Objetivo The project is aimed at demonstrating the innovative SEISBIT 3D RVSP technology developed by OGS, ENI-AGIP and PROSOL, which uses the drill bit noise for 3D onshore seismic while drilling applications. This goal will follow from two applications executed around wells drilled with roller cone bits, aimed at obtaining 3D multiple-level reverse vertical seismic profiles (RVSP) with a relevant number of surface channels and depth levels, and at using the while drilling data for 3D velocity investigation and imaging.For this purpose it is necessary to test in the field and tune the improved SEISBIT 3D-RVSP technology, by refining the acquisition and processing tools : using an innovative and modular acquisition system suited to acquire 3D data with multiple acquisition cards and multiple-line configurations at the surface, using redundancy to reduce the operational risks due to the non-repeatability of the while drilling measurements.The project is in its initial starting phase. Nevertheless, preliminary results obtained using far offset suborthogonal seismic lines during conventional well surveys demonstrated the separation of drill bit signal and coherent noise for 3D seismic while drilling investigations.The application of SEISBIT 3D RVSP will be done around onshore ENI-AGIP wells in Italy, to illuminate while drilling the surrounding area, thus obtaining a 3D imaging and data sets utilisable in deferred processing to recover detailed structural 3D information. The process consists of the following steps :1) method revision and planning of the 3D applications, including a geophysical feasibility study using modelling and imaging to design receivers lines circular and diametrical with respect to the "vertical antenna" drill bit source in the well; 2) technical revision and preparation of the system; 3) acquisition phase during drilling with roller cone bits, using the 3D SWD data to investigate the 3D velocity information and model; 4) processing multioffset RVSP to get reference 2D seismic imaging; 5) 3D WD imaging using RVSP data with offset continuation for irregular receiver position and migration; 6) any reprocessing of the 3D data volume to get information utilisable for further drilling phases (such as before side tracking); 7) method and technology revision for cost saving; 8) results diffusions and reporting. To this aim, the proposers plan to acquire two SEISBIT 3D RVSP surveys with many surface seismic channels and many depth levels, in order to allow 3D robust wave field analysis and separation. The acquisition layout, will depend on the target and on the parameters of the investigated drilling phase, such as expected rate of penetration (ROP) and total phase duration, due to limits on the total cost of the surface telemetric equipment rental. A typical target is 4000 m depth, with a covered surface area of about 2000 meters radius. To achieve this goal, the SEISBIT technology realised by OGS and ENI-AGIP in co-operation with PROSOL, and already demonstrated in 2D, has been substantially modified and reinforced to manage independent telemetric lines in 3D configurations. 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 OSSERVATORIO GEOFISICO SPERIMENTALE (OGS) TRIEST Aportación de la UE Sin datos Dirección BORGO GROTTA GIGANTE N. 42/C 34010 Sgonico Italia Ver en el mapa Coste total Sin datos
