Application of 3D seismic attribute analysis to subsurface structure interpretation and hydrocarbon exploration: southwest Pennsylvania, Central Appalachian Basin.

Abstract

Summary High quality 3D seismic data provides critical information vital to the delineation of structural fabrics and depositional facies, and it is therefore important to the development of ideas associated with structural and facies architecture and growth history of the Appalachian foreland basin. Traditional wiggle trace imagery is limited by its dominant frequency and low signal-to-noise ratio; while conventional seismic attributes, such as instantaneous phase, root mean squared amplitude (RMS) and frequency methods are not sufficient to define fractures and spatial and temporal relations between faults and folds which are crucial in achieving the hydrocarbon exploration objective in the basin. To overcome these limitations, seismic attributes such as volumetric curvature, ant tracking and waveform regression were applied to increase the resolution of stratigraphic and structural features including folds, faults and fractures. Saw-tooth forethrust to backthrust patterns and small-scale, intra-interval dѐcollemont zones were observed within the Devonian intervals. From analysis of these discontinuities, the maximum principle stress orientation during the Middle Devonian was defined at approximately 105 o to 120 o azimuth which may be instructive in designing horizontal drilling orientations in the hydraulic fracturing process. This effort demonstrates the importance of 3D seismic attribute analysis to understanding the relationship between subsurface structural features and hydrocarbon systems, which are fundamental to the success of future exploration for and production of oil and gas, both conventional and unconventional, in the Appalachian Basin.