viewed as complex and unpredictable and their study requires additional skills to those needed to understand clastic systems. The course covers the basic information that is needed to understand facies models and diagenetic environments. Sequence stratigraphy is a conceptual and predictive framework that enables geoscientists to improve their understanding of the location and likely quality of carbonate 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 limestones and dolomites and therefore have an important, sometimes overriding, control on reservoir quality. Images of various diagenetic textures and structures will be studied from SE Asian examples and their porosity and permeability discussed.

Part 3 examines the basin-scale controls on the accumulation of strata and introduces the concepts of carbonate sequence stratigraphy and the tectonic controls on the on formation of different types of platforms. Sequence stratigraphic building blocks; systems tracts, parasequences and depositional sequences are studied together with the significant surfaces that divide up stratigraphies; marine flooding surfaces and sequence boundaries (unconformities). Tectonic controls on the formation of carbonate platforms are significant in SE Asia and Bosences recent genetic classification of platform types will be introduced.

Part 4 will integrate the skills learnt in parts 1 to 3 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 fractures. The different types of pore systems, their origin and their permeabilities will be discussed. Case studies of different reservoir types will be studied, using examples from SE Asia as well the different schemes that are used to classify different carbonate reservoir rock types.

Planned Agenda

Part 1 - Day 1
1. Introduction to carbonate depositional systems, carbonate minerals, carbonate rocks
and their classification.
2. Skeletal grain production and reef-rimmed, attached platforms.
3. Non-skeletal grain production and facies models for rimmed carbonate shelves.
4. Carbonate ramps; arid-climate, peritidal carbonates and ramp facies models.

Part 2 - Day 2
5. Principles of carbonate sequence stratigraphy.
6. Sequence stratigraphy of rimmed carbonate shelves and isolated platforms.
7. Sequence stratigraphy of mixed carbonate-evaporite and carbonate-clastic systems.
8. Sequence stratigraphy of carbonate ramps.
9. Numerical forward modelling of carbonate systems.

Part 3 - Day 3
10. Early diagenesis of limestones; mineralogy, textures and porosity evolution.
11. Dolomites and dolomitization.
12. Late stage diagenesis of limestones and dolomites.
13. Environments and trends in diagenesis.
14. Recognition of different porosity types and their origin and significance.

Part 4 - Day 4
15. Application of sequence stratigraphy to Tertiary and Mesozoic successions, including
SE Asia.
16. Tectonic and basin-scale controls on the occurrence and nature of carbonate
platforms with examples from SE Asia.
17. Sequence stratigraphic analysis of seismic and outcrop datasets.

Part 4 - Day 5
18. Carbonate pore system types and carbonate reservoir rock types.
19. Carbonate reservoirs; depositional versus diagenetic versus structural controls.
20. Carbonates through time; the present is not always the key to the past.

Who should attend

This course is aimed at geoscientists who require an understanding of carbonate depositional systems, diagenesis, modern facies models and the role of sequence stratigraphy in reservoir prediction. The course will build from first principles and assumes no prior knowledge of carbonates.

Prerequisites and linking courses

There are no prerequisites for this course.

The Nautilus Training Alliance portfolio of carbonate classes includes field-based classes such as N059 (Applied Carbonate Geology), N091 (Carbonate Reservoir Architecture and Applied Carbonate Sequence Stratigraphy) and N235 (Exploring for Carbonate Reservoirs) which cover additional aspects of carbonate reservoir systems. More specialised and advanced topics are addressed by a range of classroom and field-based classes.

Click on a name to learn more about the instructor

Dan Bosence