AT-BIT DOWNHOLE SENSOR AND TRANSMITTER

摘要

A system and method of transmitting measurement-while-drilling (MWD) data while drilling a wellbore in a subterranean formation are provided. The system utilizes a transmission sub located uphole of the drill bit which transmits an electromagnetic signal through the surrounding drilling fluid to a receiver assembly located farther uphole at a position suitable for relaying the signal to the surface.

主权项

1. A method of transmitting measurement-while-drilling (MWD) data while drilling a wellbore in a subterranean formation, the method comprising the steps of:
forming the wellbore with a drill string ending in a drill bit, said drill string further comprising a transmission sub located uphole of the drill bit, a mud motor located uphole of the data transmission sub and a receiver assembly located uphole of the mud motor and wherein the transmission sub has a first gap at an uphole end of the transmission sub, and the receiver assembly has a second gap; taking one or more measurements by a sensor contained in the transmission sub; and transmitting the measurements from the transmission sub to the receiver assembly by the transmission sub generating an electromagnetic signal across the first gap and the receiver assembly detecting the signal by measuring voltage across the second gap.