Comparative Study of Gravity and Magnetic Inversion for Estimating Sedimentary Basin Geometry Using Synthetic Data

Abstract Indonesia hosts 128 sedimentary basins with potential reserves of oil and natural gas. Accurate estimation of basement geometry during the initial exploration phase is critical for identifying petroleum systems within these basins. Gravity and magnetic methods are commonly employed for this purpose, utilizing inversion techniques to analyze basements configuration. This study investigates the effectiveness of gravity and magnetic data inversion in estimating basement depth and geometry, using synthetic models as the basis for analysis. The synthetic models incorporate two proposed basement configurations, characterized by a combination of horst and graben structures. Forward modeling was used to simulate gravity and magnetic anomalies corresponding to these configurations. The inversion results demonstrate that both gravity and magnetic methods can effectively estimate the basement structure. However, the results indicate that magnetic inversion demonstrates slightly superior performance in terms of misfit accuracy when compared to the synthetic model. It should be noted that these comparative results may not be applicable to all scenarios. It can be inferred that the accuracy of this inversion approach heavily relies on a priori information as an input, such as the estimated basement depth, the density contrast between the sediment and basement rock, and the filter parameters. These factors are crucial for enhancing the precision of the results.