Gas and Water Detection in Dolomite Reservoirs Based on Multi-Wave Amplitude Attribute

Abstract

Summary The grain beach dolomite reservoir develops in Cambrian Longwangmiao Formation of China Sichuan Basin. But the reservoir pore is usually filled with gas, water and asphalt. To effective identify the pore fluid, we used well-matched multi-wave 3D3C seismic data and conducted multi-wave seismic response analysis of wells with different pore filled medium, combined with multi-wave forward modelling and rock physics experiment results of actual core sample, finally getting the conclusion that, for the dolomite reservoir with various pore fillings of Longwangmiao Formation of Sichuan Basin, when the reservoir contains gas, the PP wave usually forms strong reflection while PS wave weak. While, when the porosity is high, the PS wave will also form strong reflection. When the asphalt is filled, similar characteristics to the gas will occur (PP strong and PS weak). When saturated with water, the PP wave get weaken and PS wave become strong. The amplitude difference between PP and PS can effectively identify the gas-bearing zone and the water-bearing zone, which provides a fast and effective method for detecting gas and water in a dolomite reservoir.