Vanessa Nunez-Lopez - Academia.edu (original) (raw)

Papers by Vanessa Nunez-Lopez

International Journal of Greenhouse Gas Control, 2020

The use of CO 2 for enhanced oil recovery (CO 2-EOR) is a promising alternative for reducing the ... more The use of CO 2 for enhanced oil recovery (CO 2-EOR) is a promising alternative for reducing the cost of carbon capture and storage (CCS). In this study the techno-economic potential of integrated CCS-EOR projects for reducing greenhouse gas (GHG) emissions in the Colombian oil industry is estimated. For this purpose, a sourcesink matching process is carried out, including CO 2 capture potentials in sources from the petroleum, cement, power generation, and bioethanol industries, as well as from the CO 2 storage in suitable oil fields for EOR. The results indicate that a total of 142 million tons of carbon dioxide (MtCO 2) could be stored, while delivering 465 MMbbl through five CCS-EOR projects in four clusters identified around the country. The levelised cost for capture ranged between 12-209 €/tCO 2 , followed by the cost of CO 2 during EOR operations with a variation of 24-59 €/tCO 2 , and finally the CO 2 transport, from 1 €/tCO 2 to 23 €/tCO 2. The CO 2 mitigation potential of CCS-EOR represents 25 % of the forecasted oil industry emissions in Colombia for the period of 2025-2040. As compared to the intended nationally determined contribution (INDC) target set by the Colombian government, CCS-EOR projects could contribute 7 % of the total accumulated emissions reductions by 2040.

SSRN, 2019

CCS is considered a primary strategy to curb CO2 emissions. In many models, CCS is an essential t... more CCS is considered a primary strategy to curb CO2 emissions. In many models, CCS is an essential technology to meet the 2C target [1]. Drastically reducing GHG emissions in the oil and gas industry will be needed to reach the 2C target as this industry is one of the five most energy and GHG intensive sectors [2]. The implementation of CCS technologies has been widely studied for the refining stage of the oil value chain. According to Berghout et al. [3], between 80 to 90% of GHG emissions in the refining industry could be reduced using CCS. However, the cost involved for its implementation, make it an unattractive pathway. CO2-EOR is currently a promising alternative to reduce CCS costs [4], and would be able to produce an oil with low-associated emissions during its recovery. This paper aims to estimate the techno-economic potential of CO2-EOR for reducing GHG emissions in the Colombian oil industry. For this purpose, the supply and demand of CO2 is studied by including the CO2 capture potential of the oil industry, cement, power generation and bioethanol, as well as the storage potential of CO2 through the oil recovery miscible process. The state-owned oil company Ecopetrol S.A. was taken as a case study, which represent the oil value chain in Colombia, with about 70% of crude oil produced and 100% of oil transported and refined in the country. A total of 193 Mt CO2 between 2025 and 2040 could be stored through CO2-EOR. As the projected emissions of the oil and gas industry in Colombia from 2010 to 2040 are estimated at 570 Mt CO2 [11], this is equivalent to a potential 34% reduction in CO2 emissions. This mitigation represents approximately 20% of the total reduction under the INDC target for the period 2025 to 2030.

SSRN, 2019

This study evaluates and identifies CO2 enhanced oil recovery (EOR) operational strategies that a... more This study evaluates and identifies CO2 enhanced oil recovery (EOR) operational strategies that are conducive to the cooptimization of geologic carbon storage (GCS) and incremental oil recovery. The subject of co-optimization has been a focus of carbon capture, utilization, and storage (CCUS) research studies during the last decade [1, 2]. Even though the goals of EOR (produce more oil/money with less purchased CO2) and GCS (store more expensive CO2) are in conflict, if the CO2 flood is sweep efficient, the reservoir volumetric accounting for both EOR and GCS can be in balance. More specifically, when CO2 efficiently contacts the oil within the target reservoir, more oil is produced. At the same time, the pressure relief from the oil production increases CO2 storage capacity in the reservoir. In short, efficient oil production increases ultimate CO2 storage volume. This is particularly true in continuous gas injection projects. The goal of our study is better understand EOR field development schemes that can lead to the co-optimization of economic and environmental performance of CCUS projects. In our study, the environmental performance is provided by a dynamic carbon lifecycle analysis, a novel co-optimization approach that accounts for the environmental burden of the CCUS system. Assuming both the oil field and the anthropogenic CO2 volumes have been acquired and secured for the CCUS project, and economic decisions have been made in that regard, our economic performance parameter is directly associated with oil production, and our environmental performance parameter is associated with net volumes of CO2 emission reduction. The latter is a balance between the CO2 permanently stored in the oil reservoir and the GHG penalty imposed by direct and indirect CO2 emissions, onsite and downstream. Direct emissions are those mostly associated with the combustion of the refined crude oil produced, and indirect emissions are those associated with the energy consumption at the EOR site, during transportation, and at the refinery. As carbon geologic storage is the only component providing an environmental benefit, CO2 storage volume automatically becomes a highly sensitive parameter in the net carbon balance equation. In that context and knowing that field operational strategies have a significant impact on reservoir engineering aspects that affect storage (i.e. sweep efficiency, flood conformance, fluid saturation distribution), we evaluated different EOR field development strategies in terms of the aforementioned economic and environmental parameters. A parameter of interest to EOR operators is the CO2 utilization ratio (CO2 volume injected per barrel of oil produced, MSCF/STB), as it relates to the efficiency of the flood. We also focus on CO2 utilization ratios in our study, gross and net, as they combine our economic and environmental indicators in a dynamic way. An important contribution of our study, and essential to the subject of co-optimization, is that our simulation results produced curves of these indicators, which allowed us to understand the evolution of oil production and net carbon balance, as well as to provide information that can be used in decision making of carbon capture, use, and storage (CCUS) projects. Results show that flood efficiency as a function of CO2 net utilization ratios is best for the hybrid WAG+WCI scenario, where oil is recovered faster producing earlier revenues and potentially the best net present value. However, WAG appears to have a better potential for co-optimization, providing the best compromise between oil production and net carbon storage.

