The Lake of Oil - Oil storage before the
pipelines were laid was a problem

Facts

Oil in place: 1 billion bbls

Ultimate recoverable reserves: 400+ million bbls of oil

Production to date: 340 million bbls of oil

Oil characteristics: °API gravity 35 to 40, Paraffinic Initial GOR 350

Initial field pressure: 600 psi

Reservoir temperature: 85°F to 100°F

Original reservoir drive: solution gas

Present reservoir drive: waterflood

Field size: 27,440 acres

Well spacing: 10 acres

Present decline rate: 10 to 15%

Original drilling and completions practices

Drilling: cable tool drilling rig with chisel bit and natural mud

Surface casing: 10 in diameter to 275 ft

Completion: open hole

Stimulation: natural or 200 to 250 quarts of nitroglycerine

Logging: driller's logs and cores

Primary reservoir

Bartlesville ("Glenn") sandstone of the Boggy Formation

Depth: 1,450 ft

Age: Pennsylvanian

Gross thickness: 200 ft.

Net thickness: 100 ft. (180 ft. maximum)

Lithology: Very fine- to medium-grained, moderately-well sorted sandstone deposited as a incised valley fill

Porosity: 17 to 24%

Permeability: 0 to 450 md

Seal: Sonora Formation shale

Source rock: Pennsylvanian Cherokee Group shales (1 to 8% TOC)

Trap

Stratigraphic - an updip pinchout of the Bartlesville Sandstone to the East, there is a regional, homoclinal dip down to the west-southwest at 40 ft/mile

Secondary reservoir

Wilcox ("Mounds") sandstone

Depth: 2,300 ft.

Age: Ordovician