It is introduced in brief that the domestic and foreign employed situation of straight welded casing, manufacture technology and production condition, and some researches being done at present.
简要介绍了直缝焊套管国内外使用情况，生产技术以及国内外生产现状，目前正在进行的一些试验研究工作。
2
It has reference role to the researches, manufacture and the usage of straight welded casing in our nation.
对我国有关单位今后研究、生产、使用直缝焊接套管有参考作用。
3
With the continuously improvement of the production and manufacture technology of tubing and casing, current API 5c3 model can not predict the actual casing strength.
随着套管制造工艺的不断改进和制造水平的显著提高，现有的A PI 5c3模型已不能正确地预测套管的实际抗挤强度。