Changes

| Reservoir performance is controlled by sedimentary facies, lithology and/or geometry || Determine sedimentary characteristics and origin of facies through [[core description]] and construct predictive models for lateral variability and heterogeneity of reservoir units

| Reservoir performance is controlled by sedimentary facies, lithology and/or geometry || Determine sedimentary characteristics and origin of facies through [[core description]] and construct predictive models for lateral variability and heterogeneity of reservoir units

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| Reservoir performance and formation permeabilities are negatively impacted by presence of [http://dictionary.reference.com/browse/detrital detrital] or [http://dictionary.reference.com/browse/authigenic authigenic] clays (very common) || Identify and map reservoir facies with the least detrital clay content; avoid treatment of formation by [[Stimulation#Acidizing|acidization]] or injection of any fluids; use [[Drilling_fluid#Oil-based_muds|oil-based muds]]; enhance recovery through [[Stimulation#Hydraulic_fracturing|artificial fracturing]] of the formation<ref name=pt06r93>Moslow, T. F., Tillman, R. W., 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0250/0271.htm Sedimentary facies and reservoir characteristics of Frontier Formation sandstones, southwestern Wyoming], in Spencer, C. W., Mast, R. F., eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 271–295.</ref>

| Reservoir performance and formation permeabilities are negatively impacted by presence of [http://dictionary.reference.com/browse/detrital detrital] or [http://dictionary.reference.com/browse/authigenic authigenic] clays (very common) || Identify and map reservoir facies with the least detrital clay content; avoid treatment of formation by [[Stimulation#Acidizing|acidization]] or injection of any fluids; use [[Drilling_fluid#Oil-based_muds|oil-based muds]]; enhance recovery through [[Stimulation#Hydraulic_fracturing|artificial fracturing]] of the formation<ref name=pt06r93>Moslow, T. F., and R. W. Tillman, 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0250/0271.htm Sedimentary facies and reservoir characteristics of Frontier Formation sandstones, southwestern Wyoming], in C. W. Spencer, and R. F. Mast, eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 271–295.</ref>

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| Reservoir performance is dictated by origin and distribution of natural fractures || Evaluate the relationship between [[fracture]] occurrence and lithology<ref name=pt06r100>Pitman, J. K., Sprunt, E. S., 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0200/0221.htm Origin and distribution of fractures in Lower Tertiary and Upper Cretaceous rocks, Piceance basin, Colorado, and their relation to the occurrence of hydrocarbons] in Spencer, C. W., Mast, R. F., eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 221–234.</ref>

| Reservoir performance is dictated by origin and distribution of natural fractures || Evaluate the relationship between [[fracture]] occurrence and lithology<ref name=pt06r100>Pitman, J. K., and E. S. Sprunt, 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0200/0221.htm Origin and distribution of fractures in Lower Tertiary and Upper Cretaceous rocks, Piceance basin, Colorado, and their relation to the occurrence of hydrocarbons] in C. W. Spencer, and R. F. Mast, eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 221–234.</ref>

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| Fracture mineralization impacts reservoir performance. || Determine the nature, origin, and timing of mineralization through petrographical and [[Wikipedia:Isotope geochemistry|stable isotope techniques]]<ref name=pt06r100 />

| Fracture mineralization impacts reservoir performance. || Determine the nature, origin, and timing of mineralization through petrographical and [[Wikipedia:Isotope geochemistry|stable isotope techniques]]<ref name=pt06r100 />

| [[Porosity]] and [[permeability]] trends are controlled by clay [[diagenesis]] or [[secondary cements]] || Determine the petrological and mineralogical history of reservoir facies; identify and map “diagenetic facies” relative to sedimentary facies

| [[Porosity]] and [[permeability]] trends are controlled by clay [[diagenesis]] or [[secondary cements]] || Determine the petrological and mineralogical history of reservoir facies; identify and map “diagenetic facies” relative to sedimentary facies

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| Reservoir gas [[accumulation]]s lack a [[floored]] [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=gas-water+contact gas-water contact] || Map structural, isothermal, and pressure gradient contours that are likely coincident with boundaries of the gas envelope<ref name=pt06r113>Rose, P. R., Everett, J. R., Merin, I. A., 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0100/0111.htm Potential basin-centered gas accumulation in Cretaceous Trinidad Sandstone, Raton Basin, Colorado] in Spencer, C. W., Mast, R. F., eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 111–128.</ref>

| Reservoir gas [[accumulation]]s lack a [[floored]] [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=gas-water+contact gas-water contact] || Map structural, isothermal, and pressure gradient contours that are likely coincident with boundaries of the gas envelope<ref name=pt06r113>Rose, P. R., J. R. Everett, and I. A. Merin, 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0100/0111.htm Potential basin-centered gas accumulation in Cretaceous Trinidad Sandstone, Raton Basin, Colorado] in C. W. Spencer, and R. F. Mast, eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 111–128.</ref>

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| [[Overpressure causes|Overpressured]] formation or reservoir (occurs frequently due to common distribution of [[Evaluating tight gas reservoirs|tight gas]] with basin center locations and excessive overburden) || Requires appropriate exploration strategies or reservoir engineering approach to gas recovery

| [[Overpressure causes|Overpressured]] formation or reservoir (occurs frequently due to common distribution of [[Evaluating tight gas reservoirs|tight gas]] with basin center locations and excessive overburden) || Requires appropriate exploration strategies or reservoir engineering approach to gas recovery