Integrated Study of a Lacustrine Petroleum System (France)

The Lodève Permian basin, located West of Montpellier in Southern France, represent an accessible oilfield analogue of the Northern North Sea half-graben basins. It presents outstanding outcrops of mature black shales, carbonate and clastic reservoirs, enriched with stratigraphic and structural unconformities, and also fault and fracture networks.
Based on concepts, field observation and hands-on petroleum systems modelling, participants will discuss source rock maturation scenarios and explain observed live oil seeps and fault bitumen. The outcomes of the petroleum systems analysis will be discussed in terms of regional prospectivity and compared to worldwide analogues.

1. By interpreting outcrops, the participants will understand the structural and stratigraphic architecture of the Lodève half graben basin, and the associated petroleum systems elements.
2. The evolution of the basin will be discussed, based on observation of faults, fractures, unconformities, and volcanism.
3. Participants will set into dynamic context the evidence of source rock maturation, oil expulsion and migration as spotted in the field.
4. Basin and petroleum systems modelling will be performed, generating a dynamic model integrating the above, and analysing the unknowns such as past heat flow and erosion amounts.
5. Finally, the learning points will be extrapolated to areas with less information in a discussion encouraging regional and worldwide analogue thinking.

This petroleum systems analysis field course is designed as a group exercise where each participant must contribute to build a common understanding of the evolution of the Lodève basin, and its implication for the petroleum system. This is achieved through a blended mixture of concept, outcrop observation and interpretation, and numerical modelling:

• Class room presentations and exercises are limited to introductory sessions.
• Each participant learns by making his own analytical observations. Then, he is invited to express and argue his deductions.
• Most of the time is spent at the outcrops, where individual interpretations are shared and discussed with the group.
• “In-situ” field lectures support and complement the outcrop observations.
• Two half days are reserved for the modelling group exercise.
• Daily morning synthesis and evening wrap-up, at the outcrop location, allow everybody to progressively strengthen his understanding.

Each participant is required to provide a yearly medical certificate before attending this field course. Participants must be in good health and physical conditions to attend.  Yet, every outcrop or panorama is easily accessible, and do not require specific training.
Attendees must also wear adapted shoes (suitable for pebbly hiking) and bring clothing for hot day time temperatures (sun hat, sun glasses, etc.), and potential rainfalls.

• 1h transfer from Montpellier airport or hotel to Lodève
• General introduction – Presentation, agenda, HSE
• Petroleum systems – Introduction, case studies
• Lodève Basin – Introduction, analogues, view point.

• Basal unconformity and Cambrian dolomitic “basement” reservoir
• Pre-rift Grey Permian stratigraphy and clastic reservoirs/carrier beds
• Autunian Black Shales – Detailed log, TOC & vitrinite reflectance measurements – Field lecture source rock deposition and Rock Eval
• Pre-rift/syn-rift unconformity and syn-rift Red Permian stratigraphy
• Permo-Triassic unconformity
• Wrap-up session drawing the overall stratigraphic log

• Syn-rift fan geometry
• Fault systems and bitumen – SGR, faults as migration conduits
• Overburden fractures
• Volcanism
• Wrap-up session drawing a cross section, and generating a dynamic model

• 1D basin and petroleum systems modelling group exercise – Permian heat flow history and missing strata/erosion, calibration to vitrinite reflectance, black shale kinetics, Permian maturation history scenarios
• Post-Permian stratigraphy – Triassic clastic reservoirs and Jurassic overburden

• Continuation of 1D basin and petroleum systems modelling group exercise – Maturation history scenarios from Permian to recent times
• Discussion of expulsion, migration – Presentation of 2D and 3D models and comparison to observed live oil seeps and bitumen
• Extrapolation to areas with less information and discussion of regional and worldwide analogues
• 1h transfer back to Montpellier airport or hotel

Note:
A shorter, more synthetic program can be organized on purpose, for team building objectives or any other specific groups (experts, national representatives, NOC etc.).