Changes

“Net” pay (see [[Effective pay determination]]) implies that some formation thickness has been excluded from consideration by either (1) occurring below an oil-water contact (or above a gas-water contact), or (2) having porosity and/or [[permeability]] values below a “cutoff” limit for productivity. Not all net pay is necessarily productive at a given well spacing. Discontinuous productive horizons between wells might be described, for example, by the concept of net pay to net connected pay ratio<ref name=pt06r103>Poston, S. W., 1987, Development plan for oil and gas reservoirs, in Bradley, H. B., ed., Petroleum Engineering Handbook: Richardson, TX, Society of Petroleum Engineers, p. 36-1–36-11.</ref>.

“Net” pay (see [[Effective pay determination]]) implies that some formation thickness has been excluded from consideration by either (1) occurring below an oil-water contact (or above a gas-water contact), or (2) having porosity and/or [[permeability]] values below a “cutoff” limit for productivity. Not all net pay is necessarily productive at a given well spacing. Discontinuous productive horizons between wells might be described, for example, by the concept of net pay to net connected pay ratio<ref name=pt06r103>Poston, S. W., 1987, Development plan for oil and gas reservoirs, in Bradley, H. B., ed., Petroleum Engineering Handbook: Richardson, TX, Society of Petroleum Engineers, p. 36-1–36-11.</ref>.

[[file:subsurface-maps_fig5.png|thumb|{{figure number|5}}Porosity-weighted average water saturation map for Layer 2 of a Middle Eastern carbonate reservoir.]]

[[file:subsurface-maps_fig5.png|thumb|left|{{figure number|5}}Porosity-weighted average water saturation map for Layer 2 of a Middle Eastern carbonate reservoir.]]

===[[Porosity]]===

===[[Porosity]]===