Abstract:

By using the combined implicit characteristic line method，the calculation of the transient surge pressure in the flow conduit of a drilling well has been resolved in this paper, The dynamic wave equation and the definite solution conditions of a compressive fluid in different flow conduits of elastic pipes in a well have also been derived.Different combinations of pipe-casing flow conduits in a drilling well are defined，and the numerical solution in each condition has been obtained Compared with the steady surge pressure calculation method, the transient method more closely coinsides with the actual hole condition，so that surge pressure and the rational velocity for pulling and running pipes be calculated more precisely by the method given here.

Key words: Surge pressure, Dynamic wave equation, Tripping