흑산분지 내 천연가스 탐지를 위한 3차원 탄성파 탐사자료 AVO 분석

Abstract

By the results of processing and interpretation of 3-D seismic data acquired in the Heuksan Basin of the Korea continental shelf, an anticlinal structure was identified within the range from 120 to 140 number of inline and around 1000 ms by Two way travel time (TWT). A flat seismic event considered as the typical fluid contact appears in the interior of the anticlinal structure. This anticlinal structure is also found within the range from 900 to 1100 ms on time slice map of 3-D seismic volume. This structure is a nose type of anticline structure which has the 4 km in diameter and extends from northeast to southwest direction. AVO (Amplitude versus Offset) analysis was performed for the whole survey data for detection of free-gas zone. The results of the analysis show that the zone of strong AVO anomaly existed in the vicinity of the anticlinal structure. On the cross plotting of gradient and intercept, AVO anomaly appeared in first and third quadrant. which means a typical natural gas layer.