EORI Library
Find publications about Enhanced Oil Recovery (EOR).

Evaluation of ROZ in the Tensleep Formation, Northeastern Bighorn Basin, Wyoming

Nick Jones of EORI explores the application of Permian Basin ideas to the Bighorn Basin through the use of cores, cuttings, well logs, PI cards, and more.

Field Guide to the Minnelusa Formation Ranch A and Newcastle Area, Wyoming and South Dakota

Eolian petroleum reservoirs are found worldwide, many having high-volume production of both oil and gas. As with any geological rock unit, each oil/gas field has production characteristics peculiar to its geological history. However, certain common factors link most eolian reservoirs. Cross-stratification due to bedform migration can influence sweep direction and efficiency. The various kinds of primary eolian strata have different poroperm characteristics. Moreover, stacking of sand seas or bedforms through geological time can create distinctive reservoir flow units in the subsurface. Tectonic activity, especially faults, may create shear zones with reduced poroperm, or partition a reservoir into structurally defined flow units. Faults may also create high-permeability zones that allow water breakthrough. Eolian reservoirs are commonly thought of as clean, and rather simple. However, in some places they are complex in terms grain composition or texture. They are commonly cemented by carbonates, anhydrites or salt, which sets up fabricselective or non-fabric selective patterns of secondary porosity in reservoirs.

Polymer Flooding the Minnelusa in the Powder River Basin of Wyoming

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.

Electrifying the Oilfield: The Comparative Economics of Grid Power and Onsite Gas Generators (Draft Jan 30 2017)

When it comes to electrifying the oilfield, the industry narrows its focus onto monthly energy charges (energy, demand, and basic charges), somewhat disregarding the considerable capital expenditures necessary to build out and maintain electric infrastructure. Onsite generation may not be the optimal solution in every application, but at least in terms of cost in the current environment, generators appear to offer a competitive alternative.