Changes

For exploratory prospects (including shallow pool, deeper pool, and extension wildcats, commonly managed by development geologists), the recommended procedure is for the geotechnical professional to express his or her confidence independently in four critical geological aspects of any prospect:

For exploratory prospects (including shallow pool, deeper pool, and extension wildcats, commonly managed by development geologists), the recommended procedure is for the geotechnical professional to express his or her confidence independently in four critical geological aspects of any prospect:

# ''What is the probability (or confidence) that '''reservoir rock '''is present, of sufficient [[porosity]] and [[permeability]] to be productive, and in some minimal thickness and extent sufficient to contain detectable (i.e., measurable) quantities of mobile hydrocarbons, or to tempt a prudent onshore domestic operator to attempt a completion?''

# ''What is the probability (or confidence) that '''reservoir rock '''is present, of sufficient [[porosity]] and [[permeability]] to be productive, and in some minimal thickness and extent sufficient to contain detectable (i.e., measurable) quantities of mobile hydrocarbons, or to tempt a prudent onshore domestic operator to attempt a completion?''

#: One approach is to estimate the minimum required flow rate and relate this flow rate to thickness and [[permeability]]. In any case, what we seek is the geologist's confidence in the existence of at least a minimal reservoir—thickness, extent, [[porosity]], and effective [[permeability]]. Under this approach, encountering a wet, commercial-quality sandstone would not be a failure in the reservoir category, but rather in one of the other categories, such as an unexpected structural low, an absence of [[Calculating charge volume|hydrocarbon charge]], or a leaky trap. However, the presence of a 1-ft-thick tight siltstone where a 10-ft-thick porous sandstone objective had been predicted would be a reservoir failure!

#: One approach is to estimate the minimum required flow rate and relate this flow rate to thickness and [[permeability]]. In any case, what we seek is the geologist's confidence in the existence of at least a minimal reservoir—thickness, extent, [[porosity]], and effective [[permeability]]. Under this approach, encountering a wet, commercial-quality [[sandstone]] would not be a failure in the reservoir category, but rather in one of the other categories, such as an unexpected structural low, an absence of [[Calculating charge volume|hydrocarbon charge]], or a leaky trap. However, the presence of a 1-ft-thick tight siltstone where a 10-ft-thick porous sandstone objective had been predicted would be a reservoir failure!

# ''What is the probability (or confidence) that the '''geological structure''' of the reservoir objective is, in reality, essentially as represented on maps and [[cross section]]s?''

# ''What is the probability (or confidence) that the '''geological structure''' of the reservoir objective is, in reality, essentially as represented on maps and [[cross section]]s?''

#: It is important to note here that we do not require an actual "structure," such as a domal anticline or a fault closure, only that prospect maps and sections accurately depict the structural configuration. For example, if only regular monoclinal south [[dip]] is required in the case of a stratigraphic trap prospect, then the geologist should express confidence—as a probabilistic estimate—that the structure in the vicinity of the prospect actually is indeed regular monoclinal south dip.  

#: It is important to note here that we do not require an actual "structure," such as a domal anticline or a fault closure, only that prospect maps and sections accurately depict the structural configuration. For example, if only regular monoclinal south [[dip]] is required in the case of a stratigraphic trap prospect, then the geologist should express confidence—as a probabilistic estimate—that the structure in the vicinity of the prospect actually is indeed regular monoclinal south dip.