Crustal stress calculation method and device for sand shale interbed tight gas reservoir

Abstract

The invention provides a crustal stress calculation method for a sand shale interbed tight gas reservoir. The method comprises the following steps of: calculating to obtain a shear wave time difference, and carrying out correlation analysis on the shear wave time difference and a logging shear wave time difference obtained by actual measurement logging to obtain a corrected shear wave time difference after correction; calculating to obtain rock dynamic mechanical parameters, and converting the rock dynamic mechanical parameters into continuous static parameters in combination with discontinuous static parameters obtained by an indoor rock core test; and acquiring crustal stress data through a crustal stress calculation model on the basis of the continuous static parameters, and correcting the crustal stress data by using a field fracturing construction curve and calculated fracture pressure obtained by the fracture pressure calculation model to obtain a crustal stress profile. According to the crustal stress calculation method, reliable rock dynamic mechanical parameters are obtained through calculation and correction of the shear wave time difference, continuous static parameters are obtained through related conversion of the rock dynamic mechanical parameters and the rock static mechanical parameters, and a reliable data foundation is laid for subsequent crustal stress calculation.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to an in-situ stress calculation method and device for sand-shale interbedded tight gas reservoirs. Background technique [0002] In-situ stress is the local load acting on the underground rock formation, which is the force on the internal unit area caused by the gravity of the overlying rock formation, the vertical and horizontal movements inside the crust and other factors, which can be decomposed into a vertical stress and 2 horizontal stresses, where the 2 horizontal stresses are usually not equal. The in-situ stress profile can reflect the variation law of the in-situ stress field in the vertical direction, and the accurate acquisition of layered in-situ stress parameters can provide a basis for decision-making and design in various links such as drilling engineering, oil and gas reservoir engineering, and oil production engineering, especially in hydrauli...

AI Technical Summary

Problems solved by technology

Logging methods can continuously measure rock mechanical properties, but conventional logging data usually lack shear wave logging data, and when used to simulate and calculate stress, the data errors are large; the mechanical properties measured by core laboratory tests are accurate, but the test accuracy Affected by many factors, the test cost is high and the data is limited; on-site fracturing test is currently the most accurate method for measuring in-situ stress, and its test results can often be used as a standard for testing the accuracy of other tests, but limited by conditions, this method Rarely used, and can not obtain a continuous in-situ stress profile

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