Characterization of fluvio-deltaic gas reservoirs through AVA deterministic, stochastic, and wave-equation-based seismic inversion: A case study from the Carnarvon Basin, Western Australia

Abstract

Multiple state-of-the-art inversion methods have been implemented to integrate 3D seismic amplitude data, well logs, geologic information, and spatial variability to produce models of the subsurface. Amplitude variation with angle (AVA) deterministic, stochastic, and wave-equation-based amplitude variation with offset (WEB-AVO) inversion algorithms are used to describe Intra-Triassic Mungaroo gas reservoirs located in the Carnarvon Basin, Western Australia. The interpretation of inverted elastic properties in terms of lithology- and fluid-sensitive attributes from AVA deterministic inversion provides quantitative information about the geomorphology of fluvio-deltaic sediments as well as the delineation of gas reservoirs. AVA stochastic inversion delivers higher resolution realizations than those obtained from standard deterministic methods and allows for uncertainty analysis. Additionally, the cosimulation of petrophysical parameters from elastic properties provides precise 3D models of reservoir properties, such as volume of shale and water saturation, which can be used as part of the static model building process. Internal multiple scattering, transmission effects, and mode conversion (considered as noise in conventional linear inversion) become useful signals in WEB-AVO inversion. WEB-AVO compressibility shows increased sensitivity to residual/live gas discrimination compared to fluid-sensitive attributes obtained with conventional inversions.

Naïve Bayesian classification of cumulative oil production from stochastic amplitude variation with angle inversion attributes: As applied to SEAM and a West Africa Field

“…Amplitude variation with offset (AVO) and amplitude variation with angle (AVA) seismic data methods are commonly applied to solve for rock properties and to differentiate fluid content of reservoir formations, with theoretical work coming from Knott and Zoeppritz at the beginning of the twentieth century (Knott, 1899; Zoeppritz, 1919; Feng and Bancroft, 2006). A primary use of AVA is to determine gas‐bearing versus non‐gas‐bearing sands (Ostrander, 1984; Rutherford and Williams, 1989; Contreras et al ., 2020). AVO and AVA inversions are sensitive to specific earth attributes such as Vp / Vs , porosity and density (Hampson et al ., 2005).…”

Feature Extraction of Music Signal Based on Adaptive Wave Equation Inversion

“…In music signal recognition technology, the key issue is to establish an acoustic model of music signal recognition primitives [7]. At present, some technologies for the acoustic model of music signals have not been completely solved, resulting in the performance of some products that are still difficult to meet the ideal use requirements [8].…”