3D seismic attribute-assisted fracture detection in the Middle Devonian Marcellus Shale, southwestern PA, Central Appalachian Basin

Abstract

The analyses of conventional structural attributes (first derivative, ant-tracking, phase, curvature, and variance) indicate very complex fracture systems within a Middle Devonian unconventional gas reservoir of the Central Appalachian Basin. In this presentation, we propose to investigate such complexity and the implications of fault networks to the exploration for and production of hydrocarbons. Spectral decomposition (iso-frequency) amplitude analysis was utilized in order to define spectral amplitude response to the fracture facies. The results will be useful to characterize fractured reservoir properties such as fault networks and fracture intensity. We calibrated spectral decomposition attributes using previous petrophysical studies or using structure attributes such as curvature and ant-tracking to determine relationships between spectrally decomposed amplitude attributes and fracture intensity of the reservoir. As a result, this study can potentially enhance the quality of interpretation of seismic data and better define the fracture facies that have important implications for unconventional gas-shale reservoir characterization and CO2 sequestration in the deep subsurface.

3D Seismic Interpretation, Mechanical Stratigraphy and Production Analysis of the Marcellus Shale in Northern West Virginia

“…The Marcellus shale has been studied extensively through 3D seismic analysis, log analysis and production analysis. Previous 3D seismic studies assess the structure and discontinuity of the Marcellus shale in the Appalachian basin through utilization of seismic attributes (Donahoe, 2001;Babarsky, 2012;Zhu;Hart, 2014;Wilson et al, 2016).…”

Structure Segmentation and Transfer Faults in the Marcellus Shale, Clearfield County, Pennsylvania: Implications for Gas Recovery Efficiency and Risk Assessment Using 3D Seismic Attribute Analysis

“…However, work pertaining to attribute analysis of 3D seismic data has escalated due to the activity surrounding the basin's natural gas industry. Similar studies, including more recent 3D seismic work in southwest Pennsylvania by Donahoe and Gao (2012), Babarsky and Gao (2012), and Zhu (2013) focused on detection of faults and fractures in the Marcellus Shale using 3D seismic attributes and will be used for comparison of this research.…”