A method for quantitative determination of water saturation in sandstone reservoirs based on petrophysical templates

Abstract

The invention provides a method for quantitatively determining the water saturation of a sandstone reservoir based on a petrophysical template, establishing a variable water saturation petrophysical template based on seismic elasticity information, and obtaining an iso-water saturation trend line through fitting and calculation in the petrophysical template, And extract the dip angle information of the iso-water saturation trend line, and finally construct the relationship between the dip angle of the iso-water saturation trend line and the water saturation, so as to obtain the calculation formula for accurate calculation of reservoir water saturation based on seismic elasticity information. The multi-solution exists in the process of predicting water saturation with conventional attenuation attributes, quantitatively determines the relationship between water saturation and seismic elasticity information, and obtains a linear formula for accurate calculation of water saturation, which greatly improves the reservoir water saturation. The accuracy of prediction reduces the risk of exploration and development.

Description

technical field [0001] The invention relates to the technical field of petroleum exploration, in particular to a method and a device for quantitatively determining the water saturation of a sandstone reservoir based on a petrophysical template. Background technique [0002] With the deepening of oil and gas exploration and development, the exploration targets are becoming more and more refined, and reservoir prediction has gradually developed from qualitative description to quantitative prediction. Conventional reservoir physical property prediction is generally based on seismic data attribute analysis. By using logging information to demarcate attribute information and establish an empirical relationship between the two, the lateral prediction of reservoir physical properties in the work area can be achieved. This method is to a certain extent. It provides technical support for seismic prediction of reservoir physical properties, expands the application range of seismic att...

AI Technical Summary

Problems solved by technology

In the actual prediction process, porosity and density generally have a good fitting relationship, so the density body obtained by pre-stack inversion is usually used to predict reservoir porosity. However, it is difficult to establish a relationship between water saturation and seismic elasticity information, so Seismic attenuation attributes are usually used to describe. However, seismic attenuation is affected by many factors, and water saturation is only one of the influencing factors, and multiple factors are coupled together, resulting in low accuracy and multi-solution in predicting water saturation based on seismic attenuation attributes. Very strong, affecting the accuracy of the prediction results

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