Iterative Deblending of Land Seismic Data

Seismic acquisition is a trade-off between economical and quality considerations. Generally seismic data is recorded with large time delays between illuminating sources in order to avoid interference in time. The consequence is a poorly sampled shot domain. However, in the concept of blended acquisition, the time delay between sources is reduced significantly. Moreover, the sources may transmit encoded signals. Depending on the acquisition objectives, blended acquisition significantly improves the economics or quality or both by adding additional degrees of freedom in the acquisition design. By a deblending procedure, the individual source responses are retrieved. However, the deblended result contains residual noise due to the interference from other sources. The level of this noise depends on the choice of blending parameters. E.g., in the case of a simple code like linear phase encoding (i.e., applying time delays), it is larger than in the case of a more sophisticated code like transmitting sweeps as in vibroseis technology. In this paper an iterative approach is proposed for deblending, based on the estimation and subsequent adaptive subtraction of the interference noise. The type of coding that is applied is one of the factors that determines the required number of iterations.