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For the initial volume and distribution of oil existed before the anthropogenic invasion refer to Oil Initial In Place (OIIP).
The concepts of Oil In Place (OIP) and Oil Initial In Place (OIIP) are equivalent before the anthropogenic invasion.
See Also
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Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petroleum Geology / Petroleum Reservoir / Petroleum Reservoir Fluids / Hydrocarbon In Place (HCIP)
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