Effect and processing technology of different oil casing

Effect and processing technology of different oil casing

Oil casing is a kind of large diameter pipe material, which plays a role in fixing oil and gas well wall or hole. The casing is inserted into the borehole and fixed with cement to prevent the borehole from separating the strata and borehole collapse, and to ensure the circulation of drilling mud, so as to facilitate drilling and mining. Different types of casing used in the process of oil production: surface oil casing - Protective drilling to prevent pollution from shallow water and gas layers, support wellhead equipment and maintain the weight of other layers of casing. And separate the casing from the casing to protect the normal flow of fluid. Oil casing - oil and gas are extracted from the reservoir below the surface and used to protect the well and separate the drilling mud. In the production of oil casing, the outer diameter is usually 114.3 mm to 508 mm.

For 27MnCrV steel, AC1 = 736 ℃, AC3 = 810 ℃, and the heating temperature is 740-810 ℃. The subcritical quenching temperature is 780 ℃ and the holding time is 15min; after quenching, the tempering temperature is 630 ℃ and the tempering heating holding time is 50min. Because the intercritical quenching is heated in the α + γ two-phase region and quenched in the state of partially undissolved ferrite, the toughness is improved while maintaining high strength.

At present, the process has been applied in the steel pipe processing plant. The quality assurance data show that the yield strength rt0.6, tensile strength RM and impact toughness Akv are 820-860mpa, 910-940mpa and 65-85j respectively. The data show that 27MnCrV steel pipe is a good high-grade oil casing. On the other hand, it also shows that Subcritical Quenching Process is a good method to avoid high-temperature brittleness in steel products production. At the same time, the low-temperature quenching is lower than the conventional temperature, which reduces the quenching stress and thus reduces the quenching deformation, which ensures the smooth operation of the heat treatment production, and provides a good raw material for the follow-up wire turning processing.