Use of New Information in the Evaluation of Yet-to-Find Resources
Assessment of the yet-to-find potential of frontier plays often encompasses broad uncertainties owing to limited constraints on the underlying geologic interpretations. New information, especially well results but also seismic or rock samples, can significantly reduce the range of plausible geologic scenarios and thus the uncertainty in the assessment. The magnitude and type of change will depend on how the new information relates to the original interpretation(s). If the new information validates part or all of the geologic interpretation, the play (marginal) chance of adequacy will be uplifted. The magnitude and extent of the uplift depend on the geologic interpretation. A discovery exceeding the assessment minimum volume increases play chance to 1.0 for areas of similar geology near the well. In a map sense, de-risking the play element polygons containing the discovery can uplift multiple subplay polygons. Risk-dependency relationships among play element polygons can extend the uplift spatially. A well does not have to be a discovery in order to uplift play chance. For example, dry hole could validate the presence of porous reservoir or top seal. New information could also narrow the range of future field sizes or the number of future fields. Valid negative information can eliminate one of more geologic scenarios, thereby decreasing the range of possible outcomes. Play-element risk dependency relationships should control the extent and magnitude of the impact of negative information. If the underlying geologic interpretation is heterogeneous (patchy), new play tests may be inconclusive. Successive inconclusive tests can provide information that lead to lower marginal and conditional chances of adequacy.
AAPG Search and Discovery Article #90177©3P Arctic, Polar Petroleum Potential Conference & Exhibition, Stavanger, Norway, October 15-18, 2013