TIME REVERSE MODELING OF HYDROCARBON DETECTION FOR PASSIVE SEISMIC SOURCE LOCALIZATION: A CASE STUDY OF SYNTHETICS AND REAL DATA FROM THE SOUTH SUMATRA BASIN, INDONESIA

Abstract

Subsurface passive seismic source localization, which is associated with hydrocarbon indication, has become animportant tool for passive seismic data modeling. A time-reverse modeling(TRM) algorithm, which was applied topassive seismic data, has been developed and implemented to locate passive seismic sources by using an acoustic finite difference technique. By performing TRM, the recorded passive seismic amplitudes can be focused at their source depth, even though the focused point cannot be warranted as a source point. This paper aims to verify the ability of the developed TRM algorithm in localizingthe passive seismic source associated with reservoir depth by means the possible movement of fluid.TRM was applied to synthetic and recorded passive seismic data from a gas reservoir area in the South Sumatra Basin. Synthetic passive seismic data were generated within a two-dimensional velocity model and calculated by using a finite difference algorithm simulating acoustic low-frequency wave propagation. TRM application to the synthetic data showed that passive seismic sources can be properly located in the same position as the original source. In addition, our application to the real passive seismic data sets showed that the passiveseismic sourceis distributed randomly in the depth range of 700 m up to 1500 m, which wasrepresented by high particle velocities.