Application of greenberg-castagna model in igneous rock region

Summary: In recent years, with the extensive application of prestack inversion technology, the rock-physics modeling technique has become very popular. For sand-shale stratigraphy we can select a suitable rock-physics model to simulate and predict shear waves based on the available information such as geological features, reservoir characteristics and situation of fluid development in the study area. In a region with extensive development of igneous rocks (non-igneous reservoir), there is no existing models for igneous rocks, and therefore rock-physics modeling has become difficult. In this paper, we propose a methodology to take into account of the complexity features of different rocks in the study area, and to select appropriate existing model (Greenberg-Castagna model) to estimate S-wave velocities. We also set up different rock-physics templates for sands, mudstone, igneous rock and fluid (oil, gas and water).