oa Multi-survey acquisition and processing in the Nile Delta

The challenges associated with acquiring and processing multi-environment data in Egypt’s Nile Delta are presented. In 2006, approximately 1,200 square km of new land, transition (TZ) and ocean-bottom cable (OBC) seismic data were added to approximately 1,600 square km of existing data in the western Nile Delta. Two contractors, operating in concert with two recording systems, three source types, and four different detector types proved operationally challenging but not impossible to coordinate. Continuous processing of the field data resulted in several fast-track volumes providing interpreters with new data to analyze. Following the successful acquisition and delivery of preliminary processing volumes, the project area was expanded considerably to include data from adjoining surveys. Merging the newly acquired land, TZ, and OBC 3-D seismic data with existing multi-vintage streamer and OBC data provides nearly 3,000 square km of continuous data for pre and post data interpretation and analysis. There are, however, significant data processing challenges in producing a continuous volume. The challenges included deriving a consistent demultiple solution for adjoining land, OBC and towed marine data, as well as regularizing the noise levels in these diverse data sets. To achieve a seamless final data set, a broad portfolio of demultiple and noise-attenuation techniques were needed. Results from the multi-survey methodology will be presented. With increasing activity in the Mediterranean Sea and Nile Delta, data-sharing agreements are becoming more common. This has brought into focus the need for robust data processing solutions for multi-vintage data, as well as acquisition systems and crews that can operate cooperatively.