Relation of lithofacies and diagenesis to porosity development, Mississippian Mission Canyon formation, eastern Montana and western North Dakota

Conference · Mon Aug 01 04:00:00 EDT 1983 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6386269

Chimney, P J; Wittstrom, M D

The ability to map lithofacies trends suitable for hydrocarbon reservoirs is critical for a successful exploration program. In exploring basins with carbonate reservoirs, diagenetic alterations must also be understood in relation to porosity development. During the Mississippian the Williston basin was the site of subtidal to supratidal carbonate deposition. In general, depositional environments became more restricted from Montana eastward into North Dakota. Sub-surface mapping suggests a strong relationship between the degree of marine restriction and diagenesis and porosity development in carbonate sediments. Two fields that produce from the Mission Canyon interval illustrate this relationship. MonDak field, situated on the Montana-North Dakota border, lies west of the limit of massive Mission Canyon anhydrite in a sequence of normal marine sediments. Reservoir porosity is due to fracturing of tight, fine-grained limestones. Low matrix porosity and sparse, erratic fracturing are responsible for low daily production rates. The Billings Nose-Little Knife trend (Billings, Dunn, and McKenzie Counties, North Dakota) is well within the limit of massive anhydrite. Reservoir porosity consists of a thick sequence of intertidal-supratidal sucrosic dolomites which are sealed by 20 to 25 m (65 to 82 ft) of massive anhydrite. Reflux of magnesium-rich brines is believed to be the process leading to dolomitization. Good matrix porosity and permeability allow for higher daily production rates. Regional mapping indicates that the presence or absence of anhydrite correlates directly with the development of good matrix porosity.

• Research Organization: Gulf Oil Exploration and Production Co., Casper, WY
• OSTI ID: 6386269
• Report Number(s): CONF-8309274-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 67:8
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ALKALINE EARTH METAL COMPOUNDS
ANHYDRITE
CALCIUM COMPOUNDS
CALCIUM SULFATES
CARBONATE ROCKS
DIAGENESIS
EXPLORATION
FEDERAL REGION VIII
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
MAPPING
MINERAL RESOURCES
MINERALS
MONTANA
NORTH AMERICA
NORTH DAKOTA
OXYGEN COMPOUNDS
PETROLEUM DEPOSITS
POROSITY
RESERVOIR ROCK
RESOURCES
ROCKS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
SULFATE MINERALS
SULFATES
SULFUR COMPOUNDS
USA