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Line 26: − − [[file:GumelarFigure4.jpg|thumb|300px|{{figure number|4}}Allan Mapping Principles<ref name=Allan_1989 />. (A) Fault displacement can provide a cross-fault seal by juxtaposing impermeable units against potential reservoir units. (B) In three dimensions, the interactions of juxtaposed units on the fault surface can be complex. (C) Allan's Mapping technique resolves the fault surface into a flat plane and maps the position of the footwall and hanging-wall. The trap and spill point can then be determined from the alignment of the lithology units.]] + +
Fault seal analysis for reservoir development (view source)
Revision as of 19:13, 13 September 2022
, 19:13, 13 September 2022no edit summary
[[file:GumelarFigure3.jpg|center|framed|{{figure number|3}}Illustration of three factors that influence fault analysis: juxtaposition seal, fault rock seal and fault reactivation<ref name=Yieldingetal_2010>Yielding, G., P. Bretan, and B. Freeman, 2010, Fault seal calibration: A brief review, ''in'' S. J. Jolley, Q. J. Fisher, R. B. Ainsworth, P. J. Vrolijk, and S. Delisle, eds., Reservoir compartmentalization: Geological Society (London) Special Publication 347, p. 243-255.</ref>.]]
[[file:GumelarFigure3.jpg|center|framed|{{figure number|3}}Illustration of three factors that influence fault analysis: juxtaposition seal, fault rock seal and fault reactivation<ref name=Yieldingetal_2010>Yielding, G., P. Bretan, and B. Freeman, 2010, Fault seal calibration: A brief review, ''in'' S. J. Jolley, Q. J. Fisher, R. B. Ainsworth, P. J. Vrolijk, and S. Delisle, eds., Reservoir compartmentalization: Geological Society (London) Special Publication 347, p. 243-255.</ref>.]]
==Allan diagram==
==Allan diagram==
Allan<ref name=Allan_1989>Allan, U. S. 1989, Model for hydrocarbon migration and entrapment within faulted structures: AAPG Bulletin, v. 73, p. 803–811.</ref> developed a graphic technique to map the relative position of the lithology cut-offs on both the footwall and the hanging-wall. This methodology is often called Allan Mapping. Using this approach, cross-fault spill points and hydrocarbon flow path potential can be determined from the lithological alignment (juxtaposition), based on the assumption that the fault itself does not have sealing properties and that it is not an open channel for flow. Allan's mapping relies on the construction of the fault surface section ([[:file:GumelarFigure4.jpg|Figure 4]]) which is defined as the appearance of the stratigraphic geometry that touches across the fault by removing the hanging-wall<ref name=Allan_1989 />. The representation of a part of the fault surface is often a vertical or planar surface. The lithology of the footwall and hanging-wall fault blocks is projected onto the surface portion of the fault and is used to determine where the reservoir lithology of one fault block is juxtaposed with the non-reservoir lithology of the opposite fault block.
Allan<ref name=Allan_1989>Allan, U. S. 1989, Model for hydrocarbon migration and entrapment within faulted structures: AAPG Bulletin, v. 73, p. 803–811.</ref> developed a graphic technique to map the relative position of the lithology cut-offs on both the footwall and the hanging-wall. This methodology is often called Allan Mapping. Using this approach, cross-fault spill points and hydrocarbon flow path potential can be determined from the lithological alignment (juxtaposition), based on the assumption that the fault itself does not have sealing properties and that it is not an open channel for flow. Allan's mapping relies on the construction of the fault surface section ([[:file:GumelarFigure4.jpg|Figure 4]]) which is defined as the appearance of the stratigraphic geometry that touches across the fault by removing the hanging-wall<ref name=Allan_1989 />. The representation of a part of the fault surface is often a vertical or planar surface. The lithology of the footwall and hanging-wall fault blocks is projected onto the surface portion of the fault and is used to determine where the reservoir lithology of one fault block is juxtaposed with the non-reservoir lithology of the opposite fault block.
[[file:GumelarFigure4.jpg|center|framed|{{figure number|4}}Allan Mapping Principles<ref name=Allan_1989 />. (A) Fault displacement can provide a cross-fault seal by juxtaposing impermeable units against potential reservoir units. (B) In three dimensions, the interactions of juxtaposed units on the fault surface can be complex. (C) Allan's Mapping technique resolves the fault surface into a flat plane and maps the position of the footwall and hanging-wall. The trap and spill point can then be determined from the alignment of the lithology units.]]
[[file:GumelarFigure5.jpg|thumb|300px|{{figure number|5}}Juxtaposition diagram<ref name=Knipe_1997 />. (A) Simple normal fault with increasing linear displacement from left to right. (B) Generic juxtaposition diagram with the order of the footwall completely offsetting itself.]]
[[file:GumelarFigure5.jpg|thumb|300px|{{figure number|5}}Juxtaposition diagram<ref name=Knipe_1997 />. (A) Simple normal fault with increasing linear displacement from left to right. (B) Generic juxtaposition diagram with the order of the footwall completely offsetting itself.]]