关键词: 石油套管; SEW 工艺; 热张力减径; 高抗挤套管; 膨胀套管

Abstract: Oil casings of the SEW series, such as J55, N80Q, P110, BSG- 80TT, BSG- 110TT and BX55 expandable casing, are developed by means of the processes like HFW, heat stretch-reducing and pipe over-length heat treatment. The developed casings of the SEW series are tested for sizes and mechanical properties. The results indicate that the SEW oil casings have a better performance for strength and toughness than seamless casing of the same steel grade. The impact tenacity of the SEW casing is improved by about 30 percent. The consumption of steel pipe is reduced by about 3 percent at the same well depth owing to high geometric precision and small wall thickness tolerance of the SEW casing. Collapse resistant strength of BSG-80TT/110TT is 8 percent higher than the required value of Q/ SY 1394-2011. The SEW expandable casing of BX55 steel grade is successfully used in expandable casing completion service for deep sidetrack horizontal well in Tahe Oilfield, making three domestic records for expandable casing at that time-the deepest well for tripping-in, the largest deviation angle and the longest distance of continuous expansion.

Key words: petroleum casing, SEW process, heat stretch-reducing, high collapse resistance oil casing