A profitability study of CO₂-EOR and subsequent CO₂ storage in the North Sea under low oil market prices

A wide-scale application of CO2-enhanced oil recovery (CO2-EOR) in North Sea oil fields can have many advantages, especially when followed by CO2 geological storage. Under the current low oil prices though, even maintaining basic oil production is challenging. A techno-economic assessment is made of the Claymore oil field with the PSS IV simulator, focusing on uncertainty and investment risk. For a stochastic oil price ranging between 10 and 70 €/bbl, a stochastic CO2 revenue of -10 to 70 €/t and stochastic reservoir parameters, an average NPV of almost 500 M€ is obtained with a 73% chance on a positive NPV if the investment is made. Disregarding uncertainty relating to the underground by fixing the stochastic reservoir parameters, leads remarkably, but also erroneously, to a lower average NPV. Results also show that geological uncertainty is an important factor for determining the economic threshold level of an EOR project, and a proper assessment of the real uncertainties can make the difference between profit and loss. In case of assuming a fixed CO2 revenue at 30 €/t, the probability of implementing EOR becomes higher, but the average NPV and project success rate are significantly lower, at 300 M€ and 63% respectively. This demonstrates that a fixed CO2 tax is not a generic CGS enabling solution. It not well-weighted, it can hamper the deployment of certain technologies. A phase of CO2 geological storage (CGS) after oil production becomes economically interesting from a CO2 revenue of 17€/t. If such a price level can be guaranteed, then continuation of CO2 injection can reduce investment risk for both the EOR and CGS investment, reduces the investment hurdle, and can be a catalyzer for large-scale and widespread CO2 storage in Europe

Successful immunization against a parasitic nematode by vaccination with recombinant proteins

AbstractInfection of humans and livestock with parasitic nematodes can have devastating effects on health and production, affecting food security in both developed and developing regions. Despite decades of research, the development of recombinant sub-unit vaccines against these pathogens has been largely unsuccessful. We have developed a strategy to identify protective antigens from Teladorsagia circumcincta, the major pathogen causing parasitic gastroenteritis in small ruminants in temperate regions, by studying IgA responses directed at proteins specific to post-infective larvae. Antigens were also selected on the basis of their potential immunomodulatory role at the host/parasite interface. Recombinant versions of eight molecules identified by immunoproteomics, homology with vaccine candidates in other nematodes and/or with potential immunoregulatory activities, were therefore administered to sheep in a single vaccine formulation. The vaccine was administered three times with Quil A adjuvant and the animals subsequently subjected to a repeated challenge infection designed to mimic field conditions. Levels of protection in the vaccinates were compared to those obtained in sheep administered with Quil A alone. The trial was performed on two occasions. In both trials, vaccinates had significantly lower mean fecal worm egg counts (FWECs) over the sampling period, with a mean reduction in egg output of 70% (Trial 1) and 58% (Trial 2). During the period of peak worm egg shedding, vaccinates shed 92% and 73% fewer eggs than did controls in Trials 1 and 2, respectively. At post mortem, vaccinates had 75% (Trial 1) and 56% (Trial 2) lower adult nematode burdens than the controls. These levels of protection are the highest observed in any system using a nematode recombinant sub-unit vaccine in the definitive ruminant host and indicate that control of parasitic helminths via vaccination with recombinant subunit vaccine cocktails is indeed an alternative option in the face of multi-drug resistance

Identification of biomolecule mass transport and binding rate parameters in living cells by inverse modeling

BACKGROUND: Quantification of in-vivo biomolecule mass transport and reaction rate parameters from experimental data obtained by Fluorescence Recovery after Photobleaching (FRAP) is becoming more important. METHODS AND RESULTS: The Osborne-Moré extended version of the Levenberg-Marquardt optimization algorithm was coupled with the experimental data obtained by the Fluorescence Recovery after Photobleaching (FRAP) protocol, and the numerical solution of a set of two partial differential equations governing macromolecule mass transport and reaction in living cells, to inversely estimate optimized values of the molecular diffusion coefficient and binding rate parameters of GFP-tagged glucocorticoid receptor. The results indicate that the FRAP protocol provides enough information to estimate one parameter uniquely using a nonlinear optimization technique. Coupling FRAP experimental data with the inverse modeling strategy, one can also uniquely estimate the individual values of the binding rate coefficients if the molecular diffusion coefficient is known. One can also simultaneously estimate the dissociation rate parameter and molecular diffusion coefficient given the pseudo-association rate parameter is known. However, the protocol provides insufficient information for unique simultaneous estimation of three parameters (diffusion coefficient and binding rate parameters) owing to the high intercorrelation between the molecular diffusion coefficient and pseudo-association rate parameter. Attempts to estimate macromolecule mass transport and binding rate parameters simultaneously from FRAP data result in misleading conclusions regarding concentrations of free macromolecule and bound complex inside the cell, average binding time per vacant site, average time for diffusion of macromolecules from one site to the next, and slow or rapid mobility of biomolecules in cells. CONCLUSION: To obtain unique values for molecular diffusion coefficient and binding rate parameters from FRAP data, we propose conducting two FRAP experiments on the same class of macromolecule and cell. One experiment should be used to measure the molecular diffusion coefficient independently of binding in an effective diffusion regime and the other should be conducted in a reaction dominant or reaction-diffusion regime to quantify binding rate parameters. The method described in this paper is likely to be widely used to estimate in-vivo biomolecule mass transport and binding rate parameters

