Five-dimensional facies-driven seismic inversion for igneous reservoirs based on rock physics modelling

Igneous reservoir has become an important exploration target for increasing reserves and production of oil and gas in Junggar Basin. However, the igneous reservoir exploration is restricted because the seismic exploration of high-quality igneous reservoir is difficult and the anisotropy induced by high angle fractures cannot be neglected. To implement the characterization of igneous reservoir, we first study the correlation between anisotropy parameters and physical properties of igneous rock, and we propose a five-dimensional facies-driven inversion method based on rock physics, which means we employ 3D seismic data at different incidence angles and azimuths to implement the estimation of hydrocarbon reservoir constrained by the igneous rock facies. We also present an anisotropic igneous rock physics model, in which micro petrophysical characteristics, strong heterogeneity of skeleton minerals, pore structures are considered. Since a reasonable initial model is important for seismic inversion, we propose a facies-driven modeling seismic inversion method, in which we use facies obtained based on the difference between rock composition, reservoir physical parameters and elastic parameters of different lithofacies igneous rocks to constrain the seismic inversion. Finally, we present a step seismic inversion method of employing seismic data to estimate multi-parameters of HTI media. Therefore, the comprehensive processes of rock-physics modelling, inversion model establishment, and reservoir prediction of high-quality igneous rocks are proposed in this study, which demonstrates effective application for igneous reservoirs in China.