Prism-shaped rock-physics template

Abstract

Despite the emergence of statistical and intelligent approaches for quantitative seismic interpretation in recent years, Rock Physics Templates (RPTs) are still preferred because of their simplicity and easy implementation. RPTs have been introduced as a fundamental tool for lithology and fluid discrimination based on well-log and seismic data, which have already been proven in terms of accuracy and reliability. Considering the demand for comprehensive RPTs and improving their efficiency, I proposed a novel three-dimensional prism-shaped template for lithology and fluid discrimination, called a prism-shaped rock physics template (P-RPT). For this, a theoretical methodology for designing conventional RPT was introduced with the aim of bounds and hybrid rock physics models. Next, some novel triangular and rectangular ternary and binary templates were designed and connected to one another to build a prism for fluid discrimination and lithology identification. Two ternary charts were used for fluid and lithology, incorporating the P- and S-wave velocity ratios and Lambda-Mu parameters. Further, binary charts, including acoustic impedance, Lamé parameters, and porosity, were designed and modified from literature for fluid and lithology identification. Next, the obtained templates were successfully validated on blind data sets (ultrasonic, well logging, and seismic data) in different reservoirs with various lithologies and fluid types. The results showed that the P-RPT could integrate the available RPTs into a 3D diagram and give a reliable framework for applications in seismic interpretation. User-friendliness and generalizability are the most prominent advantages of the proposed template for detecting fluid type and lithology based on well logs and seismic inversion, the results of which can be interpreted on a single chart rather than analyzing the data with different templates. The methodology and framework for implementing and generating templates were thoroughly explained in theory and practice to localize P-RPT or update new RPT for another region.