RESERVOIR CHARACTERIZATION USING SCALED Qp and Qs (SQp SQs) AT POSEIDON FIELD, BROWSE BASIN, NORTHWEST AUSTRALIA

Abstract

Reservoir characterization plays an important role in hydrocarbon exploration and development. Over time, several methods have been used to characterize reservoirs, one of which involves analyzing seismic wave attenuation. Seismic wave attenuation is closely related to the physical properties of rocks. The Scaled Qp and Qs methods are an advanced development of seismic attenuation techniques, which help to discriminate reservoir lithology and fluid content based on the attenuation of P-waves and S-waves. This study aims to observe the distribution of reservoir lithology and fluids using SQp and SQs in the Plover Sandstone Formation of the Poseidon Field. The data used in this research includes well log data from three wells, Kronos, Poseidon 1, and Poseidon 2, and 3D partial angle stack seismic data. This seismic data was used to perform simultaneous inversion, which became the input to generate the SQp and SQs models. The crossplot of SQp and SQs shows that low SQp values around 0.02 to 0.2 represent sandstone lithology, while high SQp values 0.2 to 0.7 represent of shale lithology. For the fluid indicator, high SQs values 0.55 to 0.7 are interpreted as gas-bearing zones, and low SQs values 0.4 to 0.55 indicate brine-saturated reservoirs. Based on the SQp and SQs volume and slicing results, gas-saturated sandstone reservoirs with low SQp and high SQs values are distributed from the southwest to the northeast. All three wells (Kronos, Poseidon-1, and Poseidon-2) are located in areas with low SQp and high SQs values. From this study, it can be concluded that the SQp and SQs methods are effective for distinguishing between reservoir and non-reservoir lithology and for identifying zones that may contain hydrocarbons.