A tubular string for a subterranean well comprises a first string that is located in the well and that can access or traverse horizons of interest, such as during drilling, completion, or workover. A second tubular string is assembled above this first tubular string and is selected so that only this second tubular string normally traverses a blow out preventer during periods when there is an elevated risk that the blow out preventer will be actuated. The second tubular string is made of a more easily shearable material than the first tubular string, such as a titanium alloy, an aluminum alloy, or a composite material. A third or further tubular strings may be assembled above the second tubular string, such as in subsea applications.