Presenting an integrated strategy for porosity mapping in a genetic-based seismic inversion framework in a heterogeneous reservoir

Accurate representation of the subsurface geological structure and the rock properties model is an essential step in the sequence of reservoir characterization (Al-Bulushi et al. 2012). Various advanced methods are available to derive precise model of reservoir characteristics and provide information of reservoir properties in different scales (Chen and Durlofsky 2006). Seismic reservoir characterization in heterogeneous media is essential to resolve some of the ambiguities in petroleum field management. Previous studies have shown that the homogeneity of the porous media has the highest influence on production (namely 40%), while its effectiveness vanishes in heterogeneous media to 37% (Balouchi et al. 2013; Nozohour-leilabady and Fazelabdolabad 2015). Thus, an optimum practical approach consists of incorporating the impact of the reservoir heterogeneity in modeling reservoir characters (Benisch et al. 2015). Herewith, accurate modelling of reservoir properties, such as porosity and permeability, is essential. However, obtaining accurate and precise relationship between seismic parameters, which are the main sources of information in seismic reservoir characterization, is a challenging task, specifically in a heterogeneous reservoir even with simple structures (Ahmadi et al. 2015; Daraei et al. 2017). Various studies have shown that the distribution of reservoir characteristics, like porosity and permeability, depends on the rock properties of the reservoir, which could be extracted from seismic attributes (Maffucci et al. 2015, Soleimani 2017a). Hence, several studies have been performed to use seismic attributes in various strategies for seismic reservoir characterization. However, a seismic attribute by itself is not a reliable source of information. Therefore, it was proposed to combine various seismic attributes for seismic reservoir characterization (Noorbakhsh et al. 2014; Oyeyemi et al. 2019). This implies performing literature review on the selection of appropriate attributes for desired reservoir characteristics and, subsequently, an appropriate strategy for integration of selected attributes, to obtain a unique reliable model (Soleimani 2017b). However, an individual seismic attribute by itself could not be used directly for extraction of reservoir characters, but it should be used as an intermediate product or for evaluation of intermediate products, such as the acoustic impedance (Abdel-Rasoul et al. 2014). Mostly, selected attributes or any integrated attribute would be used for evaluation of the seismic inversion result. Since the acoustic impedance model conventionally is obtained by other sources of information, like sonic and density logs, evaluating its result with seismic attributes is not rationally acceptable (Ahmadi et al. 2015). In this study, we introduce a procedure for obtaining inversion result in such a way that could be evaluated by a combined single attribute result. The proposed strategy then would be applied on selected petroleum field in the southwest of Iran, with two reservoir target formations.