Descriptions - Muslow State B-27, Sec 27, T130N, R102W, Bowman Co., ND Red River A, B, C and D Zones
Well: B-27 STATE MUSLOW
Location: NWNE SEC. 27-T130N-R102W
Interval: RED RIVER A,B,C & D
Elevation 2908 ft KB
Reported Core Interval 9340-9530
Adjusted Core Interval 9343-9533
9340-9347.5 - Dark gray skeletal lime mudstone and wackestone. Skeletal fragments are dominantly brachiopods with lesser numbers of crinoids and rugose corals. There is no visible porosity.
9047.5-9050.3- Brown at the base and light brown at the top, laminated dolomudstone. Porosity is intercrystalline, but poorly preserved and developed. The contact with the overlying unit is stylolitized.
9050.3-9053.5- Gray mottled and nodular bedded dolomudstone. Visible porosity is poor. Contact with the overlying unit is gradational.
9053.5-9369 - Dark gray skeletal and burrow mottled mudstone to wackestone. Burrow structures are dominantly large Thalassinoides. Contact with the overlying unit is stylolitized. There is no visible porosity or oil show. Deposition was in open to slightly restricted shelf environments.
9369-9372 - No recovery.
9372-9382 - Gray, bedded and slightly enterolithic anhydrite with a thin anhydritic dolomite bed at 9372.3-9373.
9382-9389 - Brown laminated dolomudstone. Laminations are both subparallel and slightly bulbous, especially near the top of the unit. The unit has fair to good oil staining, especially near the top of the unit.
9389-9424.3 - Dark gray, skeletal lime mudstone with thin skeletal wackestone beds. Skeletal fragments are dominantly small crinoids and brachiopods. Burrow structures are dominated by moderately large Thalassinoides. There is no visible porosity or oil show. At the base of the unit a thin reworked bed with rip up fragments from the underlying substrate marks the transition form shallower water or intertidal environments to deeper water deposition.
9424.3-9434.3- Gray bedded and enterolithic anhydrite.
9434.3-9442.5- Light brown laminated dolomudstones with a thin anhydrite bed at 9436-9436.6. The dolomite beds have well developed laminations, some of which show moderate relief (algal). There is minor visible porosity, but no oil show.
9442.5-9447 - Gray bedded and enterolithic anhydrite.
9447-9476 - Light brown to brown, laminated dolomudstone with thin beds of rip up clasts and associated thin, dark gray to black dolomudstone interbeds. There is sparse visible porosity throughout, and a minor oil show from 9453-9458. Laminations near the top have moderate relief and are probably algal in origin.
9476-9505 - Brown to dark brown and gray, skeletal mudstone to wackestone. Skeletal fragments are sparse ostracods. Thin beds of rip up clasts are common and at 9479-9479.6 the rip up clasts form a packstone texture. These clasts are probably related to storm reworking of shallow substrates. Zones of minor stylolitization are common near the top and middle of the unit. A chert replaced bed is present at 9500.
9505-9518.2 - Brown to gray, burrowed and slightly skeletal dolomitic limestone. Dolomite occurs in patches that resemble Thalassinoides burrows. Oil occurs within the dolomites and also within bugs in the limestone matrix.
9518.2-9520.2- Black to dark gray, shaley and skeletal lime mudstone to wackestone. Skeletal fragments are dominantly small crinoids. The shaley beds are thinly laminated.
9520.2-9528 - This interval was poorly recovered and contains rubble. From the rubble, this unit is a brown skeletal dolomudstone to dolowackestone with well developed intercrystalline porosity. Oil staining is fair to good.
9528-9529 - Black to dark gray, shaley and skeletal lime mudstone to wackestone. Skeletal fragments are dominantly small crinoids. As with the overlying unit, the shaley beds are thinly laminated.
9529-9530 - This unit is a brown skeletal dolomudstone to dolowackestone with well developed intercrystalline porosity. Oil staining is fair.