The Delphi Acquisition and Preprocessing project (node1) aims at improved data acquisition geometries as well as new preprocessing concepts for land and marine seismic data.

The acquisition and preprocessing project (A&P) contains the following interrelated research topics:

• interactive design for optimum acquisition geometries , including the effect of blending and the extra illumination properties of the multiples;

• the concept of dispersed source arrays (DSA's);

• deblending technology for separating overlapping shot records;

• analyzing the effect of ghosts on realistic sea states;

• source and receiver deghosting, by considering the proper wave theory and realistic sea states;

• solving the complex near-surface problem via integrated full wavefield imaging and velocity estimation technology (i.e. Joint Migration Inversion).

The goal of the Delphi Multiple Estimation and Structural Imaging project (node 2) is the transformation of marine (single-component), as well as OBC and land (multi-component) seismic measurements into highly resolved structural images.

The multiple estimation and structural imaging project (M&I) contains the following interrelated research topics:

• surface-related and internal multiple estimation;
• using multiples to estimate missing (near) offsets;
• imaging of blended seismic data, optionally including surface multiples;
• imaging using also internal multiples, i.e. full wavefield migration (FWM);
• estimation of the velocity model , i.e. joint migration-inversion (JMI), also including anisotropy and fine-layering effects.

The focus in the M&I project is not only separating primaries from multiples, but also using both primaries and multiples in the migration process (FWM). Hence, multiples are considered as important information. In addition, the migration process has been extended to simultaneously estimate velocity as well (JMI). We expect that multiple utilization and simultaneous velocity estimation will improve the quality of seismic images beyond expectation

The Delphi Dynamic Characterization and Reservoir Monitoring project (C&M) aims at bridging the gap between seismic imaging and reservoir engineering.

The C&M project involves the following topics:

• Joint migration inversion of VSP data (JMI for VSP);
• Broadband, nonlinear, full waveform seismic inversion by using both primaries an internal multiples (FWI-res);
• Reservoir monitoring with JMI and FWI-res (4D);
• Estimation of lithology and porefill, using the output of FWI-res.,
• Joint inversion of seismic and EM data (data assimilation).


Similar to the objective to use multiple scattering in our imaging research, we also utilize multiple scattering in characterization. Using the velocity model as a background medium (output of JMI), it involves a full inversion of the seismic data, not in terms of boundary parameters but in terms of layer parameters (velocity and density). In this way a high-resolution estimate of the elastic reservoir parameters is obtained directly from the seismic data (data-driven inversion).
The main advantage is that internal multiples will contribute to the quality of the reservoir properties, meaning that the concept of primary reflection input is not used anymore.