Novel dual metal composite pipes and preparation method

The invention relates to a novel bimetallic composite pipe, which is applied in exploiting oil and natural gas fields. The novel bimetallic composite pipe is characterized in that an inner lining pipe is arranged in an outer wall pipe. Short joints are welded at both ends of the outer wall pipe, welding seams are arranged between the outer wall pipe and the short joints, and both end parts of the inner lining pipe are welded on the inner wall of the short joints. At least 1 through hole with the diameter of 2 to 10 millimeters is drilled on the wall of the outer wall pipe. Electric welding is adopted to completely weld the through hole after the water pressure test, namely, electric welding is used for solidly filling the through hole after the water pressure test. Screw threads are machined at both ends of the novel bimetallic composite pipe or the both ends of the novel bimetallic composite pipe are machined into two welding grooves. The novel bimetallic composite pipe has the advantages that a carbon steel pipe or a low alloy steel pipe is adopted as the substrate material of the outer wall pipe, to exert the superior capability of mechanics of machinery and the low price characteristic of the carbon steel pipe or the low alloy steel pipe; the inner lining adopting layer corrosion resistant alloy is provided with excellent corrosion resistant capability and superior capability of mechanics of machinery. The screw threads coupling connection sealing problem and the bimetallic composite pipe ground welding problem occurring when the prior bimetallic composite pipes are in use are thoroughly solved, the application field of the bimetallic composite pipe is enlarged, and the cost of the oil field exploitation is saved.