ANALISIS PERBANDINGAN METODE EXTENDED ELASTIC IMPEDANCE DENGAN METODE MULTIATTRIBUTE SEISMIC DALAM MENGIDENTIFIKASI LITOLOGI BATUAN LAPANGAN PENOBSCOT

Abstract

The Penobscot Field is an exploration field located in the Scotia Basin, Nova Scotia, Canada. The reservoir zone is situated within the Mississauga Formation, composed of sandstone, siltstone, limestone, and shale. To determine the distribution of sandstone and shale lithology, an analysis was conducted using the Extended Elastic Impedance method in zones from sand 4 to sand 6. The multi-attribute seismic method was applied for comparison and assistance in analyzing the distribution of sandstone and shale lithology in the area of interest. The results of determining the gamma-ray parameter angle indicated an optimum rotation angle of 23° with a correlation of 0.78 in well L-30 and 0.74 in well B-41. The results from the inversion of the gamma-ray log using Extended Elastic Impedance showed the lithology distribution in the area of interest, which is predominantly dominated by sandstone characterized by gamma-ray values <70 API. There is shale lithology spreading towards the northwest of well B-41 and the southwest of well L-30. This finding was confirmed through the comparison of multi-attribute data, which exhibited relatively similar distribution patterns with variations in the extent of distribution shown by each method. Therefore, it is evident that the Extended Elastic Impedance method can provide valuable information about the lithology distribution in the reservoir zone of the Penobscot Field, Nova Scotia, Canada.