The significance of stylolitization and intergranular pressure solution in the formation of pressure compartment seals in the St. Peter Sandstone, Ordovician, Michigan basin

Conference · Fri Mar 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5793700

Drzewiecki, P A; Simo, T; Moline, G; Bahr, J M; Nadon, G; Shepherd, L; Vandrey, M R ^[1]

---

1. Univ. of Wisconsin, Madison (United States)

The Middle to Late Ordovician St. Peter Sandstone of the Michigan basin is a fine- to medium-grained quartz sandstone. Extensive stylolitization and intergranular pressure solution have been major factors in reducing the porosity of certain horizons within the St. Peter, resulting in pressure compartmentation of the reservoir. Pressure versus depth data for various Michigan basin wells indicate that the basin contains compartments that are overpressured by as much as 500 psi. Horizons bounding these compartments are often affected by intense stylolitization (or intergranular pressure solution) and quartz cementation and have been correlated with zones of low porosity and permeability ({phi} = 0-3%, k = <50 {mu}d). These tight zones can be correlated within single gas fields, and some may extend across the Michigan basin. The St. Peter Sandstone has been buried to depths of about 3,500 m in the central part of the basin and 1,500 m at the margins. Intensely stylolitized zones are found at all depths throughout the basin and do not appear to change in abundance or style with depths. Factors that influence the formation, morphology, and abundance of stylolites in the St. Peter include (1) clay intraclasts, (2) intergranular clay, and (3) fine-grained, feldspar-rich sand. Stylolites also occur at contacts between quartz-cemented and carbonate-cemented zones and within well-cemented sands. Intergranular pressure solution and stylolites may be responsible for the formation of a compartment seal. Understanding their genesis can allow prediction of variations in porosity in Michigan basin well cores.

• OSTI ID: 5793700
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
MICHIGAN
NATURAL GAS DEPOSITS
RESERVOIR ROCK
DIAGENESIS
POROSITY
CEMENTS
GEOLOGIC FORMATIONS
MINERALIZATION
ORDOVICIAN PERIOD
RESERVOIR PRESSURE
SANDSTONES
SEDIMENTARY BASINS
BUILDING MATERIALS
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
MATERIALS
MINERAL RESOURCES
NORTH AMERICA
PALEOZOIC ERA
RESOURCES
ROCKS
SEDIMENTARY ROCKS
USA
030200* - Natural Gas- Reserves
Geology
&amp; Exploration