Rapid calculating method of marine riser operation window

The invention relates to a rapid calculating method of a marine riser operation window. The rapid calculating method of the marine riser operation window includes the following steps that (1) as for each ocean current flow speed, an operation parameter when platform offset is 0 is calculated, and whether the operation parameter meets requirement of operation limit of a well drilling connection mode or not is determined; (2) when two critical points are located on two sides of a platform offset zero line, the two critical points are searched by a nonlinear searching method; (3) when the two critical points are located on the same side of the platform offset zero line, critical points of a current ocean current operating condition are calculated on the basis of the two critical points of last ocean current operating condition; (4) the critical points under all ocean current operating conditions are connected to draw the marine riser operation window. By means of the rapid calculating method of the marine riser operation window, required calculation times for obtaining the operation window can be extremely reduced, the analysis time can be greatly reduced, requirements of on-site analysis instantaneity can be met, and the rapid calculating method can be widely applied to relevant fields of marine riser safety analysis of deep water well drilling and completion, marine riser research technique services that specialized corporations carry on and performance analysis of products of marine riser manufacturers.