BOTTOMHOLE REMOTE SENSING SYSTEM INFORMATION TRANSMISSION METHOD AND DEVICE Russian patent published in 2006 - IPC E21B47/12 

FIELD: well drilling, particularly means for transmitting measuring-signals from the well to the surface with the use of wireless communication line.

SUBSTANCE: method involves transmitting information in coded electric signals; receiving the coded electric signals by land-based receiving means with the use of reference electrode and transforming the coded signals. Galvanic communication line is used for the information transmission. The galvanic communication line is based on shift of natural electrochemical potential of upper drilling string part connected to electrically isolated lower one through current-conductive bus and commutation means. Land-based receiving means is high-resistance and adapted to measure the drilling string potential shift relative with regard to electrode. Voltage with changeable polarity is applied from power source to current conductive bus circuit through resistors, which limit current to be transmitted, between information transmission cycles. Time of above voltage application is set as time of the first information transmission cycle termination and time of the second information transmission cycle initiation. Device comprises electrically insulated dividing sub, which separates lower drilling string part from upper one, current-conductive bus linked in parallel to it; commutating means controlled by coded bottomhole remote sending system signal to link current-conveying bus in parallel to the sub, reference electrode and land-based receiving means. The reference electrode may be submersed in circulating drilling mud and formed as solid-state electrode or the reference electrode may be inserted in vessel filled with electrolyte electrically, linked with circulating drilling mud through electrolyte contact and porous partition. In the last case the reference electrode is made as porous pot. Land-based receiving means is made as high-resistance microvoltmeter having the first input connected to upper drilling string end and another input linked with reference electrode output. Microvoltmeter output may be connected with one input of information gathering system having output connected with computer input.

EFFECT: provision of information transmission independence and reduced power inputs necessary for information transmission.

7 cl, 2 dwg