Mohr-Coulomb theory based mechanical stability quantitative analysis method for exploitation of aquo-complex

Abstract

The invention discloses a Mohr-Coulomb theory based mechanical stability quantitative analysis method for the exploitation of an aquo-complex. The method comprises the following steps: (1) calculatingthrough numerical simulation to obtain the condition of stress distribution of a reservoir stratum in the exploitation of the aquo-complex; (2) establishing a quantitative index for a mechanical stability coefficient s on the basis of the Mohr-Coulomb shearing strength theory; (3) substituting the stress distribution obtained in the step (1) into the mechanical stability coefficient s, and obtaining distribution of the mechanical stability coefficient; and (4) quantitatively analyzing the mechanical stability of the reservoir stratum on the basis of the mechanical stability coefficient obtained in the step (3). The method overcomes the defects that the traditional Mohr-Coulomb shearing strength theory only can qualitatively analyze in the analysis of the mechanical stability in the exploitation of aquo-complex, the concept of the stability coefficient is used to quantitatively describe the mechanical stability, the stability within the full research scope is quantitatively described,the method is more convenient and intuitive to use, the quantitative analysis result is more accurate, and the method has higher practical reference and application values.

Description

technical field [0001] The invention relates to the technical field of mechanical stability analysis for exploitation of marine natural gas hydrate resources, in particular to a quantitative analysis method for the mechanical stability of hydrate exploitation based on the Moore-Coulomb theory. Background technique [0002] Natural gas hydrate has huge resources and high energy density, making it an efficient and clean energy source. International and domestic hydrate production tests show that mechanical stability is an important factor restricting hydrate production. When hydrate is mined under pressure, on the one hand, the decrease in pore pressure causes the increase of sediment shear stress, which increases the load on the sediment; on the other hand, the hydrate acts as a cement in the sediment. strength will be reduced. When the load of the sediment exceeds the strength of the sediment, the hydrate reservoir may be destabilized and destroyed; at the same time, due t...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to propose a quantitative analysis method for the mechanical stability of hydrate mining based on the Moore-Coulomb theory, which can not only quantitatively analyze the hydrate The stability of the wellbore or reservoir during production, giving the "stability" index, can also realize the stability analysis of the wellbore and reservoir in the whole area

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