scholarly journals Modelling of the Long-Term Acid Gas Sequestration and Its Prediction: A Unique Case Study

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4701
Author(s):  
Wiesław Szott ◽  
Piotr Łętkowski ◽  
Andrzej Gołąbek ◽  
Krzysztof Miłek
Keyword(s):  
Geological Structure ◽  
Monitoring Data ◽  
Large Set ◽  
Unique Case ◽  
Acid Gas ◽  
Gas Leakage ◽  
Simulation Results ◽  
Basic Characteristics

A twenty-four-year on-going project of acid gas sequestration in a deep geological structure was subject to detailed modelling based upon a large set of geological, geophysical, and petrophysical data. The model was calibrated against available operational and monitoring data and used to determine basic characteristics of the sequestration process, such as fluid saturations and compositions, their variation in time due to fluid migrations, and the gas transition between free and aqueous phases. The simulation results were analysed with respect to various gas leakage risks. The contribution of various trapping mechanisms to the total sequestrated amount of injected gas was estimated. The observation evidence of no acid gas leakage from the structure was confirmed and explained by the simulation results of the sequestration process. The constructed and calibrated model of the structure was also used to predict the capacity of the analysed structure for increased sequestration by finding the optimum scenario of the risk-free sequestration performance.

Long-term sequestration process in the Borzęcin structure – observation evidence of the injected acid gas migration and possible leakage

2020 ◽  
Author(s):  
Jan Lubaś ◽  
Wiesław Szott ◽  
Piotr Łętkowski ◽  
Andrzej Gołąbek ◽  
Krzysztof Miłek ◽  
...  
Keyword(s):  
Ground Surface ◽  
Gas Migration ◽  
Acid Gas ◽  
Gas Leakage ◽  
Additional Information ◽  
Well Completion ◽  
Future Performance ◽  
Structure Observation ◽  
Basic Characteristics

The monograph presents the results of research carried out under the European SECURe (Subsurface Evaluation of CCS and Unconventional Risks) project in the years 2018-2020. A significant part of the SECURe project comprised evaluation of the effects of the long-term CO₂-H₂S sequestration process in the Borzęcin reservoir structure. This monograph includes all historical operational data determining assumed and implemented parameters of the process and various tests and analyses performed on downhole, as well as surface samples of reservoir fluids, taken from selected wells of the structure. They were aimed at identifying the propagation and intensity of acid gas migration within the structure and potential leakage pathways towards the ground surface. Some of the tests such as analysis of soil gas samples or samples of gas dissolved in brine have never been conducted before, and provided additional information on the safety of geological storage of acid gases within the Borzęcin structure. Corrosion potentials of well tubing and cement were also examined and analysed as they are crucial factors of well completion and leakage prevention. Key components of performed studies and analyses included a simulation model of the Borzęcin structure, constructed from a broad set of geological, geophysical and petrophysical data. The model was calibrated against available operational and measured data, and used to determine basic characteristics of the sequestration process such as: fluid saturations and compositions, their variation in time due to fluid migrations and the transition between various phases. The observation evidence indicating the absence of acid gas leakage from the Borzęcin structure was confirmed and explained by the simulation results of the sequestration process. The constructed and calibrated model of the structure was also used to predict the future performance of the current sequestration project. In addition, the capacity of the Borzęcin structure for increased sequestration was assessed by finding the optimum scenario of the risk-free sequestration performance.

scholarly journals Simulated Fishing to Untangle Catchability and Availability in Fish Abundance Monitoring

2021 ◽  
Vol 19 (3) ◽  
Author(s):  
Vanessa Tobias ◽  
Keyword(s):  
San Francisco ◽  
Water Clarity ◽  
Ecological Monitoring ◽  
Monitoring Data ◽  
Delta Smelt ◽  
Individual Based Simulation ◽  
The Relationship ◽  
True Population

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are the result of changing water clarity affecting catchability.

scholarly journals Simulated Fishing to Untangle Catchability and Availability in Fish Abundance Monitoring

2021 ◽  
Author(s):  
Vanessa Tobias
Keyword(s):  
San Francisco ◽  
Water Clarity ◽  
Ecological Monitoring ◽  
Monitoring Data ◽  
Delta Smelt ◽  
Individual Based Simulation ◽  
The Relationship ◽  
True Population

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear that is used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well-monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are due to an effect of changing water clarity on catchability.

