The first joint AAPG-EAGE Geoscience Technology Workshop on Fractured Carbonates was held in Bali, February 15-17, 2012. 132 attendees from around the world gathered for two days of lecture and discussion, and a third day of core viewing. Presenters included experts from both industry and academia. Topics included structure/geomechanics; seismic; reservoir characterization; diagenesis; outcrop studies; and SE Asia and worldwide case studies. Cores from four Indonesia fields were displayed following overview presentations by each presenting company.
Keynote presentations were given on the two lecture days. SyamsuAlam (President Director, PT Pertamina EP) discussed “Fractured Basement Reservoir in NW Java Basin, Indonesia: an Exploration Opportunity and Challenge;” and Mateu Esteban (External Advisor of Carbonate Geology, Repsol) and Conxita Taberner (Principal Carbonate Geologist, Shell) addressed “Fractures and Diagenesis: From Concepts to Production in Carbonate Reservoirs.”
An important component of these workshops is discussion, and these were held at the end of each day. There was especially good discussion on the topic of reservoir characterization—best practices, the need to identify critically-stressed fractures that are the contributors to flow, the need to incorporate more dynamic data, and the importance of outcrop analogs. Feedback from engineers in the group stressed the importance of direct discussions between geologist and engineers, including concepts, feedback loops, and a common understanding of key parameters and their distribution. It was recommended that there be a forthcoming geology-engineering workshop.
Core discussion was vigorous as well. Mechanical and sequence stratigraphic controls were demonstrated and discussed, as were the implication and interpretation of poor core recovery (generally, the more fractures, the poorer the core recovery), and best practices for optimizing recovery (rate of penetration, bit types). “What is a fracture” generated a lot of discussion: do we lump or split? Do stylolites, although not fractures per se, effectively act as fractures / flow conduits when subjected to relaxation of stress? How does one predict open vs. closed? Do engineers care? The latter question led to feedbackon the importance of talking with the engineering team early in the work flow to plan if and to what degree additional work is relevant and necessary.
Feedback from the GTW attendees was that the meeting was beneficial in many ways. There was a good mix of regional (SE Asia) and international case studies; and good breadth of topics. The range of methods will help workers generate ideas for “out of the box” approaches to thinking about fractures. It was a great chance for people to exchange ideas with others. Finally, it was agreed that one of the key benefits from theworkshopwas tohear ideas about new approaches, new technology, and analogs from many different areas, so that the ultimate goal of prediction can be improved.
Julie Kupecz
2 April 2012