A computer implemented method of modelling a subsurface region of the earth for hydrocarbon exploration, development, or production, the method comprising: receiving into a processing system pre-stack seismic datasets measured for one or more locations within the subsurface region and well log datasets measured from wells within the subsurface region, wherein the seismic datasets comprise three-dimensional, 3D, seismic amplitude data and wherein the well log datasets comprise core data and elastic logs; selecting, with the processing system, key wells from among the wells based on the well log datasets; generating, based on the seismic datasets, a 3D geophysical model, wherein generating the 3D geophysical model includes: measuring, based on the seismic amplitude data and the well log datasets for the key wells, an amplitude variation with offset response of the seismic amplitude data to determine whether the measured AVO response meets prescribed requirements, iteratively re-processing the seismic amplitude data and repeating the step for measuring AVO at least until determining that the AVO response meets the prescribed requirements, and performing a seismic inversion process on the re-processed seismic amplitude data, wherein the seismic inversion process comprises a stochastic inversion; generating based on the well log datasets, a geological model, wherein generating the geological model includes: defining core facies from the core data for the key wells, generating, based on the elastic logs for the key wells, an elastic facies model for predicting elastic facies from elastic logs, and associating the elastic facies with the core facies; generating a conceptual depositional model of the subsurface region; and integrating the generated 3D geophysical model, geological model and conceptual depositional model into a three-dimensional, 3D, reservoir model for the subsurface region, wherein the seismic inversion process is performed using the same 3D grid as the 3D reservoir model. receiving into a processing system pre-stack seismic datasets measured for one or more locations within the subsurface region and well log datasets measured from wells within the subsurface region, wherein the seismic datasets comprise three-dimensional, 3D, seismic amplitude data and wherein the well log datasets comprise core data and elastic logs; selecting, with the processing system, key wells from among the wells based on the well log datasets; generating, based on the seismic datasets, a 3D geophysical model, wherein generating the 3D geophysical model includes: measuring, based on the seismic amplitude data and the well log datasets for the key wells, an amplitude variation with offset response of the seismic amplitude data to determine whether the measured AVO response meets prescribed requirements, iteratively re-processing the seismic amplitude data and repeating the step for measuring AVO at least until determining that the AVO response meets the prescribed requirements, and performing a seismic inversion process on the re-processed seismic amplitude data, wherein the seismic inversion process comprises a stochastic inversion; measuring, based on the seismic amplitude data and the well log datasets for the key wells, an amplitude variation with offset response of the seismic amplitude data to determine whether the measured AVO response meets prescribed requirements, iteratively re-processing the seismic amplitude data and repeating the step for measuring AVO at least until determining that the AVO response meets the prescribed requirements, and performing a seismic inversion process on the re-processed seismic amplitude data, wherein the seismic inversion process comprises a stochastic inversion; generating based on the well log datasets, a geological model, wherein generating the geological model includes: defining core facies from the core data for the key wells, generating, based on the elastic logs for the key wells, an elastic facies model for predicting elastic facies from elastic logs, and associating the elastic facies with the core facies; defining core facies from the core data for the key wells, generating, based on the elastic logs for the key wells, an elastic facies model for predicting elastic facies from elastic logs, and associating the elastic facies with the core facies; generating a conceptual depositional model of the subsurface region; and integrating the generated 3D geophysical model, geological model and conceptual depositional model into a three-dimensional, 3D, reservoir model for the subsurface region, wherein the seismic inversion process is performed using the same 3D grid as the 3D reservoir model.