Petrology and reservoir quality of the Katakturuk dolomite, Arctic National Wildlife Refuge, Alaska

Conference · Tue May 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:6762532

The Katakturuk Dolomite comprises up to 2,500 m of cyclically deposited upper Proterozoic( ) dolostones underlying the Sadlerochit and Shublik mountains and at least part of the adjacent arctic coastal plain. The bulk of the Katakturuk Dolomite consists of carbonates deposited in shoaling-upward subtidal to supratidal cycles 5 to 50 m thick. Early dolomitization of matrix, allochems, and early cements preserves original depositional fabric, but together with later cementation greatly reduces porosity and permeability. Dolomicrites are predominantly peloids, cryptalgal fragments, and algal-laminated clasts. Allochems include ooids, pisolites, oncolites, peloids, mud pellets, coated grains, fragments of algal mats and stromatolites, and grains formed by diminution dolomicrite envelopes. Dolomite rhombs (2 to 6 {mu}m) replace calcium carbonate allochems, micriter, and cements. Internal molds in ooid, pisoid, and fenestral cavities in algal mats and stromatolites are filled with acicular dolomite and dolospar, silica, and spar calcite. Intercrystal pores are filled with acicular dolomite, columnar dolomite dolospar, and silica. Much of the upper half of the formation is massive dolostone composed of 100- to 500-micron rhombs of xenotropic dolomite, the intercrystal pore space of which is mostly filled with dolospar, calcite, and silica. Pervasive fracturing associated with Brooks Range thrust faulting may enhance reservoir characteristics of the Katakturuk Dolomite. The formation is fractured and cut by conjugate high-angle faults that sole in a basal thrust fault in the Sadlerochit Mountains. Earlier workers reported low porosity and permeability values from outcrop and core samples, values that probably reflect reservoir characteristics related to depositional fabric and diagenetic history.

• OSTI ID: 6762532
• Report Number(s): CONF-900605--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000 -- Geosciences
ALASKA
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATES
DIAGENESIS
DOLOMITE
FEDERAL REGION X
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGY
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MINERAL RESOURCES
MINERALS
NORTH AMERICA
OXYGEN COMPOUNDS
PERMEABILITY
PETROLEUM DEPOSITS
PETROLOGY
POROSITY
RESERVOIR ROCK
RESOURCES
USA