oa Reduction of Noise Effects from Low Frequency Passive Seismic Data

Anthropogenic noise effects have always been a great concern for passive seismic because they are<br>usually strong and difficult to remove. The problem is addressed by analysis of 2D (time-space)<br>attribute sections derived from the recorded data. On the attribute sections transient noise appears as<br>isolated points or distinctive linear trends and therefore can be suppressed by common filtering<br>techniques. We applied the approach on a passive seismic data set from a survey line at an oil and gas<br>field in Voitsdorf, Austria. The data set is noisy and the presence of hydrocarbon reservoirs could not<br>be convincingly indicated by conventional analysis techniques. Attribute sections, after being filtered to<br>reduce noise effects show a good agreement between reservoir locations and high amplitude trends on<br>the sections. A modelling study reveals that the anomalies observed on the attribute sections match<br>well with attribute values computed<br>from synthetic data.