120 steel grade drill pipe and manufacturing process method thereof

Abstract

The invention relates to a 120 steel grade drill pipe and a manufacturing process method thereof. A pipe body of the 120 steel grade drill pipe is made of 27CrMnMo, and subs are made of AISI4137HM, wherein the subs comprise the following chemical compositions by mass percentage: less than or equal to 0.40 percent of C, less than or equal to 0.015 percent of S, less than or equal to 0.010 percent of P, less than or equal to 0.009 percent of N, and less than or equal to 0.005 percent of B, sizes of the pin and box subs are the same as that of a G105 drilling tool, and mechanical properties respectively comprise that: the yield strength is between 130 and 150Ksi, the elongation rate is more than or equal to 17 percent, the brinell hardness HB is between 290 and 330, the longitudinal ballistic work is 80J, the transverse ballistic work is 60J, and the contraction of cross-section area is more than or equal to 45 percent. The manufacturing process method for the drill pipe comprises the steps such as pipe body manufacturing, sub manufacturing, butt welding and the other processes. The 120 steel grade drill pipe has excellent mechanical properties, is suitable for deep drilling with a depth between 4,000 and 5,000m, is favorable for the hydraulic drilling effect during the drilling due to the enlargement of inner holes of the stubs, can full play the function of a high-power drilling pump, and improve mechanical drilling rate; and the manufacturing process method has the advantages of easy implementation, practicability, reliability and excellent effect.

Description

Technical field: [0001] The invention relates to a drilling tool used for oil drilling engineering, especially medium-deep well drilling and its manufacturing process, which belongs to the oil drilling engineering and mechanical processing technology category. Background technique: [0002] Oil drill pipe is an important tool and consumable in the process of oil drilling. With the development of the oil and gas industry and the gradual reduction and depletion of shallow oil and gas layers, the drilling depth has gradually increased from about 2000m to about 4000m, and some wells have reached more than 4000m. , Exploration well depth reaches 5000-7000m, even reaches 10000m. Due to the increase in drilling depth, the drilling rigs and drilling tools used in the drilling construction process need to be upgraded accordingly to replace the original shallow drilling equipment and tools. At present, the drill pipes used in oil drilling on site usually adopt the manufacturing stand...

AI Technical Summary

Problems solved by technology

For the actual working conditions of drilling engineering, the strength of G105 steel grade drill pipe is low, while the strength of S135 drill pipe exceeds 135Ksi, but the diameter of the inner hole of the male joint is small, the flow cross section is small, and it is prone to brittleness during drilling. In actual production, it is necessary to introduce a new type of steel grade drill pipe with sufficient strength and good brittle fracture resistance

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