Description

Multi-component seismic data had proved its merits in characterizing reservoirs as many documented case studies showed. PS converted waves jointly with conventional PP seismic data provide more constrained and robust solutions when imaging subsurface as well as inverting elastic moduli that are transformed to reservoir properties.

In more details the main purpose of multicomponent seismic, is to record and utilize both compressional P and shear S wave modes, where recording both wave modes captures more information related to rock properties. P-waves are influenced by all three bulk rock properties (compressibility, rigidity and density) while S-waves are influenced by rigidity and density only. Combining these observations allows more accurate estimation of key reservoir characteristics, Where Multicomponent PP/PS recordings, has many vital uses including lithology identification, fluid discrimination, imaging through gas, fracture and stress field characterization and density estimation.

Multicomponent PS data provides important complementary seismic information by incorporation with conventional PP data through AVO analysis and results, as anisotropic AVO simultaneous inversion of PP/PS data, as well as a simultaneous inversion on both of the PS fast and slow azimuths, are used to determine fracture/stress density and orientation and to provide fluid and lithology discrimination and reservoir characterization, moreover AVO techniques are used to derive S-wave impedances and velocities.

Also by using seismic joint inversion of PP/PS, seismic rock properties can be characterized in much more precision, where PP data alone requires the use of very dense acquisitions and very long offsets, Joint PP and PS inversion provides S-wave properties directly and hence better fluid and lithology depiction than PP or PS only. Additionally methods that exploits the anisotropic AVO as simultaneous inversion of the PP/PS data, as well as simultaneous inversion on both of PS fast and slow azimuths, are able to determine fractures and stress density and orientation.

Another major advantage of multi component PP/PS data is, due to geologic challenges where low P-wave impedance across the geologic interfaces occurs, PP datasets are difficult to interpret, PS or converted wave shear components have a different impedance contrast at these boundaries and can plausibly provide another seismic volume that is a complement to the traditional PP volume to aid in the interpretation. Also the determination of the Vp/Vs ratio’s over different geologic sections can provide information to help identify lithology. With the added benefit of the Shear Wave information, the offshore fields be better managed.Processing multicomponent PP and PS seismic data is more challenging compared to conventional PP seismic data due to the asymmetric ray paths caused by velocity variation between P and S waves.

This workshop will highlight optimal processing workflows that improve quality of multi-component seismic data. Moreover, it will focus on processing workflows that can be optimized for specific objectives such as fractures characterization and accurate estimation of reservoir properties. Anisotropic processing for this type of data will be highlighted emphasizing its impact on improving subsurface images, in particular. Where a successful converted wave project is that one in which the added advantages to interpretation and reservoir characterization has been gained by the supplementary PS dataset.

Workshop Programme