SSRN, 2021

A realistic and practical understanding of storage capacity is essential during the scoping and p... more A realistic and practical understanding of storage capacity is essential during the scoping and planning phases of carbon capture, utilization, and storage (CCUS) projects. This study developed from the need to redefine carbon storage capacity in a way that it provides CCUS project developers with the information they need, not only on the size of the accessible pore volume they would require, but also-and as importantly-on the rate at which CO2 can be injected into it considering geological, technical, and economic constraints. In this paper, we think of geologic storage capacity as the rate at which CO2 can be technically and economically injected into an accessible pore volume for a period of time constrained by either a maximum injection pressure or a geologic boundary. We applied this concept to a region in the Offshore Northern Gulf of Mexico to understand the opportunities of its oil and gas fields. To estimate the accessible storage capacity we used EASiTool (Enhanced Analytical Simulation Tool) capacity calculator, a closed-form analytical solution in a public Windows application that provides fast, yet reliable estimates in any geologic setting. Results from EASiTool capacity assessments indicate that the total accessible CO2 storage capacity for pure carbon storage (no production) in oil and gas fields within the area of study is up to ~200 MTonnes. This paper illustrates how an average, representative reservoir in the area of study would have an open boundary storage capacity of 2.3 MTonnes, accessible over a period of 8 years at a rate of 0.28 MTonnes/year through one injection well. This carbon storage resource is an attractive complement to the vast storage capacity of the Offshore Northern Gulf of Mexico stratigraphy.

This final report summarizes the work that was conducted to achieve the project’s general objecti... more This final report summarizes the work that was conducted to achieve the project’s
general objective of developing a clear and repeatable methodology to determine whether the
oil produced in a conventional CO2 enhanced oil recovery (CO2-EOR) operation can be
classified as Net Carbon Negative Oil (NCNO). The report also summarizes the reservoir mass
accounting methodology and the monitoring, verification, and accounting (MVA)
methodology, which are critical elements that support the general objective and were
conceived as project goals.

Energy Procedia, 2017

The question of whether carbon dioxide enhanced oil recovery (CO2-EOR) constitutes a valid altern... more The question of whether carbon dioxide enhanced oil recovery (CO2-EOR) constitutes a valid alternative for greenhouse gas emission reduction has been frequently asked by the general public and environmental sectors. Through this technology, operational since 1972, oil production is enhanced by injecting CO2 into depleted oil reservoirs in order displace the residual oil toward production wells in a solvent/miscible process. For decades, the CO2 utilized for EOR has been most commonly sourced from natural CO2 accumulations. More recently, a few projects have emerged where anthropogenic CO2 (A-CO2) is captured at an industrial facility, transported to a depleted oil field, and utilized for EOR. If carbon geologic storage is one of the project objectives, all the CO2 injected into the oil field for EOR could technically be stored in the formation. Even though the CO2 is being prevented from entering the atmosphere, and permanently stored away in a secured geologic formation, a question arises as to whether the total CO2 volumes stored in order to produce the incremental oil through EOR are larger than the CO2 emitted throughout the entire CO2-EOR process, including the capture facility, the EOR site, and the refining and burning of the end product. We intend to answer some of these questions through a DOE-NETL funded study titled "Carbon Life Cycle Analysis of CO2-EOR for Net Carbon Negative Oil (NCNO) Classification". NCNO is defined as oil whose carbon emissions to the atmosphere, when burned or otherwise used, are less than the amount of carbon permanently stored in the reservoir in order to produce the oil. In this paper, we focus on the EOR site in what is referred to as a gate-to-gate system, but are inclusive of the burning of the refined product, as this end member is explicitly stated in the definition of NCNO. Finally, we use Cranfield, Mississippi, as a case study and come to the conclusion that the incremental oil produced is net carbon negative.

