Nelson, Travis A.¹, John Fountain¹ 
(1) University at Buffalo Geology Department, Buffalo, NY

ABSTRACT: The Use of Soil Gas Surveys to Delineate Subsurface Structure: Cross-Strike Discontinuity Locations for the Bass Island Trend in Western New York

Soil gas studies were undertaken to investigate the existence of cross-strike discontinuities (CSD's), in a portion of the Bass Island oil and gas reservoir in Western New York State. The Bass Island structural trend is a complex fracture system with cross-strike discontinuities that cross the major trend of thrust faults. The locations of CSD’s are important in the location of natural gas and oil because they offset the major structural trend and potentially provide a seal between sections of the Bass Island Trend. It is known that open fractures can provide preferential pathways for the migration of thermogenic gases, primarily methane and ethane, to the surface. Data from geochemical analysis at the surface define gas anomalies that suggest the existence of open fractures, potentially allowing detection of the Bass Island Trend if structure associated with the trend reach the surface. There were over 4,800-soil gas samples collected from 28 different traverses totaling 113,930 feet / 34,725 meters of terrain traversed. The resulting data delineated 7 CSD's in and around an underground natural gas storage facility. The results from this study have demonstrated the usefulness and applicability of soil gas analyses in locating and characterizing CSD’s related to oil and gas prospects along the Bass Island Trend.

AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.