A three-stage tubing string design method and device

Abstract

The invention provides a design method of three-level tubing strings and a device thereof. The design method specifically comprises the following steps: related parameters of multiple sets of three-level tubing string materials are obtained; the related parameters of the multiple sets of three-level tubing string materials are substituted into a following formula to obtain service lives of corresponding sets of tubing strings and lengths of all levels; and the service lives of all sets of tubing strings and the lengths of all levels are compared with preset thresholds to obtain an optimal design scheme of the three-level tubing strings. Thereby, the service lives of the tubing strings are accurately predicted, and the reasonable lengths are selected, so that the safety of the tubing strings can be largely improved, and steel materials of the tubing strings can be saved to reduce the production cost; and the safety risk of the tubing strings in a gas well is reduced or prevented.

Description

technical field [0001] The invention relates to oil and gas well safety production technology in oil and gas industry and coal bed methane industry, especially the life design method of oil and gas deep well three-stage tubing string under corrosive environment conditions. Background technique [0002] At present, in China, there are very few literatures on the design of tertiary tubing strings, and there are almost none. If there are, the equal-strength design method is usually adopted. However, there are certain technical defects in adopting the equal-strength design method. For example, after oil and gas wells have been exploited for a period of time, due to the influence of corrosion and other factors on the tubing string, the strength of the dangerous section of the third-stage tubing string will no longer be equal. The strength of the tubing string of the other two stages decreases rapidly, and the strength of the other two stages of tubing strings decreases slowly, wh...

AI Technical Summary

Problems solved by technology

However, there are certain technical defects in adopting the equal-strength design method. For example, after oil and gas wells have been exploited for a period of time, due to the influence of corrosion and other factors on the tubing string, the strength of the dangerous section of the third-stage tubing string will no longer be equal. The strength of the tubing string of the other two stages decreases rapidly, and the strength of the other two stages of tubing strings decreases slowly, which causes one stage of tubing string to be damaged first, and the other two stages of tubing string to be damaged later, and the life of the entire tubing string is determined by the first stage of tubing string determined by the string, thus shortening the life of the entire tubing string

Therefore, due to the imperfect design in the early stage, the target three-stage tubing in the later stage cannot achieve the expected purpose; in view of this, how to effectively design a three-stage tubing string has become an urgent problem in this field.

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