Patent ID: 6662884
Filing Date: 2003-12-16
Classification: E21B

Abstract:
A method for determining the efficiency or effectiveness of a sweep for removing cuttings from a borehole penetrating a subterranean formation during an operation employing drilling fluid in drilling said borehole, said method comprising:determining the volume, density, and rheological properties of the drilling fluid; determining a baseline equivalent circulating density of said drilling fluid; determining the volume, density, and rheological properties of the sweep; pumping said sweep into said borehole and circulating said sweep in said borehole causing drill cuttings to be incorporated into said sweep for bringing said cuttings out of said borehole with said sweep; measuring downhole density of said sweep during said pumping and during said circulating of said sweep as a function of time and measuring the pump rate during said pumping; determining the specific gravity of the formation; calculating the total equivalent circulating density; determining the sweep's contribution to the total equivalent circulating density; and calculating the sweep efficiency.