Minerals Report - International Seabed Authority

ITIPRHC = Vnr φHC γ 103 (Mmtoe),
Where Vnr is the volume of natural reservoirs, measured in km 3 ; φHC, the
total hydrocarbon concentration coefficient, expressed as a fraction; and γ,
the average hydrocarbon density, measured in g/cm 3 .
It should be noted that both methods are applied to frontier basins.
Where the initial data available were insufficient, more accurate
calculation methods were applied.
The latter are the comparative geologic and volume-genetic
resource evaluation methods. The comparative geologic method is based
on the selection of a mature standard (reference) basin, with which the
studied basin is compared in terms of geologic parameters. To make up
for the difference in the compared sediment thicknesses, reservoirs, seals,
etc., correction coefficients are introduced.
We have applied a modified version of this method (the standard
scanning method, worked out in the Petroleum Institute of JSC
VNIIZarubezhgeologia) for the evaluation of basins related to continental
margins. A number of basins, for which the data on organic matter and
maturity were available, were evaluated using the volume-genetic
method. This method, essentially, consists of the calculation of a possible
volumes of hydrocarbons that could be generated by source rocks, the
possible volumes of hydrocarbon migration from source rocks, and the
amount of oil and gas which might accumulate in available traps after
migration losses. It should be noted that this method is widely applied in
many countries. In recent years, it was modified to take into account the
concept of petroleum system 7 .
4. Oil and Gas Resources of Deep-Sea Areas and their Geographical
Distribution
According to our calculations, the initial total recoverable oil
resources of the world are 540 Bt, and gas, 546 Tm 3 . By comparison, the
latest world petroleum potential estimates given by the US Geological
Survey are 372 Bt oil and 358 Tm 3 gas 8 . Apart from different calculation
methods, the principal cause of the difference is the underestimation of
hydrocarbon resources in the CIS countries. Indeed, Masters et al. 8
estimate the gas resources in the CIS at 107 Tm 3 , whereas the official
GAZPROM estimate (prepared jointly by a number of research institutes
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