Improved Fault Definition and Seismic Images Through Full Azimuth Angle Domain Imaging in A Dense Single Receiver Broadband Acquired Datasets within a Low Dune Area

Abstract Full azimuth angle domain imaging (CRAM-LAD) was applied on a +1000 km2 single-source, single-receiver full azimuth seismic survey targeting a better fault definition, fracture characterization and reservoir management of very subtle low-relief structures, geological environments of carbonate reservoirs in the Middle East desert environment. The previous seismic processing in this area was based on conventional pre-stack time and depth Kirchhoff migrations methods. New results allow us to have a better characterization of faults and fractures. Using EarthStudy 360 full-azimuth anisotropic seismic imaging in Local Angle Domain (LAD) technology, we were able to better delimitate structural inhomogeneities in the target reservoir levels, including small fault detection and characterization. The use of angle gathers allows us to improve the shallow velocities leading to better statics models incorporated in the Depth Velocity Model along with a multi-azimuth tomography also in the angle domain to improve the velocities in the overburden. Post-migration (imaging) procedures separate reflections from diffraction on directional angle gathers. Post-stack seismic attributes using diffracted events can show geological features that normal imaging methods cannot. Main achievements include the production of Full Azimuth, angle-dependent reflection and directional (dip and azimuth) data components. From Reflection angle gathers with higher signal to noise ratio, we obtained seismic section for a reliable geological interpretation preferred by interpreters and angle stacks with much less stretching effects in comparison with Kirchhoff methods more suitable for seismic Inversion. AVA amplitudes and attributes are superior in comparison to those obtained in previous studies. The deepest reservoir exhibits a better continuity for reservoir still on development. Directional gathers allow us to split its specular component from which we generated a seismic volume with higher signal to noise ratio in the reservoir levels. The diffracted energy also extracted using designed filter in this project, allows to extract geological features like small faults and fractures that traditional imaging methods are not able to map accurately. The rich azimuth information and angle ready datasets, obtained from non-regularized pre-migrated gathers, clearly define faulty planes, channels and karst zones from top to bottom. CRAM LAD imaging is widely used in the middle east for more effective imaging and analysis in fracture carbonate reservoirs. Here we demonstrate that can be used to improve the image quality for desert environments, especially in full azimuth single receiver datasets. AVAZ inversion for the definition of small fractures based in horizontal anisotropy measurements is also a benefit of the application of this kind of imaging technology.