Publications

A green field gas reservoir carbonate was planned for development. The field has only three exploration wells covering 25 km long and 5 km wide of elongated carbonate reservoir structure which consequently have high uncertainty in undrilled well location. A robust porosity modeling is critical to target porous carbonate for development well location.

Prior utilizing the seismic data, acoustic impedance and porosity log were analyzed to identify the correlation. For big scale correlation down to basement, seismic showing strong relation with porosity data. However, it is showing low correlation in reservoir section. Even though seismic has a low correlation in reservoir section, it can still be utilized as a secondary variable in reservoir porosity modeling only as 2D horizontal data or as a trend map.

Seismic acoustic impedance trend map showing study area of the eastern area has a lower acoustic impedance value compared with western area. To explain seismic trend map result, a carbonate field conceptual geology was interpreted. The conceptual geology east to west study area is simulated with better properties on the eastern area compared to the western area, as the secondary porosity of carbonate occurred on the eastern part where it is interpreted as a higher basement morphology and carbonate build up on the bottom of the reservoir.

As a result, the porosity model was build based on seismic acoustic impedance trend map as secondary variable supported by conceptual geology interpreted in the field. It has captured the possible porous carbonate for targeting development wells. As a conclusion, this methodology has enabled a more robust porosity modeling showed by lower acoustic impedance value associated with high porosity located in eastern part of study area where the best location for development wells.