Best Seismic Tomography services in India - Parsan

1. What are the Benefits of Seismic Tomography in India? Tomography involves the production of an image of a medium from the data, which are line integrals of the parameter that has to be imaged. Seismic Tomography is the modeling of changes in seismic wave- speed via 3- D mapping. The average structure of the Earth’s surface is made up of layers and we know what the main layers are and the main study of seismic tomography is detecting the variations in how fast the seismic waves travel through the layers, how seismic wave- speed changes its depth and more. Seismic tomography is a technique that is similar to the medical imaging methods like the CAT scan, except the fact that the energy source comes from like drilling or earthquakes instead of from a controlled source like X- rays in CAT Scans. The Borehole seismic data that is collected during and after the drilling of exploration and the appraisal wells provides important and valuable information, which is crucial for the characterization of the reservoir. In combination with the seismic data the Borehole seismic surveys can help in the calibration of results and improve the predictability, as well as the image specific reservoir features found around the borehole. The drill pipe conveyed systems are used for collecting information on seismic velocities during drilling and for predicting lithological changes in advance. The wire- line conveyed tools and systems are used for acquiring high- resolution images for seismic tomography in and beyond the borehole. Functioning of Seismic Tomography Surveys This survey method requires striking a source location with a sledge- hammer that is attached with a trigger, which is further connected to a seismograph. This graph records the recording of the first arrival of the seismic wave at stations, where the receivers (geophones) have been installed. The geophones are mounted to a rib with the help of bolt plates that are drilled, tapped and then surveyed with the help of the mine coordination system. Each of the geophone is hooked to a seismic cable that is connected to the seismograph, and a two pair shielded cable that is used for two purposes: communication and as the trigger for the seismograph. A signal- stacking seismograph is used for recording the P- wave arrivals, and all the seismic data is transferred from the seismograph to personal computer. The travel times that is the first arrivals are picked from the seismic records. All the receiver and the source location coordinates (x, y, z) are added into the spreadsheet and the travel times are further entered into a software program for reconstruction. After the final product is prepared by the software it is presented and interpreted as per the requirement of the survey. Benefits of Seismic Tomography in India •Identification of features like: - Fault Zones

2. - Voids •Mapping of loose zones, sinkholes, anomalous zones in structures such as dams etc. •Study of old foundations The experts at PARSAN have been involved in high resolution seismic tomography surveys for numerous projects across the country, and have been using it for number of new application areas.