Ovine IgA-reactive proteins from Teladorsagia circumcincta infective larvae

AbstractInfection of small ruminants with Teladorsagia circumcincta has, until now, been controlled using a combination of pasture management and frequent anthelmintic treatments. Resistance to the commonly used anthelmintics has driven research into the development of a subunit vaccine, encouraged by the demonstration of development of protective immunity in sheep following exposure to this parasite. Local immune effectors in the abomasum, in particular IgA, are thought to play important roles in naturally- and experimentally-acquired immunity. L3s represent the first contact of this pathogen with the host immune system and, herein, the presence of L3 antigen-specific IgA was demonstrated in abomasal mucus from immune sheep. This antibody source was used to immunoaffinity purify and identify IgA-reactive molecules present in L3s. We identified 155 different proteins in this way, including a number of activation-associated secretory proteins, venom allergen-like-type proteins, detoxifying enzymes, galectins and a suite of other potential vaccine candidate molecules. Levels of immunoaffinity-enriched L3 antigen-specific IgA in gastric lymph from previously-infected sheep were statistically significantly higher (P=0.004) than those measured in helminth-free sheep and a statistically significant negative correlation (P=0.005, rs=−0.565) was identified between immunoaffinity-enriched L3 antigen-specific IgA levels in efferent gastric lymph and total T. circumcincta burden measured at necropsy. In addition, a statistically significant positive correlation (P=0.007, rs=0.534) was measured between immunoaffinity-enriched L3 antigen-specific IgA levels in efferent gastric lymph and the percentage of inhibited L4s enumerated at necropsy. These results indicate that the purified antigens contain components that could be strongly considered as vaccine candidates

A profitability study of CO2-EOR and subsequent CO2 storage in the North Sea under low oil market prices

© 2017 The Authors. A wide-scale application of CO2-enhanced oil recovery (CO2-EOR) in North Sea oil fields can have many advantages, especially when followed by CO2geological storage. Under the current low oil prices though, even maintaining basic oil production is challenging. A techno-economic assessment is made of the Claymore oil field with the PSS IV simulator, focusing on uncertainty and investment risk. For a stochastic oil price ranging between 10 and 70 €/bbl, a stochastic CO2revenue of -10 to 70 €/t and stochastic reservoir parameters, an average NPV of almost 500 M€ is obtained with a 73% chance on a positive NPV if the investment is made. Disregarding uncertainty relating to the underground by fixing the stochastic reservoir parameters, leads remarkably, but also erroneously, to a lower average NPV. Results also show that geological uncertainty is an important factor for determining the economic threshold level of an EOR project, and a proper assessment of the real uncertainties can make the difference between profit and loss. In case of assuming a fixed CO2revenue at 30 €/t, the probability of implementing EOR becomes higher, but the average NPV and project success rate are significantly lower, at 300 M€ and 63% respectively. This demonstrates that a fixed CO2tax is not a generic CGS enabling solution. It not well-weighted, it can hamper the deployment of certain technologies. A phase of CO2geological storage (CGS) after oil production becomes economically interesting from a CO2revenue of 17€/t. If such a price level can be guaranteed, then continuation of CO2injection can reduce investment risk for both the EOR and CGS investment, reduces the investment hurdle, and can be a catalyzer for large-scale and widespread CO2storage in Europe.status: publishe

Opportunities for a CO2-enhanced oil recovery project in the North Sea: Analysis of profitability and environmental impact

peer reviewedThe economic and environmental impact of an integrated CO2-EOR project in the Buzzard field in the North Sea is investigated through a life cycle analysis, a standard economic analysis and a more advanced geo-economic simulation. Results show the benefits of combining EOR with CO2 storage. However, the current economic environment provides insufficient long-term outlooks to justify the investment. © 2018 European Association of Geoscientists and Engineers, EAGE. All rights reserved

Opportunities for a CO2-enhanced oil recovery project in the North Sea: Analysis of profitability and environmental impact

The economic and environmental impact of an integrated CO2-EOR project in the Buzzard field in the North Sea is investigated through a life cycle analysis, a standard economic analysis and a more advanced geo-economic simulation. Results show the benefits of combining EOR with CO2 storage. However, the current economic environment provides insufficient long-term outlooks to justify the investment