This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Gravity stable injection of immiscible Nitrogen into steeply dipping, high permeable reservoirs c... more Gravity stable injection of immiscible Nitrogen into steeply dipping, high permeable reservoirs can recover substantial quantities of oil which are not recoverable by water flooding. Gravity stable gas displacement presents a complicated problem in reservoir engineering.
Publisher Summary Depleted oil and gas reservoirs are candidates for underground CO2 storage. The... more Publisher Summary Depleted oil and gas reservoirs are candidates for underground CO2 storage. The Roar field is a high-porosity, low-permeability chalk carbonate reservoir in the Danish North Sea, and a detailed reservoir model has been used for a simulation study of the influencing factors during CO2 injection. Roar is an anticlinal structure, induced through tectonic uplift. The reservoir is located at a depth of 2000 m and covers an area of 14 km2. The reservoir rock is chalk, with porosities in the range of 35–45% and matrix permeability between 0.01 and 10 mD. There are only a few significant natural fractures. Some of the promising geological structures for underground CO2 storage are depleted or nearly depleted oil and gas reservoirs. Most Danish hydrocarbon reservoirs are composed of chalk carbonate characterized by very low matrix permeabilities, which may cause concern that the injectivity is prohibitively low. The accumulation consists of free gas and a thin oil zone. The gas contains condensate. The ECLIPSE reservoir simulator is used to predict the state of the reservoir after 16 years of production and to model the subsequent injection of CO2 over a period of 30 years. Various CO2 injection scenarios have been simulated and a number of factors and parameters are identified which have a considerable influence on the field injectivity and simulated results. The advantage of selecting a gas field for CO2 storage rather than an oil field is that the top seal integrity will not be challenged to the same extent, because the pressure difference across the seal upon CO2 flooding will be comparable to the initial difference prior to reservoir depletion.
Greenhouse Gas Control Technologies - 6th International Conference, 2003
Publisher Summary The carbon dioxide sequestration policy is often based on the volume estimation... more Publisher Summary The carbon dioxide sequestration policy is often based on the volume estimation of (depleted) reservoirs or aquifers multiplied with a sweep efficiency factor. In this approach, the local processes involved in CO2 injection are not taken into account. One of the targets of European Potential for Geological Storage of Carbon Dioxide from Fossil Fuel Combustion (GESTCO) is to carry out a number of case studies in a broad spectrum of natural circumstances. So, experience could be acquired in the behavior of the local injection processes and in the resulting sequestrated CO2 volume. For this target, simulation studies of 12 real cases were carried out. The choice of these case studies was diverse in geographical as in operational respect. The cases originate from diverse geological situations—sandstone, chalk and dolomite reservoirs. Depth ranges from 1220 to 1970 m and reservoir pore fills are water, gas and oil. For each case, a numerical model study was carried out of the injection of CO2, using the well facilities available. In many cases, an existing reservoir input set was reused. In other cases, the spatial and geological characteristics, parameters, fluid presence, and properties had to be estimated. The results of these case studies in terms of injection capacity have a large range. These differences are the result of the many factors influencing the injection capacity for CO2, of which the injection pressure is the major factor.
International Journal of Greenhouse Gas Control, 2018
This manuscript has been reproduced from the microfilm master. UMI films the text directly from t... more This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction.
The presented modeling study illustrates how even small-scale heterogeneity has implications for ... more The presented modeling study illustrates how even small-scale heterogeneity has implications for how the CO 2 is distributed and trapped in sedimentary sequences, and outlines a workflow for the study of these effects. The starting point for the study is a 2D model for crossbedded shallow-marine/tidal sands with 8 sediment classes, ranging from high-permeable sand to low permeable clay included as thin layers. The very small grid cell size of 3.5 mm ensures that the sedimentary details and contrasts are reflected in the petrophysical model. The initial flow simulation results show that in addition to the capillary trapped CO 2 which remains after an imbibition process and which is caused by well explained hysteresis, some is also arrested by the architecture of the low-permeability layers due to permeability and capillary heterogeneity and this fraction becomes partly or fully immobilized. This contribution from heterogeneity trapping could add an element of increased containment safety and may in some cases add hyper-trapping capacity exceeding the prior established endpoint values from the saturation functions normally used to reflect the process in the simulations as well as in other more simple capacity estimates.
In a previous project swirl stabilized pulverized-coal flames were investigated experimentally in... more In a previous project swirl stabilized pulverized-coal flames were investigated experimentally in Risoe National Laboratory`s 1.3 MW tunnel furnace. Different flame types were obtained by varying the swirl number and the position of the movable coal lance. By means of laser techniques as well as conventional methods a comprehensive set of data was obtained. The resulting detailed mapping of local gas velocity, temperature and composition including inlet profiles are well suited for the assessment and verification of numerical simulation models. In the work described in the present paper three of the pulverized-coal flames measured during the above mentioned project have been modeled by means of the computational fluid dynamics code FLOW3D release 3.2 developed by Harwell Laboratory. Observations and conclusions are presented regarding the performance of mathematical models and numerical methods employed in the code and the calculated results are compared to the measurements. It is c...
