Patent ID: 7548068
Filing Date: 2009-06-16
Classification: G01V

Abstract:
1. A method for identifying properties of a downhole electromagnetic network in a downhole drill string, comprising: disposing a column of connected tubulars downhole to penetrate a wellbore in a subsurface formation, the tubulars forming a downhole electromagnetic network having an electromagnetic signal path therethrough, one of the tubulars comprising a first node having a sensor disposed thereon; sending a test signal through the electromagnetic signal path between the first node and a second node linked to the electromagnetic signal path; determining a property of the electromagnetic network between the first and second nodes using the test signal sent between the nodes; determining a downhole parameter using the sensor on the first node; sending a signal representative of the downhole parameter to the second node through the electromagnetic signal path; and adjusting a property of the electromagnetic network using the determined electromagnetic network property wherein the adjustable property comprising pass-band tuning, or impedance tuning property.