Steel with stable transverse and longitudinal performance and high product of strength and elongation for petroleum casing pipe and production method

The invention discloses high-strength-and-ductility-product steel with stable transverse and longitudinal performance for a petroleum casing and a production method, and belongs to the technical field of steel for petroleum casings. The steel for the petroleum casing pipe comprises the following chemical components in percentage by weight: 0.40 to 0.65 percent of C, 0.20 to 0.30 percent of Si, 2.00 to 2.50 percent of Mn, 1.00 to 1.50 percent of Cr, 0.10 to 0.50 percent of Mo, 0.05 to 0.25 percent of Ni, 0.10 to 0.30 percent of V + Nb, less than or equal to 0.020 percent of P, less than or equal to 0.015 percent of S and the balance of Fe and inevitable impurities. The production method comprises the working procedures of steel billet forging, rolling, annealing homogenization treatment, quenching and partition heat treatment. And one-time narrow steel transverse rolling is carried out in the second pass or the third pass in the rolling process. A bainite structure is obtained after the steel for the petroleum