Oil and Gas
Business impact: The course will help participants develop a detailed understanding of chalk depositional processes, facies, diagenetic processes and products, and how these are controlled by primary productivity, sea level, local tectonics and other extrinsic factors (e.g. Milankovitch cyclicity). This provides a firm basis for understanding parameters that control reservoir quality in chalk depositional systems, and is applicable throughout the E&P life cycle.
The course focuses on the identification, characterization and interpretation of chalk facies, including pelagic chalks, redeposited chalks, condensed sequences (including hardgrounds), and the parameters controlling reservoir properties in each of these. Diagenetic processes affecting poroperm will be considered in detail. The fracture characteristics and history, and affects on permeability of each facies will also be covered.
The Normandy coast provides extensive exposures of Cenomanian to Santonian Chalks, which record progressive deepening of the Cretaceous sea, recorded in the gradual cut-off of clastic supply and an increasingly oceanic depositional regime in which white pelagic chalks dominated. The region was strongly affected by deep erosive currents that created spectacular channels, on the flanks of which, extensive redeposition took place in the form of slump sheets and debris flows, analogous with those present in the Central Graben of the North Sea.
Duration and Training Method
A field course comprising fieldwork and classroom presentations and exercises in a 75:25 ratio. Practical class and field-based exercises are based on field logging, identification of key lithologies and diagenetic processes and their interpretation in terms of depositional systems.
Participants will learn to:
- Assess a number of different chalk facies and how these fit into the depositional systems in which they form.
- Characterise the depositional processes which control facies distribution within a variety of chalk successions.
- Develop an understanding of how sea level changes control stacking patterns, sequences and facies distributions in chalks and hence overall reservoir potential.
- Evaluate the diagenetic processes taking place in chalks, the interaction between sedimentation and diagenesis, and the products of these and their affects on poroperm.
- Integrate logs for correlations with coeval successions, identify marker horizons and incorporate other data including biostratigraphy and chemostratigraphy.
- Relate the physical characteristics of individual facies to fracture style and thus controls on permeability.
- Assess redeposited chalks, and assess their likely lateral extent, geometries and reservoir potential.
Day 1: Travel and Introduction
- Travel to Domaine Saint Clair, Etretat, France and transfer to hotel
- Afternoon: Safety brief and introductory lectures on chalk petrography and sedimentological control on facies
- Afternoon: Short excursion to view the cliffs in Etretat
Day 2: Fieldwork and Classroom
- Morning: Lectures
- Dagenesis and its control on poroperm
- Corelation in chalks (what is possible and how can it be achieved?)
- Chalk reservoirs
- Afternoon: Fieldwork
- Port Petrolier; Field identification of chalk facies and diagenetic products, assessing poroperm, logging, sequence stratigraphy, exercises
- Tilleul: slump sheets; channels, mounds, exercise
Day 3: Fieldwork
- Morning: Fecamp; fractures, reservoir examples
- Afternoon: Senneville; chalk facies variability, debris flows, regional hardgrounds and basinwide correlation
Day 4: Fieldwork and Classroom
- Morning: Fieldwork at Vaucottes; slump sheets
- Afternoon: Fieldwork at Banc a Cuves; channels, slump sheets, seismic resolution, exercise
- Evening: Course wrap up and summary
Day 5: Departure
Who Should Attend and Prerequisites
This course is multi-disciplinary and is designed for geoscientists, petrophysicists, and reservoir engineers involved in exploring carbonate basin settings or appraising and developing fine grained carbonate reservoirs. The lectures and exercises, as well as field discussions will integrate the various disciplines.
Professor Andy Gale is currently director of consulting firm Brading Geoscience Ltd, and emeritus Professor of the University of Portsmouth. He is also Scientific Associate of the Natural History Museum, London, UK.
Andy received a BSc and PhD in Geology from King’s College, University of London, in 1975 and 1984 respectively. He was a lecturer at City of London Polytechnic (1985-1990), Imperial College London (1990-1997) and a professor at the University of Greenwich (1997-2006). He then joined the University of Portsmouth as senior lecturer and subsequently professor (2007-2016).
Andy's interests in Earth Science range through sedimentology, paleontology and stratigraphy, with a special interest in chalk and the Cretaceous world. He has published about 300 papers on various aspects of Earth Science, including geochemistry, structural geology and stratigraphy. Andy has run numerous courses for the hydrocarbon industry, especially on aspects of chalk geology.
Affiliations and Accreditation
PhD King’s College, University of London - Geology
BSc King’s College, University of London - Geology
W030: Chalk - a Geology and Geophysics Workshop