Patent ID: 11060396

Abstract:
The disclosure relates to a method for estimating a transit time of an element circulating in a borehole during the drilling of the borehole. The transit time is representative of a time period for the element to move from the bottom of the borehole to its exit at the surface. The method comprises measuring a plurality of drilling parameters, computing a first signal of a first indicator based on a first set of measured drilling parameters and a second signal of a second indicator based on a second set of measured drilling parameters versus time. The first indicator is representative of a first type of events happening at the bottom of the borehole and the second indicator is representative of a second type of events happening at the exit of the borehole linked to the first type of events. The method also comprises characterizing a correlation between the first and second signals and determining a shift between the first and second signals. An estimated transit time is then determined from the shift.