Silo field, Laramie County, Wyoming: A guide for future fractured Niobrara production

Conference · Sat Jun 01 04:00:00 EDT 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5791787

Sonnenberg, S A; Weimer, R J

The Silo field is located in the northern part of the Denver basin. Production is from the fractured Niobrara Formation at depths ranging from 7,600 to 8,500 ft (2,318 to 2,593 m). Cumulative production from 40 vertical wells at Silo is in excess of 1.3 million bbl of oil. Two wells have produced 437,000 bbl of oil. Two wells have produced 437,000 bbl of oil. Recent drilling success with horizontal wells suggests much greater future production. Initial potentials from the new horizontal wells range from 500 to 2,000 bbl of oil/day. The dominant lithologies of the Niobrara are limestones (chalks) and interbedded calcareous and organic-rich shales. Four limestone intervals, averaging 30 ft (9.2 m), and three intervening shale intervals occur regionally and are easily recognized on geophysical logs. The lower limestone is named the Fort Hays, and the overlying units are grouped together as the Smoky Hill member. The fractures are concentrated in the more brittle limestones. The intervening shales have high organic matter content and served as source beds. Open fracture systems are essential to Niobrara production because little matrix porosity exists in the limestones. High resistivities are observed in limestone beds at Silo. These resistivity anomalies appear to be realted to the presence of a large hydrocarbon accumulation delineated by isoresistivity mapping. Factors present at Silo will serve as a model for future Niobrara produciton in the Rocky Mountain region. These factors include (1) mature source rocks interbedded with brittle limestone; (2) open fractures to form the reservoir; (3) resistivity anomalies indicating accumulation; and (4) technology to efficiently produce the reservoir.

• OSTI ID: 5791787
• Report Number(s): CONF-9107109--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:6
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
020300 -- Petroleum-- Drilling & Production
CARBONATE ROCKS
DEVELOPED COUNTRIES
DIRECTIONAL DRILLING
DRILLING
ELECTRICAL SURVEYS
FEDERAL REGION VIII
FRACTURED RESERVOIRS
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
GEOPHYSICAL SURVEYS
LIMESTONE
MINERAL RESOURCES
NORTH AMERICA
OIL FIELDS
OIL WELLS
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
PRODUCTION
RESISTIVITY SURVEYS
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SHALES
SOURCE ROCKS
SURVEYS
USA
WELLS
WYOMING