oa Acquisition and processing of single sensor seismic data

Surface seismic data are normally acquired using arrays of receivers; each array forms a group, which is recorded into a single seismic channel. Two of the main drawbacks of conventional analog arrays are that the outputs of each receiver element are simply summed without any preprocessing and that the spatial sampling is fixed at the survey design stage. A new acquisition system has been developed which can record up to 30,000 channels so each component of the array can be digitised and recorded individually, this is called single sensor recording. The system consists of the acquisition hardware and a suite of software tools for processing the data. Single sensor data will yield improved data quality as improved noise attenuation results from the process of digital group forming (DGF). In addition, eliminating intra-array static variations retains high frequencies lost when statics are averaged in conventional analog arrays. DGF also allows greater flexibility in the processing centre. Output sampling may be varied during processing so different processing schemes can be employed for different temporal and spatial parts of the survey. In a single survey, shot to image multiple targets, the workflow can be optimised for each target. The new system moves us a step closer to decoupling the geophysics of the imaging process from the acquisition hardware and reduces the levels of noise and distortion, which limit the bandwidth of seismic data