EOR: Current Status and Opportunities

Abstract

A considerable portion of current world oil production comes from mature fields and the rate of replacement of the produced reserves by new discoveries has been declining steadily over the last few decades. To meet the growing need for economical energy throughout the world, the recoverable oil resources in known reservoirs that can be produced economically by applying advanced IOR and EOR technologies will play a key role in meeting the energy demand in years to come. This paper presents a comprehensive review of EOR projects. Specifically, the paper presents an overview of EOR field projects by reservoir lithology (sandstone, carbonate, and turbidite formations) and offshore versus onshore fields. More than 1,500 field projects are reviewed and summarized to evaluate feasibility of EOR technologies. Another area of growing interest is the combination of near-well-bore and in-depth conformance technologies with chemical EOR technologies such as SP and ASP. However, these are in early stages of evaluation. Examples of numerical simulations combining chemical conformance and EOR technologies are presented showing the potential of this recovery strategy in waterflooded reservoirs. Impacts of carbon capture cost and volatility of oil and carbon-credit markets on CO2-EOR projects based on anthropogenic sources is also addressed. Based on this review, it is evident that thermal and chemical EOR projects dominate in sandstone formations while gas and water-based recovery methods dominate carbonate, turbidite, and offshore fields. The review also shows the growing trend of CO2 (from natural sources), high-pressure air injection (HPAI), and chemical flooding including in-depth conformance field projects in the U.S. and abroad. CO2-EOR / sequestration in offshore fields and chemical EOR processes offshore (e.g., polymer-based methods) and onshore, including heavy crude oil reservoirs, are some of the opportunities identified for the next decade based on preliminary evaluations and proposed or ongoing pilot projects. The critical review will help to identify the next challenges and opportunities in EOR. Hybrid schemes combining IOR/EOR as well as CO2-EOR/sequestration can be ranked on the basis of adequate simulation procedures.

Mixtures of Anionic/Cationic Surfactants: A New Approach for Enhanced Oil Recovery in Low-Salinity, High-Temperature Sandstone Reservoir

“…During the past few decades, considerable attention has been paid to mixtures of anionic and cationic surfactants (Antón et al 2008;Gralbner et al 2008;Kume et al 2008;Li and Hao 2008;Sohrabi et al 2008;Lioi et al 2009;Yin et al 2009;Fernandes et al 2010;Kayali et al 2010;Stocco et al 2010;Panswad et al 2011;Tah et al 2011). Because of electrostatic attraction between oppositely charged surfactant head groups and intermolecular attraction between the hydrophobic hydrocarbon chains, anionic and cationic surfactants when mixed tend to form ion pairs that exhibit many unique properties, different from each of the individual surfactants, such as ultralow CMC; high surface activity caused by the electrostatic attraction between oppositely charged surfactant head groups that leads to an effective reduction of the area of surfactant head groups; and new microstructures, such as vesicles and/or rod-like micelles.…”

Performance Evaluation of a Horizontal Well With Multiple Fractures by Use of a Slab-Source Function

“…This means that the pressure and its derivative curve bend toward the pseudosteady flow. One can explain this phenomenon by the occurrence of the stimulated reservoir volume (Mayerhofer et al 2010). The fractured well can only produce from the volume trapped between fractures.…”

Upscaling Polymer Flooding to Model Sub-gridblock Geological Heterogeneity and Compensate for Numerical Dispersion

“…Chemical EOR projects have not increased significantly over the last decade and their contribution to overall world oil production is minimal (Manrique et al, 2010). Reasons for this include fluctuating oil prices in addition to the feasibility of using chemical EOR in comparison with other EOR methods.…”