Abstract: Perspectives on Petroleum Risk Analysis: Lessons Learned and Future Directions

NEDERLOF, MARINUS H

Ideas about risking exploration ventures have evolved over the last 50 years from a completely subjective "single" estimate of possible hydrocarbon (HC) volumes to sophisticated statistical models based on worldwide experience. In all phases of development of risk analysis (RA) techniques, such methodology has contributed to more efficient exploration than would have been possible by an unstructured, subjective ranking of opportunities, whether involving whole plays or individual structures.

However, bias, such as overestimation of volumes and underestimation of uncertainty has prevailed. One of the tasks of risk analysis is to reduce, or eliminate such bias. It seems that this can only be done by having a RA system that incorporates the present knowledge of the HC process. A fairly complex appraisal model has to be used, which is calibrated by statistical (preferably bayesian) techniques to the real world, wherever possible.

While most recent efforts are directed to the generation of HC, trends are toward complete dynamic modeling of the HC process. This includes the complex domains of secondary migration and top and lateral seal. In future, most systems will become integrated with the economic evaluation and ranking. The well-known discovery models for plays can be extended to take the individual predictive distributions of the prospects into account, as well as their interdependence. A dynamic modeling of the discovery process then generates a number of discovery scenarios in terms of volumes, but also in terms of cashflow.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria