Stress characteristic analysis method for a statically indeterminate structure

Abstract

The invention discloses a stress characteristic analysis method for a statically indeterminate structure. the four packer pipe columns after the packer is set are simplified; The tubular column is fixed by the four fixing ends, each fixing end can provide three counterforces, but the tubular column in a common well only bears the axial forces, and each fixing end only provides the horizontal counterforce, so that the structure is simplified into a three-time statically indeterminate structure, and if three redundant constraints in the statically indeterminate structure are removed, the structure becomes a basic structure of a force method; If the redundant constraint is removed, the redundant unknown force X1 is substituted at the corresponding position; X2 and X3, a statically indeterminate structure containing redundant unknown force can be obtained; the purpose of axial force and axial deformation of each packer pipe column section after solving is achieved; According to the method,the limitation that constraint among the packers is solved section by section in a traditional analysis method is overcome, the axial force of each section of pipe column among the packers can be calculated at the same time, the established model better conforms to the actual stress condition after setting of multiple packer pipe columns, and the calculation result is more accurate.

Description

technical field [0001] The invention relates to the technical field of oil and gas well exploitation, in particular to a method for analyzing the stress characteristics of a statically indeterminate structure. Background technique [0002] In the process of oil and gas well exploitation, in order to improve oil and gas recovery and increase reservoir contact area, vertical well layering and horizontal well segmenting technologies are often used. To implement these two techniques, multiple packers (ie, more than three packers) need to be employed. The function of the packer is positioning and sealing. From a mechanical point of view, the existence of multiple packers introduces the problem of redundant constraints, that is, the original oil well tubular structure becomes a statically indeterminate structure. [0003] Since the 1960s, many domestic and foreign experts and scholars have conducted research on the mechanics of oil and gas well strings. In 1980, Hammerlindl took...

AI Technical Summary

Problems solved by technology

[0004] The defect of the existing technology is that the statically indeterminate constraint conditions are not considered in the double packer structure, and only the static balance equation is established for solution, while the multi-packer structure establishes the deformation equation of the hyperstatically indeterminate structure from the deformation coordination conditions, and divides Calculate the force and deformation of the pipe string segment by segment

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