Frictional wear prediction method for high-temperature, high-pressure and high-yield tubing string casing

Abstract

The invention discloses a frictional wear prediction method for a high-temperature, high-pressure and high-yield tubing string casing. The method comprises the steps of determining the total relative slippage displacement Lh of an oil casing of the tubing string casing according to a kinetic model of the tubing string casing; determining the contact force N of an oil pipe and the inner wall of the casing according to a high-temperature, high-pressure and high-yield gas well tubing string critical buckling load calculation model; carrying out an oil casing frictional wear unit test according to the field actual working condition material and the completion fluid to determine the sliding friction coefficient mu and the wear efficiency eta/Hb of the oil casing; and determining the wear volume and the wear area of the oil casing according to the total relative slippage displacement Lh of the oil casing, the contact force N of the oil pipe and the inner wall of the casing, the sliding friction coefficient mu and the wear efficiency eta/Hb. The invention provides a calculation method for buckling critical loads of tubing strings in different well sections and a calculation method for contact loads of oil casings, aiming at the problem of frictional wear failure of the oil casings caused by vibration of the tubing strings of the high-temperature, high-pressure and high-yield gas well; and the high-temperature, high-pressure and high-yield gas well tubing string frictional wear loss calculation model is established, the wear volume of the oil casing can be accurately calculated, and the wear depth is calculated accordingly.

Description

technical field [0001] The invention relates to a high-temperature, high-pressure, high-yield oil string casing friction and wear prediction method. Background technique [0002] High-temperature, high-pressure and high-production gas wells are mainly directional wells and horizontal wells. During the production process, the tubing string undergoes longitudinal and transverse coupling flow-induced vibration, which leads to contact and collision with the casing in the lateral direction, and friction and wear with the casing in the longitudinal direction. The anti-collapse strength of the tubing after wear is greatly reduced. If this is not paid attention to, it will directly lead to the damage of the tubing, the occurrence of downhole accidents, and more seriously, the scrapping of the gas well. [0003] In the production process of high-temperature, high-pressure and high-yield oil and gas strings, affected by complex downhole working conditions, the wear mechanism of tubing...

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Problems solved by technology

[0008] 2) Three-body abrasive wear

[0011] (2) Adhesive

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