Changes

[[file:evaluating-fractured-reservoirs_fig4.png|300px|thumb|{{figure number|4}}Total reservoir pore volume due to fractures plotted as a function of fracture width, fracture spacing, and matrix porosity. © Nelson, 1985; courtesy of Gulf Publishing Co.]]

[[file:evaluating-fractured-reservoirs_fig4.png|300px|thumb|{{figure number|4}}Total reservoir pore volume due to fractures plotted as a function of fracture width, fracture spacing, and matrix porosity. © Nelson, 1985; courtesy of Gulf Publishing Co.]]

In doing core and outcrop analyses of [[fracture]]s to determine reservoir properties and reservoir type, it is often difficult to judge the relative effect of the fracture system. Two crossplots can be used to alleviate this problem ([[:file:evaluating-fractured-reservoirs_fig3.png|Figures 3]] and [[:file:evaluating-fractured-reservoirs_fig4.png|4]]). These plots are the percentage of total reservoir permeability ([[:file:evaluating-fractured-reservoirs_fig3.png|Figure 3]]) and porosity ([[:file:evaluating-fractured-reservoirs_fig4.png|Figure 4]]) as a function of fracture width and fracture spacing for various orders of magnitude of matrix values. Assumptions can be made for width of the fractures at depth. Matrix properties are determined from core analyses, thin sections, etc. and the relative contribution of the fracture system for various spacings can then be read off the graph. Ideally, ranges in values for width and spacing of fractures are used and a box or area created on the graph within which the actual value is likely to occur. These figures assume one set of regularly spaced fractures, hydraulic apertures, and parallel plate laminar flow.<ref name=pt06r95 />

In doing core and outcrop analyses of [[fracture]]s to determine reservoir properties and reservoir type, it is often difficult to judge the relative effect of the fracture system. Two crossplots can be used to alleviate this problem ([[:file:evaluating-fractured-reservoirs_fig3.png|Figures 3]] and [[:file:evaluating-fractured-reservoirs_fig4.png|4]]). These plots are the percentage of total reservoir [[permeability]] ([[:file:evaluating-fractured-reservoirs_fig3.png|Figure 3]]) and [[porosity]] ([[:file:evaluating-fractured-reservoirs_fig4.png|Figure 4]]) as a function of fracture width and fracture spacing for various orders of magnitude of matrix values. Assumptions can be made for width of the fractures at depth. Matrix properties are determined from [[Overview of routine core analysis|core analyses]], [[Thin section analysis|thin sections]], etc. and the relative contribution of the fracture system for various spacings can then be read off the graph. Ideally, ranges in values for width and spacing of fractures are used and a box or area created on the graph within which the actual value is likely to occur. These figures assume one set of regularly spaced fractures, [http://www.taskgeoscience.com/glossary.asp?id=88 hydraulic apertures], and [http://hyperphysics.phy-astr.gsu.edu/hbase/ppois.html parallel plate laminar flow].<ref name=pt06r95 />

==Checklist for sequence of study==

==Checklist for sequence of study==