Drilling monitor with downhole torque and axial load transducers

Abstract

In a drilling monitor downhole transducers provide signals representative of torque (T) and axial load (F). A downhole computer apparatus (5) receives the torque and load signals and computes coefficients representative of drilling conditions. These coefficients may then be combined into a surface sendable signal indicative of drilling conditions. Signals representing T and F are received from downhole transducers (1,2) at input ports (3,4) of the downhole computer (5). From T and F measurements a relationship between T and F may be established, based on short term modeling. From the system model, torque may be predicted and correlated with the measured values received from the torque transducer (1). Values from the coefficients are computed and combined for sending from a transmitter (6) to a receiver (7) over a single low speed telemetry channel (8) for display and recording at the surface.