Changes

  | topg    = 277

  | topg    = 277

  | author  = Mike Shepherd

  | author  = Mike Shepherd

  | link    = http://archives.datapages.com/data/specpubs/memoir91/CHAPTER34/CHAPTER33.HTM

  | link    = http://archives.datapages.com/data/specpubs/memoir91/CHAPTER34/CHAPTER34.HTM

  | pdf    = http://archives.datapages.com/data/specpubs/memoir91/CHAPTER34/IMAGES/CHAPTER33.PDF

  | pdf    = http://archives.datapages.com/data/specpubs/memoir91/CHAPTER34/IMAGES/CHAPTER34.PDF

  | store  = http://store.aapg.org/detail.aspx?id=788

  | store  = http://store.aapg.org/detail.aspx?id=788

  | isbn    = 0891813721

  | isbn    = 0891813721

| Valley fills on bedrock unconformities || 12-1400 m (39-4593 ft); most < 500 m (1640 ft) || 75 m-52 km (246 ft-32 mi); most < 10 km (6 mi) || 2-870; highly variable; mainly 2-100

| Valley fills on bedrock unconformities || 12-1400 m (39-4593 ft); most < 500 m (1640 ft) || 75 m-52 km (246 ft-32 mi); most < 10 km (6 mi) || 2-870; highly variable; mainly 2-100

|-

|-

| Valley fills within alluvial and marine strata || 2-210 m (6-689 ft); most < 60 m (197 ft) || 0.1-105 km (0.06-65 mi); common range 0.2-25 km (0.1-15 mi) || 4.6-3640; highly variable; common range 10-1000; many from 100 to 1000

| Valley fills within [[alluvial]] and marine strata || 2-210 m (6-689 ft); most < 60 m (197 ft) || 0.1-105 km (0.06-65 mi); common range 0.2-25 km (0.1-15 mi) || 4.6-3640; highly variable; common range 10-1000; many from 100 to 1000

|-

|-

| colspan="4" | ¹''From Gibling<ref name=Gibling_2006 />, Journal of Sedimentary Research. Reprinted with permission from, and &copy; by, the SEPM (Society for Sedimentary Geologists).''

| colspan="4" | ¹''From Gibling<ref name=Gibling_2006 />, Journal of Sedimentary Research. Reprinted with permission from, and &copy; by, the SEPM (Society for Sedimentary Geologists).''

|}

|}

Some very big oil fields are known from braided river reservoirs, including the Prudhoe Bay field in Alaska and several giant oil fields in the Sirte basin of Libya.

Some very big oil fields are known from braided river reservoirs, including the [[Prudhoe Bay field]] in Alaska and several giant oil fields in the Sirte basin of Libya.

==Lateral continuity==

==Lateral continuity==

Lateral continuity is typically excellent in braided fluvial reservoirs. The net to gross of these systems is normally very high (&gt;80%), and, as such, these types of reservoirs are usually well connected laterally. In detail, they can be internally complex with intervals of upward-decreasing permeability profiles, but the lack of organized stratification or laterally continuous shales results in braided fluvial reservoirs showing effectively layer-cake geometry and acting as a single integrated reservoir at the larger scale.<ref name=Gallowayandhobday_1996>Galloway, W. E., and D. K. Hobday, 1996, Terrigenous clastic depositional systems: Applications to petroleum, coal, and uranium exploration: New York, Springer-Verlag, 489 p.</ref>

[[Lateral]] continuity is typically excellent in braided fluvial reservoirs. The net to gross of these systems is normally very high (&gt;80%), and, as such, these types of reservoirs are usually well connected laterally. In detail, they can be internally complex with intervals of upward-decreasing permeability profiles, but the lack of organized stratification or laterally continuous shales results in braided fluvial reservoirs showing effectively layer-cake geometry and acting as a single integrated reservoir at the larger scale.<ref name=Gallowayandhobday_1996>Galloway, W. E., and D. K. Hobday, 1996, Terrigenous clastic depositional systems: Applications to petroleum, coal, and uranium exploration: New York, Springer-Verlag, 489 p.</ref>

Braided river systems normally comprise medium to coarse-grained sands and gravels, and the rock properties can be excellent. Oil recovery factors can be very high in braided river reservoirs, commonly more than 50%.<ref name=Martin_1993>Martin, J. H., 1993, A review of braided fluvial hydrocarbon reservoirs: The petroleum engineer's perspective, in J. L. Best and C. S. Bristow, eds., Braided rivers: Geological Society Special Publication 75, p. 333–367.</ref> Laterally extensive braided river reservoirs tend to be in communication with strong aquifers.

Braided river systems normally comprise medium to coarse-grained sands and gravels, and the rock properties can be excellent. Oil recovery factors can be very high in braided river reservoirs, commonly more than 50%.<ref name=Martin_1993>Martin, J. H., 1993, A review of braided fluvial hydrocarbon reservoirs: The petroleum engineer's perspective, in J. L. Best and C. S. Bristow, eds., Braided rivers: Geological Society Special Publication 75, p. 333–367.</ref> Laterally extensive braided river reservoirs tend to be in communication with strong aquifers.

| Thief zones present in coarse-grained intervals || - || Poor sweep

| Thief zones present in coarse-grained intervals || - || Poor sweep

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==See also==

==See also==

* [[Meandering fluvial reservoirs]]

* [[Meandering fluvial reservoirs]]

* [[Deltaic reservoirs]]

* [[Deltaic reservoirs]]

* [[Deep-water marine reservoirs]]

* [[Deep-water marine reservoirs]]

* [[Carbonate reservoirs]]

* [[Carbonate reservoir]]

==References==

==References==