Territorija Neftegas № 12 2017

The article presents the experience of high-strength casing and tubing production from corrosion-resistant martensitic steels with 13 wt. % of Cr. The work was carried out under the agreement between Gazprom PJSC and TMK PJSC about production, supply, engineering maintenance, and also support and repair services of import-substituting products for guaranteed deferred deliveries. The chemical composition of steel and technology of the threaded oil pipes production were developed to achieve the goal of TMK PJSC. Main properties of the created production are as follows: high resistance to the carbon dioxide corrosion; cold resistance; a wide range of strength characteristics, including minimum yield strength 552–758 MPa in the standard and low-temperature pipes. There are also a possibility of mass production at the pipe plants, an economic expediency and a high export potential. Besides that, it was necessary to ensure an absolute gas tightness of threaded joints for casing and tubing. The usage of corrosion-resistant steel grades with increased and high strength (L80, C95, P110 groups), containing 13 wt. % of Cr, in the pipe production was a rational way of ensuring a compliance of pipe products to the requirements of the contract. These steels are mainly consist of the martensite tempering products. The part of the production is produced from steels, additionally alloyed with nickel and molybdenum to achieve the required index of impact toughness at 60 °С. The production of a range of gas-tight threaded premium joints, including streamline joints, for various mining and geological conditions of well construction was established to ensure the tightness of joints. Bench and field testing of pipes and developed threaded joints confirmed the compliance of products to the declared requirements. The products are used at the facilities of Gazprom Group according to the tests results.