Changes

#: This geological chance factor deals with such questions as the volumetric adequacy of petroleum source rocks, the generation of oil and/or gas, the migrational pathways to the site of the prospect, and the concentration of hydrocarbons in the reservoir fluid (hydrocarbon saturation of at least 50% is required). The question of timing is ''not'' addressed here. In most frontier basins, the hydrocarbon charge issue is very important. In established basins and producing trends, however, its significance tends to be slightly diminished. Obviously, for development projects, the hydrocarbon charge requirement has ordinarily been satisfied.

#: This geological chance factor deals with such questions as the volumetric adequacy of petroleum source rocks, the generation of oil and/or gas, the migrational pathways to the site of the prospect, and the concentration of hydrocarbons in the reservoir fluid (hydrocarbon saturation of at least 50% is required). The question of timing is ''not'' addressed here. In most frontier basins, the hydrocarbon charge issue is very important. In established basins and producing trends, however, its significance tends to be slightly diminished. Obviously, for development projects, the hydrocarbon charge requirement has ordinarily been satisfied.

# ''What is the probability (or confidence) that a '''sealed trap''' exists, based on the lithologic combinations and structural configurations depicted, and that the trapping configuration was already formed when hydrocarbons were migrating into the area of the prospect?''

# ''What is the probability (or confidence) that a '''sealed trap''' exists, based on the lithologic combinations and structural configurations depicted, and that the trapping configuration was already formed when hydrocarbons were migrating into the area of the prospect?''

#: Here we address three questions. First is the idea of the ''sealing capability'' between reservoir and top seals, seat seals, and lateral seals (whether formed by stratigraphic contrasts or sealing faults). Fluid [[viscosity]], bed thickness, differential [[permeability]], and fault history all influence the seal question. The second question is about ''timing,'' as noted in item #3 above: if the trapping configuration came into being after migration occurred, then the gate has been shut only after the horse got out. The third question has to do with ''preservation'' from subsequent freshwater flushing or degradation of reservoired hydrocarbons. As used here, the term ''trap'' has no implications of geometry or configuration—only of containment and sealing. The troublesome issue of "fill-up" (best represented as a percentage) falls into this category. For most development wells, the sealed trap requirement has been satisfied.

#: Here we address three questions. First is the idea of the ''sealing capability'' between reservoir and top seals, seat seals, and [[lateral]] seals (whether formed by stratigraphic contrasts or sealing faults). Fluid [[viscosity]], bed thickness, differential [[permeability]], and fault history all influence the seal question. The second question is about ''timing,'' as noted in item #3 above: if the trapping configuration came into being after migration occurred, then the gate has been shut only after the horse got out. The third question has to do with ''preservation'' from subsequent freshwater flushing or degradation of reservoired hydrocarbons. As used here, the term ''trap'' has no implications of geometry or configuration—only of containment and sealing. The troublesome issue of "fill-up" (best represented as a percentage) falls into this category. For most development wells, the sealed trap requirement has been satisfied.

The voice of experience warns you that for exploration projects, do not use probabilities of 1.0—you simply cannot be that sure! "Absolute certainty" is 0.9 or 0.95.

The voice of experience warns you that for exploration projects, do not use probabilities of 1.0—you simply cannot be that sure! "Absolute certainty" is 0.9 or 0.95.