| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an oil well pipe having self-perforation which can be self-repaired even when petroleum extraction port is blocked during use. SOLUTION: A sliding layer made of material whose stiffness coefficient ranges between 10<-5> and 10<3> N/m<2> in the state of one year use under use environmental temperature of an oil well pipe, and a protection layer for protecting the sliding layer are sequentially arranged on an outer surface of a steel pipe. In such an oil well pipe, the protection layer is made of polypropyrene or ethyrene propyrene complymer resin. The thickness of the protection layer is 5 mm or less.</p> |
