Patent ID: 6608565
Filing Date: 2003-08-19
Classification: E21B

Abstract:
A method for downward communication in a borehole containing a pipe string, comprising the steps of:a) imparting a series of rotary motions to an upper portion of the string, said rotary motions representing at least two levels of a coded data sequence, said rotary motions imparted to said string upper portion effecting generally comparable motions at a string lower portion, b) said motions at the string lower portion effecting a downhole detectable condition or conditions indicative of said imparted rotary motions, c) detecting said condition or conditions to determine a corresponding coded data sequence, d) and processing said corresponding data sequence to recover the imparted coded data sequence, from which a unique transmitted message is determinable, e) said detecting including providing and operating means to detect said downhole condition or conditions, there being an accelerometer having an output which is filtered and amplified.