Descriptions - Rassmussen 31-27, Nohly Field, sec. 27, T26N, R59E, Richland Co., MT
Well: 31-27 RASMUSSEN, NOHLY FIELD
Location: NW NE SEC. 27-T26N-R59E
Interval: RATCLIFFE
Reported Core Interval 8951-9010.5
Adjusted Core Interval 8955-9014.5
8951-8971.4
Brown, peloidal, algal, and skeletal mudstones and wackestones. Skeletal fragments are ostracods and sparse crinoids. Algal fragments are Ortonella nodules and calcispheres. Deposition was principally in shallow shoal environments.
8971-8973
White peloidal and algal packstones and displacive nodules of anhydrite.
8973-8982
Brown peloidal and algal mudstone to wackestone. Calcispheres are common at the base of the unit. Fractures are present in the middle and lower portion of the unit. Deposition was in shoaling environments along a low energy shelf.
8982-9003.4
Brown skeletal and dolomitic mudstones and interbeds of black skeletal wackestones. The skeletal wackestones contain crinoid debris. The dolomitic mudstones are burrowed, in part, by Planolites and Chondrites. The upper portion of the interval is fractured. There is fair to good oil staining in the upper half of the interval and poor staining at the base.
9003.4-9010.5
Black skeletal mudstones and wackestones. Skeletal fragments are crinoids and tabulate corals. The unit is burrowed, but there is no visible porosity or oil staining.