ORIGIN AND OCCURRENCE OF OIL 45
the choice of the prevalent in situ alteration process depends upon
the prevalent conditions to which the petroleum is subject. A particular mechanism for alteration may be the prime operative, or all
may contribute to determining the ultimate character of the petroleum. The determining factor is site specificity.
2.3 Reservoir Classification
Briefly, a reservoir is a porous and permeable underground formation containing an individual and separate natural accumulation
of producible hydrocarbons (oil and /or gas), which is confined by
impermeable rock or water barriers and is characterized by a single
natural pressure system (Chapter 2).
A conventional petroleum reservoir (i.e. an anticline) is a dome
or vault of impermeable rock, formed by the folding or faulting of
the rock layers or by the rise of salt domes, with permeable rocks
beneath it. Generally, there is a layer of natural gas at the top of
the dome, with petroleum below, and water or brine beneath the
oil. However, not all reservoirs have the above characteristics, and
there are also unconventional or continuous reservoirs in which the
oil is not trapped as described above. Therefore, reservoir characterization is an essential part of petroleum technology and offers an
understanding or indication of the applicable method(s) of recovery.
Petroleum reservoir characterization is the process of identifying and quantifying those properties of a given petroleum reservoir that affect the distribution and migration of fluids within that
reservoir. These aspects are controlled by the geological history of
the reservoir. Furthermore, the ultimate goal of a hydrocarbon reservoir characterization study is the development of a reasonable
physical description of a given reservoir. This physical description
can then be used as a basis for simulation studies, which, in turn,
are used to assess the effectiveness of various recovery strategies.
An accurate physical description of the reservoir often will lead to
the maximum production of hydrocarbons from the reservoir leading to decision on the economic viability of a reservoir.
The type of reservoir from which it originates and the method
of recovery appear to be the most appropriate method(s) for classifying petroleum, heavy oil, and tar sand bitumen. Thus, a general
classification scheme has been developed for petroleum reservoirs
contained in US Department of Energy's tertiary-oil-recovery
the choice of the prevalent in situ alteration process depends upon
the prevalent conditions to which the petroleum is subject. A particular mechanism for alteration may be the prime operative, or all
may contribute to determining the ultimate character of the petroleum. The determining factor is site specificity.
2.3 Reservoir Classification
Briefly, a reservoir is a porous and permeable underground formation containing an individual and separate natural accumulation
of producible hydrocarbons (oil and /or gas), which is confined by
impermeable rock or water barriers and is characterized by a single
natural pressure system (Chapter 2).
A conventional petroleum reservoir (i.e. an anticline) is a dome
or vault of impermeable rock, formed by the folding or faulting of
the rock layers or by the rise of salt domes, with permeable rocks
beneath it. Generally, there is a layer of natural gas at the top of
the dome, with petroleum below, and water or brine beneath the
oil. However, not all reservoirs have the above characteristics, and
there are also unconventional or continuous reservoirs in which the
oil is not trapped as described above. Therefore, reservoir characterization is an essential part of petroleum technology and offers an
understanding or indication of the applicable method(s) of recovery.
Petroleum reservoir characterization is the process of identifying and quantifying those properties of a given petroleum reservoir that affect the distribution and migration of fluids within that
reservoir. These aspects are controlled by the geological history of
the reservoir. Furthermore, the ultimate goal of a hydrocarbon reservoir characterization study is the development of a reasonable
physical description of a given reservoir. This physical description
can then be used as a basis for simulation studies, which, in turn,
are used to assess the effectiveness of various recovery strategies.
An accurate physical description of the reservoir often will lead to
the maximum production of hydrocarbons from the reservoir leading to decision on the economic viability of a reservoir.
The type of reservoir from which it originates and the method
of recovery appear to be the most appropriate method(s) for classifying petroleum, heavy oil, and tar sand bitumen. Thus, a general
classification scheme has been developed for petroleum reservoirs
contained in US Department of Energy's tertiary-oil-recovery