A method and device for gas layer identification and evaluation based on rock acoustic characteristics

Abstract

The present invention discloses a gas reservoir identification evaluating method based on an acoustic characteristic of rock and a device thereof, which belongs to the field of evaluating a compact sandstone gas reservoir. The gas reservoir identification evaluating method comprises the following steps: selecting a series of sandstone samples in a target area, and measuring analysis data of the series of sandstone samples; calculating longitudinal wave time differences and longitudinal / transverse wave speed ratio acoustic parameters of the series of sandstone samples; establishing an acoustic parameter coordinate system according to the measured longitudinal wave time differences and the longitudinal / transverse wave speed ratio, and preparing a saturation quantitative explanation plate of the series of sandstone samples at various porosities; and performing explanation evaluation on the measured gas reservoir through the prepared the saturation quantitative explanation plate. The device comprises the following components: a selecting and measuring module, an acoustic parameter calculating module, a saturation quantitative explanation plate preparing module and an evaluating module. According to the method and the device of the invention, through preparing the saturation quantitative explanation plate, quantitative identification for reservoir porosity and gas saturation is realized, and explanation evaluation precision for the compact sandstone reservoir is improved.

Description

technical field [0001] The invention relates to the technical field of evaluation of tight sandstone gas layers, in particular to a gas layer identification and evaluation method and device based on rock acoustic characteristics, mainly aimed at the gas layer identification and evaluation of low-porosity and low-permeability tight sandstone reservoirs, and can accurately recognize fluids Interpretation and evaluation of reservoirs are performed on the basis of properties. Background technique [0002] Low porosity and low permeability greatly reduce the contribution of fluid in the reservoir to the logging response, coupled with the complexity of fluid properties and lithology, resulting in distortion of some logging information reflecting the formation, increasing logging Therefore, low-porosity and low-permeability gas layers are often missed in the initial stage of oilfield exploration and development. [0003] The dipole shear wave imaging logging tool can measure basic...

AI Technical Summary

Problems solved by technology

However, at present, conventional methods for identifying gas layers using dipole acoustic logging data mostly use intuitive qualitative interpretation methods such as crossplots, difference ratios, overlapping displays, and differences in baseline values. Acoustic feature information, resulting in a high misjudgment rate in reservoir fluid identification, which increases the uncertainty of further interpretation and evaluation of tight sandstone gas layers

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