Society of Independent Professional
Earth Scientists

 Click here for the 2026 S.I.P.E.S. Dues Form - please use this form to update your contact information as well

Click here to pay your dues online

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Next Event:

February 26, 2026

Our Presenter:

Stephen Sonnenberg

"Niobrara of the Powder River Basin"

All attendees MUST RSVP!

Please RSVP by 11:30 a.m. on February 23

Click here to RSVP

When: Thursday, February 26, 2026, 11:30 a.m. - 1:30 p.m.

Where: Wynkoop Brewery - 1634 18th Street, Denver, CO 80202

Cost Structure:

• Members $25 (Presentation & Meal)
• Non-members $30 (Presentation & Meal)
• Walk-ins will no longer be allowed due to an issue with the Wynkoop.  Please pre-purchase a lunch to attend.  Sorry for the inconvenience!

Please feel free to share this information with any friends and colleagues who might be interested!

Mask requirements voluntary for vaccinated attendees.

Abstract:

The Niobrara Total Petroleum System (TPS) covers an extensive area across the Rocky Mountain Region, USA. In the Powder River Basin (PRB), the petroleum system consists of source beds in the Upper Cretaceous Niobrara Formation as well as reservoirs in the Upper Cretaceous Frontier, Turner, Niobrara, Sussex, Shannon, Parkman, Teapot, and Teckla, and Paleocene and Eocene Fort Union and Wasatch formations, respectively. The Niobrara is a
deep-water hemipelagic carbonate mudrock and will be the subject of this talk.

The Niobrara in the southern PRB is Coniacian to early Campanian in age and approximately 150 to 650 ft thick. The formation, where productive, has low porosity (< 10%), low permeability (<0.01 md), and pore throat sizes less than 0.1 micron. The immature-mature present-day depth boundary is approximately 8,000 ft. The formation is subdivided informally into three units in the PRB (A, B, and C). The units consist of cycles of marls and chalks.
The main reservoir target is the B chalk/marl zone.

Geologic factors related to successful exploration and development include excellent source-rock quality, source rock maturity, reservoir thickness, matrix and fracture porosity and permeability development, high geothermal gradients, overpressure, oil gravity, gas-oil ratios, and regional fracture development.

Recent drilling success utilizing horizontal drilling and multi-stage hydraulic fracture stimulation suggests the opportunity for a large (giant) unconventional petroleum accumulation. The Niobrara in the PRB is experiencing significant growth in drilling permits, up 93% since 2020.  This suggests strong momentum for oil and gas exploration in the PRB.  The PRB has seen a 14% increase in production over the last five years (driven by the Niobrara and Mowry).

Bio:

Stephen A. Sonnenberg: Boettcher Chair Petroleum Geology, Colorado School of Mines

WHAT IS SIPES?

The Society of Independent Professional Earth Scientists (SIPES) is the only national organization designed exclusively for the independent or consulting professional earth scientist. Members include geologists, engineers, geophysicists, geochemists, and other earth scientists. 

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Our Mission

To be the pre-eminent organization for furthering the professional business interests of independent practitioners of earth sciences. 

• Professional Competence

• Professional Business Ethics

• Presenting a favorable, credible and effective image of Society



Local Events:

Monthly Meetings

Meetings for 2026 will be held at the

Wynkoop Brewery

1634 18th Street

Denver, CO 80202