Descriptions - Four Mile 4-5, sec. 5, T25N, R59E, Richland Co., MT
Well: 4-5 FOUR MILE, CATTAILS FIELD
Location: NE NW SEC. 5-T25N-R59E
Interval: RATCLIFFE
Reported Core Interval 8939-8977
Adjusted Core Interval 8929-8967
8939-8940.5
Dark brown, peloidal, algal and skeletal wackestone. Algal fragments are Ortonella nodules, and skeletal fragments are ostracod carapaces. There is no visible porosity or oil show.
8940.5-8951
Brown dolomitic mudstone to wackestone. The unit is burrowed by Planolites. There are thin wispy shale laminations and sparse ostracod fragments. A thin Ortonella wackestone bed is present within the middle of the unit. There is poor to fair visible porosity and fair oil staining. The interval is extensively fractured. Deposition was in protected shelf environments.
8951-8953.5
Dark brown to black skeletal wackestone. Skeletal fragments are crinoids and rugose and tabulate corals. Deposition was in shallow shelf environments.
8953.5-8969.5
Brown dolomitic mudstone to wackestone. The unit is burrowed by Planolites. There are thin wispy shale laminations and sparse crinoid fragments. There is poor visible porosity and poor oil staining in the upper portion of the unit. Thin interbeds of black skeletal wackestones are common. Deposition was in protected shelf to shallow shelf environments.
8969.5-8977
Black skeletal mudstones to wackestones. Skeletal fragments are principally crinoids and sparse rugose corals. There is no visible porosity or oil stain.