Determining the length of a borehole or rate of penetration

摘要

A device and method for determining a geophysical characteristic of a borehole, such as borehole length or rate of penetration, using at least one logging device is provided, wherein the at least one logging device includes at least one sensing device 204. The method includes associating the at least one sensing device 204 with the borehole, wherein the at least one sensing device includes a sensing device measurement length. The method also includes operating the at least one sensing device 204 to generate borehole data responsive to a borehole portion disposed essentially adjacent the sensing device measurement length, wherein the borehole data includes start time of scan, location of the at least one sensing device at start time of scan, stop time of scan and location of the at least one sensing device at stop time of scan. Furthermore, the method includes correlating the borehole data to determine the geophysical characteristic. The sensing device may be associated with a device housing, the sensing device being able to transverse the length M of the housing to scan the measurement length.