| 摘要 |
<p>A process for optimizing the penetration speed of a drilling tool driven by a motor whose torque decreases with an increasing running speed and vice-versa, comprising the steps of alternately increasing and decreasing the load on the tool about its optimum value by acting on the tensile stress exerted on the drill string, thereby defining periods of increase and periods of decrease of the ratio -( DELTA Va/T ) which is, with a changed sign the ratio between the variation of the penetration speed of the tool and the corresponding variation of the tensile stress exerted on the drill string, of controlling the passage from a tensile stress-increasing period, at the latest when the ratio -( DELTA Va/T) attains, while decreasing, a lower limit value and of controlling the passage from a tensile stress-decreasing period to a tensile stress-increasing period at the latest when said ratio attains, while increasing, an upper limit-value, said lower and upper limit values being preselected and adjustable.</p> |
