Objetivo The main objective is to provide the oil-companies with a new exploration methodology that allow hydrocarbon mapping below volcanic rocks like basalts. Basalts are obscuring current exploration methods to the extent that the results are inadequate and unreliable.The hydrocarbon potential in strata underlying the volcanic rocks are high since these geologic strata are the main reservoirs elsewhere on the European continental shelf where volcanics like basalts are absent. This sub-basalt hydrocarbon potential might be as high as 15 billion TOE.The new methodology will be demonstrated in three full scale field tests selected with varying degree of complexity of the volcanic overburden. This complexity effect the seismic waves with respect to penetration and scattering characteristics and is related to the thickness of the volcanics and of the irregular interface between sediments and volcanics. The penetration is improved by focusing the seismic waves over a large areal aperture and thereby maximizing the energy incident onto the volcanic rock. The scattering is reduced by controlling the directivity of the seismic beam from the areal antennae to illuminate very limited parts of the irregular interface between the sediments and the volcanic rocks.The new methodology consists of a combination of a novel data acquisition and data analysis techniques. The data acquisition will be carried out using source- and receiver-antenna. This will boost the energy incident on the volcanic rock and thereby significantly improve the energy penetration.Findings from computer simulations and experiences from analysing signals from earthquakes suggest that shear-waves have more advantageous propagation characteristics through volcanics than pressure-waves. However shear-waves do not propagate through water. So if shear-waves are to be exploited the receiver antennae will have to be placed on the seabed. A new seabed receiver system consisting of four component sensors (x-,y-,z-geophones and hydrophones) has been developed for this purpose. From computer simulation the main energy leakage for seismic waves travelling through basalts are caused by mode conversions between pressure- and shear-waves. By recording both waves types the total reflected seismic energy is maximized and can be used to map the interfaces between sediments and volcanics.In cases where these interfaces are highly irregular in shape significant energy scattering will occur. With focusing areal antennaes this energy loss is reduced since the antennaes will be focused on the interface between sediments and volcanics. This way only a limited part of the interface will be illuminated and energy scattering reduced.To facilitate this analysis of multi-component recording a new data analysis system has been developed. The system can also synthesize focusing areal antennaes as described above. Parts of the systems has been pattented. In addition special attenuation procedures for reverberations caused by basalts will be applied to suppress the strong coherent noise superimposed on the weak signals from the sub-basaltic reflectors. Ámbito científico natural sciencescomputer and information sciencesdata sciencenatural scienceschemical sciencesorganic chemistryhydrocarbonsnatural sciencesearth and related environmental sciencesgeologyseismologyengineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringsensorsnatural sciencesmathematicsapplied mathematicsmathematical model Programa(s) FP4-NNE-THERMIE C - Specific programme for research and technological development, including demonstration in the field of non-nuclear energy, 1994-1998 Tema(s) 1 - OIL AND GAS Convocatoria de propuestas Data not available Régimen de financiación DEM - Demonstration contracts Coordinador GECO-PRAKLA UK Ltd Aportación de la UE Sin datos Dirección BUCKINGHAM GATE SCHLUMBERGER HOUSE RH6 ONZ Gatwick Reino Unido Ver en el mapa Coste total Sin datos