Frontiers in Climate, 2019

This paper provides an overview of carbon dioxide enhanced oil recovery (CO2-EOR) and its ability... more This paper provides an overview of carbon dioxide enhanced oil recovery (CO2-EOR) and its ability to reduce greenhouse gas (GHG) emissions (even to the point of negative emissions), the role it needs to play in the challenge of decarbonization, and the need to scale up implementation and deployment in order to meet climate goals. Limitations in current legal and regulatory frameworks for CO2 injection are explored for both economic and environmental purposes, as well as the economic implications of combining CO2-EOR with geologic carbon storage. Results from a recent study, which demonstrate that all CO2-EOR operations produce negative emissions oil during the first several years of production, are analyzed in the context of the urgency of climate change mitigation. Acknowledging that fossil fuels currently provide the energy foundation upon which global societies function, and that a sudden shift in the composition of that foundation can potentially destabilize the global economy and key elements of modern society, we bring CO2-EOR to the fore as it can supply reduced carbon oil to support the current energy foundation as it steadily transitions toward decarbonization. In order to meet this urgent transition, greater fiscal, and regulatory incentives are needed to begin scaling CO2-EOR with storage around the globe. A viable and large-scale CO2-EOR/storage industry depends upon significant capital investments for CO2 capture and transportation infrastructure. Policy consistency and predictability, combined with targeted subsidies, will help to achieve this goal.

This study evaluates the potential of carbon dioxide-enhanced oil recovery (CO2-EOR) to reduce gr... more This study evaluates the potential of carbon dioxide-enhanced oil recovery (CO2-EOR) to reduce greenhouse gas emissions without compromising oil production goals. A novel, dynamic carbon lifecycle analysis (d-LCA) was developed and used to understand the evolution of the environmental impact (CO2 emissions) and mitigation (geologic CO2 storage) associated with an expanded carbon capture, utilization and storage (CCUS) system, from start to closure of operations. EOR operational performance was assessed through CO2 utilization rates, which relate usage of CO2 to oil production. Because field operational strategies have a significant impact on reservoir engineering parameters that affect both CO2 storage and oil production (e.g., sweep efficiency, flood conformance, fluid saturation distribution), we conducted a scenario analysis that assessed the operational and environmental performance of four common and novel CO2-EOR field
development strategies. Each scenario was evaluated with and without stacked saline carbon storage, an EOR/storage combination strategy where excess CO2 from the recycling facility is injected into an
underlying saline aquifer for long-term carbon storage. The dynamic interplay between operational and environmental performance formed the basis of our CCUS technology analysis. The results showed that all CO2-EOR evaluated scenarios start operating with a negative carbon footprint and, years into the project, transitioned into operating with a positive carbon footprint. The transition points were significantly different in each scenario. Water-alternating-gas (WAG) was identified as the CO2 injection strategy with the highest potential to co-optimize EOR and carbon storage goals. The results provide an understanding of the evolution of the system’s net carbon balance in all four field development strategies studied. The environmental performance can be significantly improved with stacked storage, where a negative carbon footprint can be maintained throughout the life of the operation in most of the injection scenarios modeled. This information will be useful to CO2-EOR operators seeking value in storing more CO2 through a carbon credit program (e.g., the 45Q carbon credit program in the USA). Most importantly, this study serves as confirmation that CO2-EOR can be operationally designed to both enhance oil production and reduce greenhouse gas emissions into the atmosphere.

Carbon Management Technology Conference, 2012

A research-focused large-scale carbon dioxide (CO2) injection project at Cranfield field, Mississ... more A research-focused large-scale carbon dioxide (CO2) injection project at Cranfield field, Mississippi, conducted as part of the Southeast Regional Sequestration Partnership (SECARB), is building experience in technologies and approaches that may be valuable in commercial deployment of CO2 storage projects. Since July 2008, more than 3 million tons of CO2 have been injected into a 25 m thick interval of the Lower Tuscaloosa Formation at 3.2 km depth, with the general goal of providing policy makers with the information needed to increase confidence in CO2 geologic storage capacity predictions and retention estimates. A suite of novel and traditional monitoring technologies was utilized to observe the evolution of the CO2 plume and obtain data about the performance of the reservoir in multiphase flow conditions. The monitoring program focused on above-zone pressure surveillance, down dip plume-edge mapping, and the multiphase flow process in heterogeneous sandstone. The project began CO2 injection into the oil bearing formation of the field and advanced injection into the associated water leg, linking enhanced oil recovery (EOR) and downdip brine storage. Monitoring and injection continues through 2017.
Key findings: CO2 moved in preferential paths along fluvial channels. A number of successfully deployed imaging tools support this channel-dominated flow theory. CO2 moved downdip and not preferentially updip, indicating that buoyancy forces were not flow dominating at the interwell scale of the experiment.
We hope that results from this experimental project provide a strong foundation for transferable research and lessons from the monitoring program and, given both the strengths and weaknesses of applied monitoring technologies, will be relevant in future commercial CO2 storage applications.

