Method for determining reserve volume of nonhomogeneous sandstone reservoir

Abstract

The invention relates to a method for determining reserve volume of a nonhomogeneous sandstone reservoir. The method comprises the following steps of: obtaining original stratum conditional parameters of an oil reservoir, carrying out logging data liquid displacement to obtain a corresponding elastic parameter curve corresponding to saturated water of a reservoir; based on saturated water loggingcurve as well as shale content and porosity distribution function of the sandstone reservoir and a mudstone interlayer which are obtained by statistics, determining a rock physical model by utilizingrock physical diagnosis, and calculating relation between elastic parameter variation of the nonhomogeneous sandstone reservoir and water saturation and net gross ratio of the reservoir; calculating accumulated impedance attribute by utilizing earthquake impedance data, quantitatively interpretating effective sandstone thickness and oil-gas-bearing saturation of the reservoir by virtue of the built template, and producting to obtain the reserve volume of the oil reservoir. In the method provided by the invention, elastic parameter calculation in earthquake scale and plate establishment are carried out, and earthquake accumulated impedance attribute is utilized, thus quantitative evaluation on the net gross ratio and the saturation of the nonhomogeneous sandstone reservoir is realized, andthe aim of determining the reserve volume is achieved.

Description

technical field [0001] The invention relates to a heterogeneous oil and gas field seismic exploration and oil reservoir prediction and evaluation method, in particular to a method for determining the reserves of a heterogeneous shale reservoir. Background technique [0002] The exploration and development of heterogeneous mudstone reservoirs has always been the difficulty and focus of oil and gas exploration and development research in my country, as well as the difficulty and focus of exploration geophysics and reservoir geophysics. At present, the focus of research on heterogeneous oil and gas reservoirs is how to improve the resolution of seismic data and the precision of thin layer inversion, so as to realize the accurate characterization and description of heterogeneous oil and gas reservoirs. However, excessively improving the seismic resolution through processing methods will affect the fidelity of seismic data, and improving the identification accuracy of thin layers...

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Problems solved by technology

[0003] In conclusion, the main problems in the research on seismic evaluation methods of heterogeneous shale-sandstone reservoirs are as follows: 1. The structure of heterogeneous shale-sandstone reservoirs is complex, and the thickness of thin mudstone and sandstone layers exceeds the ability of identification based on seismic data range, it is impossible to achieve a fine description of a single thin layer based on seismic data, and it is even more difficult to achieve quantitative analysis and evaluation of a single thin layer based on seismic data

2. The relationship between reservoir parameters and rock elastic parameters is affected by the measurement scale. The relationship between reservoir parameters and rock elastic parameters established based on well logging data and laboratory core measurement data cannot be directly applied to the interpretation of seismic wave impedance inversion data

3. The traditional seismic attributes are greatly affected by the changes in the combination of thin mudstone and sandstone layers in the reservoir, while the combination of heterogeneous mudstone reservoirs changes greatly. Therefore, it is difficult to use traditional attributes to analyze the overall It is impossible to determine the reservoir reserves through horizontal comparison and evaluation

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