The high quality 37Mn5 tubular billet for oil well pipe has been developed and produced in Laigang by the following short flow process: UHP EAF smelting-LF refining-continuous casting – hot charging – rolling,in which some process measures such as prepared burden,strengthening deoxidation,protective casting and so on have been adopted.

Development Situation of OCTG and Production Localization of Hi-grade OCTG(Part Ⅱ);

Development Situation of OCTG and Production Localization of Hi-grade OCTG(Part Ⅰ);

Standardization Development of "OCTG Engineering" in China;

The Special Steel Plant successfully developed 37Mn steel for Class J55 oil well pipes on its first test,by adopting the measures such as the use of EAR-LF-CC process flow to set down reasonable technical measures,strictly controlling aim carbon content,preliminary elimination of oxygen,adjustment of refining slag and protective casting.

The stress relaxation characteristics of three kinds of high grade oil well pipe steel were studied,and the residual stresses after warm straightening at different temperature in pipes made of these steels were measured by means of X ray diffraction.

By using ANSYS software,this paper makes the mechanical analysis on the structure of oil well casing,builds the mechanical model in accordance with the actual projects and conducts nonlinear contact analysis solution for it,which is more practical than simply for the casing and whose conclusion is more reasonable.

The deformation of oil well casing by creep of surrounding rocks is analysed with finite element methods.

Combined with practical engineering of oil fields,the influences of one opening and multi-openings with different shapes on a oil well casing are studied in this paper.