The authors use multivariate statistics to highlight best practices in the drilling of Codell and Niobrara reservoirs of the northern Denver-Julesburg (DJ) Basin in southeastern Wyoming. The conclusions in this paper differ from a 2017 report by the Wyoming State Geological Survey on the same topic and illustrate why simple crossplots are not sufficient to properly analyze plays where a number of variables must be addressed and weighed simultaneously.
For the Codell, this study reveals that the attributes of Proppant Volume, Horizontal Length, Gas-Oil Ratio (GOR), and Treatment Rate have the greatest influence on 6-, 12-, and 18-month cumulative oil production. By examining the individual attribute responses, the current best design in the Codell is a lateral length of at least 9,600 feet (ft), a job size of 12 million (MM) lbs, a treatment rate of at least 40 barrels per minute (bpm), and a GOR of 570 standard cubic feet per barrel (scf/bbl). The type curves from decline curve analysis provided predictive monthly production. The best EURs were obtained with the optimized design and yielded better overall economics when entered into the economic model.
Wyoming, perhaps more than any other state, is dependent on revenues generated from the development and sales of minerals within its borders and has a vested interest in ensuring that its resources are properly and efficiently exploited. Maximizing the efficiency of oil and gas production in Wyoming is one of the primary goals of the Enhanced Oil Recovery Institute (EORI). Potential methods or practices that can improve or enhance the recovery efficiency of oil and gas production in the state are of paramount interest. Likewise, those policies or practices that hinder such efforts are also important to discuss.
Wyoming has nearly one billion barrels of proved oil reserves, a significant portion of which is still on primary production. Assessing the potential for secondary recovery from current oil fields is always a daunting task and requires evaluations regarding whether any given field will respond favorably to secondary recovery efforts.
This paper makes general assumptions regarding the feasibility of using a water flood to enhance oil recovery in a field based on publicly available data. The conclusions resulting from these assumptions are meant to be a guideline for the potential of future water flooding and are not meant to provide detailed evaluations of any given field’s ultimate recovery.
There are two main themes of this poster. The first theme is to provide an update on the stratigraphy and sedimentology of the Tensleep/Casper Formation of Southeast Wyoming (and parts of Northern Colorado), and oil production from these rocks. We incorporate new measured sections, stratigraphic analysis and petrographic work undertaken by the authors. To this end we created a new database in ArcGis (geographic information software) of tops and other information that updates the historical well database of the Wyoming Oil and Gas Commission archived in Casper. This new database has been used to create Common Risk Segment (CRS) maps of the Upper Tensleep oil play in Southeast Wyoming. These CRS maps indicate trends in Tensleep reservoir, charge and trap that are useful in planning further exploration. It is possible that use of advanced seismic techniques applied over the complex structural terrains in the identified high potential areas of SE Wyoming will produce new leads and ultimately, new discoveries.
The purpose of this field trip and the lectures is to acquaint participants with the sedimentology of the Middle and Upper Minnelusa Formation, using outcrops in the Black Hills of Wyoming and South Dakota. The trip provides a good opportunity to examine in outcrop many of the sedimentary facies that strongly control oil production in the nearby Minnelusa oil play. Along with study of the outcrops, we review important principles of oil and gas production from eolian reservoirs using modern and ancient oil field and outcrop examples. These ideas may be useful in analyzing eolian reservoirs for secondary or tertiary recovery operations, or understanding past reservoir behavior.
Osage Partners, LLC. a Wyoming based operator contacted EORI and requested the institute’s assistance regarding their Muddy/Newcastle assets. The operator provided EORI with core from four wells and associated data related to the Osage field in the Powder River Basin. The operator requested that EORI characterize the clay mineralogy of the pay sands using XRD, SEM, and CEC analysis of samples from the provided core.