Publications

The offshore Globigerina Field in Madura Strait has hydrocarbons trapped in a uniquely high quality bioclastic limestone reservoir of the Pliocene age Mundu Formation. The reservoir is mainly formed of Globigerina planktonic foraminifera tests. Since there are no published papers that use seismic attributes and inversion analysis to understand this unique carbonate reservoir, a comprehensive study utilizing 3D seismic and data from three wells were conducted to address the reservoir characterization problem. The internal reservoir features have been characterized on seismic by using horizons mapping, seismic attributes and seismic inversion combined with the well data. The study reveals that the observed changes in reservoir thicknesses are related to the paleotopography at the base of the formation. The fault and fracture distribution in the reservoir has been mapped by using coherency seismic attribute volume. This indicates that the faults and fractures are more intense in the western part of the field which is possibly related with reservoir facies. The cleaner facies tend to be more fragile to fracturing compared with the muddy reservoir. The general porosity trends in the reservoir have been identified using a seismic inversion volume. The more porous reservoir is located in the upper part of the Mundu Formation. There are two defined flat spots in the reservoir that have been characterized using seismic attributes. The lower flat spot is related to a paleo oil to water contact and it is confirmed by the log signature from the well. Meanwhile, the upper flat spot is the present hydrocarbon to water contact. By integrating these various analyses, the study can be used to delineate the reservoir. Hence, thick reservoir, highly fractured, better porosity value and thick hydrocarbon column are the characteristics of the best reservoir in the study area.