Selection of indicator species for State of the Environment reporting: A case study from New Zealand

2010 ◽  
Vol 16 (2) ◽  
pp. 76 ◽  
Author(s):  
Joanne M. Hoare ◽  
Colin F. J. O’Donnell ◽  
Elaine F. Wright
Keyword(s):  
New Zealand ◽  
Indicator Species ◽  
Species Concepts ◽  
Monitoring Data ◽  
Environmental Reporting ◽  
Environmental Attributes ◽  
State Of The Environment ◽  
Selection Of

Indicator species approaches are widely used in conservation as a shortcut to measuring attributes of species and ecosystems. A variety of indicator species concepts are in use and are applicable to a range of situations. Indicator species are increasingly being used in environmental reporting to evaluate trends in environmental attributes quantitatively. We use the most recent State of the Environment report from New Zealand as a case study to evaluate: (1) how indicator species concepts are being applied to environmental reporting and (2) the selection of individual species as indicators. At present indicator species used in environmental reporting in New Zealand reflect biases in national monitoring data towards forest-dwelling, terrestrial vertebrates that are vulnerable to predation by introduced mammals. Scientific literature generally supports links between selected taxa and the aspect of ecosystem health they are purported to indicate, but their roles as long-term indicators of environmental health have yet to be evaluated. A primary goal of State of the Environment reporting is to set a benchmark against which environmental outcomes can be monitored over time; thus it is recognized that taxa reported should represent a broader range of environmental attributes. However, selection of taxa for environmental reporting is severely constrained by limited national species monitoring data. A strategic approach to national measurement, storage and analysis of long-term monitoring data is required to support selection of representative species for environmental reporting. We support current initiatives to select taxa for future measurement and reporting in an objective, transparent manner and recommend that they encompass representation of: (1) taxonomic diversity, (2) ecosystem types, (3) key environmental pressures and (4) threat status.

scholarly journals A Case Study of Casework Tinkering

2018 ◽  
Vol 5 (2) ◽  
pp. 57-71 ◽  
Author(s):  
Maj Nygaard-Christensen ◽  
Bagga Bjerge ◽  
Jeppe Oute
Keyword(s):  
Ad Hoc ◽  
Welfare System ◽  
Care Work ◽  
Short Term ◽  
Unique Case ◽  
Complex Problems ◽  
Single User ◽  
To Receive

Citizens with complex problems are often in touch with different welfare services and administrative systems in order to receive the help, they need. Sometimes these services overlap and sometimes they conflict. The lack of ready-made services to match the complex, multiple, and often shifting needs of citizens with complex problems presents a challenge to caseworkers in the welfare system. In this article, we zoom in on the management of a single user´s case, in order to examine in detail how caseworkers nevertheless make casework ‘work’. We employ the concept of ‘tinkering’ to highlight the ad hoc and experimental way in which caseworkers work towards adjusting services to the unique case of such citizens. Tinkering has previously been used in studies of human-technology relations, among others in studies of care-work in the welfare system. In this paper, we employ the concept to capture and describe a style of working that, although not a formally recognized method, might be recognizable to many caseworkers in the welfare system. We show how tinkering involves the negotiation of three topics of concern, namely the availability of services, the potentials of services to be adjusted to the particular problems of the citizen, and finally, the potential for interpreting these problems and the citizen’s needs in a way that they match the service. We further demonstrate that casework tinkering involves both short-term and long-term negotiation of services. Firstly, tinkering is involved in the continual adjustment and tailoring of services to the immediate needs of the citizen, but secondly, it also speaks to a more proactive process of working towards a more long-term goal.

A Framework for Using Dynamic Modeling to Support Lean Sustainment in a Complex Setting

2021 ◽  
pp. 91-110
Author(s):  
Marc Haddad ◽  
Rami Otayek
Keyword(s):  
Systems Thinking ◽  
System Performance ◽  
Demand Uncertainty ◽  
Integrated Approach ◽  
Dynamics Modeling ◽  
Work In Process ◽  
Simulation Results ◽  
Thinking Tools

This chapter proposes a framework for integrating lean and systems thinking tools to explore the dynamics of lean implementations in manufacturing. The value of this integrated approach is in supplementing the operational level principles of lean with the strategic outlook of systems thinking to mitigate adverse impacts of operational complexity on system performance. In particular, the focus of the framework is to enable the sustainment of lean gains in the long-term, a major challenge in manufacturing settings. The application of the framework is illustrated with a case study of a lean implementation for reducing work-in-process (WIP) at a clothing manufacturer dealing with a number of operational complexities such as demand uncertainty, a high product mix and inefficient processes. The case study highlights the usefulness of system dynamics modeling in revealing counterintuitive system behaviors that could compromise the success of the lean initiative. The simulation results demonstrate the application of the framework for sustaining lean implementations in practice.

