Comparison of Factorial Kriging Analysis Method and Upward Continuation Filter to Recognize Subsurface Structures — A Case Study: Gravity Data from a Hydrocarbon Field in the Southeast Sedimentary Basins of the East Vietnam Sea

Abstract

To interpret geophysical anomaly maps, it is necessary to filter out regional and sometimes noise components. Each measured value in a gravity survey consists of different components. Upward continuation (UC) is one of the most widely used filters. The shortcoming of this filter is not to consider the spatial structure of the data, and also the fact that the trial and error approach and expert's judgment are needed to adjust it. This study aims to compare the factorial kriging analysis (FKA) and UC filters for separation of local and regional anomalies in the gravity data of a hydrocarbon field in the southeast sedimentary basins of the East Vietnam Sea. As shown in this paper, FKA method permits to filter out all of the identified structures, while the UC filter does not possess this capability. Therefore, beside general and classic filtering methods, the COMPARISON OF FKA METHOD AND UPWARD CONTINUATION 399 FKA method can be used as a strong method in filtering spatial structures and anomaly component.

Evidence for the Upwelling of Mafic Bodies into the Upper Crust beneath the N40-50°E Branch of the Pan-African Central Cameroon Shear Zone from Gravity Studies

“…In order to enhance the signatures of mafic materials into the upper crust, observed data are separated into regional and residual anomalies [38] using polynomial fitting based on the least-squares method. In order to choose the order of the regional field which fixes the resi-dual one, this method which is the most flexible and efficient analytical technique [39] [40] is combined with optimum upward continuation method [38] to determine the best surface representing regional field. The selection criterion of the regional field is the more objective, as it is based on the correlation between the regional analytical and the regional spectral.…”