Study and application of solid expandable tubular in patching the casing below thepreviously installed tubular

The inner casing diameter would be reduced after casing being patched by the solid expandable tubular, so the casing failure part below the installed tubular could not be patched by the conventional technology. The novel technology was proposed, which employed the piston and cylinder as powering system, and the anchor to fix the position of the tubular, the expansion unit was put outside of the tubular and consequently the passing ability and expansion rate of the tubular could be further enhanced. Experimental results, both field and indoors, showed that the new technology was characterized by its simple structure and easily assembled; the tubular, after expanded by 8%, showed more than 8t gripping force with 1m long casing; the powering system could withstand 30 MPa load. The field application technique was scientifically designed and solved the problem successfully.