OCTG consuming about 21% to 25% of total consumption of seamless steel pipe. Volume in the 1990s spent between 75 to 90 million t. 1997 Apparent consumption 800 000 t, 1998 years 920 000 t. 1998 domestic oil pipes 660 000 t, the domestic market share of 72%. 2000 Estimated cost less than 100 million t. Production capacity and apparent consumption fundamentally equal. Due to the high functionality of a hard commodity supply, its lack of practice value, it still has to import annually.
Scale required specifications can be supplied. But only steel grade oil casing J55, N80, P110, during the J55, N80 more than 85%, from the practical needs of many high-grade steel have a greater interval.
Seamless pipe market oil vocational technical progress and economic importance to promote the production casing to the small-caliber (Φ139.7mm) aspects of handling. And sometimes do not surface casing, intermediate casing, or replaced with a pipe. Surface casing pipe has become an inevitable choice, seamless steel pipes oil consuming a certain decline in the number of cases with the footage.
Domestic market share of OCTG now exceed 80%, and has 2 consecutive years become a net exporter of commodities. In terms of types of development, many domestic companies to be creative, not only by the output of the API specification requirements K, N, C, P grade steel casing, also based on user demand sleeve has developed a series of independent intellectual property rights, such as Tianjin steel tube company has developed a series of anti-TP collapse casing, casing corrosion resistance, high temperature heat recovery wells with casing, casing and ultra-deep with special buckle airtight casing, high resistance to collapse during TPl30TT its casing collapsing strength reach 167MPa above; TPll0TSS high resistance to corrosion-resistant casing collapse in a 5% sodium chloride, 0.5% acetic acid oxidizing etching solution, 720 hours does not crack; TP140V casing go down to reach the 6936 m depth (recently this record will be broken); NC 3Cr a carbon dioxide anti-corrosion casing has been sent to the bulk Tarim Oilfield downhole use. In addition, Baosteel, Chengdu seamless also developed from a series of products.
Although China seamless steel pipe seamless steel pipe market occupation achieved in terms of OCTG impressive results, but in some high-end product development is still not cross the border, such as 13Cr, super 13Cr steel inclusions and S, P content manipulation ( S is less than 10ppm, P less than 15ppm), heat treatment and threading control function processing quality control, there are still a series of problems, flexible tubing, casing swollen development is still blank.