"Importantly, a natural gas seep has been located on top of one of these elongated anticlines." 82% of wells drilled near seeps were comercially successful according to this Schumacher article
"To assess the association of seepage and subsurface accumulations of petroleum, Schumacher (2012) compiled seepage survey results for more than 2,700 exploration wells and compared the results with subsequent drilling outcomes. Locations were in frontier and mature basins, onshore and offshore, and in a wide variety of geologic settings. Subsurface drilling targets were from 300 m (984 ft) to more than 4,900 m (16,076 ft), and there was a full spectrum of trap styles. The presence of seepage was inferred from soil gas, microbial, iodine, radiometric, and/or magnetic surface surveys.
Eighty-two percent of wells associated with surface seepage anomalies were considered commercial discoveries, and 11 % of wells drilled without a documented surface seepage anomaly resulted in discoveries. The measure of association was economic viability determined by external factors, and not the presence or absence of petroleum in the subsurface. The sites chosen for analysis in this study were not random; they were based on conventional prospect evaluation methods. This study illustrates that seeps are often only surveyed for in areas suspected of being oil and gas prospects, thus limiting geographic coverage."