Investigation into the Niobrara Formation and Missing Section Associated with Pre-lithification Faults, Wattenberg Field (CO)

• Main Author: Clark, Cameron Wilhite
• Language: EN
• Published: University of Louisiana at Lafayette 2019
• Subjects: Geology|Petroleum geology
• Online Access: http://pqdtopen.proquest.com/#viewpdf?dispub=10817209

<p>The Denver-Julesburg Basin (DJ Basin) has been a productive oil and gas field since 1970 where operators began targeting the J sandstone (Sonnenberg 2013). Within the DJ Basin, the Wattenberg field has been the ?hot spot? for the past several years due to its high gas to oil ratio. The Niobrara Formation has added new value to this area as the use of horizontal drilling and hydraulic fracturing has become common practice for operators in the Wattenberg since 2009 (Sonnenberg 2013). This formation is a ?tight? rock that has very little connectivity making the hydraulic fracturing technique a necessity for economical wells. There are a large number of faults seen in the Wattenberg field that can have just a few feet of displacement to very large faults with 100+ feet of displacement. These faults are likely part of a polygonal fault system that has been linked to dewatering events that occurred prelithification in the Wattenberg Field (Underwood 2013). Along some of these major faults we see sections of Niobrara Formation that are missing, and these fault planes provide a pathway for the expulsion of this sediment. Understanding the pre-lithification faulting and missing section in the Niobrara Formation could result in added economic value as this could lead to finding optimal well placement for maximizing oil recovery. This study was driven by the hypothesis that the missing section of Niobrara Formation could be linked to the Pierre Shale?s Tepee Buttes. To determine the origin of the Tepee Buttes seismic data, well logs, thin sections, and XRF data was used to further investigate the Tepee Buttes, Niobrara Formation Chalks and Marls, Fort Hays Limestone, and Pierre Shale.