Patent ID: 7880640
Filing Date: 2011-02-01
Classification: E21B,F16L,G01V

Abstract:
1. A method of providing downhole information from a downhole evaluation tool located in a wellbore to a surface unit, the wellbore formed by advancing a drilling tool into the earth, the method comprising: positioning the downhole evaluation tool in the wellbore, the downhole evaluation tool having an electromagnetic telemetry system adapted to communicate via an electromagnetic field with the surface unit, wherein the electromagnetic telemetry system comprises a pair of collars matingly connected with a non-conductive insulation coating therebetween, the non-conductive insulating coating defining a gap, and wherein the electromagnetic telemetry system further comprises a non-conductive insulation member extending across the gap about one of an inner surface of the collars, an outer surface of the collars and combinations thereof, the insulation member conforming to the shape thereof; measuring downhole data using sensors positioned in the downhole tool; storing the downhole data in a memory unit positioned in the downhole tool; and transmitting at least a portion of the downhole data to the surface via the electromagnetic field.