AVO OF FORWARD MODELLING OF FRACTURED BASEMENT WITH EMPHASIS ON A FIELD IN MALAY BASIN

Over a decade ago, the trend of exploring hydrocarbon as shifted from conventional sedimentary reservoirs to fractured reservoirs, which consists of igneous rocks and coal bed methane. Fractured reservoir is referred as reservoir that has large enough naturally-occurred fractures to contain hydrocarbon. The discovery of igneous reservoir in Malay basin was made in 2004 by Petronas Carigali. The project begins with the outcrop study of Tanjung Kempit in eastern Johor which consist of meta-sedimentary rocks that could relate to the understanding of fractured basement rock. The project is followed by rock physics study that involves the measurement of compressional wave and shear wave velocities based on the core samples from onshore. Fore core samples are prepared with different fracture orientation; vertical, tilted, single horizontal and double horizontal. The P-wave velocities decrease after the rocks are fractured, while the S-wave velocities increase. Finally, well data from an actual field is used to generate AVO model based on two methods; Blocky Average and synthetic gathers for sand-shale interface and sand-basement interface. The AVO allows the determination of seismic response and detection of anisotropy.