Changes

==Typical settings for deep-water marine reservoirs==

==Typical settings for deep-water marine reservoirs==

[[File:M91FG193.JPG|thumb|300px|{{figure number|1}} Depositional model for channelized turbidites and a basin-floor fan complex, Brushy Canyon, Texas. From Beaubouef<ref name=Beaubouef1999>Beaubouef, R. T., C. Rossen, F. B. Zelt, M. D. Sullivan, D. C. Mohrig, and G. D. C. Jennette, 1999, Field guide for AAPG Hedberg field Research Conference, April 15–20, 1999, Deep-water sandstones, Brushy Canyon Formation, west Texas: AAPG Continuing Education Course Note Series 40, 48 p.</ref>. Reprinted with permission from the AAPG.]]

[[File:M91FG193.JPG|thumb|300px|{{figure number|1}} Depositional model for channelized turbidites and a basin-floor fan complex, Brushy Canyon, Texas. From Beaubouef.<ref name=Beaubouef1999>Beaubouef, R. T., C. Rossen, F. B. Zelt, M. D. Sullivan, D. C. Mohrig, and G. D. C. Jennette, 1999, Field guide for AAPG Hedberg field Research Conference, April 15–20, 1999, Deep-water sandstones, Brushy Canyon Formation, west Texas: AAPG Continuing Education Course Note Series 40, 48 p.</ref>]]

The main settings include

The main settings include

==Production from channel-levee complexes==

==Production from channel-levee complexes==

[[File:M91FG195.JPG|thumb|300px|{{figure number|3}}Schematic section across a deep-water channel-levee complex based on outcrops from the Cerro Toro Formation, Upper Cretaceous, southern Chile (from Beaubouef<ref name=BB2004 />). The lower section shows a series of idealized gamma ray logs. Reprinted with permission from the AAPG.]]

[[File:M91FG195.JPG|thumb|300px|{{figure number|3}}Schematic section across a deep-water channel-levee complex based on outcrops from the Cerro Toro Formation, Upper Cretaceous, southern Chile (from Beaubouef<ref name=BB2004 />). The lower section shows a series of idealized gamma ray logs.]]

Channel-levee complexes can show highly variable continuity between the channels and levees ([[:File:M91FG195.JPG|Figure 3]]). It is common for hydrocarbons in the channel-fill sandstones to be poorly connected with the levee sediments. The channel fills may be younger than the levees themselves, and the beds in the proximal levee deposits may be discontinuous.<ref>Cronin, B. T., A. Hurst, H. Celik, and I. Turkmen, 2000, Superb exposures of a channel, levee and overbank complex in an ancient, deep-water slope environment: Sedimentary Geology, v. 132, p. 205–216.</ref><ref name=BB2004>Beaubouef, R. T., 2004, [http://archives.datapages.com/data/bulletns/2004/11nov/1471/1471.HTM Deep-water leveed channel complexes of the Cerro Toro formation, Upper Cretaceous, southern Chile]: AAPG Bulletin, v. 11, p. 1471–1500.</ref> Kneller et al.<ref>Kneller, B., M. Dykstra, and P. Thompson, 2007, Collapse of submarine channel levees, examples from outcrop and subsurface, and reservoir implications: Abstracts of the 2007 AAPG Annual Convention and Exhibition, p. 77.</ref> noted that collapse structures, including rotated blocks, slide sheets, slump folds, and thick debris flows, are common on levee margins and may contribute to poor reservoir continuity.

Channel-levee complexes can show highly variable continuity between the channels and levees ([[:File:M91FG195.JPG|Figure 3]]). It is common for hydrocarbons in the channel-fill sandstones to be poorly connected with the levee sediments. The channel fills may be younger than the levees themselves, and the beds in the proximal levee deposits may be discontinuous.<ref>Cronin, B. T., A. Hurst, H. Celik, and I. Turkmen, 2000, Superb exposures of a channel, levee and overbank complex in an ancient, deep-water slope environment: Sedimentary Geology, v. 132, p. 205–216.</ref><ref name=BB2004>Beaubouef, R. T., 2004, [http://archives.datapages.com/data/bulletns/2004/11nov/1471/1471.HTM Deep-water leveed channel complexes of the Cerro Toro formation, Upper Cretaceous, southern Chile]: AAPG Bulletin, v. 11, p. 1471–1500.</ref> Kneller et al.<ref>Kneller, B., M. Dykstra, and P. Thompson, 2007, Collapse of submarine channel levees, examples from outcrop and subsurface, and reservoir implications: Abstracts of the 2007 AAPG Annual Convention and Exhibition, p. 77.</ref> noted that collapse structures, including rotated blocks, slide sheets, slump folds, and thick debris flows, are common on levee margins and may contribute to poor reservoir continuity.

==Production from sheet complexes==

==Production from sheet complexes==

[[File:M91FG112.JPG|thumb|300px|{{figure number|4}}Formation tester data taken in wells that have been drilled postproduction provide invaluable data on how the reservoir splits up into hydraulic units showing different pressures. This example is from the Magnus field in the UK North Sea (from Morris et al).<ref>Morris, P. H., S. N. J. Payne, and D. P. J. Richards, 1999, Micropalaeontological biostratigraphy of the Magnus Sandstone Member (Kimmeridgian to early Volgian), Magnus field, UK North Sea, in R. W. Jones and M. D. Simmons, eds., Biostratigraphy in production and development geology: Geological Society (London) Special Publication 152, p. 55–73.</ref> Reprinted with permission from the Geological Society. GR = Gamma Ray; RFTtrade = Repeat Formation Tester; UKCF = Upper Kimmeridge Clay Formation.]]

[[File:M91FG112.JPG|thumb|300px|{{figure number|4}}Formation tester data taken in wells that have been drilled postproduction provide invaluable data on how the reservoir splits up into hydraulic units showing different pressures. This example is from the Magnus field in the UK North Sea (from Morris et al).<ref>Morris, P. H., S. N. J. Payne, and D. P. J. Richards, 1999, Micropalaeontological biostratigraphy of the Magnus Sandstone Member (Kimmeridgian to early Volgian), Magnus field, UK North Sea, in R. W. Jones and M. D. Simmons, eds., Biostratigraphy in production and development geology: Geological Society (London) Special Publication 152, p. 55–73.</ref> Reprinted with permission from, and &copy by, the Geological Society. GR = Gamma Ray; RFTtrade = Repeat Formation Tester; UKCF = Upper Kimmeridge Clay Formation.]]

Sheet sandstones form excellent reservoirs. Their characteristics include simple tabular geometries, good lateral continuity, and few erosional features.<ref name=WeimerandSlatt /> A large volume of deep-water sheet sandstones can be produced by a single production well. Width-to-thickness ratios are large, more than 500:1 for sheet complexes compared to a range of 10:1 to 300:1 for channels.<ref name=WeimerandSlatt /> Vertical connectivity can be variable depending on the amount of interbedded shales or the degree of sand-on-sand amalgamation.

Sheet sandstones form excellent reservoirs. Their characteristics include simple tabular geometries, good lateral continuity, and few erosional features.<ref name=WeimerandSlatt /> A large volume of deep-water sheet sandstones can be produced by a single production well. Width-to-thickness ratios are large, more than 500:1 for sheet complexes compared to a range of 10:1 to 300:1 for channels.<ref name=WeimerandSlatt /> Vertical connectivity can be variable depending on the amount of interbedded shales or the degree of sand-on-sand amalgamation.