Method for determining long-term strength parameter of surrounding rock of underground water seal petroleum storage cavern

Abstract

The invention discloses a method for determining a long-term strength parameter of surrounding rock of an underground water seal petroleum storage cavern. The long-term strength parameter of the underground water seal petroleum storage cavern is calculated through a stress-strain isochronous curve or a rheological rate in a constant-speed steady-state rheological stage according to rheological test data, obtained from triaxial rheological mechanics tests, of a rock sample. According to the method, a relatively actual long-term strength parameter can be obtained by fully considering a stress-seepage flow coupling effect for judging the stability of the surrounding rock of a cavern group. The method is actual and reliable, in the method, the stress-seepage flow coupling effect is fully considered for the first time during the determining of the long-term strength parameter of the surrounding rock of the underground water seal petroleum storage cavern, and the value of the long-term strength parameter is smaller than a value of a long-term strength parameter obtained without considering the seepage effect, relatively accurately reflects the characteristic of the surrounding rock of the underground water seal petroleum storage cavern, and has a reference value for accurately evaluating the long-term safety stability of the underground water seal petroleum storage cavern.

Description

technical field [0001] The invention relates to the field of rock mechanics, in particular to a method for evaluating long-term strength parameters of surrounding rock. Background technique [0002] With the rapid development of my country's economy, the demand for oil is increasing day by day. Strategic oil reserves are of great significance for responding to emergencies, stabilizing the relationship between oil supply and demand, and ensuring the safe and rapid development of the national economy. With the increase in oil imports, storing oil and natural gas in underground water-sealed caverns with superior location conditions is a storage solution with good comprehensive economic benefits. Compared with the traditional above-ground oil storage methods, the construction of underground water-sealed caverns in areas with superior geological conditions has its unique advantages: the performance of fire prevention, explosion-proof and war-proof performance of underground water...

AI Technical Summary

Problems solved by technology

Common evaluation methods include simple stress state method and complex stress state method, each of which has its own advantages and disadvantages: the simple stress state method is based on the stress state of uniaxial compression, and can determine simple stress states such as torsion and tension However, the rock in practical engineering is in a complex stress state, and the real stress state of the rock cannot be simulated by a simple uniaxial compression test, so the long-term strength of rock determined under a simple stress state cannot be accurately described and reflected. Realistic long-term rock strength under complex stress states

Most of the complex stress state methods are tested with various triaxial instruments, which takes a long time and a large workload, and cannot consider the real stress state of the surrounding rock under the coupling of seepage and stress

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