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[en] A forward model was constructed to numerically predict surface subsidence and reservoir compaction following the approach of Segall [Pure Appl. Phys. 139 (1992) 536]. A nucleus of poroelastic strain is numerically integrated over a rectangular prism assuming constant pressure change. This fundamental geometry allows a reservoir to be divided into many small cubic blocks in a manner similar to reservoir simulation. The subsidence and compaction effects of the pressure change throughout the reservoir are calculated by the superposition of results from each individual block. Using forward modeling, pressure boundary conditions can be acquired from pressure test data or reservoir simulation predictions. An inversion model also was developed that can track pressure fronts in a subsurface reservoir using surface displacements. The capability of the inversion model was demonstrated using synthetic examples of one-well and four-well cases with different layouts of surface observation locations. The impact of noise on the inversion result is also included
[en] This paper describes some new techniques for stochastic modeling of three-dimensional fracture networks. We use geostatistical simulation methods to reproduce features of the spatial structure of the rock such as the variation of fracture density and fracture orientation in space. For an example of the method we use mapped fracture data from the Fanay-Augeres mine, in Limousin, France. Two different sections of a drift wall, S1 and S2, were mapped. The S1 section is wet, and the S2 section is dry. For each case, the fractures are divided into five different sets and each set is modeled separately. The fractures in each set are represented as discs placed randomly in space. The diameter of each disc is chosen independently from a fixed probability distribution determined from the trace length distribution. For the location of discs a point process called the parent-daughter process is used. This process gives a clumping or swarming of fractures not found in the usual Poisson model. The orientation of the discs is characterized as a fluctuation about the mean orientation for the set. This fluctuation has a spatial structure that is simulated with geostatistics. Geostatistical simulations of the two fracture systems are under way. The connectivities of the simulations will be assessed to see if there is any correlation with the fact that the S1 section of drift is wet and the S2 section is dry
[en] Studies on Paleontological heritage of Majorca (Balearic archipelago, West Mediterranean) allow to divide the post-tectonic Miocene into depositional cycles separated by sedimentary discontinuities. In this work these sequences are ordered according to Mediterranean glacio-eustatic oscillations. The Tortonian marine cycle end with a restricted lagoon record with grey sapropelic marls and an erosive surface (T/M episode). The marine Messinian transgression starts with a new marine-tidal cycle (entry of Globorotalia mediterranea. MI Synthem-Fm. Calizas de Santanyí) with four diverse records (infralittoral, mangrove-low coastal lagoon etc.) depending on the influence of the emerged relief. The last Messinian Salinity Crisis (MSC) is characterized with a new restricted record and a singular Lagomare fauna (MII-Fm. Calizas Pont d’Inca; MIII-Fm. Margas y conglomerados de RafalSon Seguí) The resulting paleoenvironmental diversity supports the proposed stratigraphic interpretation. This work thus proposes the differentiation of a tidal marine messinian cycle for the last Miocene of Mallorca, between two restricted episodes. The Majorcan messinian record documents the distension experienced by the Balearic arc according to the influence of relief, which can provide new perspectives regarding the MSC-Lagomare and the settlement of the archipelago in the Messinian age.
[es]Los estudios en el patrimonio paleontológico de Mallorca (archipiélago Balear, Mediterráneo occidental) posibilitan dividir el Mioceno postectónico de la isla en secuencias deposicionales separadas por discontinuidades sedimentarias. Estas se han ordenado de acuerdo con las oscilaciones glacio-eustáticas mediterráneas. El finitortoniense documentado comprende margas lagunares y superficie erosiva (T/M). La transgresión marina posterior se inicia con un nuevo ciclo litoral/mareal (entrada de Globorotalia mediterranea. Messiniense I-MI-Fm. Calizas de Santanyí) y con hasta 4 registros sedimentarios distintos según influencia del relieve emergido. La crisis finimessiniense se manifiesta con nuevos registros restringidos y nuevo ciclo litoral con fauna marina brackish-Lagomare (Sintema MII-Fm. Calizas Pont d’Inca; Sintema MIII-Fm. Margas y conglomerados de Rafal-Son Seguí). La ordenación estratigráfica propuesta se refuerza con una primera interpretación paleoambiental. Para el finimioceno de Mallorca este estudio ha supuesto la diferenciación de un ciclo litoral mareal messiniense entre dos episodios restringidos. El registro messiniense estudiado documenta la distensión del relieve emergido y aporta nuevas perspectivas para interpretar la crisis de salinidad mediterránea (registro de cuenca marginal) y el poblamiento finimioceno del archipiélago.
