Study On The Influence Of Structural Parameters On Connection Performance Of Oil Casing With Special Thread In Flat Connection

The special thread of oil casing has the advantages of high connection strength and good sealing performance.It is one of the important technologies to solve pipeline working under high temperature and high pressure environment.However,the special thread of advanced casing is still faced with many problems,such as fatigue cracking and corrosive wear of the thread,and a series of problems such as pipeline leakage.At present,finite element analysis and test method are mainly used in the research of special thread.This kind of method is better to observe the stress and deformation of thread and the corresponding degree of leakage.At the same time,there is no recognized technical standard for special threaded casing.Each major pipeline company has its own design standard and maintenance strategy,and each major casing company has its own strict and precise sealing structure form and related core design theory and analysis software.In order to improve the performance of the thread,it is necessary to analyze and understand the design principle of the thread,and improve its design parameters,so as to better enhance the performance of the special thread casing.This paper mainly designs and optimizes the thread of offshore oil casing with flat connection,and further improves and studies the special thread of oil casing with HST flat connection.It uses theoretical modeling method to simulate and analyze the thread connection of special thread oil casing.It includes the theoretical model of torque on special thread of oil casing,the theoretical model of pretightening and axial working mechanics,the theoretical model of connection strength and the theoretical model of contact stress on sealing surface.