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Gravity stable injection of immiscible Nitrogen into steeply dipping, high permeable reservoirs c... more Gravity stable injection of immiscible Nitrogen into steeply dipping, high permeable reservoirs can recover substantial quantities of oil which are not recoverable by water flooding. Gravity stable gas displacement presents a complicated problem in reservoir engineering.
Publisher Summary Depleted oil and gas reservoirs are candidates for underground CO2 storage. The... more Publisher Summary Depleted oil and gas reservoirs are candidates for underground CO2 storage. The Roar field is a high-porosity, low-permeability chalk carbonate reservoir in the Danish North Sea, and a detailed reservoir model has been used for a simulation study of the influencing factors during CO2 injection. Roar is an anticlinal structure, induced through tectonic uplift. The reservoir is located at a depth of 2000 m and covers an area of 14 km2. The reservoir rock is chalk, with porosities in the range of 35–45% and matrix permeability between 0.01 and 10 mD. There are only a few significant natural fractures. Some of the promising geological structures for underground CO2 storage are depleted or nearly depleted oil and gas reservoirs. Most Danish hydrocarbon reservoirs are composed of chalk carbonate characterized by very low matrix permeabilities, which may cause concern that the injectivity is prohibitively low. The accumulation consists of free gas and a thin oil zone. The gas contains condensate. The ECLIPSE reservoir simulator is used to predict the state of the reservoir after 16 years of production and to model the subsequent injection of CO2 over a period of 30 years. Various CO2 injection scenarios have been simulated and a number of factors and parameters are identified which have a considerable influence on the field injectivity and simulated results. The advantage of selecting a gas field for CO2 storage rather than an oil field is that the top seal integrity will not be challenged to the same extent, because the pressure difference across the seal upon CO2 flooding will be comparable to the initial difference prior to reservoir depletion.
Greenhouse Gas Control Technologies - 6th International Conference, 2003
Publisher Summary The carbon dioxide sequestration policy is often based on the volume estimation... more Publisher Summary The carbon dioxide sequestration policy is often based on the volume estimation of (depleted) reservoirs or aquifers multiplied with a sweep efficiency factor. In this approach, the local processes involved in CO2 injection are not taken into account. One of the targets of European Potential for Geological Storage of Carbon Dioxide from Fossil Fuel Combustion (GESTCO) is to carry out a number of case studies in a broad spectrum of natural circumstances. So, experience could be acquired in the behavior of the local injection processes and in the resulting sequestrated CO2 volume. For this target, simulation studies of 12 real cases were carried out. The choice of these case studies was diverse in geographical as in operational respect. The cases originate from diverse geological situations—sandstone, chalk and dolomite reservoirs. Depth ranges from 1220 to 1970 m and reservoir pore fills are water, gas and oil. For each case, a numerical model study was carried out of the injection of CO2, using the well facilities available. In many cases, an existing reservoir input set was reused. In other cases, the spatial and geological characteristics, parameters, fluid presence, and properties had to be estimated. The results of these case studies in terms of injection capacity have a large range. These differences are the result of the many factors influencing the injection capacity for CO2, of which the injection pressure is the major factor.
International Journal of Greenhouse Gas Control, 2018
This manuscript has been reproduced from the microfilm master. UMI films the text directly from t... more This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction.
The presented modeling study illustrates how even small-scale heterogeneity has implications for ... more The presented modeling study illustrates how even small-scale heterogeneity has implications for how the CO 2 is distributed and trapped in sedimentary sequences, and outlines a workflow for the study of these effects. The starting point for the study is a 2D model for crossbedded shallow-marine/tidal sands with 8 sediment classes, ranging from high-permeable sand to low permeable clay included as thin layers. The very small grid cell size of 3.5 mm ensures that the sedimentary details and contrasts are reflected in the petrophysical model. The initial flow simulation results show that in addition to the capillary trapped CO 2 which remains after an imbibition process and which is caused by well explained hysteresis, some is also arrested by the architecture of the low-permeability layers due to permeability and capillary heterogeneity and this fraction becomes partly or fully immobilized. This contribution from heterogeneity trapping could add an element of increased containment safety and may in some cases add hyper-trapping capacity exceeding the prior established endpoint values from the saturation functions normally used to reflect the process in the simulations as well as in other more simple capacity estimates.
In a previous project swirl stabilized pulverized-coal flames were investigated experimentally in... more In a previous project swirl stabilized pulverized-coal flames were investigated experimentally in Risoe National Laboratory`s 1.3 MW tunnel furnace. Different flame types were obtained by varying the swirl number and the position of the movable coal lance. By means of laser techniques as well as conventional methods a comprehensive set of data was obtained. The resulting detailed mapping of local gas velocity, temperature and composition including inlet profiles are well suited for the assessment and verification of numerical simulation models. In the work described in the present paper three of the pulverized-coal flames measured during the above mentioned project have been modeled by means of the computational fluid dynamics code FLOW3D release 3.2 developed by Harwell Laboratory. Observations and conclusions are presented regarding the performance of mathematical models and numerical methods employed in the code and the calculated results are compared to the measurements. It is c...
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