| 摘要 |
A method whereby a downhole drilling transmission device that communicates to the surface automatically modifies its transmission parameters in order that it substantially improves its ability to adequately communicate with a surface receiver despite increasing signal attenuation between the two as the length of drillpipe increases. This utilizes a simple measure of localized downhole pressure that then relies upon a look-up table or similar that provides a correspondence between said pressure and measured depth. Such a look-up table or similar can be readily built by incorporating appropriate features of the planned well such as drilling fluid flow rate, drilling fluid density, drilling fluid viscosity, well profile, bottom hole assembly component geometry, drillpipe geometry, and indications as to whether the fluid is flowing or stationary. Upon determining the measured depth the tool then can attempt to modify or augment appropriate telemetry parameters in order to keep the signal received at surface within required parameters, thus offsetting the degradation due to increasing attenuation.
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