The reservoir-rocks contact rock contact surface limiting the size of the permeable petroleum reservoir where the practical fluid flow may occur.
The way producing or or injecting wells respond to the actual reservoir boundary maybe very complex due to limited observation time and cross-well and cross-layer interference.
Most well tests can only detect the dynamic effect of the reservoir flow boundary or its absence (infinite acting reservoir flow boundary).
The actual petroleum reservoir is always constrained in volume but in most practical applications the observation time is too short to see the effects of the reservoir boundaries (see )There are some production analysis techniques based on long-term flowrate and bottomhole pressure data readings which can reveal the size of the actual petroleum reservoir (see, for example, Multiwell Retrospective Testing), but again only a certain part of it which was continuously engaged into the reservoir flow process.
See Also
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Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petroleum Geology
[ Infinite reservoir boundary ] [ Reservoir flow boundary ] [ Multiwell Retrospective Testing (MRT) ]