Changes

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.

Allan's Mapping Technique produces a two-dimensional model of the 3-D fault surface. It is a static model showing the lithological cut-off relationship across the fault surface for a specific temporal stage in the fault deformation history. Therefore, this model is less used in distinguishing cross-fault lithology relationships for other temporal stages in the structural evolution of faults. Knipe<ref name=Knipe_1997>Knipe, R. J., 1997, Juxtaposition and seal diagrams to help analyze fault seals in hydrocarbon reservoirs: AAPG Bulletin, v. 81, p. 187-195.</ref> introduced a technique known as the Juxtaposition Diagram ([[:file:GumelarFigure5.jpg|Figure 5]]) which can be used to determine the relative alignment of the lithology for each structural configuration. This technique uses a one-dimensional stratigraphic column of the footwall at a single spatial point along the length of the fault surface, vertically offsetting itself, to construct a diagram showing the relative alignment of the lithology across faults for a hanging-wall thrown between zero and maximum (usually equal to vertical thickness. stratigraphic column). Subject to the assumption that the footwall and hanging-wall stratigraphy are identical, the alignment relationship for the number of throwlines can be ascertained by dropping the throwline through the corresponding position on the diagram ([[:file:GumelarFigure5.jpg|Figure 5]]) using this technique, the alignment of the relationship positions at any point in time in the structural evolution of the fault can be investigated.  

Allan's Mapping Technique produces a two-dimensional model of the 3-D fault surface. It is a static model showing the lithological cut-off relationship across the fault surface for a specific temporal stage in the fault deformation history. Therefore, this model is less used in distinguishing cross-fault lithology relationships for other temporal stages in the structural evolution of faults. Knipe<ref name=Knipe_1997>Knipe, R. J., 1997, Juxtaposition and seal diagrams to help analyze fault seals in hydrocarbon reservoirs: AAPG Bulletin, v. 81, p. 187-195.</ref> introduced a technique known as the Juxtaposition Diagram ([[:file:GumelarFigure5.jpg|Figure 5]]) which can be used to determine the relative alignment of the lithology for each structural configuration. This technique uses a one-dimensional stratigraphic column of the footwall at a single spatial point along the length of the fault surface, vertically offsetting itself, to construct a diagram showing the relative alignment of the lithology across faults for a hanging-wall thrown between zero and maximum (usually equal to vertical thickness. stratigraphic column). Subject to the assumption that the footwall and hanging-wall stratigraphy are identical, the alignment relationship for the number of throwlines can be ascertained by dropping the throwline through the corresponding position on the diagram ([[:file:GumelarFigure5.jpg|Figure 5]]) using this technique, the alignment of the relationship positions at any point in time in the structural evolution of the fault can be investigated.