Analysis and identification of a drilling fluid column channel filter characteristics based on decoding of measurement while drilling signals

摘要

The present invention comprises a method and apparatus for estimating and identifying the channel filter characteristics of the drilling fluid communictions channel (e.g. standpipe) based on surface decoding of the MWD data signal. The channel filter characteristics can be mathematically defined by the transfer function of the channel. The transfer function is a mathematical model defining the input-output relationship of a physical system. The present invention may also characterize the channel filter defined by the drilling mud in the annulus between the borehole and the drillstring.