Other Assessment Methods—An Overview
153
Superpopulation methods
•
—USGS log-geometric, Zipf’s law,
creaming, and Long’s
The regression method
•
The fractal method
•
Specifi c data and assumptions can be applied to each of these methods. Some of the assumptions can be validated by the data whereas others cannot. These methods have their own merits and disadvantages.
Geological Approach
The geological approach has been used for the past several decades
and is a qualitative method. This section discusses the volumetric yield
method and the basin classifi cation method.
Volumetric Yield by Analogous Basin Method
Volumetric yield using the analogous basin method was the earliest
method of petroleum resource evaluation applied to frontier basins. It
requires knowledge of the volume of a basin and its characteristics (e.g.,
tectonic, sedimentation, thermal generation, migration, and accumulation). Based on comparative studies, geologists are able to apply a
hydrocarbon yield factor per unit volume (i.e., barrels of oil/cubic unit
of sediment) from one known basin to an unknown basin with similar
characteristics. Thus, for conceptual basins, this provides some information about the richness of an unknown basin. The advantages are
the following:
It is suitable for the evaluation of conceptual basins.
1.
It is easy to understand.
2.
It combines geochemical data and/or experience from mature
3.
basins.
The disadvantages are:
The “mirror image” of a resource in one basin can be unreli1.
able when applied to another basin.
The assessment obtained cannot be validated at the time of
2.
assessment.
153
Superpopulation methods
•
—USGS log-geometric, Zipf’s law,
creaming, and Long’s
The regression method
•
The fractal method
•
Specifi c data and assumptions can be applied to each of these methods. Some of the assumptions can be validated by the data whereas others cannot. These methods have their own merits and disadvantages.
Geological Approach
The geological approach has been used for the past several decades
and is a qualitative method. This section discusses the volumetric yield
method and the basin classifi cation method.
Volumetric Yield by Analogous Basin Method
Volumetric yield using the analogous basin method was the earliest
method of petroleum resource evaluation applied to frontier basins. It
requires knowledge of the volume of a basin and its characteristics (e.g.,
tectonic, sedimentation, thermal generation, migration, and accumulation). Based on comparative studies, geologists are able to apply a
hydrocarbon yield factor per unit volume (i.e., barrels of oil/cubic unit
of sediment) from one known basin to an unknown basin with similar
characteristics. Thus, for conceptual basins, this provides some information about the richness of an unknown basin. The advantages are
the following:
It is suitable for the evaluation of conceptual basins.
1.
It is easy to understand.
2.
It combines geochemical data and/or experience from mature
3.
basins.
The disadvantages are:
The “mirror image” of a resource in one basin can be unreli1.
able when applied to another basin.
The assessment obtained cannot be validated at the time of
2.
assessment.