scholarly journals Inclinometer monitoring system for stability analysis: the western slope of the Bełchatów field case study

2016 ◽  
Vol 38 (2) ◽  
pp. 3-13 ◽  
Author(s):  
Marek Cała ◽  
Joanna Jakóbczyk ◽  
Katarzyna Cyran
Keyword(s):  
Geological Structure ◽  
Western Slope ◽  
The North ◽  
Geotechnical Monitoring ◽  
Slip Surfaces ◽  
North Part ◽  
Horizontal Displacements ◽  
Sedimentation Processes

Abstract The geological structure of the Bełchatów area is very complicated as a result of tectonic and sedimentation processes. The long-term exploitation of the Bełchatów field influenced the development of horizontal displacements. The variety of factors that have impact on the Bełchatów western slope stability conditions, forced the necessity of complex geotechnical monitoring. The geotechnical monitoring of the western slope was carried out with the use of slope inclinometers. From 2005 to 2013 fourteen slope inclinometers were installed, however, currently seven of them are in operation. The present analysis depicts inclinometers situated in the north part of the western slope, for which the largest deformations were registered. The results revealed that the horizontal displacements and formation of slip surfaces are related to complicated geological structure and intensive tectonic deformations in the area. Therefore, the influence of exploitation marked by changes in slope geometry was also noticeable.

scholarly journals Simulated Fishing to Untangle Catchability and Availability in Fish Abundance Monitoring

2021 ◽  
Author(s):  
Vanessa Tobias
Keyword(s):  
San Francisco ◽  
Water Clarity ◽  
Ecological Monitoring ◽  
Monitoring Data ◽  
Delta Smelt ◽  
Individual Based Simulation ◽  
The Relationship ◽  
True Population

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear that is used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well-monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are due to an effect of changing water clarity on catchability.

scholarly journals Simulated Fishing to Untangle Catchability and Availability in Fish Abundance Monitoring

2020 ◽  
Author(s):  
Vanessa Tobias
Keyword(s):  
San Francisco ◽  
Water Clarity ◽  
Ecological Monitoring ◽  
Monitoring Data ◽  
Delta Smelt ◽  
Individual Based Simulation ◽  
The Relationship ◽  
True Population

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear that is used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well-monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are due to an effect of changing water clarity on catchability.

scholarly journals Optimization of Construction Parameters and Deformation Characteristics of Large-Section Loess Tunnel: A Case Study from Xi’an Metro

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Mingji Zhao ◽  
Yun Cheng ◽  
Zhanping Song ◽  
Tong Wang ◽  
Yuwei Zhang ◽  
...  
Keyword(s):  
Numerical Model ◽  
High Reliability ◽  
Geological Structure ◽  
Surface Settlement ◽  
Monitoring Data ◽  
Horizontal Deformation ◽  
Large Section ◽  
Construction Monitoring ◽  
Initial Support

Loess geological tunnels are characterized by weak geological structure and poor self-stability of surrounding rock, so effectively controlling the excavation face distances of different caverns is of great significance for guiding the safe construction of large-section tunnels. Based on the excavation of large-section loess tunnel from Xi’an Metro Line 4, the optimal excavation face distance is determined based on Midas numerical model. Then, the surface settlement and horizontal deformation are analyzed based on monitoring data, and, finally, the rationality of excavation face distance is verified. The results show that the influence of excavation face distance on surface settlement, vault settlement, and horizontal deformation is consistent. The surface settlement mainly occurs in the range of −20∼20 m from the tunnel centerline and the settlement trough formed has asymmetric characteristics. The vault settlement and horizontal deformation undergo first a rapid settlement and then a slow settlement. The connection between initial support and middle partition is mainly tensile stress and the middle and bottom parts of the supporting structure are mainly compressive stress. Numerical results suggest that the optimal excavation faces distance of L1, L2, and L3 which can be 4, 9, and 9 m, respectively. Construction monitoring data show that the double-sides heading method has a significant effect on surface settlement, vault settlement, and horizontal deformation. The surface settlement occurs within the range of −17∼6 m from the tunnel centerline. The maximum vault settlement and horizontal deformation are 73.00% and 65.50% of the maximum allowable. It can be seen that the actual excavation parameters optimized by Midas numerical model have high reliability.

Sign in / Sign up

Export Citation Format

Share Document