3D ANALYSIS OF FOLD-THRUST-BELT DEFORMATION USING SANDBOX MODELING: IMPLICATIONS FOR NEW HYDROCARBON PLAY OF EASTERN INDONESIA

Fold-Thrust-Belt (FTB) geometry is one of the most complicated structural geology. Therefore, special techniques need to be applied for studying their fault geometry and mechanism. In this paper, we introduce an integrated 3D analysis of FTB using 3D seismic interpretation, balancing cross-section and analogue sandbox modeling. Internal deformation and mechanism of FTB was evaluated using particle velocity analysis for understanding fault sequences as well as timing. In addition, the result of the study was applied in evaluating hydrocarbon potential along Timor and Tanimbar FTB of Eastern Indonesia. 3D seismic interpretation shows three different styles of deformation occurred in the study area including early normal faults following by fold-thrust belt and late normal faults system. Using balancing cross-section approaches we generated 3D palinspatic reconstructions of the FTB and the result was used as based for conducting sandbox modeling. The quantitative comparison between modeling and field data was done in term of fault dips, fault sequences, morphology of the FTB including their slope. Our analysis suggested that development of FTB is mostly controlled by several geological parameters such as interbedded lithology types, layer thickness as well as pre-existing geological condition such as basement configuration. Three different cases and 5 experimental setting were run to get better match between analogue modeling and field data. The results exhibit that FTB in the study area experienced more than 36% shortening with flat-ramp geometry involving Cretaceous stratigraphy as major detachment. Hydrocarbon prospect was identified as structural traps mostly formed 3-way dip closure involving Tertiary carbonate sequences.