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

نوع مقاله: مقاله تحقیقی‌ (پژوهشی‌)

نویسندگان

1 Professor Assistant, Faculty of Engineering, Asia Pacific University of Technology & Innovation (APU)

2 دانشکده مهندسی معدن، نفت و ژئوفیزیک، دانشگاه صنعتی شاهرود

3 Professor, Faculty of Engineering, Asia Pacific University of Technology & Innovation (APU),

4 Associate Professor, Faculty of Engineering, Asia Pacific University of Technology & Innovation (APU),

10.30499/ijg.2020.223648.1261

چکیده

Seismic reservoir characterization is a state-of-the-art procedure in using various sources of data. Generally, seismic data, due to their low resolution are randomly used in the final steps of reservoir characterization. However, extensive coverage of 3D seismic data, compared to well data, makes it possible to be applicable for the distribution of characters through the whole reservoir. In this regard, seismic data should be inverted to illustrate desired characters throughout the media. Conventionally, seismic inversion uses well logs that have defects in its derivation steps, such as wavelet extraction and its propagation through media. The proposed strategy to resolve such deficiencies, is the genetic inversion. However, genetic inversion has its own deficiency in accuracy. In this study, we propose an integrated strategy for using various sources of data in an iterative manner for resolving this obstacle. The proposed strategy uses a combined related attribute to evaluate initial acoustic impedance inverted model by genetic inversion. The model then would be updated to satisfy well data. The proposed strategy was applied to a heterogeneous reservoir from the southwest of Iran. Three seismic attributes were integrated to produce a unique attribute for initial model evaluation. The final model was then evaluated by well data. Results were also compared with the conventional method of seismic inversion. The result of the proposed strategy in the genetic inversion depicted improvement in the final acoustic impedance and the porosity distribution model.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

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

نویسندگان [English]

  • Amin Shahbazi 1
  • Mehrdad Soleimani monfared 2
  • Vinesh Thiruchelvam 3
  • Thang Ka Fei 4
1 Professor Assistant, Faculty of Engineering, Asia Pacific University of Technology & Innovation (APU),
2 Faculty of mining, petroleum and geophysics, shahrood university of technology,
3 Professor, Faculty of Engineering, Asia Pacific University of Technology & Innovation (APU),
4 Associate Professor, Faculty of Engineering, Asia Pacific University of Technology & Innovation (APU),
چکیده [English]

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.

کلیدواژه‌ها [English]

  • seismic reservoir characterization
  • Genetic inversion
  • Seismic attributes
  • porosity distribution