[en] Consideration is given to the tectonic patterns expected on the surface of a synchronously rotating planet or satellite as a result of tidal deformation by the primary. The lithosphere of the satellite is treated as a thin elastic shell which maintains the equilibrium shape of a tidally distorted body, with stresses developing as the equilibrium shape changes during orbital evolution. Tectonic patterns are then obtained by the use of the relation of Anderson (1951) between stress and faulting. The predicted pattern for a body such as the moon, which has receded from the earth, is found not to be rotationally symmetric, with a region of north-south striking thrust faults around the sub-earth point and its antipode, normal faults striking from the near side to the far side at the polar regions, and strike slip faults near the limbs. It is pointed out that little photogeological evidence exists at present for these faults on the moon, however the crucial polar regions have not been mapped well the patterns may also be evident on the Galilean satellites of Jupiter
[en] Full text: This paper is a case history of the improved characterization of a complex structure in the Azerbaijan offshore achieved by application of advanced seismic tools such as 3 D Pre-Stack Depth Migration and Continuity Depth Cube volumes.The investigation focuses on the Kurdashi Permit and adjacent areas of southern most Azerbaijan, near its boundary with Iran (Fig.1).It considers the techniques used to visualize the subsurface, the resulting subsurface model and implications for its geological history revealed by the more detailed seismic tools.The Kurdashi Permit is operated by AGIP AZERBAIJAN, a subsidiary of the Italian ENI Agip Division.The permit itself encompasses a faulted regional anticlinorium of Neogene series clastic rocks comprising three separate culminations.Seismic imaging in this area is challenged by widespread shallow or near-surface gas, steep dips, and mud volcanoes connected to irregularly shaped mud chambers and associated velocity anomalies.Targets are relatively deep measured in TWT due to both their actual depth and the relatively slow velocities of the sedimentary section.A 3D seismic survey covering about 900 sq km was acquired by Caspian Geophysical over the entire permit.The conventional time processing was executed by Veritas.Subsequently AGIP generated a 3D Pre-Stack Depth Migration and Continuity Cube and the relevant interpretations.
[en] Data have gradually been accumulated on the physical properties of nuclear test sites at the U. S. Energy Research and Development Administration (USERDA) Nevada Test Site (NTS) since underground testing began there in 1957. These data have been stored in the Lawrence Livermore Laboratory (LLL) K-Division Test Effects Data Bank. This report briefly describes the principal test areas Yucca Flat, Pahute Mesa, and Rainier Mesa) and media (alluvium, tuff, Climax Stock (granite) and Paleozoic rocks) at NTS. Background information is given on the data base and the various methods used to measure geophysical parameters at NTS are described. The mean, standard deviation, and range of values for each test area and medium are given. However, specific properties for individual sites are not contained in this report. Properties for which averages are given include overburden and working-point density; seismic velocity both near the working point and from the working point to the surface; and water content, porosity, and water saturation of the rocks in the working point vicinity
[en] The purpose of this paper is to present the results of preliminary assessment on the orbitolinids discovered for the first time from an isolated hillock (locally known as Peinyoin Hill) situated at just northwest of Lebyin village (lying on the Thazi-Shwenyaung Rail Road), and from the limestone lenses embedded within a sequence of tuffaceous sandstone, mudstone and conglomerates that is exposed on the west of the Myit-thar Stream. The present preliminary examination reveals that the orbitolinid fauna at the limestone hillock consists of Paracoskinolina cf. sunnilandensis Iraqia sp., and Simplorbitolina spp., indicating an early Cretaceous age (probably Aptian-Albian). On the other hand, the limestone lenses exposed on the west of the Myit-thar Stream bear Iraqia thailandensis (=Haurania thailandensis Kemper]. From this faunal evidence and prevailing lithostratigraphic characteristics, it has reached to the final conclusion that these controversial outcrops are no longer needed to be lumped in the Late Paleozoic Lebyin Group in the Plateau Limestone Group, but must be designated as a southern continuation of the Pan Laung Formation of Jurassic-Cretaceous age. (author)
[en] The application of the seismological and geological knowledge of the area has of late gained importance in the methods of calculating the seismic hazard to the locality selected for the construction of a nuclear power plant. Next to the seismostatic estimate of the magnitude of the maximum calculated earthquake it is also necessary to incorporate in the calculation seismological criteria specifying this value. This includes the determination of the time behaviour of ground motion in the given locality owing to the effects of an earthquake. This is mainly the time course of acceleration, i.e., the accelerogram which determines the scale of antiseismic measures for structures. As on the territory of Czechoslovakia the direct measurement of strong effects of earthquakes practically does not come into consideration, such approach has to be selected which is founded on the determination of analogical accelerograms. (Z.M.)