Two different 3D seismic survey geometries for relatively low-fold exploration objectives are compared. The sparse geometry (S3D) is executed in swaths using a crew with 960 active channels. It is fast and cost effective, and has been used extensively in Saudi Arabia. The low fold conventional geometry (LFC3D) is acquired in blocks using a crew with about 4000 active channels. LFC3D geometries offer better geophysical attributes, with less variability of offsets and azimuths between common midpoints (CMPs), improved statics control, and higher fold with less source effort. LFC3D geometries have greater flexibility for different survey objectives than S3D geometries, and are competitive with S3D geometries in terms of cost, speed, and data quality.

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The near-surface model for static corrections requires a consistent regional depth/velocity model, while incorporating the fidelity of additional static solutions. We addressed the challenge of tying new seismic acquisition to a depth/velocity model, in which there are static corrections derived independently for each seismic data. The generalized method is a four-step procedure that starts with the grafting of the additional shifts to the recipient static model. The time shifts were then adjusted to constrain the long wavelength at defined locations. The next procedure was to split the time shifts into high- and low-frequency components. The final procedure inverted the high frequency into the shallowest layers and the long wavelength to the velocity from base of model to datum. The result was an updated regional depth/velocity model into which new 2D depth/velocity models could be tied. The generalized solution would work with any additional near-surface static corrections, which could include, and not be limited to, those built from surface waves, remote sensing, and joint inversion with nonseismic data. The inversion of the additional time shifts was primarily intended to provide a solution to their tie and any image improvement is serendipitous. We progressively learned lessons from a simple inversion and achieved the generalized solution.