Lifecycle Energy Accounting of Three Small Offshore Oil Fields

Small oil fields are expected to play an increasingly prominent role in the delivery of global crude oil production. As such, the Energy Return on Investment (EROI) parameter for three small offshore fields are investigated following a well-documented methodology, which is comprised of a “...

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Main Authors: David Grassian, Daniel Olsen
Format: Article
Language:English
Published: MDPI AG 2019-07-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/12/14/2731
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author David Grassian
Daniel Olsen
author_facet David Grassian
Daniel Olsen
author_sort David Grassian
collection DOAJ
description Small oil fields are expected to play an increasingly prominent role in the delivery of global crude oil production. As such, the Energy Return on Investment (EROI) parameter for three small offshore fields are investigated following a well-documented methodology, which is comprised of a &#8220;bottom-up&#8221; estimate for lifting and drilling energy and a &#8220;top-down&#8221; estimate for construction energy. EROI is the useable energy output divided by the applied energy input, and in this research, subscripts for &#8220;lifting&#8221;, &#8220;drilling&#8221;, and &#8220;construction&#8221; are used to differentiate the types of input energies accounted for in the EROI ratio. The EROI<sub>Lifting</sub> time series data for all three fields exhibits a decreasing trend with values that range from more than 300 during early life to less than 50 during latter years. The EROI<sub>Lifting</sub> parameter appears to follow an exponentially decreasing trend, rather than a linear trend, which is aligned with an exponential decline of production. EROI<sub>Lifting</sub> is also found to be inversely proportional to the lifting costs, as calculated in USD/barrel of crude oil. Lifting costs are found to range from 0.5 dollars per barrel to 4.5 dollars per barrel. The impact of utilizing produced gas is clearly beneficial and can lead to a reduction of lifting costs by as much as 50% when dual fuel generators are employed, and more than 90% when gas driven generators are utilized. Drilling energy is found to decrease as the field ages, due to a reduction in drilling intensity after the initial production wells are drilled. The drilling energy as a percentage of the yearly energy applied is found to range from 3% to 8%. As such, the EROI<sub>Lifting+Drilling</sub> value for all three fields approaches EROI<sub>Lifting</sub> as the field life progresses and the drilling intensity decreases. The construction energy is found to range from 25% to 63% of the total applied energy over the life of the field.
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spelling doaj.art-49bc9b5f69d6491d9f9e143f0f20ac782022-12-22T04:01:21ZengMDPI AGEnergies1996-10732019-07-011214273110.3390/en12142731en12142731Lifecycle Energy Accounting of Three Small Offshore Oil FieldsDavid Grassian0Daniel Olsen1Program in Systems Engineering, Walter Scott Jr. College of Engineering, Colorado State University, Fort Collins, CO 80523-1302, USAProgram in Systems Engineering, Walter Scott Jr. College of Engineering, Colorado State University, Fort Collins, CO 80523-1302, USASmall oil fields are expected to play an increasingly prominent role in the delivery of global crude oil production. As such, the Energy Return on Investment (EROI) parameter for three small offshore fields are investigated following a well-documented methodology, which is comprised of a &#8220;bottom-up&#8221; estimate for lifting and drilling energy and a &#8220;top-down&#8221; estimate for construction energy. EROI is the useable energy output divided by the applied energy input, and in this research, subscripts for &#8220;lifting&#8221;, &#8220;drilling&#8221;, and &#8220;construction&#8221; are used to differentiate the types of input energies accounted for in the EROI ratio. The EROI<sub>Lifting</sub> time series data for all three fields exhibits a decreasing trend with values that range from more than 300 during early life to less than 50 during latter years. The EROI<sub>Lifting</sub> parameter appears to follow an exponentially decreasing trend, rather than a linear trend, which is aligned with an exponential decline of production. EROI<sub>Lifting</sub> is also found to be inversely proportional to the lifting costs, as calculated in USD/barrel of crude oil. Lifting costs are found to range from 0.5 dollars per barrel to 4.5 dollars per barrel. The impact of utilizing produced gas is clearly beneficial and can lead to a reduction of lifting costs by as much as 50% when dual fuel generators are employed, and more than 90% when gas driven generators are utilized. Drilling energy is found to decrease as the field ages, due to a reduction in drilling intensity after the initial production wells are drilled. The drilling energy as a percentage of the yearly energy applied is found to range from 3% to 8%. As such, the EROI<sub>Lifting+Drilling</sub> value for all three fields approaches EROI<sub>Lifting</sub> as the field life progresses and the drilling intensity decreases. The construction energy is found to range from 25% to 63% of the total applied energy over the life of the field.https://www.mdpi.com/1996-1073/12/14/2731oil and gasenergy accountingEROIenergy intensitylifting energydrilling energyconstruction energylifting cost
spellingShingle David Grassian
Daniel Olsen
Lifecycle Energy Accounting of Three Small Offshore Oil Fields
Energies
oil and gas
energy accounting
EROI
energy intensity
lifting energy
drilling energy
construction energy
lifting cost
title Lifecycle Energy Accounting of Three Small Offshore Oil Fields
title_full Lifecycle Energy Accounting of Three Small Offshore Oil Fields
title_fullStr Lifecycle Energy Accounting of Three Small Offshore Oil Fields
title_full_unstemmed Lifecycle Energy Accounting of Three Small Offshore Oil Fields
title_short Lifecycle Energy Accounting of Three Small Offshore Oil Fields
title_sort lifecycle energy accounting of three small offshore oil fields
topic oil and gas
energy accounting
EROI
energy intensity
lifting energy
drilling energy
construction energy
lifting cost
url https://www.mdpi.com/1996-1073/12/14/2731
work_keys_str_mv AT davidgrassian lifecycleenergyaccountingofthreesmalloffshoreoilfields
AT danielolsen lifecycleenergyaccountingofthreesmalloffshoreoilfields