Energy Return on Investment (EROI) for Forty Global Oilfields Using a Detailed Engineering-Based Model of Oil Production

Abstract

Studies of the energy return on investment (EROI) for oil production generally rely on aggregated statistics for large regions or countries. In order to better understand the drivers of the energy productivity of oil production, we use a novel approach that applies a detailed field-level engineering model of oil and gas production to estimate energy requirements of drilling, producing, processing, and transporting crude oil. We examine 40 global oilfields, utilizing detailed data for each field from hundreds of technical and scientific data sources. Resulting net energy return (NER) ratios for studied oil fields range from ≈2 to ≈100 MJ crude oil produced per MJ of total fuels consumed. External energy return (EER) ratios, which compare energy produced to energy consumed from external sources, exceed 1000:1 for fields that are largely self-sufficient. The lowest energy returns are found to come from thermally-enhanced oil recovery technologies. Results are generally insensitive to reasonable ranges of assumptions explored in sensitivity analysis. Fields with very large associated gas production are sensitive to assumptions about surface fluids processing due to the shifts in energy consumed under different gas treatment configurations. This model does not currently include energy invested in building oilfield capital equipment (e.g., drilling rigs), nor does it include other indirect energy uses such as labor or services.

Lifecycle Energy Accounting of Three Small Offshore Oil Fields

“…An additional dimension related to the source of direct energy used for EROI-Lifting was derived to differentiate between external and internal energy sources. Net Energy Return (NER) includes both internal and external energy investments, while External Energy Return (EER) only includes external energy investments such as imported fuel gas, liquid fuels such as diesel, and electricity imported from an external grid [17]. NER and EER ratios are described by Equations (2) and (3).…”

“…The ratio of returned energy output to invested energy input, as described by Equation (1), is commonly referred to as the Energy Return on Investment (EROI), a parameter that has been applied to a wide number of energy-related industries. Concerning the oil and gas industry, there have been numerous EROI studies covering a wide range of boundaries, such as for global production, for country level production, and for specific fields [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”

How Does Energy Resource Depletion Affect Prosperity? Mathematics of a Minimum Energy Return on Investment (EROI)

“…From prior work (Brandt et al 2015(Brandt et al , 2012Cleveland 2005;Guilford et al 2011) the direct self-consumption of energy within the energy sector for producing crude oil from the Earth ranges from ≤1 to 30% of the energy content of produced crude oil. The high end of this range is observed in thermal enhanced oil recovery and oil sands projects.…”

“…Material consumption by the energy sector Material consumption per oil well was found by Brandt (2015) and Beath et al (2012Beath et al ( , 2014 to be of order 100s to 1000s tonnes of material per well. For example, Brandt's default well has direct material consumption for wellbore, cement, surface facilities, and long-distance transport of 750 tonnes per well (Brandt 2015).…”

“…For example, Brandt's default well has direct material consumption for wellbore, cement, surface facilities, and long-distance transport of 750 tonnes per well (Brandt 2015). In the US, average per-well lifetime productivity (estimated ultimate recovery per well) is of order 130,000 bbl, while global productivities are closer to 1 ×10 6 bbl per well.…”