Publications

In their study, Open Water Capital Partners highlights solutions to mitigate the long-term effects of a sustained downturn in coal, oil and natural gas and introduces strategies to limit the downturn’s impact while supporting Wyoming’s energy industry.

Open Water Capital Partners introduce strategies to curtail this impact to Wyoming’s economy with a three-pronged approach providing “immediate financial relief to operators, access to longer term liquidity amidst the volatility, and establishes a platform to more broadly diversify state revenue streams. 

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.

Polymer-augmented waterflooding of the Minnelusa in Wyoming has proven to be a successful method for improving production in most cases compared to normal waterfloods. Polymer is a lowcost, low-risk option when considering a method for enhancing production of a particular field. Its primary function is to improve the mobility ratio of the injected water by increasing its viscosity, thereby improving the volumetric sweep and conformance within the reservoir.

Advantages of using polymer include: (1) low cost, (2) preventing early water breakthrough, (3) improving volumetric sweep and conformance, (4) increasing oilwater ratios, (5) mobilizing oil that would likely have been bypassed under normal waterflood conditions, (6) mitigating heterogeneous permeabilities within the reservoir, and (7) other enhanced oil recovery injection technologies can still be applied after the polymer flood. Most, but not all, Minnelusa fields examined exhibited improved recoveries using polymer compared to fields under conventional waterfloods. Uneconomical polymer floods can be caused by a variety of factors, chief of which is the failure to properly understand the internal architecture of the reservoir prior to initiating the flood.

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.

For the Niobrara, a 9MM lb job size with a lateral length of 10,000 ft, a GOR of 900 scf/bbl, and a treatment rate between 40 and 45 bpm is optimal. Due to lack of available pricing data and the inability to generate valid type curves of production, an economic analysis could not be conducted for the Niobrara.

The Great Plains Institute (GPI) and the University of Wyoming’s Jeffrey Brown explore the planning of CO₂ transportation networks on a regional scale and ascertains the economic and environmental benefits that can be achieved through economies of scale to meet the US midcentury decarbonization goals.

This paper represents the results of modeling efforts to identifying regional scale CO₂ transport infrastructure that would serve existing facilities and allow participation by new capture projects and facilities in the near future.

After several decades of decline Wyoming’s oil production is now turning higher thanks to higher oil prices, the development of condensates, and investments in tertiary methods such as CO2 Enhanced Oil Recovery (CO2-EOR). The present work brings together two prior pieces of research by integrating the economic impact model of Cook (2013a) with the scoping estimates of Wyoming’s CO2-EOR potential found in Cook (2013b). The hope is that discussing the potential economic contribution of CO2-EOR will help inform industry participants and policy makers for the further development of CO2 infrastructure in the state.

The North Cross (Devonian) Unit, currently operated by Occidental Oil and Gas, was discovered in 1944. The field was developed using regular 40 acre spacing and produced under primary recovery until 1964. Subsequently, a partial pressure maintenance program was constituted to inject residue gas in an updip location in the field. Large-scale continuous CO2 injection began in April 1972 and was expanded over time to provide CO 2 support throughout the field. The field has been under continuous CO 2 flood for over four decades. Currently, over 200% hydrocarbon pore volume (HCPV) of CO2 has been injected, and over 60% of the latest estimate of its target original-oil-in-place (OOIP) has been recovered. The field continues to perform well with a gross utilization (MCF CO2 injected/bbl oil recovered) of approximately 30 MCF/BO (20 MCF/BOE). North Cross is an excellent example of a successful mature continuous CO2 flood.

This study will seek a methodology to improve (a) accuracy in estimates of oil recovery factors and (b) planning field development including well spacing and arrangement. Further, we will create and apply laboratory measurements to understand movement of petroleum fluids at small scales in order to better evaluate upscaling techniques and verify the underlying assumptions of previous works. The proposed study has the potential to impact reserves estimates and production in Wyoming, because it addresses phenomena that constitute bulk properties of all eolian reservoirs in Wyoming and their remaining reserves along with new fields that may be discovered in eolian system rocks such as the Tensleep, Minnelusa, Leo, and Navajo Sandstones.

During 2004-2010 the authors studied the sand dunes of Oman using trenches, OSL age dating and modern wind data. This work was supported by Petroleum Development Oman to define modern analogs for ancient dune reservoirs that produce oil and gas in the Sultanate. An unintended consequence of our work was the recognition of a band of high wind energy along the East Coast of Oman that might be suitable for commercial wind power extraction, especially during the peak wind season of the Indian Monsoon. Our geological work indicates that this basic wind regime has been in place for at least 200K years, and is thus not a fluke of modern times.

A summary and quantification of the impact of EORI's contributions to the oil and gas industry in Wyoming.

In this issue:

• From the desk of the director
• Update on EORI Chemical Flooding Unit
• AAPG Annual Meeting Presentations
• GSA Rocky Mountain Section Meeting Papers
• New Horizons in Database Management

In this issue:

• From the desk of the director
• EOR and technology
• Low salinity waterflooding
• New staff
• Recent publications
• Events
• Looking ahead