Energy Procedia, 2014

ABSTRACT The applicability of Distributed Temperature Sensing (DTS) as a technology to monitor CO... more ABSTRACT The applicability of Distributed Temperature Sensing (DTS) as a technology to monitor CO2 flow within CO2 injection zones at the inter-well scale, as well as to detect CO2 leakage into the overburden, is studied in this paper. An onshore CO2 injection site in the U.S. Gulf Coast that has received more than 5 million metric tons of CO2 is the setting for this study. Temperature measurements were acquired every meter along two dedicated CO2 observation wellbores, with sample rates that ranged from 2 to 15 minutes, from November 2009 through November 2010 and from September 2011 to January 2012. More than five hundred million temperature measurements were recorded during these time periods. As part of our analysis, we discuss the thermal processes and mechanisms expected to contribute to the thermal signal recorded by the DTS system, as well as the temperature changes induced by the temperature discrepancy between the injectate and the reservoir fluids. Results indicate that DTS can be a useful supporting tool when used in combination with pressure monitoring and imaging technologies.

Natural Resources Research

The East Texas Basin and southeastern Texas Gulf Coast contain a variety of co-located CO2 source... more The East Texas Basin and southeastern Texas Gulf Coast contain a variety of co-located CO2 sources and sinks that may facilitate development of new clean-coal facilities. These facilities can be linked to mature oil fields with potential for enhanced oil recovery (EOR) from miscible CO2 floods. Twenty-three reservoirs in the East Texas Basin and southeastern Texas Gulf Coast, assuming a 15% recovery factor of original oil in place (OOIP), have a CO2-EOR potential for recovery of ~9,697,000 m3 [~62.2 million stock tank barrels] of oil. A network of new CO2 pipelines can link these fields to existing power plants near lignite mine mouths in east and southeast Texas. Representative oil fields in the Woodbine Group illustrate fluvial and deltaic facies variability and different sandstone-body architectures with varying controls on potential CO2 capacity. Reservoir heterogeneity, fluid flow, hydrocarbon production, and potential CO2 capacity in the Woodbine Group in the structurally simp...

The vision of the Gulf Coast Carbon Center is to seek to impact global levels of GHG in the atmos... more The vision of the Gulf Coast Carbon Center is to seek to impact global levels of GHG in the atmosphere by doing science and engineering studies that will support reduction of CO2 emissions and enable the development of an economically viable, multifaceted, CO2 sequestration industry in the Gulf Coast. This industrial-academic consortium is investigating issues related to assessing the pathways that would make capture and pipeline transportation economically feasible and environmentally effective within a specific regional context. Key issues considered are capture in the context of the current market, pipeline infrastructure, the role of enhanced oil recovery, and permanence in a basin with many wells. .

Greenhouse Gases: Science and Technology, 2012

ABSTRACT Enhanced oil recovery (EOR) through carbon dioxide (CO2) injection provides an excellent... more ABSTRACT Enhanced oil recovery (EOR) through carbon dioxide (CO2) injection provides an excellent opportunity for commercial sequestration of anthropogenic CO2. A fluvio-deltaic, deep-seated salt dome and a strand-plain, roll-over anticline from the Gulf Coast region are currently under investigation for the design and implementation of monitoring, verification, and accounting (MVA) plans, in coordination with the commercial surveillance of independent, large-volume (>1 million ton/year) CO2-EOR operations. Characterization with wireline logs demonstrates the vertical extent and areal continuity of reservoir sands and geometries of faults that offset the reservoir. To develop the monitoring plan, we focused on several elements: (i) characterization of the zones above the confining unit for above-zone pressure monitoring, (ii) collection and development of input data for ‘quick-look’ dynamic modeling of CO2 plume extent and pressure elevation, and (iii) identifying intersections of faults with wellbores in intervals above the regional confining unit for thermal monitoring. Other uncertainties addressed during characterization are the upper extent of faults and the juxtaposition of layers to assess the potential for cross-fault fluid migration. Successful use of such techniques for MVA, based on uniting elements of existing regulatory monitoring expectations, would lead to the establishment of commercial best practices for effective and rapid characterization of EOR sites in the Gulf Coast region. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd

Natural Resources Research, 2012