  We explore the interplay of electron-electron correlations and spin-orbit
coupling in the model Fermi liquid Sr2RuO4 using laser-based angle-resolved
photoemission spectroscopy. Our precise measurement of the Fermi surface
confirms the importance of spin-orbit coupling in this material and reveals
that its effective value is enhanced by a factor of about two, due to
electronic correlations. The self-energies for the $\beta$ and $\gamma$ sheets
are found to display significant angular dependence. By taking into account the
multi-orbital composition of quasiparticle states, we determine self-energies
associated with each orbital component directly from the experimental data.
This analysis demonstrates that the perceived angular dependence does not imply
momentum-dependent many-body effects, but arises from a substantial orbital
mixing induced by spin-orbit coupling. A comparison to single-site dynamical
mean-field theory further supports the notion of dominantly local orbital
self-energies, and provides strong evidence for an electronic origin of the
observed non-linear frequency dependence of the self-energies, leading to
`kinks' in the quasiparticle dispersion of Sr2RuO4.
