The Application of Array Acoustic Wave Data to Tight Sandstone Gas Reservoir in Tuha Oilfield

Low porosity,poor permeability and complicate pore structure are the most obvious characteristics of Tuha basin tight sandstone reservoir,so it is difficult to make an effective reservoir evaluation with conventional log data.Based on the acoustic characteristics experiments of the tight sandstone,analysed are the change rules of P-wave(compressional wave) and S-wave(shear wave) and other parameters of core samples under the conditions of saturated water and saturated gas.DTS and DTC are acquired from array acoustic log data;Bulk density is obtained from density log data.And the DTS,DTC and bulk density are used to calculate the Poisson's ratio and bulk compressibility coefficient which are effective parameters in gas reservoir recognition.The core acoustic physics experiments prove that the Poisson's ratio and bulk compressibility coefficient are sensitive to changes of gas-bearing saturation under the condition of higher gas-bearing saturation.The Poinsson's ratio and bulk compressibility coefficient crossplot may virtually identify the gas reservoir,and is better used in the tight sandstone reservoir in Tuha oilfield.