ANALISIS INVERSI IMPEDANSI ELASTIK UNTUK IDENTIFIKASI PENYEBARAN RESERVOIR BATUPASIR

Abstract

The Elastic Impedance (EI) Inversion Method in this research is utilized to identify and map the spread of hydrocarbon fluid in DST-06 layer, which is located at Talang Akar Formation with its sandstone lithology. Attributive result of AVO analysis indicate that AVO graphical response of DST-06 layer is a class IIp AVO anomaly. DST-06 reservoir is a low impedance sand, which means it has lower impedance value compared to its enclosing rock that its reflective coefficient at the top is negative. Result of sensitivity analysis indicate that EI at 31o is the most sensitive angle for the separation of sandstone and claystone lithology. Therefore, Elastic Impedance inversion at 31o angle proved to be the most sensitive for the mapping of fluid spread and lithology. Analytical result of 31o Elastic Impedance mapping in line 1746 show that the sandstone lithology of the target zone has an EI value of (135-155) (m/s)2*gr/cc, with the sandstone spreading area in DST-06 layer reservoir is oriented to Northwest-Southeast direction. This sandstone spreading at DST-06 reservoir is on a height. Hence, it can be inferred that DST-06 reservoir has an anticline structure trapping system.