The pre-launch Planck Sky Model: a model of sky emission at submillimetre to centimetre wavelengths

We present the Planck Sky Model (PSM), a parametric model for the generation of all-sky, few arcminute resolution maps of sky emission at submillimetre to centimetre wavelengths, in both intensity and polarisation. Several options are implemented to model the cosmic microwave background, Galactic diffuse emission (synchrotron, free-free, thermal and spinning dust, CO lines), Galactic H-II regions, extragalactic radio sources, dusty galaxies, and thermal and kinetic Sunyaev-Zeldovich signals from clusters of galaxies. Each component is simulated by means of educated interpolations/extrapolations of data sets available at the time of the launch of the Planck mission, complemented by state-of-the-art models of the emission. Distinctive features of the simulations are: spatially varying spectral properties of synchrotron and dust; different spectral parameters for each point source; modeling of the clustering properties of extragalactic sources and of the power spectrum of fluctuations in the cosmic infrared background. The PSM enables the production of random realizations of the sky emission, constrained to match observational data within their uncertainties, and is implemented in a software package that is regularly updated with incoming information from observations. The model is expected to serve as a useful tool for optimizing planned microwave and sub-millimetre surveys and to test data processing and analysis pipelines. It is, in particular, used for the development and validation of data analysis pipelines within the planck collaboration. A version of the software that can be used for simulating the observations for a variety of experiments is made available on a dedicated website.Comment: 35 pages, 31 figure

Characterization of dense zones within the Danian chalks of the Ekofisk Field, Norwegian North Sea

The Ekofisk Field is a giant field which has been producing at a high level for more than forty years and, since 1987, this production has taken place with the support of sea-water injection. The Danian-aged chalk deposits of the Ekofisk Formation and the Maastrichtian Tor Formation form the main reservoir units in the Ekofisk Field. The Ekofisk Formation principally consists of porous resedimented chalks intercalated with relatively thin and lower porosity beds, called dense zones. A multi-scale study of dense zones, from scanning electron microscopy to wells and seismic impedance data, has allowed the characterization and mapping of these deposits. Five main dense zone lithotypes have been identified: (1) argillaceous chalk; (2) chalk with abundant flint nodules; (3) chalk beds cemented with silica/nano-quartz; (4) calcite-cemented chalk; and (5) stylolitized chalk. The different types of dense zones tend to cluster in certain stratigraphic intervals, such as the EE and EM reservoir units at the base and in the middle part of the Ekofisk Formation. Dense zones have different mechanical properties compared to porous chalks and, depending on the connectivity of their fracture networks, they can act as preferential conduits or baffles for the reservoir fluids. An increased understanding of the distribution, characteristics and geological factors at the origin of the dense zones is fundamental to better define the reservoir architecture and ultimately identify unswept zones for future infill drilling targets. © 2013 EAGE/Geological Society of London.status: publishe

Characterization of dense zones within the Danian chalks of the Ekofisk Field, Norwegian North Sea

<p>The Ekofisk Field is a giant field which has been producing at a high level for more than forty years and, since 1987, this production has taken place with the support of sea-water injection. The Danian-aged chalk deposits of the Ekofisk Formation and the Maastrichtian Tor Formation form the main reservoir units in the Ekofisk Field. The Ekofisk Formation principally consists of porous resedimented chalks intercalated with relatively thin and lower porosity beds, called dense zones. A multi-scale study of dense zones, from scanning electron microscopy to wells and seismic impedance data, has allowed the characterization and mapping of these deposits. Five main dense zone lithotypes have been identified: (1) argillaceous chalk; (2) chalk with abundant flint nodules; (3) chalk beds cemented with silica/nano-quartz; (4) calcite-cemented chalk; and (5) stylolitized chalk. The different types of dense zones tend to cluster in certain stratigraphic intervals, such as the EE and EM reservoir units at the base and in the middle part of the Ekofisk Formation. Dense zones have different mechanical properties compared to porous chalks and, depending on the connectivity of their fracture networks, they can act as preferential conduits or baffles for the reservoir fluids. An increased understanding of the distribution, characteristics and geological factors at the origin of the dense zones is fundamental to better define the reservoir architecture and ultimately identify unswept zones for future infill drilling targets. </p